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    Biguanide and Thiazolidinedione (Glitazone) Antidiabetic Combinations

    BOXED WARNING

    Acidemia, acute myocardial infarction, cardiogenic shock, dehydration, hypoxemia, lactic acidosis, metabolic acidosis, sepsis

    Pioglitazone; metformin is contraindicated in patients with metabolic acidosis. Metformin is associated with an increased risk for lactic acidosis. Lactic acidosis should be suspected in any diabetic patient with metabolic acidosis lacking evidence of ketoacidosis (ketonuria and ketonemia). Lactic acidosis is a rare, but serious complication that can occur due to metformin accumulation and is fatal in approximately 50% of cases. Lactic acidosis may also occur in association with a number of pathophysiologic conditions, including diabetes mellitus, and whenever there is significant tissue hypoperfusion and hypoxemia or significant renal dysfunction. Certain medications that are eliminated via the kidney when used concomitantly with metformin may also increase the risk of lactic acidosis. Acute congestive cardiac failure, cardiogenic shock, or acute myocardial infarction and other conditions characterized by acute hypoxia have been associated with the development of lactic acidosis and may cause prerenal azotemia. To reduce the risk of lactic acidosis, pioglitazone; metformin should be promptly withheld in the presence of any condition associated with hypoxemia, dehydration, or sepsis. Lactic acidosis is characterized by elevated blood lactate levels, acidemia, electrolyte disturbances, an increased anion gap, and an increased lactate/pyruvate ratio. When metformin is implicated as the cause of lactic acidosis, metformin plasma levels more than 5 mcg/mL are generally noted. The reported incidence of lactic acidosis in patients receiving metformin is very low (approximately 0.03 cases/1,000 patient-years). A nested case-control study of 50,048 patients with type 2 diabetes mellitus demonstrated that during concurrent use of oral diabetes drugs, there were 6 identified cases of lactic acidosis. The crude incidence rate was 3.3 cases per 100,000 person-years in patients treated with metformin; it should be noted that all of the subjects had relevant comorbidities known to be risk factors for lactic acidosis. The onset of lactic acidosis often is subtle, and accompanied only by nonspecific symptoms such as malaise, myalgias, respiratory distress, increasing somnolence, and nonspecific abdominal distress. There may be associated hypothermia, hypotension, and resistant bradycardia with more marked acidemia. The patient and the prescriber must be aware of such symptoms and the patient should be instructed to notify the physician immediately if they occur. Metformin should be withdrawn until the situation is clarified. Serum electrolytes, ketones, blood glucose, and, if indicated, blood pH, lactate levels, and even blood metformin levels may be useful.

    Acute heart failure, cardiac disease, edema, heart failure, peripheral edema, pulmonary edema

    Pioglitazone; metformin is contraindicated in patients with pre-existing New York Heart Association (NYHA) Class III or IV heart failure and should be used with caution in any patient with cardiac disease. Acute decompensation in cardiac status (e.g., acute heart failure, cardiogenic shock, or acute myocardial infarction) characterized by hypoxia has been associated with the development of lactic acidosis in patients taking metformin. Thiazolidinediones (TZDs), including pioglitazone, when used alone or in combination with other antidiabetic agents, can cause or exacerbate congestive heart failure. Patients should be carefully observed for signs and symptoms of heart failure including excessive, rapid weight gain, dyspnea, and/or edema (peripheral edema, pulmonary edema) after drug initiation and changes in dose. If these signs and symptoms develop, the heart failure should be managed according to current standards of care, and clinicians must consider reducing the dose or discontinuing pioglitazone; metformin. Therapy should be discontinued if deterioration in cardiac status occurs. The incidence of heart failure associated with pioglitazone use is higher in those patients receiving concomitant insulin therapy, older adult patients (65 years of age and older), those receiving higher doses of pioglitazone, and those with risk factors for congestive heart failure. In addition, in postmarketing experience with pioglitazone, cases of congestive heart failure have been reported in patients both with and without previously known cardiac disease. When compared with glyburide during a postmarketing safety study, pioglitazone was associated with a higher incidence of overnight hospitalization for congestive heart failure (9.9% for pioglitazone vs. 4.7% for glyburide). Dose-related edema and weight gain have been reported in patients treated with pioglitazone therapy; caution is advised in patients with preexisting edema. An association between pioglitazone and myocardial infarction has not been demonstrated. In a study of patients with type 2 diabetes, the addition of pioglitazone to existing diabetes therapy did not result in increased all-cause mortality or total macrovascular events such as non-fatal myocardial infarction, stroke, acute coronary syndrome, cardiac intervention, major leg amputation, or leg revascularization (HR 0.90, 95% CI 0.80 to 1.02, p = 0.1). Dose-related edema and weight-gain has been reported in patients treated with pioglitazone therapy.

    DEA CLASS

    Rx

    DESCRIPTION

    Oral combination of pioglitazone, a thiazolidinedione (TZD), and metformin, a biguanide
    Used in adults for type 2 diabetes mellitus; use with caution with insulin
    Risk of lactic acidosis due to metformin is low; TZDs may cause or exacerbate heart failure; monitor closely

    COMMON BRAND NAMES

    Actoplus Met

    HOW SUPPLIED

    Actoplus Met XR Oral Tab ER: 15-1000mg, 30-1000mg
    Actoplus Met/Pioglitazone Hydrochloride, Metformin Hydrochloride/Pioglitazone, Metformin Hydrochloride Oral Tab: 15-500mg, 15-850mg

    DOSAGE & INDICATIONS

    For the treatment of type 2 diabetes mellitus not controlled by diet and exercise.
    For use when either metformin or pioglitazone alone is inadequate.
    Oral dosage (regular-release tablets)
    Adults

    Initially, 15 mg pioglitazone with 500 mg metformin PO twice daily or 15 mg pioglitazone with 850 mg metformin PO once daily with meals. Titrate to target goals, usually every 8 to 12 weeks. Max: pioglitazone 45 mg/day with metformin is 2,550 mg/day (i.e., 3 tablets per day of any dose strength). If metformin dose is more than 2,000 mg/day, dividing the dose 3 times daily may be better tolerated. Generally, the elderly should not be titrated to the maximum dose. Pioglitazone use is not recommended in patients with symptomatic heart failure. In patients with NYHA Class III or IV congestive heart failure, use is contraindicated. When using pioglitazone in patients with or without symptomatic heart disease and diabetes, monitor closely for signs of weight gain, peripheral edema, or congestive heart failure. Discontinue pioglitazone if any deterioration in cardiac status occurs.

    Oral dosage (extended-release tablets)
    Adults

    Initially, 15 mg pioglitazone with 1,000 mg metformin or 30 mg pioglitazone with 1,000 mg metformin PO once daily with a meal. Titrate to target goals, usually every 8 to 12 weeks. Max: pioglitazone 45 mg with metformin 2,000 mg PO once daily. Generally, do not titrate the elderly to the maximum dose. Monitor for edema or weight gain; discontinue if cardiac status deteriorates.

    To switch a patient already taking pioglitazone plus metformin to the combination product.
    Oral dosage (regular-release tablets)
    Adults

    Initially, use the dose of pioglitazone and metformin already being taken by the patient. Titrate to target goals, usually every 8 to 12 weeks. Max: pioglitazone 45 mg/day with metformin is 2,550 mg/day (i.e., 3 tablets per day of any dose strength). If metformin dose is more than 2,000 mg/day, dividing the dose 3 times daily may be better tolerated. Generally, the elderly should not be titrated to the maximum dose. Monitor for edema or weight gain; discontinue if cardiac status deteriorates.

    Oral dosage (extended-release tablets)
    Adults

    Initially, use the dose of pioglitazone and metformin already being taken by the patient. Gradually titrate after assessing adequacy of therapeutic response, usually every 8 to 12 weeks. Max: pioglitazone 45 mg with metformin 2,000 mg PO once daily. Generally, do not titrate the elderly to the maximum dose. Monitor for edema or weight gain; discontinue if cardiac status deteriorates.

    Use in combination with insulin.
    Oral dosage
    Adults

    When pioglitazone; metformin is used in combination with insulin, a lower insulin dose may be needed in order to reduce the risk of hypoglycemia. In patients taking pioglitazone; metformin with insulin who experience hypoglycemia, reduce the insulin dose by 10% to 25%. Individualize dosing; titrate to target goals. Max: 45 mg/day PO pioglitazone and 2,550 mg/day PO metformin for regular-release tablets (in divided doses) OR 45 mg pioglitazone with 2,000 mg metformin PO once daily for XR tablets. Generally, do not titrate the elderly to the maximum dose. Monitor closely. The risk of edema, weight gain, or congestive heart failure is increased when pioglitazone is used in combination with insulin in patients at risk of heart failure. Discontinue if any deterioration in cardiac status occurs.

    MAXIMUM DOSAGE

    Adults

    45 mg/day PO pioglitazone and 2550 mg/day PO metformin for regular-release tablets; 45 mg/day PO pioglitazone and 2000 mg/day PO metformin for extended-release tablets.

    Geriatric

    In general do not titrate to the adult maximum dosage.

    Adolescents

    Safe and effective use has not been established.

    Children

    Safe and effective use has not been established.

    DOSING CONSIDERATIONS

    Hepatic Impairment

    Pioglitazone; metformin should be avoided in patients with clinical or laboratory evidence of hepatic impairment. Hepatic impairment increases the risk of metformin-associated lactic acidosis.

    Renal Impairment

    eGFR more than 45 mL/minute/1.73 m2: No dosage adjustment needed. Obtain an eGFR at least annually in all patients taking metformin.
    eGFR 30 to 45 mL/minute/1.73 m2: Initiation of pioglitazone; metformin is not recommended. Obtain an eGFR at least annually in all patients taking pioglitazone; metformin. In patients whose eGFR is initially greater than 45 mL/minute/1.73 m2, and later falls below 45 mL/minute/1.73 m2, assess the benefits and risks of continuing treatment. Discontinue pioglitazone; metformin if the patient's eGFR later falls below 30 mL/minute/1.73 m2. The ADA and others suggest it is reasonable to decrease the dose by 50% (or use one-half the maximum recommended dose) and monitor renal function every 3 months in those with an eGFR less than 45 mL/minute/1.73 m2. Do not initiate the drug in patients at this stage. Additional caution is required in patients with anticipated significant fluctuations in renal status or those at risk for abrupt deterioration in kidney function, based on previous history, other comorbidities, albuminuria, and medication regimen (e.g., potent diuretics or nephrotoxic agents).
    eGFR less than 30 mL/minute/1.73 m2: Use is contraindicated.
     
    Intermittent hemodialysis
    Pioglitazone; metformin use is contraindicated. Metformin is dialyzable; hemodialysis will efficiently remove accumulated metformin in the case of drug-induced lactic acidosis, provided metformin administration is halted.

    ADMINISTRATION

    Oral Administration
    Oral Solid Formulations

    Regular-release tablets:
    Administer with meals to improve gastrointestinal tolerance.
     
    Extended-release tablets:
    Usually administered with meals.
    Do not crush or chew; swallow whole.
    The inactive ingredients may occasionally be eliminated in the feces as a soft mass that may resemble the original tablet.

    STORAGE

    Actoplus Met:
    - Avoid excessive humidity
    - Protect from moisture
    - Store between 68 to 77 degrees F, excursions permitted 59 to 86 degrees F
    Actoplus Met XR :
    - Avoid excessive heat (above 104 degrees F)
    - Avoid excessive humidity
    - Store at 77 degrees F; excursions permitted to 59-86 degrees F

    CONTRAINDICATIONS / PRECAUTIONS

    General Information

    This monograph discusses the use of pioglitazone; metformin for the management of type 2 diabetes. Clinicians may wish to consult the individual drug monographs for more information.
     
    Do not use pioglitazone; metformin in patients who have a known metformin or pioglitazone hypersensitivity, or a known or suspected allergy to any of the inactive ingredients.

    Diabetic ketoacidosis, type 1 diabetes mellitus

    Pioglitazone; metformin use is contraindicated in patients with diabetic ketoacidosis (DKA), with or without coma; DKA should be treated with insulin. This combination is not intended for the treatment of type 1 diabetes mellitus. No efficacy or safety studies have been performed specifically with Actoplus Met for the treatment of type 2 diabetes mellitus. The combination of metformin and pioglitazone has been previously approved based on clinical trials in people with type 2 diabetes inadequately controlled on metformin alone. Patients undergoing changes in diabetic therapy should be monitored for fluctuations in glycemic control.

    Acidemia, acute myocardial infarction, cardiogenic shock, dehydration, hypoxemia, lactic acidosis, metabolic acidosis, sepsis

    Pioglitazone; metformin is contraindicated in patients with metabolic acidosis. Metformin is associated with an increased risk for lactic acidosis. Lactic acidosis should be suspected in any diabetic patient with metabolic acidosis lacking evidence of ketoacidosis (ketonuria and ketonemia). Lactic acidosis is a rare, but serious complication that can occur due to metformin accumulation and is fatal in approximately 50% of cases. Lactic acidosis may also occur in association with a number of pathophysiologic conditions, including diabetes mellitus, and whenever there is significant tissue hypoperfusion and hypoxemia or significant renal dysfunction. Certain medications that are eliminated via the kidney when used concomitantly with metformin may also increase the risk of lactic acidosis. Acute congestive cardiac failure, cardiogenic shock, or acute myocardial infarction and other conditions characterized by acute hypoxia have been associated with the development of lactic acidosis and may cause prerenal azotemia. To reduce the risk of lactic acidosis, pioglitazone; metformin should be promptly withheld in the presence of any condition associated with hypoxemia, dehydration, or sepsis. Lactic acidosis is characterized by elevated blood lactate levels, acidemia, electrolyte disturbances, an increased anion gap, and an increased lactate/pyruvate ratio. When metformin is implicated as the cause of lactic acidosis, metformin plasma levels more than 5 mcg/mL are generally noted. The reported incidence of lactic acidosis in patients receiving metformin is very low (approximately 0.03 cases/1,000 patient-years). A nested case-control study of 50,048 patients with type 2 diabetes mellitus demonstrated that during concurrent use of oral diabetes drugs, there were 6 identified cases of lactic acidosis. The crude incidence rate was 3.3 cases per 100,000 person-years in patients treated with metformin; it should be noted that all of the subjects had relevant comorbidities known to be risk factors for lactic acidosis. The onset of lactic acidosis often is subtle, and accompanied only by nonspecific symptoms such as malaise, myalgias, respiratory distress, increasing somnolence, and nonspecific abdominal distress. There may be associated hypothermia, hypotension, and resistant bradycardia with more marked acidemia. The patient and the prescriber must be aware of such symptoms and the patient should be instructed to notify the physician immediately if they occur. Metformin should be withdrawn until the situation is clarified. Serum electrolytes, ketones, blood glucose, and, if indicated, blood pH, lactate levels, and even blood metformin levels may be useful.

    Diarrhea, vomiting

    Gastrointestinal side effects are common during pioglitazone; metformin initiation. However, once a patient is stabilized on any dose of pioglitazone; metformin, GI symptoms are unlikely to be drug related. Later occurrence of GI symptoms may be due to a change in clinical status and may increase the risk of lactic acidosis or may be due to lactic acidosis (from the metformin component), hepatic dysfunction (from the pioglitazone component), or other serious disease. Patients stable on pioglitazone; metformin therapy who complain of an increase in GI symptoms should undergo laboratory investigation to determine the etiology of the GI symptoms. These include, but are not limited to, diarrhea and nausea/vomiting. Furthermore, withholding pioglitazone; metformin therapy until the cause of the GI symptoms is known may be necessary. Finally, diarrhea and nausea/vomiting may alter gastric emptying and caloric intake, which could all affect blood glucose control, especially increasing the risk of low blood glucose. Patients should be advised to contact their prescriber if an increase in gastrointestinal symptoms occurs while taking pioglitazone; metformin; patients should also be advised to monitor their blood glucose concentrations more frequently.

    Renal disease, renal failure, renal impairment

    Pioglitazone; metformin is contraindicated for use in patients with renal failure or severe renal impairment, defined as estimated glomerular filtration rate (eGFR) below 30 mL/minute/1.73 m2. Metformin is substantially eliminated by the kidney and the risk of lactic acidosis increases with the degree of intrinsic renal disease or impairment. Initiating pioglitazone; metformin in patients with an eGFR between 30 to 45 mL/minute/1.73 m2 is not recommended. Before initiation of treatment and at least annually thereafter, obtain an eGFR to assess renal function. In those patients at increased risk for the development of renal impairment, such as the elderly, renal function should be assessed more frequently. In patients taking pioglitazone; metformin whose eGFR later falls below 45 mL/minute/1.73 m2, assess the benefits and risks of continuing treatment. Discontinue pioglitazone; metformin if the patient's eGFR later falls below 30 mL/minute/1.73 m2. Based on the results of a comprehensive FDA safety review, the FDA concluded that metformin can be used safely in patients with mild renal impairment, and in some patients with moderate renal impairment. The measure of kidney function used to determine whether a patient can receive metformin has been changed from serum creatinine to the eGFR; this is because in addition to serum creatinine concentration, the eGFR takes into account additional parameters that are important, such as the patient's age, gender, race and/or weight.

    Acute heart failure, cardiac disease, edema, heart failure, peripheral edema, pulmonary edema

    Pioglitazone; metformin is contraindicated in patients with pre-existing New York Heart Association (NYHA) Class III or IV heart failure and should be used with caution in any patient with cardiac disease. Acute decompensation in cardiac status (e.g., acute heart failure, cardiogenic shock, or acute myocardial infarction) characterized by hypoxia has been associated with the development of lactic acidosis in patients taking metformin. Thiazolidinediones (TZDs), including pioglitazone, when used alone or in combination with other antidiabetic agents, can cause or exacerbate congestive heart failure. Patients should be carefully observed for signs and symptoms of heart failure including excessive, rapid weight gain, dyspnea, and/or edema (peripheral edema, pulmonary edema) after drug initiation and changes in dose. If these signs and symptoms develop, the heart failure should be managed according to current standards of care, and clinicians must consider reducing the dose or discontinuing pioglitazone; metformin. Therapy should be discontinued if deterioration in cardiac status occurs. The incidence of heart failure associated with pioglitazone use is higher in those patients receiving concomitant insulin therapy, older adult patients (65 years of age and older), those receiving higher doses of pioglitazone, and those with risk factors for congestive heart failure. In addition, in postmarketing experience with pioglitazone, cases of congestive heart failure have been reported in patients both with and without previously known cardiac disease. When compared with glyburide during a postmarketing safety study, pioglitazone was associated with a higher incidence of overnight hospitalization for congestive heart failure (9.9% for pioglitazone vs. 4.7% for glyburide). Dose-related edema and weight gain have been reported in patients treated with pioglitazone therapy; caution is advised in patients with preexisting edema. An association between pioglitazone and myocardial infarction has not been demonstrated. In a study of patients with type 2 diabetes, the addition of pioglitazone to existing diabetes therapy did not result in increased all-cause mortality or total macrovascular events such as non-fatal myocardial infarction, stroke, acute coronary syndrome, cardiac intervention, major leg amputation, or leg revascularization (HR 0.90, 95% CI 0.80 to 1.02, p = 0.1). Dose-related edema and weight-gain has been reported in patients treated with pioglitazone therapy.

    Alcoholism, ethanol ingestion, ethanol intoxication, hepatic disease

    Metformin administration increases the risk for lactic acidosis. Since the liver is important for clearing accumulated lactic acid, metformin is not recommended in patients with clinical or laboratory evidence of hepatic disease as the risk of lactic acidosis may be increased. Hepatic disease also causes altered gluconeogenesis, which may affect glycemic control. Alcohol is known to potentiate the effect of metformin on lactate metabolism. Patients should be warned against excessive ethanol ingestion (ethanol intoxication) while taking pioglitazone; metformin due to the increased risk for lactic acidosis. Those with ethanol intoxication are also particularly susceptible to hypoglycemic effects of oral antidiabetic agents. Pioglitazone; metformin use should be avoided by those patients with alcoholism. Cautious use of pioglitazone is also needed for patients with hepatic disease. In all patients, obtain a liver test panel and assess the patient before pioglitazone initiation. Patients with type 2 diabetes may have fatty liver disease or cardiac disease with episodic congestive heart failure, both of which may cause liver test abnormalities, and they may also have other forms of liver disease, many of which can be treated or managed. Clinical trials with pioglitazone have generally excluded patients with serum ALT more than 2.5 times the upper limit of normal (ULN). Initiate therapy with caution in patients with abnormal liver function tests (LFTs). Measure liver tests promptly in patients who report symptoms that may indicate liver injury, including fatigue, anorexia, right upper abdominal discomfort, dark urine or jaundice. If the patient is found to have abnormal LFTs (i.e., ALT more than 3 times the ULN), interrupt treatment with pioglitazone and investigate the probable cause. Pioglitazone should not be restarted in these patients without another explanation for the liver test abnormalities. Do not restart pioglitazone in patients who have serum ALT more than 3 times the ULN with serum total bilirubin more than 2 times the ULN and do not have alternative etiologies. Pioglitazone may be used with caution in patients with lesser elevations of serum ALT or bilirubin and who have an alternate probable cause. There have been postmarketing reports of fatal and non-fatal hepatic failure in patients taking pioglitazone, although the reports contain insufficient information necessary to establish the probable cause. There has been no evidence of drug-induced hepatotoxicity in the pioglitazone controlled clinical trial database to date.

    Radiographic contrast administration

    Discontinue pioglitazone; metformin at the time of or before radiographic contrast administration in patients with an estimated glomerular filtration rate (eGFR) between 30 and 60 mL/minute/1.73 m2; in patients with a history of hepatic disease, alcoholism, or heart failure; or in patients who will be administered intra-arterial iodinated contrast. Re-evaluate the eGFR 48 hours after the imaging procedure; restart metformin if renal function is stable.

    Burns, fever, infection, surgery, trauma

    Pioglitazone; metformin therapy should be temporarily suspended for any surgery, except for minor procedures where intake of fluids and food is not restricted. Do not restart this drug until oral intake is resumed and renal function has been evaluated as normal. Temporary use of insulin in place of oral antidiabetic agents may be necessary during periods of physiologic stress (i.e., burns, systemic infection, trauma, surgery, or fever). Any change in clinical status, including substantial loss of fluids may also increase the risk of lactic acidosis and may require laboratory evaluation in patients on pioglitazone; metformin; the drug may need to be withheld. Prior to initiation or dose escalation of pioglitazone; metformin, secondary causes of poor glycemic control (i.e., infection) should be evaluated and treated.

    Adrenal insufficiency, gastroparesis, GI obstruction, hypercortisolism, hyperglycemia, hyperthyroidism, hypoglycemia, hypothyroidism, ileus, malnutrition, pituitary insufficiency

    Delayed stomach emptying may alter blood glucose control; carefully monitor patients taking pioglitazone; metformin who have diarrhea, gastroparesis, GI obstruction, ileus, or vomiting. Conditions that predispose patients to developing hypoglycemia or hyperglycemia may also alter antidiabetic agent efficacy. Conditions associated with hypoglycemia include insufficient caloric intake, strenuous exercise, debilitated physical condition, drug interactions (additional hypoglycemic agents), malnutrition, uncontrolled adrenal insufficiency, pituitary insufficiency, or hypothyroidism. Hypoglycemia may be difficult to recognize in geriatric patients and those taking beta-blockers. In addition, if hypoglycemia occurs when pioglitazone; metformin is used in combination with insulin or an insulin secretagogue (e.g., sulfonylurea), the dose of insulin or the insulin secretagogue should be reduced. Individualize any further adjustments based on glycemic response. Hyperglycemia-related conditions include drug interactions, female hormonal changes, elevated temperature, severe psychological stress, and uncontrolled hypercortisolism or hyperthyroidism. More frequent blood glucose monitoring may be necessary in patients with these conditions.

    Anemia, pernicious anemia

    Pioglitazone can cause about a 2% to 4% decrease in hemoglobin during the first 4 to 12 weeks of therapy; the drops in hemoglobin are rarely associated with significant clinical effects; however, this reduction may be significant in patients with pre-existing anemia. In addition, metformin may result in suboptimal vitamin B12 absorption, possibly due to interference with the B12-intrinsic factor complex. The interaction very rarely results in a pernicious anemia that appears reversible with discontinuation of metformin or with cyanocobalamin supplementation. Certain individuals may be predisposed to this type of anemia; a nested case-control study of 465 patients taking metformin (155 with vitamin B12 deficiency and 310 without) demonstrated that dose and duration of metformin use may be associated with an increased odds of vitamin B12 deficiency. Each 1 gram/day increment in dose significantly increased the odds of vitamin B12 deficiency (OR 2.88, 95% CI 2.15 to 3.87) as did taking metformin for 3 years or more (OR 2.39, 95% CI 1.46 to 3.91). Regular measurement of hematologic parameters are recommended in all patients on pioglitazone; metformin treatment.

    Bone fractures, osteoporosis

    Use pioglitazone; metformin with caution in female patients with osteoporosis or risk factors for osteopenia. In a randomized trial (PROactive) in patients with type 2 diabetes, an increased incidence of bone fractures was noted in female patients taking pioglitazone. During a mean follow-up of 34.5 months, the incidence of bone fracture in females was 5.1% for pioglitazone versus 2.5% for placebo. This difference was noted after the first year of treatment and remained during the course of the study. The majority of fractures observed in female patients were nonvertebral fractures including lower limb and distal upper limb. These sites of fracture are different from those usually associated with postmenopausal osteoporosis (e.g., hip or spine). No increase in fracture rates was observed in men treated with pioglitazone 1.7% vs. placebo 2.1%. The risk of fracture should be considered in the care of patients treated with pioglitazone; metformin, especially female patients, and attention given to assessing and maintaining bone health according to current standards of care.

    Contraception requirements, menstrual irregularity, polycystic ovary syndrome, pregnancy

    Limited data with pioglitazone; metformin use during pregnancy are not sufficient to determine a drug-associated risk for major birth defects or miscarriage. Animal data suggest no teratogenic effects; however, embryotoxicity (increased post-implantation losses, delayed development, reduced fetal weights, and delayed parturition) have been observed in rats receiving 10-times or above the maximum recommended human dose (MRHD) and rabbits receiving 40-times the MRHD of pioglitazone. There is a lack of data describing the use of pioglitazone during human pregnancy. There are data describing metformin for gestational diabetes as a single agent. The American College of Obstetricians and Gynecologists (ACOG) and the American Diabetes Association (ADA) continue to recommend human insulin as the standard of care in women with diabetes mellitus and gestational diabetes mellitus (GDM) requiring medical therapy; insulin does not cross the placenta. Per ACOG, in women who decline insulin therapy or are unable to safely administer insulin, metformin is the preferred second-line choice. Per the ADA, metformin monotherapy may be used to treat GDM as a treatment option; however, no long term safety data are available for any oral agent. Metformin may cause a lower risk of neonatal hypoglycemia and less maternal weight gain than insulin; however, some data suggest that metformin may slightly increase the risk of prematurity. The ADA notes that in some clinical studies, nearly 50% of GDM patients initially treated with metformin have needed the addition of insulin in order to achieve acceptable glucose control. Premenopausal anovulatory females with insulin resistance, such as those with polycystic ovary syndrome (PCOS), may resume ovulation as a result of metformin or pioglitazone use; these patients may be at risk of conception if adequate contraception is not used. Adequate contraception requirements have been recommended during pioglitazone therapy for women of childbearing potential. If unexpected menstrual irregularity occurs, the benefits of continued pioglitazone; metformin therapy should be reviewed.

    Breast-feeding

    The effects of pioglitazone; metformin on the nursing infant are unknown and therefore, the developmental and health benefits of breast-feeding should be considered along with the mother's clinical need for pioglitazone; metformin and any potential adverse effects on the nursing infant from pioglitazone; metformin or from the underlying maternal condition. Animal data suggest that pioglitazone may be excreted in milk, however, it is unknown if pioglitazone or its metabolites are excreted in human milk. Animal data show that metformin is excreted into breast milk and reaches levels similar to those in plasma. Small studies indicate that metformin is excreted in human breast milk. However, adverse effects on infant plasma glucose have not been reported in human studies. Furthermore, the use of metformin 2,550 mg/day by mothers breast-feeding their infants for 6 months does not affect growth, motor, or social development; the effects beyond 6 months are not known. In all of these studies, the estimated weight-adjusted infant exposure to metformin ranged from 0.11% to 1.08% of the mother's dose. If blood glucose is not controlled on diet and exercise alone, insulin therapy should be considered; insulin is considered by experts to be compatible with breast-feeding. Other oral hypoglycemics may also be considered as possible alternatives in some patients. Because acarbose has limited systemic absorption, which results in minimal maternal plasma concentrations, clinically significant exposure via breast milk is not expected. Metformin monotherapy can also be a consideration. Tolbutamide is usually considered compatible with breast-feeding. Glyburide may be a suitable alternative since it was not detected in the breast milk of lactating women who received single and multiple doses of glyburide. If any oral hypoglycemics are used during breast-feeding, the nursing infant should be monitored for signs of hypoglycemia, such as increased fussiness or somnolence.

    Bladder cancer, new primary malignancy

    Pioglitazone; metformin should not be used in patients with active bladder cancer. In patients with a prior history of bladder cancer, the benefits of blood sugar control should be weighed against the unknown risks for cancer recurrence. In December 2016, the FDA concluded that use of pioglitazone may be linked to an increased risk of bladder cancer; this was based on an extensive evidence review. Patients currently taking pioglitazone; metformin are encouraged to report any symptoms of bladder cancer to their health care provider. Symptoms of bladder cancer include blood or red-colored urine (hematuria), new or worsening urge to urinate, and pain when urinating. Both patients and health care providers should report pioglitazone; metformin related adverse events to the FDA's MedWatch Safety Information and Adverse Events Reporting Program. In September 2010 and June 2011, the FDA warned about the possible risk of a new primary malignancy, specifically bladder cancer, with pioglitazone based on interim results from a 10-year U.S. epidemiologic study and a French epidemiological study. Based on the results of the French study, France has suspended the use of pioglitazone and Germany has recommended not to start pioglitazone in new patients. The FDA has reviewed additional published studies evaluating the risk of bladder cancer in patients treated with pioglitazone, including the final 10-year results of the U.S. epidemiologic study. The results did not show an increased risk for bladder cancer in patients who used pioglitazone at some point (ever users) compared to patients who never used pioglitazone (never users), with a fully adjusted HR of 1.06 (95% CI 0.89 to 1.26). The investigators identified 1,075 newly diagnosed cases of bladder cancer in never users (n = 158,918) and 186 cases in ever users (n = 34,181). The study also suggested a modest trend towards higher risk with increasing duration of use, but this trend was not statistically significant; it could have been due to chance. Compared to the interim 5-year results, these final 10-year results found weaker associations that were not statistically significant. However, the directions of the associations remained unchanged. In addition, during the 3 year PROactive Study (PROspective pioglitAzone Clinical Trial In macroVascular Events), 14 patients out of 2,605 (0.54%) randomized to pioglitazone and 5 out of 2,633 (0.19%) randomized to placebo were diagnosed with bladder cancer. After excluding patients in whom exposure to study drug was less than 1 year at the time of diagnosis of bladder cancer, there were 6 (0.23%) cases receiving pioglitazone and 2 (0.08%) cases receiving placebo. In a 10-year observational follow-up of the PROactive Study, researchers investigated the occurrence of cardiovascular outcomes and malignancies after the PROactive clinical trial period ended. Among patients who entered the follow-up study, the median total follow-up (clinical trial and observational periods) was 12.8 years. Results revealed the imbalance in the number of bladder cancer cases observed in patients using pioglitazone during the clinical trial period (RR 2.83; 95% CI 1.02 to 7.85) did not persist during the combined 12.8-year period (HR 1; 95% CI 0.59 to 1.72). In contrast, in a retrospective cohort study that assessed the association between pioglitazone use and bladder cancer, statistically significant trends in the risk of bladder cancer were observed with increasing cumulative duration of use and cumulative dose of pioglitazone. The investigators used the United Kingdom Clinical Practice Research Datalink (CPRD) to identify a cohort of 145,806 patients newly treated with antidiabetic drugs (n = 10,951 initiators of pioglitazone) with a mean follow-up of 4.7 years, during which 622 patients received a diagnosis of bladder cancer. Of these, 54 developed bladder cancer after pioglitazone exposure. The fully adjusted HR for bladder cancer with pioglitazone use compared with no thiazolidinedione use was 1.63 (95% CI 1.22 to 2.19).

    Geriatric

    Use pioglitazone; metformin with caution in the geriatric patient, especially those patients with pre-existing cardiac or kidney disease, due to a risk for heart failure or lactic acidosis. Metformin is substantially excreted by the kidney and the risk of adverse reactions (including lactic acidosis) is greater in patients with reduced renal function. Because aging is associated with renal function decline, care should be taken with dose selection and titration. Obtain an estimated glomerular filtration rate (eGFR) at least annually in all patients taking pioglitazone; metformin. In patients at increased risk for the development of renal impairment such as geriatric patients, renal function should be assessed more frequently. Unless estimated renal function via the eGFR is determined to be normal, do not initiate metformin in geriatric patients 80 years and older. Generally, elderly or debilitated patients should not be titrated up to maximum metformin dosages. Geriatric, debilitated, or malnourished patients are also particularly susceptible to hypoglycemic effects of antidiabetic agents; monitor blood glucose frequently. Pioglitazone use is not recommended in geriatric patients with symptomatic or acute heart failure, and initiation in patients with established New York Heart Association (NYHA) Class III or IV heart failure is contraindicated. Observe geriatric patients receiving pioglitazone; metformin for signs and symptoms of heart failure, and if heart failure or other deterioration in cardiac status develops, discontinue the drug and monitor for diabetic control. The incidence of heart failure associated with pioglitazone use is higher in those patients receiving concomitant insulin therapy, older adult patients (65 years and older), those receiving higher doses of pioglitazone, and those with risk factors for congestive heart failure. ] According to the Beers Criteria, pioglitazone is considered a potentially inappropriate medication (PIM) for use in geriatric patients with heart failure; avoid use in these patients due to the potential for fluid retention and exacerbation of the condition. The federal Omnibus Budget Reconciliation Act (OBRA) regulates medication use in residents of long-term care facilities (LTCFs). According to OBRA, the use of antidiabetic medications should include monitoring (e.g., periodic blood glucose) for effectiveness based on desired goals for that individual and to identify complications of treatment such as hypoglycemia or impaired renal function. Pioglitazone has been associated with edema and weight gain and use should be avoided in LTCF residents with NYHA Stage III or Stage IV heart failure. Metformin has been associated with lactic acidosis, which is more likely to occur under the following conditions: serum creatinine of 1.5 mg/dL or higher in males or 1.4 mg/dL or higher in females, abnormal creatinine clearance or eGFR from any cause, age of 80 years or older unless normal renal function is verified, radiologic studies in which intravascular iodinated contrast materials are given, congestive heart failure requiring pharmacologic management, or acute/chronic metabolic acidosis with or without coma (including diabetic ketoacidosis).

    Children

    No data are available on the use of pioglitazone; metformin in children and adolescents under 18 years of age. Use of metformin; pioglitazone is not recommended in pediatric patients.

    ADVERSE REACTIONS

    Severe

    heart failure / Delayed / 1.1-5.7
    bone fractures / Delayed / 5.1-5.1
    megaloblastic anemia / Delayed / 0-1.0
    lactic acidosis / Delayed / 0-0.1
    hepatic failure / Delayed / Incidence not known
    hepatic encephalopathy / Delayed / Incidence not known
    visual impairment / Early / Incidence not known
    macular edema / Delayed / Incidence not known
    new primary malignancy / Delayed / Incidence not known
    rhabdomyolysis / Delayed / Incidence not known

    Moderate

    peripheral edema / Delayed / 1.6-26.7
    hypoglycemia / Early / 0-8.5
    vitamin B12 deficiency / Delayed / 7.0-7.0
    fluid retention / Delayed / 3.0-6.0
    edema / Delayed / 3.0-6.0
    anemia / Delayed / 0-2.0
    elevated hepatic enzymes / Delayed / 0.3-0.3
    metabolic acidosis / Delayed / 0-0.1
    dyspnea / Early / Incidence not known
    folate deficiency / Delayed / Incidence not known
    cholestasis / Delayed / Incidence not known
    jaundice / Delayed / Incidence not known
    hyperbilirubinemia / Delayed / Incidence not known
    hepatitis / Delayed / Incidence not known
    blurred vision / Early / Incidence not known
    osteopenia / Delayed / Incidence not known

    Mild

    infection / Delayed / 4.4-16.0
    weight gain / Delayed / 2.7-13.9
    dysgeusia / Early / 1.0-10.0
    flatulence / Early / 1.0-10.0
    anorexia / Delayed / 1.0-10.0
    abdominal pain / Early / 1.0-10.0
    metallic taste / Early / 1.0-10.0
    dyspepsia / Early / 1.0-10.0
    headache / Early / 4.6-6.0
    nausea / Early / 3.6-5.8
    diarrhea / Early / 4.8-5.8
    myalgia / Early / 1.0-5.4
    dizziness / Early / 4.8-5.4
    pharyngitis / Delayed / 5.1-5.1
    malaise / Early / 1.0-5.0
    sinusitis / Delayed / 4.4-5.0
    menstrual irregularity / Delayed / 0-0.4

    DRUG INTERACTIONS

    Abacavir; Dolutegravir; Lamivudine: (Major) If these drugs are used in combination, the total daily dose of metformin must not exceed 1,000 mg/day. Dolutegravir may increase exposure to metformin. Increased exposure to metformin may increase the risk for hypoglycemia, gastrointestinal side effects, and potentially increase the risk for lactic acidosis. Consider the benefits and risks of concomitant use of dolutegravir with metformin. Close monitoring of blood glucose and patient clinical status (gastrointestinal side effects, renal function, electrolytes and acid-base balance) is recommended. When stopping dolutegravir, the metformin dose may need to be adjusted. In drug interaction studies, dolutegravir increased both the Cmax and AUC of metformin when metformin 500 mg PO twice daily was coadministered. Dolutegravir inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k]). (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Abacavir; Lamivudine, 3TC: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Abacavir; Lamivudine, 3TC; Zidovudine, ZDV: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Abiraterone: (Moderate) Closely monitor blood glucose if coadministration of pioglitazone with abiraterone is necessary. Pioglitazone is a CYP2C8 substrate and abiraterone is a weak CYP2C8 inhibitor. Concomitant use in a drug interaction trial increased pioglitazone exposure by 46%. Severe hypoglycemia has been reported when abiraterone was administered to patients receiving pioglitazone.
    Acalabrutinib: (Moderate) Consider the benefits and risks of concomitant therapy of acalabrutinib with metformin. Concomitant use o fmedications that interfere with common renal tubular transport systems involved in the renal elimination of metformin (e.g., MATE inhibitors) could increase systemic exposure to metformin and increase the risk for lactic acidosis. The active metabolite of acalabrutinib (ACP-5862) inhibits MATE1 in vitro and may have the potential to increase concentrations of coadministered substrates of these transporters.
    Acebutolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Chlorpheniramine; Phenylephrine : (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Dextromethorphan; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Dextromethorphan; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Guaifenesin; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetaminophen; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Acetazolamide: (Moderate) Carbonic anhydrase inhibitors such as acetazolamide frequently cause a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Concomitant use of acetazolamide with metformin may increase the risk for lactic acidosis; consider more frequent monitoring. Carbonic anhydrase inhibitors may also alter blood sugar; both hyperglycemia and hypoglycemia have been described. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction. (Minor) Carbonic anhydrase inhibitors may alter blood sugar. Both hyperglycemia and hypoglycemia have been described in patients treated with acetazolamide. This should be taken into consideration in patients with impaired glucose tolerance or diabetes mellitus who are receiving antidiabetic agents. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction.
    Acetohexamide: (Moderate) If hypoglycemia occurs during concomitant use of pioglitazone and a sulfonylurea, reduce the dose of the sulfonylurea. Patients receiving pioglitazone in combination with sulfonylureas may be at risk for hypoglycemia. (Moderate) Monitor blood glucose during concomitant sulfonylurea and metformin use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Acrivastine; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Adefovir: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion (e.g., adefovir) may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Aliskiren; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Aliskiren; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Aliskiren; Valsartan: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Amiloride; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Amlodipine; Atorvastatin: (Minor) Concentrations of atorvastatin may be decreased with concomitant use of pioglitazone. The effect of pioglitazone capistration on the systemic exposure of atorvastatin was determined in a drug-drug interaction study. Coadministration of pioglitazone 45 mg once daily with atorvastatin 80 mg daily for 7 days resulted in a 14% and 23% reduction in atorvastatin AUC and Cmax, respectively. In addition, coadministration resulted in a 24% and 31% reduction in pioglitazone AUC and Cmax, respectively. Patients should be evaluated more frequently with respect to glycemic control and lipid therapy.
    Amlodipine; Benazepril: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Amlodipine; Olmesartan: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Amlodipine; Valsartan: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Amlodipine; Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Amoxicillin; Clarithromycin; Omeprazole: (Moderate) The concomitant use of clarithromycin and antidiabetic agents can result in significant hypoglycemia. Careful monitoring of blood glucose is recommended. (Moderate) The concomitant use of clarithromycin and oral hypoglycemic agents can result in significant hypoglycemia. With certain hypoglycemic drugs such as the thiazolidinediones, inhibition of CYP3A enzyme by clarithromycin may be involved; however, CYP3A is not a major metabolism route for pioglitazone and rosiglitazone. Careful monitoring of glucose is recommended.
    Amphetamine: (Moderate) Monitor for loss of glycemic control when amphetamines are administered to patients taking antidiabetic agents. Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Sympathomimetic agents, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells.
    Amphetamine; Dextroamphetamine: (Moderate) Monitor for loss of glycemic control when amphetamines are administered to patients taking antidiabetic agents. Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Sympathomimetic agents, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells.
    Amphetamines: (Moderate) Monitor for loss of glycemic control when amphetamines are administered to patients taking antidiabetic agents. Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Sympathomimetic agents, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells.
    Androgens: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Angiotensin II receptor antagonists: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Angiotensin-converting enzyme inhibitors: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Aripiprazole: (Moderate) Monitor blood glucose during concomitant aripiprazole and pioglitazone use. Atypical antipsychotic therapy may aggravate diabetes mellitus. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition.
    Asenapine: (Moderate) Atypical antipsychotic therapy may aggravate diabetes mellitus and cause metabolic changes such as hyperglycemia. Monitor patients on antidiabetic agents for worsening glycemic control. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Aggravation of diabetes mellitus has been reported. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition.
    Atazanavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Atazanavir; Cobicistat: (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Atenolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Atenolol; Chlorthalidone: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Atorvastatin: (Minor) Concentrations of atorvastatin may be decreased with concomitant use of pioglitazone. The effect of pioglitazone capistration on the systemic exposure of atorvastatin was determined in a drug-drug interaction study. Coadministration of pioglitazone 45 mg once daily with atorvastatin 80 mg daily for 7 days resulted in a 14% and 23% reduction in atorvastatin AUC and Cmax, respectively. In addition, coadministration resulted in a 24% and 31% reduction in pioglitazone AUC and Cmax, respectively. Patients should be evaluated more frequently with respect to glycemic control and lipid therapy.
    Atorvastatin; Ezetimibe: (Minor) Concentrations of atorvastatin may be decreased with concomitant use of pioglitazone. The effect of pioglitazone capistration on the systemic exposure of atorvastatin was determined in a drug-drug interaction study. Coadministration of pioglitazone 45 mg once daily with atorvastatin 80 mg daily for 7 days resulted in a 14% and 23% reduction in atorvastatin AUC and Cmax, respectively. In addition, coadministration resulted in a 24% and 31% reduction in pioglitazone AUC and Cmax, respectively. Patients should be evaluated more frequently with respect to glycemic control and lipid therapy.
    atypical antipsychotic: (Moderate) Monitor blood glucose during concomitant atypical antipsychotic and metformin use. Atypical antipsychotic therapy may aggravate diabetes mellitus. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition.
    Azelastine; Fluticasone: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Azilsartan: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Azilsartan; Chlorthalidone: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Beclomethasone: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Benazepril: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Benazepril; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Bendroflumethiazide; Nadolol: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Benzphetamine: (Moderate) Monitor for loss of glycemic control when amphetamines are administered to patients taking antidiabetic agents. Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Sympathomimetic agents, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells.
    Beta-blockers: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Betamethasone: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Betaxolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Bexarotene: (Moderate) Systemic bexarotene may enhance the action of insulin sensitizers (e.g., thiazolidinediones) resulting in hypoglycemia. Patients should be closely monitored while receiving bexarotene capsules in combination with any of these agents; monitor for hypoglycemia and need for diabetic therapy adjustments. Hypoglycemia has not been associated with bexarotene monotherapy.
    Bictegravir; Emtricitabine; Tenofovir Alafenamide: (Moderate) Caution is advised when administering bictegravir with metformin, as coadministration may increase exposure to metformin and increase the risk for hypoglycemia, gastrointestinal side effects, and potentially increase the risk for lactic acidosis. Close monitoring of blood glucose and patient clinical status is recommended. In drug interaction studies, bictegravir increased both the Cmax and AUC of metformin at a metformin dose of 500 mg PO twice daily. Bictegravir inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1]).
    Bisoprolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Bisoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Bortezomib: (Moderate) During clinical trials of bortezomib, hypoglycemia and hyperglycemia were reported in diabetic patients receiving antidiabetic agents. Patients taking antidiabetic agents and receiving bortezomib treatment may require close monitoring of their blood glucose levels and dosage adjustment of their medication.
    Brexpiprazole: (Moderate) Atypical antipsychotic therapy may aggravate diabetes mellitus and cause metabolic changes such as hyperglycemia. Monitor patients on antidiabetic agents for worsening glycemic control. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Aggravation of diabetes mellitus has been reported. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition.
    Brigatinib: (Moderate) Consider the benefits and risks of concomitant therapy of brigatinib with metformin. Concomitant use of drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin (e.g., MATE inhibitors) could increase systemic exposure to metformin and increase the risk for lactic acidosis. Brigatinib inhibits MATE1 and MATE2K in vitro and may have the potential to increase concentrations of coadministered substrates of these transporters.
    Brimonidine; Timolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Brompheniramine; Carbetapentane; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Brompheniramine; Dextromethorphan; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Brompheniramine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Brompheniramine; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Brompheniramine; Pseudoephedrine; Dextromethorphan: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Budesonide: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Budesonide; Formoterol: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Budesonide; Glycopyrrolate; Formoterol: (Moderate) Coadministration of glycopyrrolate with metformin my increase metformin plasma concentrations, which may lead to increased metformin effects and possible adverse events. If coadministration is necessary, monitor clinical response to metformin and adjust metformin dose accordingly. (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Bumetanide: (Minor) Bumetanide has been associated with hyperglycemia, possibly due to potassium depletion, and, glycosuria has been reported. Because of this, a potential pharmacodynamic interaction exists between bumetanide and all antidiabetic agents. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely.
    Calcium Carbonate; Famotidine; Magnesium Hydroxide: (Minor) Famotidine may decrease the renal clearance of metformin secondary to competition for renal tubular transport systems. Such an interaction has been observed when cimetidine was administered with metformin. The decrease in renal excretion led to a 40% increase in metformin AUC. Although interactions with cationic drugs remain theoretical (except for cimetidine), caution is warranted when famotidine and metformin are prescribed concurrently. Famotidine may be less likely to interact with metformin versus cimetidine or ranitidine because of less tubular excretion.
    Candesartan: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Candesartan; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Cannabidiol: (Moderate) Consider a dose reduction of pioglitazone as clinically appropriate, if adverse reactions occur when administered with cannabidiol. Increased pioglitazone exposure is possible. Pioglitazone is a CYP2C8 substrate. In vitro data predicts inhibition of CYP2C8 by cannabidiol potentially resulting in clinically significant interactions.
    Capmatinib: (Moderate) Monitor for an increased risk of metformin-related adverse reactions including lactic acidosis if coadministration with capmatinib is necessary; consider the benefits and risks of concomitant use. Metformin is a substrate of multidrug and toxin extrusion (MATE) and capmatinib is a MATE1 and MATE2K inhibitor. Coadministration may interfere with the renal elimination of metformin and increase metformin exposure.
    Captopril: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Captopril; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Carbetapentane; Chlorpheniramine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbetapentane; Diphenhydramine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbetapentane; Guaifenesin; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbetapentane; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbetapentane; Phenylephrine; Pyrilamine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbetapentane; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbinoxamine; Dextromethorphan; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbinoxamine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Carbinoxamine; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Cariprazine: (Moderate) Atypical antipsychotic therapy may aggravate diabetes mellitus and cause metabolic changes such as hyperglycemia. Monitor patients on antidiabetic agents for worsening glycemic control. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Aggravation of diabetes mellitus has been reported. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition.
    Carteolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Carvedilol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Cephalexin: (Moderate) Monitor for metformin-related adverse reactions during concomitant cephalexin use; a metformin dosage adjustment may be necessary. Concomitant use results in increased serum metformin concentrations and decreased renal clearance of metformin. In healthy subjects given single cephalexin 500 mg doses and metformin, serum metformin mean Cmax and AUC increased by an average of 34% and 24%, respectively, and metformin mean renal clearance decreased by 14%.
    Cetirizine; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlophedianol; Dexchlorpheniramine; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlophedianol; Guaifenesin; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chloroquine: (Major) Careful monitoring of blood glucose is recommended when chloroquine and antidiabetic agents, including metformin, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with chloroquine and an antidiabetic agent. (Major) Careful monitoring of blood glucose is recommended when chloroquine and antidiabetic agents, including the thiazolidinediones, are coadministered. A decreased dose of the antidiabetic agent may be necessary as severe hypoglycemia has been reported in patients treated concomitantly with chloroquine and an antidiabetic agent.
    Chlorothiazide: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlorpheniramine; Dihydrocodeine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlorpheniramine; Ibuprofen; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlorpheniramine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlorpheniramine; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Chlorpropamide: (Moderate) If hypoglycemia occurs during concomitant use of pioglitazone and a sulfonylurea, reduce the dose of the sulfonylurea. Patients receiving pioglitazone in combination with sulfonylureas may be at risk for hypoglycemia. (Moderate) Monitor blood glucose during concomitant sulfonylurea and metformin use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Chlorthalidone: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Chlorthalidone; Clonidine: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Minor) Increased frequency of blood glucose monitoring may be required when clonidine is given with antidiabetic agents. Since clonidine inhibits the release of catecholamines, clonidine may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Clonidine does not appear to impair recovery from hypoglycemia, and has not been found to impair glucose tolerance in diabetic patients.
    Chromium: (Moderate) Chromium dietary supplements may lower blood glucose. As part of the glucose tolerance factor molecule, chromium appears to facilitate the binding of insulin to insulin receptors in tissues and to aid in glucose metabolism. Because blood glucose may be lowered by the use of chromium, patients who are on antidiabetic agents may need dose adjustments. Close monitoring of blood glucose is recommended.
    Ciclesonide: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Cimetidine: (Moderate) Concomitant administration of metformin and cimetidine may increase metformin exposure and increase the risk for lactic acidosis. If these drugs are given together, monitor for signs of metformin toxicity; metformin dose adjustments may be needed. After administration of single doses of cimetidine 400 mg and metformin 850 mg, mean metformin exposure increased by 40%. Metformin is an OCT2 substrate; cimetidine is an OCT2 inhibitor that may decrease metformin elimination by blocking renal tubular secretion.
    Cisapride: (Moderate) Because cisapride can enhance gastric emptying in diabetic patients, blood glucose can be affected, which, in turn, may affect the clinical response to antidiabetic agents. Monitor blood glucose and adjust if cliniically indicated.
    Clarithromycin: (Moderate) The concomitant use of clarithromycin and antidiabetic agents can result in significant hypoglycemia. Careful monitoring of blood glucose is recommended. (Moderate) The concomitant use of clarithromycin and oral hypoglycemic agents can result in significant hypoglycemia. With certain hypoglycemic drugs such as the thiazolidinediones, inhibition of CYP3A enzyme by clarithromycin may be involved; however, CYP3A is not a major metabolism route for pioglitazone and rosiglitazone. Careful monitoring of glucose is recommended.
    Clofarabine: (Moderate) Concomitant use of clofarabine and metformin may result in altered clofarabine levels because both agents are a substrate of OCT1. Therefore, monitor for signs of clofarabine toxicity such as gastrointestinal toxicity (e.g., nausea, vomiting, diarrhea, mucosal inflammation), hematologic toxicity, and skin toxicity (e.g. hand and foot syndrome, rash, pruritus) in patients also receiving OCT1 substrates.
    Clonidine: (Minor) Increased frequency of blood glucose monitoring may be required when clonidine is given with antidiabetic agents. Since clonidine inhibits the release of catecholamines, clonidine may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Clonidine does not appear to impair recovery from hypoglycemia, and has not been found to impair glucose tolerance in diabetic patients.
    Clozapine: (Moderate) Atypical antipsychotic therapy may aggravate diabetes mellitus and cause metabolic changes such as hyperglycemia. Monitor patients on antidiabetic agents for worsening glycemic control. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Aggravation of diabetes mellitus has been reported. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition.
    Cobicistat: (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed.
    Cobimetinib: (Moderate) If concurrent use of cobimetinib and pioglitazone is necessary, use caution and monitor for decreased efficacy of cobimetinib. Cobimetinib is a CYP3A substrate in vitro, and pioglitazone is a weak inducer of CYP3A. The manufacturer of cobimetinib recommends avoiding coadministration of cobimetinib with moderate or strong CYP3A inducers based on simulations demonstrating that cobimetinib exposure would decrease by 73% or 83% when coadministered with a moderate or strong CYP3A inducer, respectively. Guidance is not available regarding concomitant use of cobimetinib with weak CYP3A inducers.
    Codeine; Guaifenesin; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Codeine; Phenylephrine; Promethazine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Colesevelam: (Moderate) The clinical response to metformin extended-release (metformin ER) should be monitored in patients receiving concomitant therapy with colesevelam. Be alert for changes in glycemic control, increased metformin side effects, such as gastrointestinal disturbances and a risk for lactic acidosis. Colesevelam increases the Cmax and AUC of metformin ER by approximately 8% and 44%, respectively. The mechanism of the interaction is not known. Colesevelam has no significant effect on the bioavailability of immediate-release metformin.
    Conjugated Estrogens: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Conjugated Estrogens; Bazedoxifene: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Conjugated Estrogens; Medroxyprogesterone: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Corticosteroids: (Moderate) Monitor blood glucose during concomitant corticosteroid and metformin use; a metformin dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells. (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Cortisone: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Cyanocobalamin, Vitamin B12: (Minor) Metformin may result in suboptimal oral vitamin B12 absorption by competitively blocking the calcium-dependent binding of the intrinsic factor-vitamin B12 complex to its receptor. Regular measurement of hematologic parameters is recommended in all patients on chronic metformin treatment; abnormalities should be investigated.
    Cyclosporine: (Moderate) Patients should be monitored for worsening glycemic control if therapy with cyclosporine is initiated in patients receiving antidiabetic agents. Cyclosporine has been reported to cause hyperglycemia or exacerbate diabetes mellitus; this effect appears to be dose-related and caused by direct beta-cell toxicity. (Moderate) Patients should be monitored for worsening glycemic control if therapy with cyclosporine is initiated in patients receiving antidiabetic agents. Cyclosporine has been reported to cause hyperglycemia or exacerbate diabetes mellitus; this effect appears to be dose-related and caused by direct beta-cell toxicity. Also, any drug that deteriorates the renal status of the patient is likely to alter metformin concentrations in the body, so renal function should be carefully monitored during the use of cyclosporine and metformin together.
    Dabrafenib: (Major) The concomitant use of dabrafenib and pioglitazone may lead to decreased pioglitazone exposure and loss of efficacy. Use of an alternative agent is recommended. If concomitant use is unavoidable, monitor patients for loss of pioglitazone efficacy. A change in diabetes treatment may be needed based upon clinical response if dabrafenib is started or stopped during treatment with pioglitazone; do not exceed the maximum recommended dose of 45 mg/day. In vitro, dabrafenib is an inducer of CYP2C isoenzymes via activation of the pregnane X receptor and constitutive androstane receptor nuclear receptors. Pioglitazone is a moderately sensitive CYP2C8 substrate. Administration of Rifampin 600 mg/day for 5 days with a single 30 mg dose of pioglitazone decreased the AUC of pioglitazone by 54% in a drug interaction study (n = 10).
    Daclatasvir: (Moderate) Closely monitor blood glucose levels if daclatasvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as daclatasvir.
    Danazol: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Darunavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Darunavir; Cobicistat: (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Darunavir; Cobicistat; Emtricitabine; Tenofovir alafenamide: (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir : (Moderate) Closely monitor blood glucose levels if dasabuvir; ombitasvir; paritaprevir; ritonavir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as dasabuvir; ombitasvir; paritaprevir; ritonavir.
    Dasabuvir; Ombitasvir; Paritaprevir; Ritonavir: (Major) While no dosage adjustment of metformin is recommended in patients with normal hepatic or renal function, careful patient monitoring and dose adjustment of metformin and/or the potentially interfering drug is recommended with concurrent use. Monitor for signs of onset of lactic acidosis such as respiratory distress, somnolence, and non-specific abdominal distress or worsening renal function. Do not use metformin with paritaprevir in patients with renal insufficiency or hepatic impairment. Drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin could increase systemic exposure to metformin and may increase the risk for lactic acidosis. Paritaprevir is an inhibitor of the organic anion transporters OATP1B1 and OATP1B3. While initial drug-drug interaction studies of paritaprevir-containing hepatitis treatments have not noted an effect on metformin concentrations, more study is needed. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Deflazacort: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Desloratadine; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Desogestrel; Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Dexamethasone: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Dexbrompheniramine; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Dextroamphetamine: (Moderate) Monitor for loss of glycemic control when amphetamines are administered to patients taking antidiabetic agents. Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Sympathomimetic agents, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells.
    Dextromethorphan; Diphenhydramine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Dextromethorphan; Guaifenesin; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Dextromethorphan; Guaifenesin; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Diazoxide: (Minor) Diazoxide, when administered intravenously or orally, produces a prompt dose-related increase in blood glucose level, due primarily to an inhibition of insulin release from the pancreas, and also to an extrapancreatic effect. The hyperglycemic effect begins within an hour and generally lasts no more than 8 hours in the presence of normal renal function. The hyperglycemic effect of diazoxide is expected to be antagonized by certain antidiabetic agents (e.g., insulin or a sulfonylurea). Blood glucose should be closely monitored.
    Dichlorphenamide: (Moderate) Carbonic anhydrase inhibitors such as dichlorphenamide frequently cause a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Concomitant use of dichlorphenamide with metformin may increase the risk for lactic acidosis; consider more frequent monitoring. Carbonic anhydrase inhibitors may also alter blood sugar; both hyperglycemia and hypoglycemia have been described. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction.
    Dienogest; Estradiol valerate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Diethylstilbestrol, DES: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Digoxin: (Moderate) Concentrations of digoxin may be increased with concomitant use of pioglitazone. The effect of pioglitazone capistration on the systemic exposure of digoxin was determined in a drug-drug interaction study. Coadministration of pioglitazone 45 mg once daily with digoxin 0.2 mg twice daily (loading dose) then 0.25 mg daily (maintenance dose, 7 days) resulted in a 15% and 17% increase in digoxin AUC and Cmax, respectively. Carefully monitor serum digoxin concentrations; observe patients carefully for signs of digoxin toxicity. (Moderate) Metformin may increase digoxin concentrations, but the magnitude is unclear. Measure serum digoxin concentrations before initiating metformin, and periodically after that. Monitor heart rate and other clinical parameters. Adjust digoxin dose as necessary.
    Diphenhydramine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Disopyramide: (Moderate) Disopyramide may enhance the hypoglycemic effects of antidiabetic agents. Patients receiving disopyramide concomitantly with antidiabetic agents should be monitored for changes in glycemic control.
    Dofetilide: (Major) Dofetilide should be co-administered with metformin with caution since both drugs are actively secreted via cationic secretion and could compete for common renal tubular transport systems. This results in a possible increase in plasma concentrations of either drug. Reduced clearance of metformin may increase the risk for lactic acidosis; increased concentrations of dofetilide may increase the risk for side effects including proarrhythmia. Careful patient monitoring and dose adjustment of metformin and dofetilide is recommended.
    Dolutegravir: (Major) If these drugs are used in combination, the total daily dose of metformin must not exceed 1,000 mg/day. Dolutegravir may increase exposure to metformin. Increased exposure to metformin may increase the risk for hypoglycemia, gastrointestinal side effects, and potentially increase the risk for lactic acidosis. Consider the benefits and risks of concomitant use of dolutegravir with metformin. Close monitoring of blood glucose and patient clinical status (gastrointestinal side effects, renal function, electrolytes and acid-base balance) is recommended. When stopping dolutegravir, the metformin dose may need to be adjusted. In drug interaction studies, dolutegravir increased both the Cmax and AUC of metformin when metformin 500 mg PO twice daily was coadministered. Dolutegravir inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k]).
    Dolutegravir; Lamivudine: (Major) If these drugs are used in combination, the total daily dose of metformin must not exceed 1,000 mg/day. Dolutegravir may increase exposure to metformin. Increased exposure to metformin may increase the risk for hypoglycemia, gastrointestinal side effects, and potentially increase the risk for lactic acidosis. Consider the benefits and risks of concomitant use of dolutegravir with metformin. Close monitoring of blood glucose and patient clinical status (gastrointestinal side effects, renal function, electrolytes and acid-base balance) is recommended. When stopping dolutegravir, the metformin dose may need to be adjusted. In drug interaction studies, dolutegravir increased both the Cmax and AUC of metformin when metformin 500 mg PO twice daily was coadministered. Dolutegravir inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k]). (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Dolutegravir; Rilpivirine: (Major) If these drugs are used in combination, the total daily dose of metformin must not exceed 1,000 mg/day. Dolutegravir may increase exposure to metformin. Increased exposure to metformin may increase the risk for hypoglycemia, gastrointestinal side effects, and potentially increase the risk for lactic acidosis. Consider the benefits and risks of concomitant use of dolutegravir with metformin. Close monitoring of blood glucose and patient clinical status (gastrointestinal side effects, renal function, electrolytes and acid-base balance) is recommended. When stopping dolutegravir, the metformin dose may need to be adjusted. In drug interaction studies, dolutegravir increased both the Cmax and AUC of metformin when metformin 500 mg PO twice daily was coadministered. Dolutegravir inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k]).
    Donepezil; Memantine: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
    Doravirine; Lamivudine; Tenofovir disoproxil fumarate: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Dorzolamide; Timolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Drospirenone: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Drospirenone; Estetrol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Drospirenone; Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Drospirenone; Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Drospirenone; Ethinyl Estradiol; Levomefolate: (Minor) Levomefolate and metformin should be used together cautiously. Plasma concentrations of levomefolate may be reduced during treatment of type 2 diabetes with metformin. Monitor patients for decreased efficacy of levomefolate if these agents are used together. (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Efavirenz; Lamivudine; Tenofovir Disoproxil Fumarate: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Elagolix; Estradiol; Norethindrone acetate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Elbasvir; Grazoprevir: (Moderate) Closely monitor blood glucose levels if elbasvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as elbasvir.
    Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Alafenamide: (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed.
    Elvitegravir; Cobicistat; Emtricitabine; Tenofovir Disoproxil Fumarate: (Moderate) Concurrent administration of metformin and cobicistat may increase the risk of lactic acidosis. Cobicistat is a potent inhibitor of the human multidrug and toxic extrusion 1 (MATE1) on proximal renal tubular cells; metformin is a MATE1 substrate. Inhibition of MATE1 by cobicistat may decrease metformin eliminiation by blocking renal tubular secretion. If these drugs are given together, closely monitor for signs of metformin toxicity; metformin dose adjustments may be needed.
    Enalapril, Enalaprilat: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Enalapril; Felodipine: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Enalapril; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Entecavir: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion (e.g., entecavir) may decrease metformin elimination by competing for common renal tubular transport systems. Although such interactions remain theoretical, careful patient monitoring and dose adjustment of metformin and/or the interfering cationic drug are recommended.
    Ephedrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Ephedrine; Guaifenesin: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Eprosartan: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Eprosartan; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Erdafitinib: (Moderate) Consider the benefits and risks of concomitant treatment with metformin and erdafitinib. Metformin is a substrate of organic cationic transporter-2 (OCT2). Erdafitinib is an OCT2 inhibitor. Coadministration with OCT2 inhibitors could increase systemic exposure to metformin and increase the risk for lactic acidosis.
    Esmolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Esterified Estrogens: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Esterified Estrogens; Methyltestosterone: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together. (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Estradiol Cypionate; Medroxyprogesterone: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Estradiol; Levonorgestrel: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Estradiol; Norethindrone: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Estradiol; Norgestimate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Estradiol; Progesterone: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Estramustine: (Minor) Estramustine is an estrogen-containing medication and may decrease glucose tolerance. Patients receiving antidiabetic agents should monitor their blood glucose levels frequently due to this potential pharmacodynamic interaction. (Minor) Estramustine should be used cautiously in patients receiving metformin. Patients should routinely monitor their blood glucose as indicated. Estramustine may decrease glucose tolerance leading to hyperglycemia.
    Estrogens: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Estropipate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Ethacrynic Acid: (Moderate) Loop diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose concentrations. Patients receiving antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary. (Moderate) Loop diuretics can decrease the hypoglycemic effects of antidiabetic agents by producing an increase in blood glucose concentrations.Patients receiving antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Ethanol: (Major) Patients taking metformin should be advised to avoid alcohol use. Blood lactate concentrations and the lactate to pyruvate ratio are increased during excessive (acute or chronic) intake of alcohol with metformin. (Moderate) Patients should be advised to limit alcohol ingestion when treated with a thiazolidinedione. A single administration of a moderate amount of alcohol did not increase the risk of acute hypoglycemia in type 2 diabetes mellitus patients treated with thiazolidinediones in clinical studies. However, alcohol inhibits gluconeogenesis, which can contribute to or increase the risk for hypoglycemia. In some patients, hypoglycemia can be prolonged. If a patient with diabetes ingests alcohol, they should be counselled to to avoid ingestion of alcohol on an empty stomach, which increases risk for low blood sugar. Patients should also be aware of the carbohydrate intake provided by certain types of alcohol in the diet, which can contribute to poor glycemic control. If a patient chooses to ingest alcohol, they should monitor their blood glucose frequently. Many non-prescription drug products may be formulated with alcohol; instruct patients to scrutinize product labels prior to consumption.
    Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Ethinyl Estradiol; Levonorgestrel; Folic Acid; Levomefolate: (Minor) Levomefolate and metformin should be used together cautiously. Plasma concentrations of levomefolate may be reduced during treatment of type 2 diabetes with metformin. Monitor patients for decreased efficacy of levomefolate if these agents are used together. (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Ethinyl Estradiol; Norelgestromin: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Ethinyl Estradiol; Norethindrone Acetate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Ethinyl Estradiol; Norgestrel: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Ethotoin: (Minor) Ethotoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients. (Minor) Phenytoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients.
    Ethynodiol Diacetate; Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Etonogestrel: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Etonogestrel; Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Famotidine: (Minor) Famotidine may decrease the renal clearance of metformin secondary to competition for renal tubular transport systems. Such an interaction has been observed when cimetidine was administered with metformin. The decrease in renal excretion led to a 40% increase in metformin AUC. Although interactions with cationic drugs remain theoretical (except for cimetidine), caution is warranted when famotidine and metformin are prescribed concurrently. Famotidine may be less likely to interact with metformin versus cimetidine or ranitidine because of less tubular excretion.
    Fedratinib: (Moderate) Concurrent use of metformin and fedratinib may produce unpredictable effects. Concomitant administration may increase the risk for metformin adverse events (e.g., lactic acidosis) or reduce metformin's efficacy. If these drugs are given together, monitor for metformin toxicity and efficacy; metformin dose adjustments may be needed. Fedratinib inhibits the common renal tubular transport systems involved in the renal elimination of metformin (e.g., OCT2/MATE1 and MATE2). In a drug interaction study, fedratinib was observed to have no clinically meaningful effect on metformin overall exposure; however, the renal clearance of metformin was decreased by 36% and the glucose lowering effect of metformin appeared to be reduced. The baseline adjusted glucose exposure was about 50% higher in response to an oral glucose challenge when these drugs were administered together.
    Fenofibrate: (Moderate) Monitor blood glucose during concomitant metformin and fibric acid derivative use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant pioglitazone and fenofibrate use; a pioglitazone dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Fenofibric Acid: (Moderate) Monitor blood glucose during concomitant metformin and fibric acid derivative use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant pioglitazone and fenofibric acid use; a pioglitazone dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Fexofenadine: (Minor) Concentrations of fexofenadine may be increased with concomitant use of pioglitazone. The effect of pioglitazone capistration on the systemic exposure of fexofenadine was determined in a drug-drug interaction study. Coadministration of pioglitazone 45 mg once daily with fexofenadine 60 mg twice daily for 7 days resulted in a 30% and 37% increase in fexofenadine AUC and Cmax, respectively. Patients should be monitored for increased side effects from fexofenadine.
    Fexofenadine; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes. (Minor) Concentrations of fexofenadine may be increased with concomitant use of pioglitazone. The effect of pioglitazone capistration on the systemic exposure of fexofenadine was determined in a drug-drug interaction study. Coadministration of pioglitazone 45 mg once daily with fexofenadine 60 mg twice daily for 7 days resulted in a 30% and 37% increase in fexofenadine AUC and Cmax, respectively. Patients should be monitored for increased side effects from fexofenadine.
    Fibric acid derivatives: (Moderate) Monitor blood glucose during concomitant metformin and fibric acid derivative use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Fludrocortisone: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Flunisolide: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Fluoxetine: (Moderate) Monitor blood glucose during concomitant metformin and fluoxetine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and fluoxetine use; a thiazolidinedione dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Fluoxymesterone: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Fluticasone: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Fluticasone; Salmeterol: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Fluticasone; Umeclidinium; Vilanterol: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Fluticasone; Vilanterol: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Formoterol; Mometasone: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Fosamprenavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Fosinopril: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Fosinopril; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Fosphenytoin: (Minor) Fosphenytoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients. (Minor) Phenytoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients.
    Furosemide: (Minor) Furosemide may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. (Minor) Furosemide may cause hyperglycemia and glycosuria in patients with diabetes mellitus, probably due to diuretic-induced hypokalemia. Because of this, a potential pharmacodynamic interaction exists between furosemide and all antidiabetic agents. This interference can lead to a loss of diabetic control, so diabetic patients should be monitored closely.
    Garlic, Allium sativum: (Moderate) Patients receiving antidiabetic agents should use dietary supplements of Garlic, Allium sativum with caution. Constituents in garlic might have some antidiabetic activity, and may increase serum insulin levels and increase glycogen storage in the liver. Monitor blood glucose and glycemic control. Patients with diabetes should inform their health care professionals of their intent to ingest garlic dietary supplements. Some patients may require adjustment to their hypoglycemic medications over time. One study stated that additional garlic supplementation (0.05 to 1.5 grams PO per day) contributed to improved blood glucose control in patients with type 2 diabetes mellitus within 1 to 2 weeks, and had positive effects on total cholesterol and high/low density lipoprotein regulation over time. It is unclear if hemoglobin A1C is improved or if improvements are sustained with continued treatment beyond 24 weeks. Other reviews suggest that garlic may provide modest improvements in blood lipids, but few studies demonstrate decreases in blood glucose in diabetic and non-diabetic patients. More controlled trials are needed to discern if garlic has an effect on blood glucose in patients with diabetes. When garlic is used in foods or as a seasoning, or at doses of 50 mg/day or less, it is unlikely that blood glucose levels are affected to any clinically significant degree.
    Gemfibrozil: (Major) Do not exceed 15 mg/day of pioglitazone when coadministered with gemfibrozil. Coadministration may increase the exposure of pioglitazone, increasing the risk for hypoglycemia. Pioglitazone is a CYP2C8 substrate and gemfibrozil is a strong CYP2C8 inhibitor. The exposure to pioglitazone is increased approximately 3-fold when combined with gemfibrozil. Fibric acid derivatives may also enhance the hypoglycemic effects of antidiabetic agents through increased insulin sensitivity and decreased glucagon secretion. (Moderate) Monitor blood glucose during concomitant metformin and fibric acid derivative use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Glecaprevir; Pibrentasvir: (Moderate) Closely monitor blood glucose levels if glecaprevir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as glecaprevir. (Moderate) Closely monitor blood glucose levels if pibrentasvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as pibrentasvir.
    Glimepiride: (Moderate) If hypoglycemia occurs during concomitant use of pioglitazone and a sulfonylurea, reduce the dose of the sulfonylurea. Patients receiving pioglitazone in combination with sulfonylureas may be at risk for hypoglycemia. (Moderate) Monitor blood glucose during concomitant sulfonylurea and metformin use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Glimepiride; Rosiglitazone: (Moderate) If hypoglycemia occurs during concomitant use of pioglitazone and a sulfonylurea, reduce the dose of the sulfonylurea. Patients receiving pioglitazone in combination with sulfonylureas may be at risk for hypoglycemia. (Moderate) Monitor blood glucose during concomitant sulfonylurea and metformin use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Glipizide: (Moderate) If hypoglycemia occurs during concomitant use of pioglitazone and a sulfonylurea, reduce the dose of the sulfonylurea. Patients receiving pioglitazone in combination with sulfonylureas may be at risk for hypoglycemia. (Moderate) Monitor blood glucose during concomitant sulfonylurea and metformin use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Glipizide; Metformin: (Moderate) If hypoglycemia occurs during concomitant use of pioglitazone and a sulfonylurea, reduce the dose of the sulfonylurea. Patients receiving pioglitazone in combination with sulfonylureas may be at risk for hypoglycemia. (Moderate) Monitor blood glucose during concomitant sulfonylurea and metformin use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Glyburide: (Moderate) If hypoglycemia occurs during concomitant use of pioglitazone and a sulfonylurea, reduce the dose of the sulfonylurea. Patients receiving pioglitazone in combination with sulfonylureas may be at risk for hypoglycemia. (Moderate) Monitor blood glucose during concomitant sulfonylurea and metformin use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Glyburide; Metformin: (Moderate) If hypoglycemia occurs during concomitant use of pioglitazone and a sulfonylurea, reduce the dose of the sulfonylurea. Patients receiving pioglitazone in combination with sulfonylureas may be at risk for hypoglycemia. (Moderate) Monitor blood glucose during concomitant sulfonylurea and metformin use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Glycopyrrolate: (Moderate) Coadministration of glycopyrrolate with metformin my increase metformin plasma concentrations, which may lead to increased metformin effects and possible adverse events. If coadministration is necessary, monitor clinical response to metformin and adjust metformin dose accordingly.
    Glycopyrrolate; Formoterol: (Moderate) Coadministration of glycopyrrolate with metformin my increase metformin plasma concentrations, which may lead to increased metformin effects and possible adverse events. If coadministration is necessary, monitor clinical response to metformin and adjust metformin dose accordingly.
    Green Tea: (Moderate) Green tea catechins have been shown to decrease serum glucose concentrations in vitro. Patients with diabetes mellitus taking antidiabetic agents should be monitored closely for hypoglycemia if consuming green tea products. (Moderate) Green tea catechins have been shown to decrease serum glucose concentrations in vitro. Patients with diabetes mellitus taking antidiabetic agents should be monitored closely for hypoglycemia if consuming green tea products.
    Guaifenesin; Hydrocodone; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Guaifenesin; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Guaifenesin; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Hydantoins: (Minor) Phenytoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients.
    Hydralazine; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Hydrochlorothiazide, HCTZ; Methyldopa: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Hydrochlorothiazide, HCTZ; Moexipril: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Hydrocodone; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Hydrocortisone: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Hydroxychloroquine: (Moderate) Monitor blood glucose during concomitant metformin and hydroxychloroquine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and hydroxychloroquine use; a thiazolidinedione dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Hydroxyprogesterone: (Minor) Progestins, like hydroxyprogesterone, can impair glucose tolerance. Patients receiving antidiabetic agents should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued.
    Ibuprofen; Famotidine: (Minor) Famotidine may decrease the renal clearance of metformin secondary to competition for renal tubular transport systems. Such an interaction has been observed when cimetidine was administered with metformin. The decrease in renal excretion led to a 40% increase in metformin AUC. Although interactions with cationic drugs remain theoretical (except for cimetidine), caution is warranted when famotidine and metformin are prescribed concurrently. Famotidine may be less likely to interact with metformin versus cimetidine or ranitidine because of less tubular excretion.
    Ibuprofen; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Iloperidone: (Moderate) Atypical antipsychotic therapy may aggravate diabetes mellitus and cause metabolic changes such as hyperglycemia. Monitor patients on antidiabetic agents for worsening glycemic control. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Aggravation of diabetes mellitus has been reported. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition.
    Indacaterol; Glycopyrrolate: (Moderate) Coadministration of glycopyrrolate with metformin my increase metformin plasma concentrations, which may lead to increased metformin effects and possible adverse events. If coadministration is necessary, monitor clinical response to metformin and adjust metformin dose accordingly.
    Indapamide: (Moderate) A potential pharmacodynamic interaction exists between indapamide and antidiabetic agents, like metformin. Indapamide can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. (Moderate) A potential pharmacodynamic interaction exists between indapamide and antidiabetic agents, such as thiazolidinediones. Indapamide can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia.
    Indinavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Insulin Aspart: (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Insulin Aspart; Insulin Aspart Protamine: (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Insulin Degludec: (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Insulin Degludec; Liraglutide: (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Insulin Detemir: (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Insulin Glargine: (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Insulin Glargine; Lixisenatide: (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Insulin Glulisine: (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Insulin Lispro: (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Insulin Lispro; Insulin Lispro Protamine: (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Insulin, Inhaled: (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Insulins: (Moderate) Monitor blood glucose and for signs and symptoms of heart failure during concomitant pioglitazone and insulin use. Reduce the insulin dose by 10% to 25% if hypoglycemia occurs; adjust the insulin dose further based on glycemic response. Consider discontinuation of pioglitazone if heart failure occurs and manage according to current standards. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia and fluid retention which may lead to or exacerbate heart failure. (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Iodipamide Meglumine: (Contraindicated) Metformin and combination products containing metformin should be temporarily discontinued prior to the administration of iodinated contrast media. Metformin should be held for at least 48 hours after contrast administration and not restarted until renal function returns to normal post-procedure. Lactic acidosis has been reported in patients taking metformin that experience nephrotoxicity after use of iodinated contrast media.
    Ionic Contrast Media: (Contraindicated) Metformin and combination products containing metformin should be temporarily discontinued prior to the administration of iodinated contrast media. Metformin should be held for at least 48 hours after contrast administration and not restarted until renal function returns to normal post-procedure. Lactic acidosis has been reported in patients taking metformin that experience nephrotoxicity after use of iodinated contrast media.
    Ioxaglate Meglumine; Ioxaglate Sodium: (Contraindicated) Metformin and combination products containing metformin should be temporarily discontinued prior to the administration of iodinated contrast media. Metformin should be held for at least 48 hours after contrast administration and not restarted until renal function returns to normal post-procedure. Lactic acidosis has been reported in patients taking metformin that experience nephrotoxicity after use of iodinated contrast media.
    Irbesartan: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Irbesartan; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Isocarboxazid: (Moderate) Monitor blood glucose during concomitant thiazolidinedione and monoamine oxidase inhibitor (MAOI) use; a thiazolidinedione dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Isoniazid, INH; Pyrazinamide, PZA; Rifampin: (Minor) Concomitant administration of rifampin with pioglitazone resulted in a decrease in the AUC of pioglitazone. Patients receiving rifampin with pioglitazone should be monitored for changes in glycemic control; dosage adjustments may be necessary.
    Isoniazid, INH; Rifampin: (Minor) Concomitant administration of rifampin with pioglitazone resulted in a decrease in the AUC of pioglitazone. Patients receiving rifampin with pioglitazone should be monitored for changes in glycemic control; dosage adjustments may be necessary.
    Isophane Insulin (NPH): (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Itraconazole: (Moderate) Itraconazole should be used cautiously with oral antidiabetic agents. The combination of itraconazole and oral antidiabetic agents has resulted in severe hypoglycemia. Blood glucose concentrations should be monitored and possible dose adjustments of hypoglycemics may need to be made.
    Ketoconazole: (Moderate) Concomitant administration of metformin and ketoconazole may increase metformin exposure and increase the risk for lactic acidosis. If these drugs are given together, monitor for signs of metformin toxicity; metformin dose adjustments may be needed. Metformin is a human multidrug and toxic extrusion (MATE) and OCT2 substrate and ketoconazole is a MATE and OCT2 inhibitor. MATE and OCT2 inhibitors may decrease metformin elimination by blocking renal tubular secretion. (Moderate) Monitor blood glucose during concomitant ketoconazole and pioglitazone use. Concomitant use increased ketoconazole exposure and peak concentration by 34% and 14%, respectively.
    Labetalol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Lamivudine, 3TC: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Lamivudine, 3TC; Zidovudine, ZDV: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Lamivudine; Tenofovir Disoproxil Fumarate: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, such as lamivudine, may decrease metformin elimination by competing for common renal tubular transport systems.
    Lamotrigine: (Moderate) Concomitant administration of metformin and lamotrigine may increase metformin exposure and increase the risk for lactic acidosis. If these drugs are given together, monitor for signs of metformin toxicity; metformin dose adjustments may be needed. Metformin is an OCT2 substrate; lamotrigine is an OCT2 inhibitor that may decrease metformin elimination by blocking renal tubular secretion.
    Lanreotide: (Moderate) Monitor blood glucose levels regularly in patients with diabetes, especially when lanreotide treatment is initiated or when the dose is altered. Adjust treatment with antidiabetic agents as clinically indicated. Lanreotide inhibits the secretion of insulin and glucagon. Patients treated with lanreotide may experience either hypoglycemia or hyperglycemia.
    Lansoprazole; Amoxicillin; Clarithromycin: (Moderate) The concomitant use of clarithromycin and antidiabetic agents can result in significant hypoglycemia. Careful monitoring of blood glucose is recommended. (Moderate) The concomitant use of clarithromycin and oral hypoglycemic agents can result in significant hypoglycemia. With certain hypoglycemic drugs such as the thiazolidinediones, inhibition of CYP3A enzyme by clarithromycin may be involved; however, CYP3A is not a major metabolism route for pioglitazone and rosiglitazone. Careful monitoring of glucose is recommended.
    Ledipasvir; Sofosbuvir: (Moderate) Closely monitor blood glucose levels if ledipasvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agent(s) may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as ledipasvir. (Moderate) Closely monitor blood glucose levels if sofosbuvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as sofosbuvir.
    Leflunomide: (Moderate) Closely monitor for hypoglycemia and for pioglitazone-induced side effects when these drugs are used together. In some patients, a dosage reduction of pioglitazone may be required. Following oral administration, leflunomide is metabolized to an active metabolite, teriflunomide, which is responsible for essentially all of leflunomide's in vivo activity. Pioglitazone is a substrate for CYP2C8. In vivo data suggest that teriflunomide is an inhibitor of CYP2C8, as Cmax and AUC increased 1.7- and 4.2-fold, respectively, following concurrent use of another CYP2C8 substrate.
    Lente Insulin: (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Letermovir: (Moderate) Plasma concentrations of pioglitazone could be increased when administered concurrently with letermovir. If these drugs are given together, closely monitor for pioglitazone-related adverse events. Letermovir is an inhibitor of CYP2C8; pioglitazone is a CYP2C8 substrate.
    Leuprolide; Norethindrone: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Levobetaxolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Levobunolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Levoketoconazole: (Moderate) Concomitant administration of metformin and ketoconazole may increase metformin exposure and increase the risk for lactic acidosis. If these drugs are given together, monitor for signs of metformin toxicity; metformin dose adjustments may be needed. Metformin is a human multidrug and toxic extrusion (MATE) and OCT2 substrate and ketoconazole is a MATE and OCT2 inhibitor. MATE and OCT2 inhibitors may decrease metformin elimination by blocking renal tubular secretion. (Moderate) Monitor blood glucose during concomitant ketoconazole and pioglitazone use. Concomitant use increased ketoconazole exposure and peak concentration by 34% and 14%, respectively.
    Levomefolate: (Minor) Levomefolate and metformin should be used together cautiously. Plasma concentrations of levomefolate may be reduced during treatment of type 2 diabetes with metformin. Monitor patients for decreased efficacy of levomefolate if these agents are used together.
    Levonorgestrel: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Levonorgestrel; Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Levonorgestrel; Ethinyl Estradiol; Ferrous Bisglycinate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Levothyroxine: (Minor) Thyroid hormone use may result in increased blood sugar and a loss of glycemic control in some patients. Interactions may or may not be clinically significant at usual replacement doses. Monitor blood sugars carefully when thyroid therapy is added, changed, or discontinued in patients receiving metformin.
    Levothyroxine; Liothyronine (Porcine): (Minor) Thyroid hormone use may result in increased blood sugar and a loss of glycemic control in some patients. Interactions may or may not be clinically significant at usual replacement doses. Monitor blood sugars carefully when thyroid therapy is added, changed, or discontinued in patients receiving metformin.
    Levothyroxine; Liothyronine (Synthetic): (Minor) Thyroid hormone use may result in increased blood sugar and a loss of glycemic control in some patients. Interactions may or may not be clinically significant at usual replacement doses. Monitor blood sugars carefully when thyroid therapy is added, changed, or discontinued in patients receiving metformin.
    Linezolid: (Moderate) Hypoglycemia, including symptomatic episodes, has been noted in post-marketing reports with linezolid in patients with diabetes mellitus receiving therapy with antidiabetic agents, such as insulin and oral hypoglycemic agents. Diabetic patients should be monitored for potential hypoglycemic reactions while on linezolid. If hypoglycemia occurs, discontinue or decrease the dose of the antidiabetic agent or discontinue the linezolid therapy. Linezolid is a reversible, nonselective MAO inhibitor and other MAO inhibitors have been associated with hypoglycemic episodes in diabetic patients receiving insulin or oral hypoglycemic agents.
    Liothyronine: (Minor) Thyroid hormone use may result in increased blood sugar and a loss of glycemic control in some patients. Interactions may or may not be clinically significant at usual replacement doses. Monitor blood sugars carefully when thyroid therapy is added, changed, or discontinued in patients receiving metformin.
    Lisdexamfetamine: (Moderate) Monitor for loss of glycemic control when amphetamines are administered to patients taking antidiabetic agents. Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Sympathomimetic agents, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells.
    Lisinopril: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Lisinopril; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Lonapegsomatropin: (Moderate) Patients with diabetes mellitus should be monitored closely during somatropin (recombinant rhGH) therapy. Antidiabetic drugs (e.g., insulin or oral agents) may require adjustment when somatropin therapy is instituted in these patients. Growth hormones, such as somatropin, may decrease insulin sensitivity, leading to glucose intolerance and loss of blood glucose control. Therefore, glucose levels should be monitored periodically in all patients treated with somatropin, especially in those with risk factors for diabetes mellitus.
    Lopinavir; Ritonavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Loratadine; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Lorcaserin: (Moderate) In general, weight reduction may increase the risk of hypoglycemia in patients with type 2 diabetes mellitus treated with antidiabetic agents, such as insulin and/or insulin secretagogues (e.g., sulfonylureas). In clinical trials, lorcaserin use was associated with reports of hypoglycemia. Blood glucose monitoring is warranted in patients with type 2 diabetes prior to starting and during lorcaserin treatment. Dosage adjustments of anti-diabetic medications should be considered. If a patient develops hypoglycemia during treatment, adjust anti-diabetic drug regimen accordingly. Of note, lorcaserin has not been studied in combination with insulin.
    Losartan: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Losartan; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Lovastatin; Niacin: (Moderate) Niacin (nicotinic acid) interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin (nicotinic acid) is added or deleted to the medication regimen. Dosage adjustments may be necessary. (Moderate) Niacin interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin is added or deleted to the medication regimen. Dosage adjustments may be necessary.
    Lumateperone: (Moderate) Lumateperone is an atypical antipsychotic and may aggravate diabetes mellitus and cause metabolic changes such as hyperglycemia. Monitor patients on antidiabetic agents for worsening glycemic control. Also, the manufacturer of lumateperone recommends that concurrent use of pioglitazone be avoided and lists pioglitazone as a CYP3A4 inducer. Some data suggest that pioglitazone does not induce CYP3A4 to a clinically relevant extent; the potential for reduced lumateperone exposure from pioglitazone is not established, but be alert for any changes in clinical response to lumateperone.
    Lurasidone: (Moderate) Atypical antipsychotic therapy may aggravate diabetes mellitus and cause metabolic changes such as hyperglycemia. Monitor patients on antidiabetic agents for worsening glycemic control. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Aggravation of diabetes mellitus has been reported. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition.
    Mafenide: (Moderate) Monitor blood glucose during concomitant metformin and sulfonamide use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and sulfonamide use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Mecasermin rinfabate: (Moderate) Use caution in combining mecasermin, recombinant, rh-IGF-1 or mecasermin rinfabate (rh-IGF-1/rh-IGFBP-3) with antidiabetic agents. Patients should be advised to eat within 20 minutes of mecasermin administration. Glucose monitoring is important when initializing or adjusting mecasermin therapies, when adjusting concomitant antidiabetic therapy, and in the event of hypoglycemic symptoms. An increased risk for hypoglycemia is possible. The hypoglycemic effect induced by IGF-1 activity may be exacerbated. The amino acid sequence of mecasermin (rh-IGF-1) is approximately 50 percent homologous to insulin and cross binding with either receptor is possible. Treatment with mecasermin has been shown to improve insulin sensitivity and to improve glycemic control in patients with either Type 1 or Type 2 diabetes mellitus when used alone or in conjunction with insulins.
    Mecasermin, Recombinant, rh-IGF-1: (Moderate) Use caution in combining mecasermin, recombinant, rh-IGF-1 or mecasermin rinfabate (rh-IGF-1/rh-IGFBP-3) with antidiabetic agents. Patients should be advised to eat within 20 minutes of mecasermin administration. Glucose monitoring is important when initializing or adjusting mecasermin therapies, when adjusting concomitant antidiabetic therapy, and in the event of hypoglycemic symptoms. An increased risk for hypoglycemia is possible. The hypoglycemic effect induced by IGF-1 activity may be exacerbated. The amino acid sequence of mecasermin (rh-IGF-1) is approximately 50 percent homologous to insulin and cross binding with either receptor is possible. Treatment with mecasermin has been shown to improve insulin sensitivity and to improve glycemic control in patients with either Type 1 or Type 2 diabetes mellitus when used alone or in conjunction with insulins.
    Medroxyprogesterone: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Meglitinides: (Moderate) Use of metformin with a meglitinide ("glinide") may increase the risk of hypoglycemia. Meglitinides are insulin secretagogues and are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the meglitinide may be needed. Monitor blood sugar.
    Memantine: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Drugs that are eliminated by renal tubular secretion (e.g., memantine) may decrease metformin elimination by competing for common renal tubular transport systems. It should be noted that in a pharmacokinetic study in which memantine and glyburide; metformin (Glucovance) were coadministered, the pharmacokinetics of memantine, metformin, or glyburide were not altered. Regardless, careful patient monitoring is recommended.
    Mestranol; Norethindrone: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Metformin; Repaglinide: (Moderate) Use of metformin with a meglitinide ("glinide") may increase the risk of hypoglycemia. Meglitinides are insulin secretagogues and are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the meglitinide may be needed. Monitor blood sugar.
    Methamphetamine: (Moderate) Monitor for loss of glycemic control when amphetamines are administered to patients taking antidiabetic agents. Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Sympathomimetic agents, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells.
    Methazolamide: (Moderate) Carbonic anhydrase inhibitors such as methazolamide frequently cause a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Concomitant use of methazolamide with metformin may increase the risk for lactic acidosis; consider more frequent monitoring. Carbonic anhydrase inhibitors may also alter blood sugar; both hyperglycemia and hypoglycemia have been described. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction. (Minor) Carbonic anhydrase inhibitors may alter blood sugar. Both hyperglycemia and hypoglycemia have been described in patients treated with acetazolamide. This should be taken into consideration in patients with impaired glucose tolerance or diabetes mellitus who are receiving antidiabetic agents. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction.
    Methyclothiazide: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Methylprednisolone: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Methyltestosterone: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Metolazone: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Metoprolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Metoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Metyrapone: (Moderate) In patients taking insulin or other antidiabetic agents, the signs and symptoms of acute metyrapone toxicity (e.g., symptoms of acute adrenal insufficiency) may be aggravated or modified.
    Midazolam: (Minor) Administration of pioglitazone for 15 days followed by a single dose midazolam syrup, 7.5 mg PO, resulted in a 26% reduction in the midazolam AUC. Higher doses of midazolam may be necessary when coadministered with pioglitazone.
    Midodrine: (Moderate) Certain medications used concomitantly with metformin may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion, like midodrine, may decrease metformin elimination by competing for common renal tubular transport systems. Careful patient monitoring and dose adjustment of metformin and/or midodrine is recommended.
    Moexipril: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Mometasone: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Monoamine oxidase inhibitors: (Moderate) Monitor blood glucose during concomitant metformin and monoamine oxidase inhibitor (MAOI) use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and monoamine oxidase inhibitor (MAOI) use; a thiazolidinedione dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Nadolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Nandrolone Decanoate: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Naproxen; Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Nateglinide: (Moderate) Use of metformin with a meglitinide ("glinide") may increase the risk of hypoglycemia. Meglitinides are insulin secretagogues and are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the meglitinide may be needed. Monitor blood sugar.
    Nebivolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Nebivolol; Valsartan: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Nelfinavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Niacin, Niacinamide: (Moderate) Niacin (nicotinic acid) interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin (nicotinic acid) is added or deleted to the medication regimen. Dosage adjustments may be necessary. (Moderate) Niacin interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin is added or deleted to the medication regimen. Dosage adjustments may be necessary.
    Niacin; Simvastatin: (Moderate) Niacin (nicotinic acid) interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin (nicotinic acid) is added or deleted to the medication regimen. Dosage adjustments may be necessary. (Moderate) Niacin interferes with glucose metabolism and can result in hyperglycemia. Changes in glycemic control can usually be corrected through modification of hypoglycemic therapy. Monitor patients taking antidiabetic agents for changes in glycemic control if niacin is added or deleted to the medication regimen. Dosage adjustments may be necessary.
    Nicotine: (Minor) Blood glucose concentrations should be monitored more closely whenever a change in either nicotine intake or smoking status occurs; dosage adjustments of metformin may be needed. Nicotine may increase plasma glucose; tobacco smoking is known to aggravate insulin resistance. The cessation of nicotine therapy or tobacco smoking may result in a decrease in blood glucose. (Minor) Nicotine may increase plasma glucose. Blood glucose concentrations should be monitored more closely whenever a change in either nicotine intake or smoking status occurs; dosage adjustments in antidiabetic agents may be needed.
    Nifedipine: (Minor) Concentrations of nifedipine may be decreased with concomitant use of pioglitazone. The effect of pioglitazone capistration on the systemic exposure of nifedipine ER was determined in a drug-drug interaction study. Coadministration of pioglitazone 45 mg once daily with nifedipine ER 30 mg once daily for 4 days resulted in a 13% and 17% reduction in nifedipine ER AUC and Cmax, respectively. In addition, coadministration for 7 days resulted in a 5% and 4% increase in pioglitazone AUC and Cmax, respectively. Patients should be monitored for the desired cardiovascular effects on heart rate, chest pain, or blood pressure; nifedipine dosages may need to be adjusted while the patient is receiving pioglitazone. Close monitoring of blood glucose is also recommended; dosage adjustments in pioglitazone may be needed. (Minor) Nifedipine may increase the plasma metformin Cmax and AUC and increase the amount of metformin excreted in the urine. Metformin half-life is unaffected. Nifedipine appears to enhance the absorption of metformin.
    Nirmatrelvir; Ritonavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Non-Ionic Contrast Media: (Major) Discontinue metformin at the time of, or before, administration of non-ionic contrast media to patients with an eGFR of 30 to 60 mL/minute/1.73 m2, history of liver disease, alcoholism, or heart failure, or who will be administered intra-arterial iodinated contrast. Reevaluate eGFR 48 hours after the imaging procedure; restart metformin if renal function is stable. Iodinated contrast agents appear to increase the risk of metformin-induced lactic acidosis, possibly as a result of worsening renal function.
    Norethindrone Acetate; Ethinyl Estradiol; Ferrous fumarate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Norethindrone: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Norethindrone; Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Norethindrone; Ethinyl Estradiol; Ferrous fumarate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Norgestimate; Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Norgestrel: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Octreotide: (Moderate) Monitor patients receiving octreotide concomitantly with insulin or other antidiabetic agents for changes in glycemic control and adjust doses of these medications accordingly. Octreotide alters the balance between the counter-regulatory hormones of insulin, glucagon, and growth hormone, which may result in hypoglycemia or hyperglycemia. The hypoglycemia or hyperglycemia which occurs during octreotide acetate therapy is usually mild but may result in overt diabetes mellitus or necessitate dose changes in insulin or other hypoglycemic agents. In patients with concomitant type1 diabetes mellitus, octreotide is likely to affect glucose regulation, and insulin requirements may be reduced. Symptomatic hypoglycemia, which may be severe, has been reported in type 1 diabetic patients. In Type 2 diabetes patients with partially intact insulin reserves, octreotide administration may result in decreases in plasma insulin levels and hyperglycemia.
    Olanzapine: (Moderate) Atypical antipsychotic therapy may aggravate diabetes mellitus and cause metabolic changes such as hyperglycemia. Monitor patients on antidiabetic agents for worsening glycemic control. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Aggravation of diabetes mellitus has been reported. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition.
    Olanzapine; Fluoxetine: (Moderate) Atypical antipsychotic therapy may aggravate diabetes mellitus and cause metabolic changes such as hyperglycemia. Monitor patients on antidiabetic agents for worsening glycemic control. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Aggravation of diabetes mellitus has been reported. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition. (Moderate) Monitor blood glucose during concomitant metformin and fluoxetine use; a metformin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and fluoxetine use; a thiazolidinedione dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Olanzapine; Samidorphan: (Moderate) Atypical antipsychotic therapy may aggravate diabetes mellitus and cause metabolic changes such as hyperglycemia. Monitor patients on antidiabetic agents for worsening glycemic control. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Aggravation of diabetes mellitus has been reported. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition.
    Olmesartan: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Olmesartan; Amlodipine; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Olmesartan; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Olopatadine; Mometasone: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Ombitasvir; Paritaprevir; Ritonavir: (Major) While no dosage adjustment of metformin is recommended in patients with normal hepatic or renal function, careful patient monitoring and dose adjustment of metformin and/or the potentially interfering drug is recommended with concurrent use. Monitor for signs of onset of lactic acidosis such as respiratory distress, somnolence, and non-specific abdominal distress or worsening renal function. Do not use metformin with paritaprevir in patients with renal insufficiency or hepatic impairment. Drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin could increase systemic exposure to metformin and may increase the risk for lactic acidosis. Paritaprevir is an inhibitor of the organic anion transporters OATP1B1 and OATP1B3. While initial drug-drug interaction studies of paritaprevir-containing hepatitis treatments have not noted an effect on metformin concentrations, more study is needed. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Orlistat: (Minor) Weight-loss may affect glycemic control in patients with diabetes mellitus. In many patients, glycemic control may improve. A reduction in dose of oral hypoglycemic medications may be required in some patients taking orlistat. Monitor blood glucose and glycemic control and adjust therapy as clinically indicated.
    Oxandrolone: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Oxymetholone: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Paliperidone: (Moderate) Atypical antipsychotic therapy may aggravate diabetes mellitus and cause metabolic changes such as hyperglycemia. Monitor patients on antidiabetic agents for worsening glycemic control. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Aggravation of diabetes mellitus has been reported. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition.
    Pasireotide: (Moderate) Monitor blood glucose levels regularly in patients with diabetes, especially when pasireotide treatment is initiated or when the dose is altered. Adjust treatment with antidiabetic agents as clinically indicated. Pasireotide inhibits the secretion of insulin and glucagon. Patients treated with pasireotide may experience either hypoglycemia or hyperglycemia.
    Pegvisomant: (Moderate) Monitor blood glucose levels regularly in patients with diabetes, especially when pegvisomant treatment is initiated or when the dose is altered. Adjust treatment with antidiabetic agents as clinically indicated. Pegvisomant increases sensitivity to insulin by lowering the activity of growth hormone, and in some patients glucose tolerance improves with treatment. Patients with diabetes treated with pegvisomant and antidiabetic agents may be more likely to experience hypoglycemia.
    Penbutolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Pentamidine: (Moderate) Pentamidine can be harmful to pancreatic cells. This effect may lead to hypoglycemia acutely, followed by hyperglycemia with prolonged pentamidine therapy. Patients on antidiabetic agents should be monitored for the need for dosage adjustments during the use of pentamidine.
    Pentoxifylline: (Moderate) Pentoxiphylline has been used concurrently with antidiabetic agents without observed problems, but it may enhance the hypoglycemic action of antidiabetic agents. Patients should be monitored for changes in glycemic control while receiving pentoxifylline in combination with antidiabetic agents.
    Perindopril: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Perindopril; Amlodipine: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Phenelzine: (Moderate) Monitor blood glucose during concomitant thiazolidinedione and monoamine oxidase inhibitor (MAOI) use; a thiazolidinedione dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Phenobarbital: (Minor) It is possible that a decrease in exposure of pioglitazone will occur when coadministered with drugs that induce CYP2C8 including phenobarbital. Patients receiving phenobarbital in combination with pioglitazone should be monitored for changes in glycemic control; dosage adjustments may be necessary.
    Phenobarbital; Hyoscyamine; Atropine; Scopolamine: (Minor) It is possible that a decrease in exposure of pioglitazone will occur when coadministered with drugs that induce CYP2C8 including phenobarbital. Patients receiving phenobarbital in combination with pioglitazone should be monitored for changes in glycemic control; dosage adjustments may be necessary.
    Phenothiazines: (Minor) Phenothiazines, especially chlorpromazine, may increase blood glucose concentrations. Hyperglycemia and glycosuria have been reported. Patients who are taking antidiabetic agents should monitor for worsening glycemic control when a phenothiazine is instituted. (Minor) Phenothiazines, especially chlorpromazine, may increase blood glucose concentrations. Hyperglycemia and glycosuria have been reported. When such drugs are administered to a patient receiving metformin, observe the patient closely for loss of blood glucose control. When such drugs are withdrawn from a patient receiving metformin, observe the patient closely for hypoglycemia.
    Phentermine; Topiramate: (Moderate) A decrease in the exposures of pioglitazone and its active metabolites were observed in a clinical trial during concurrent use of topiramate. The clinical significance is unknown; however, results of routine blood glucose monitoring should be carefully followed during coadministration of pioglitazone and topiramate to ensure adequate glucose control. (Moderate) Consider more frequent monitoring of patients receiving metformin and concomitant topiramate due to increased risk for lactic acidosis. Carbonic anhydrase inhibitors, such as topiramate, frequently cause a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. In healthy volunteers, metformin Cmax and AUC increased by 17% and 25%, respectively, when topiramate was added, and oral plasma clearance of topiramate appears to be reduced when administered with metformin. The clinical significance of the effect on the pharmacokinetics of metformin or topiramate are not known.
    Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Phenytoin: (Minor) Phenytoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients. (Minor) Phenytoin and other hydantoins have the potential to increase blood glucose and thus interact with antidiabetic agents pharmacodynamically. Monitor blood glucose for changes in glycemic control. Dosage adjustments may be necessary in some patients.
    Pindolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Pioglitazone; Glimepiride: (Moderate) If hypoglycemia occurs during concomitant use of pioglitazone and a sulfonylurea, reduce the dose of the sulfonylurea. Patients receiving pioglitazone in combination with sulfonylureas may be at risk for hypoglycemia. (Moderate) Monitor blood glucose during concomitant sulfonylurea and metformin use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Prasterone, Dehydroepiandrosterone, DHEA (Dietary Supplements): (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Prasterone, Dehydroepiandrosterone, DHEA (FDA-approved): (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Prednisolone: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Prednisone: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Pregabalin: (Moderate) Higher rates of peripheral edema and weight gain may occur in patients who concomitantly use thiazolidinediones with pregabalin. As the thiazolidinediones and pregabalin can both cause weight gain and/or fluid retention, possibly exacerbating or leading to heart failure, care should be taken when co-administering these agents.
    Progesterone: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance.
    Progestins: (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Progestins can impair glucose tolerance. Patients receiving antidiabetic agents should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued.
    Promethazine; Phenylephrine: (Moderate) Sympathomimetic agents and adrenergic agonists tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine, phenylephrine, and other sympathomimetics are administered to patients taking antidiabetic agents. Epinephrine and other sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Propantheline: (Moderate) Propantheline slows GI motility, which may increase the absorption of metformin from the small intestine. A 19% increase in metformin AUC has been reported in studies of this interaction in healthy volunteers. However, no serious side effects resulted.
    Propranolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Propranolol; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Protease inhibitors: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Another possible mechanism is impairment of beta-cell function. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients taking antidiabetic therapy should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Pseudoephedrine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Pseudoephedrine; Triprolidine: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when pseudoephedrine is administered to patients taking metformin. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Pyrimethamine; Sulfadoxine: (Moderate) Monitor blood glucose during concomitant metformin and sulfonamide use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and sulfonamide use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Quetiapine: (Moderate) Atypical antipsychotic therapy may aggravate diabetes mellitus and cause metabolic changes such as hyperglycemia. Monitor patients on antidiabetic agents for worsening glycemic control. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Aggravation of diabetes mellitus has been reported. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition.
    Quinapril: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Quinapril; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Quinolones: (Moderate) Monitor blood glucose carefully when systemic quinolones and antidiabetic agents, including metformin, are coadministered. Discontinue the quinolone if a hypoglycemic reaction occurs and initiate appropriate therapy immediately. Disturbances of blood glucose, including hyperglycemia and hypoglycemia, have been reported in patients treated concomitantly with quinolones and an antidiabetic agent. Hypoglycemia, sometimes resulting in coma, can occur. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and quinolone use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Ramipril: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Ranitidine: (Minor) Concentrations of pioglitazone may be decreased with concomitant use of ranitidine. The effect of capistration on the systemic exposure of pioglitazone was determined in a drug-drug interaction study. Coadministration of pioglitazone 45 mg once daily with ranitidine 150 mg twice daily for 4 days resulted in a 13% and 16% reduction in pioglitazone AUC and Cmax, respectively. Close monitoring of blood glucose is recommended; dosage adjustments in pioglitazone may be needed.
    Ranolazine: (Major) Limit the dose of metformin to 1,700 mg/day in adults if coadministered with ranolazine 1,000 mg twice daily. Coadministration of metformin with ranolazine 1,000 mg twice daily results in increased exposure to metformin. There is potential for an increased risk for lactic acidosis, which is associated with high metformin concentrations. Doses of metformin do not require reduction if coadministered with ranolazine 500 mg twice daily, as metformin exposure was not significantly increased with this lower dose of ranolazine. Ranolazine inhibits common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k]). Consider the benefits and risks of concomitant use of ranolazine with metformin. Monitor blood sugar and for gastrointestinal side effects, and increase monitoring for a risk for lactic acidosis, including renal function and electrolytes/acid-base balance.
    Regular Insulin: (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Regular Insulin; Isophane Insulin (NPH): (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Relugolix; Estradiol; Norethindrone acetate: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Repaglinide: (Moderate) Use of metformin with a meglitinide ("glinide") may increase the risk of hypoglycemia. Meglitinides are insulin secretagogues and are known to cause hypoglycemia. To manage hypoglycemic risk, lower doses of the meglitinide may be needed. Monitor blood sugar.
    Reserpine: (Moderate) Reserpine may mask the signs and symptoms of hypoglycemia. Patients receiving these drugs concomitantly should be monitored for changes in glycemic control. (Moderate) Reserpine may mask the signs and symptoms of hypoglycemia. Patients receiving these drugs concomitantly with antidiabetic agents should be monitored for changes in glycemic control.
    Rifampin: (Minor) Concomitant administration of rifampin with pioglitazone resulted in a decrease in the AUC of pioglitazone. Patients receiving rifampin with pioglitazone should be monitored for changes in glycemic control; dosage adjustments may be necessary.
    Risdiplam: (Moderate) Concomitant administration of metformin and risdiplam may increase metformin exposure and increase the risk for lactic acidosis. If these drugs are given together, monitor for signs of metformin toxicity; metformin dose adjustments may be needed. Metformin is a human multidrug and toxic extrusion 1 (MATE1) substrate and risdiplam is a an MATE1/2-K inhibitor. MATE inhibitors may decrease metformin elimination by blocking renal tubular secretion.
    Risperidone: (Moderate) Atypical antipsychotic therapy may aggravate diabetes mellitus and cause metabolic changes such as hyperglycemia. Monitor patients on antidiabetic agents for worsening glycemic control. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Aggravation of diabetes mellitus has been reported. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition.
    Ritonavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Sacubitril; Valsartan: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Salicylates: (Moderate) Monitor blood glucose during concomitant metformin and salicylate use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and salicylate use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Saquinavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Segesterone Acetate; Ethinyl Estradiol: (Minor) Monitor blood glucose periodically in patients on metformin for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis. (Minor) Patients receiving antidiabetic agents like metformin should be closely monitored for signs indicating changes in diabetic control when therapy with progestins is instituted or discontinued. Progestins can impair glucose tolerance. (Minor) Patients receiving antidiabetic agents should be periodically monitored for changes in glycemic control when hormone therapy is instituted or discontinued. Estrogens can decrease the hypoglycemic effects of antidiabetic agents by impairing glucose tolerance. Changes in glucose tolerance occur more commonly in patients receiving 50 mcg or more of ethinyl estradiol (or equivalent) per day in combined oral contraceptives (COCs), which are not commonly used in practice since the marketing of lower dose COCs, patches, injections and rings. The presence or absence of a concomitant progestin may influence the significance of any hormonal effect on glucose homeostasis.
    Sofosbuvir: (Moderate) Closely monitor blood glucose levels if sofosbuvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as sofosbuvir.
    Sofosbuvir; Velpatasvir: (Moderate) Closely monitor blood glucose levels if sofosbuvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as sofosbuvir. (Moderate) Closely monitor blood glucose levels if velpatasvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as velpatasvir.
    Sofosbuvir; Velpatasvir; Voxilaprevir: (Moderate) Closely monitor blood glucose levels if sofosbuvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as sofosbuvir. (Moderate) Closely monitor blood glucose levels if velpatasvir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as velpatasvir. (Moderate) Closely monitor blood glucose levels if voxilaprevir is administered with antidiabetic agents. Dose adjustments of the antidiabetic agents may be needed. Altered blood glucose control, resulting in serious symptomatic hypoglycemia, has been reported in diabetic patients receiving antidiabetic agents in combination with direct acting antivirals, such as voxilaprevir.
    Somatropin, rh-GH: (Moderate) Patients with diabetes mellitus should be monitored closely during somatropin (recombinant rhGH) therapy. Antidiabetic drugs (e.g., insulin or oral agents) may require adjustment when somatropin therapy is instituted in these patients. Growth hormones, such as somatropin, may decrease insulin sensitivity, leading to glucose intolerance and loss of blood glucose control. Therefore, glucose levels should be monitored periodically in all patients treated with somatropin, especially in those with risk factors for diabetes mellitus.
    Sotalol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Spironolactone; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients.
    Sulfadiazine: (Moderate) Monitor blood glucose during concomitant metformin and sulfonamide use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and sulfonamide use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Sulfamethoxazole; Trimethoprim, SMX-TMP, Cotrimoxazole: (Moderate) Monitor blood glucose during concomitant metformin and sulfonamide use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and sulfonamide use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Sulfasalazine: (Moderate) Monitor blood glucose during concomitant metformin and sulfonamide use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and sulfonamide use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Sulfonamides: (Moderate) Monitor blood glucose during concomitant metformin and sulfonamide use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and sulfonamide use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Sulfonylureas: (Moderate) If hypoglycemia occurs during concomitant use of pioglitazone and a sulfonylurea, reduce the dose of the sulfonylurea. Patients receiving pioglitazone in combination with sulfonylureas may be at risk for hypoglycemia. (Moderate) Monitor blood glucose during concomitant sulfonylurea and metformin use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Sympathomimetics: (Moderate) Sympathomimetic agents tend to increase blood glucose concentrations when administered systemically. Monitor for loss of glycemic control when sympathomimetics are administered to patients taking thiazolidinediones. Sympathomimetics, through stimulation of alpha- and beta- receptors, increase hepatic glucose production and glycogenolysis and inhibit insulin secretion. Also, adrenergic medications may decrease glucose uptake by muscle cells. For treatment of cold symptoms, nasal decongestants may be preferable for short term, limited use (1 to 3 days) as an alternative to systemic decongestants in patients taking medications for diabetes.
    Tacrolimus: (Moderate) Patients should be monitored for worsening of glycemic control if therapy with tacrolimus is initiated in patients receiving antidiabetic agents. (Moderate) Tacrolimus has been reported to cause hyperglycemia. Furthermore, tacrolimus has been implicated in causing insulin-dependent diabetes mellitus in patients after renal transplantation. Tacrolimus may have direct beta-cell toxicity. Patients should be monitored for worsening of glycemic control if Tacrolimus is initiated in patients receiving antidiabetic agents.
    Tafenoquine: (Moderate) Consider the benefits and risks of coadministration of tafenoquine and metformin due to the potential for increased metformin concentrations and lactic acidosis. If coadministration cannot be avoided, monitor for metformin-related toxicities, and consider metformin dosage reduction, if needed. The effect of coadministration of tafenoquine on the pharmacokinetics of OCT2 and MATE substrates, like metformin, in humans is unknown; however, in vitro observations suggest the potential for increased concentrations of OCT2 and MATE substrates. Tafenoquine may interfere with these common renal tubular transport systems involved in the renal elimination of metformin.
    Tegaserod: (Moderate) Because tegaserod can enhance gastric emptying in diabetic patients, blood glucose can be affected, which, in turn, may affect the clinical response to antidiabetic agents. The dosing of antidiabetic agents may require adjustment in patients who receive GI prokinetic agents concomitantly. (Moderate) Because tegaserod can enhance gastric emptying in diabetic patients, blood glucose can be affected, which, in turn, may affect the clinical response to antidiabetic drugs, such as pioglitazone.
    Telmisartan: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Telmisartan; Amlodipine: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Telmisartan; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Teriflunomide: (Moderate) Increased monitoring is recommended if teriflunomide is administered concurrently with CYP2C8 substrates, such as pioglitazone. In vivo studies demonstrated that teriflunomide is an inhibitor of CYP2C8. Coadministration may lead to increased exposure to CYP2C8 substrates; however, the clinical impact of this has not yet been determined. Monitor for increased adverse effects.
    Testosterone: (Moderate) Changes in insulin sensitivity or glycemic control may occur in patients treated with androgens. In diabetic patients, the metabolic effects of androgens may decrease blood glucose and, therefore, may decrease antidiabetic agent dosage requirements. Monitor blood glucose and HbA1C when these drugs are used together.
    Thiazide diuretics: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Thiazide diuretics can decrease insulin sensitivity thereby leading to glucose intolerance and hyperglycemia. Diuretic-induced hypokalemia may also lead to hyperglycemia. Because of this, a potential pharmacodynamic interaction exists between thiazide diuretics and antidiabetic agents. It appears that the effects of thiazide diuretics on glycemic control are dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. However, patients taking antidiabetic agents should be monitored for changes in blood glucose control if such diuretics are added or deleted. Dosage adjustments may be necessary.
    Thyroid hormones: (Minor) Addition of thyroid hormones to antidiabetic or insulin therapy may result in increased dosage requirements of the antidiabetic agents. Blood sugars should be carefully monitored when thyroid therapy is added, dosages are changed, or if thyroid hormones are discontinued. (Minor) Thyroid hormone use may result in increased blood sugar and a loss of glycemic control in some patients. Interactions may or may not be clinically significant at usual replacement doses. Monitor blood sugars carefully when thyroid therapy is added, changed, or discontinued in patients receiving metformin.
    Timolol: (Moderate) Increased frequency of blood glucose monitoring may be required when a beta blocker is given with antidiabetic agents. Since beta blockers inhibit the release of catecholamines, these medications may hide symptoms of hypoglycemia such as tremor, tachycardia, and blood pressure changes. Other symptoms, like headache, dizziness, nervousness, mood changes, or hunger are not blunted. Beta-blockers also exert complex actions on the body's ability to regulate blood glucose. Some beta-blockers, particularly non-selective beta-blockers such as propranolol, have been noted to potentiate insulin-induced hypoglycemia and a delay in recovery of blood glucose to normal levels. Hyperglycemia has been reported as well and is possibly due to beta-2 receptor blockade in the beta cells of the pancreas. A selective beta-blocker may be preferred in patients with diabetes mellitus, if appropriate for the patient's condition. Selective beta-blockers, such as atenolol or metoprolol, do not appear to potentiate insulin-induced hypoglycemia. While beta-blockers may have negative effects on glycemic control, they reduce the risk of cardiovascular disease and stroke in patients with diabetes and their use should not be avoided in patients with compelling indications for beta-blocker therapy when no other contraindications are present.
    Tipranavir: (Moderate) New onset diabetes mellitus, exacerbation of diabetes mellitus, and hyperglycemia due to insulin resistance have been reported with use of anti-retroviral protease inhibitors. Onset averaged approximately 63 days after initiating protease inhibitor therapy, but has occurred as early as 4 days after beginning therapy. Diabetic ketoacidosis has occurred in some patients including patients who were not diabetic prior to protease inhibitor treatment. Patients on antidiabetic agents should be closely monitored for changes in glycemic control, specifically hyperglycemia, if protease inhibitor therapy is initiated. In addition, coadministration of atazanavir with rosiglitazone may result in elevated rosiglitazone plasma concentrations. Rosiglitazone is a substrate for CYP2C8; atazanavir is a weak inhibitor of CYP2C8.
    Tolazamide: (Moderate) If hypoglycemia occurs during concomitant use of pioglitazone and a sulfonylurea, reduce the dose of the sulfonylurea. Patients receiving pioglitazone in combination with sulfonylureas may be at risk for hypoglycemia. (Moderate) Monitor blood glucose during concomitant sulfonylurea and metformin use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Tolbutamide: (Moderate) If hypoglycemia occurs during concomitant use of pioglitazone and a sulfonylurea, reduce the dose of the sulfonylurea. Patients receiving pioglitazone in combination with sulfonylureas may be at risk for hypoglycemia. (Moderate) Monitor blood glucose during concomitant sulfonylurea and metformin use; a sulfonylurea dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Topiramate: (Moderate) A decrease in the exposures of pioglitazone and its active metabolites were observed in a clinical trial during concurrent use of topiramate. The clinical significance is unknown; however, results of routine blood glucose monitoring should be carefully followed during coadministration of pioglitazone and topiramate to ensure adequate glucose control. (Moderate) Consider more frequent monitoring of patients receiving metformin and concomitant topiramate due to increased risk for lactic acidosis. Carbonic anhydrase inhibitors, such as topiramate, frequently cause a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. In healthy volunteers, metformin Cmax and AUC increased by 17% and 25%, respectively, when topiramate was added, and oral plasma clearance of topiramate appears to be reduced when administered with metformin. The clinical significance of the effect on the pharmacokinetics of metformin or topiramate are not known.
    Torsemide: (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Because of this, a potential pharmacodynamic interaction exists between torsemide and all antidiabetic agents, including metformin. Monitor blood glucose. (Minor) Hyperglycemia has been detected during torsemide therapy, but the incidence is low. Patients on antidiabetic medications should monitor their blood glucose regularly if torsemide is prescribed.
    Trandolapril: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Trandolapril; Verapamil: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin-converting enzyme (ACE) inhibitor use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Tranylcypromine: (Moderate) Monitor blood glucose during concomitant thiazolidinedione and monoamine oxidase inhibitor (MAOI) use; a thiazolidinedione dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Triamcinolone: (Moderate) Monitor blood glucose during concomitant corticosteroid and thiazolidinedione use; a thiazolidinedione dose adjustment may be necessary. Corticosteroids may increase blood glucose concentrations. Risk factors for impaired glucose tolerance due to corticosteroids include the corticosteroid dose and duration of treatment. Corticosteroids stimulate hepatic glucose production and inhibit peripheral glucose uptake into muscle and fatty tissues, producing insulin resistance. Decreased insulin production may occur in the pancreas due to a direct effect on pancreatic beta cells.
    Triamterene: (Minor) Triamterene can interfere with the hypoglycemic effects of antidiabetic agents. This can lead to a loss of diabetic control, so diabetic patients should be monitored closely.
    Triamterene; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Minor) Triamterene can interfere with the hypoglycemic effects of antidiabetic agents. This can lead to a loss of diabetic control, so diabetic patients should be monitored closely.
    Trilaciclib: (Moderate) Concomitant administration of metformin and trilaciclib may increase metformin exposure and increase the risk for lactic acidosis. If these drugs are given together, monitor for signs of metformin toxicity; metformin dose adjustments may be needed. Metformin is an OCT2 and MATE substrate; trilaciclib is an OCT2 and MATE inhibitor that may decrease metformin elimination by blocking renal tubular secretion.
    Trospium: (Moderate) Trospium, if used concomitantly with metformin, may increase the risk of lactic acidosis. Cationic drugs that are eliminated by renal tubular secretion like trospium may decrease metformin elimination by competing for common renal tubular transport systems.
    Ultralente Insulin: (Moderate) Monitor blood glucose during concomitant metformin and insulin use; an insulin dose adjustment may be necessary. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Valsartan: (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Certain drugs, such as thiazide diuretics, tend to produce hyperglycemia and may lead to loss of glycemic control. The effects of thiazide diuretics on glycemic control appear to be dose-related and low doses can be instituted without deleterious effects on glycemic control. In addition, thiazide diuretics reduce the risk of stroke and cardiovascular disease in patients with diabetes. Patients receiving metformin should be monitored for changes in blood glucose control if any of these diuretics are added or deleted. Dosage adjustments may be necessary in some patients. (Moderate) Monitor blood glucose during concomitant metformin and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia. (Moderate) Monitor blood glucose during concomitant thiazolidinedione and angiotensin receptor blocker use. Concomitant use may cause an increased blood glucose-lowering effect with risk of hypoglycemia.
    Vandetanib: (Moderate) Vandetanib could increase systemic exposure to metformin and may increase the risk for lactic acidosis. Vandetanib increased the plasma concentrations of metformin, which is transported by the renal organic cation transporter type 2 (OCT2). Use caution and closely monitor for toxicities when administering vendetanib with metformin.
    Vonoprazan; Amoxicillin; Clarithromycin: (Moderate) The concomitant use of clarithromycin and antidiabetic agents can result in significant hypoglycemia. Careful monitoring of blood glucose is recommended. (Moderate) The concomitant use of clarithromycin and oral hypoglycemic agents can result in significant hypoglycemia. With certain hypoglycemic drugs such as the thiazolidinediones, inhibition of CYP3A enzyme by clarithromycin may be involved; however, CYP3A is not a major metabolism route for pioglitazone and rosiglitazone. Careful monitoring of glucose is recommended.
    Zafirlukast: (Moderate) It is possible that an increase in the exposure of pioglitazone may occur when coadministered with drugs that inhibit CYP2C8 such as montelukast and zafirlukast. Although montelukast or zafirlukast administered with pioglitazone in vivo did not significantly increase pioglitazone concentrations, patients should be monitored for changes in glycemic control if any of these CYP2C8 inhibitors are coadministered with pioglitazone.
    Ziprasidone: (Moderate) Atypical antipsychotic therapy may aggravate diabetes mellitus and cause metabolic changes such as hyperglycemia. Monitor patients on antidiabetic agents for worsening glycemic control. Atypical antipsychotics have been associated with metabolic changes, including hyperglycemia, diabetic ketoacidosis, hyperosmolar, hyperglycemic states, and diabetic coma. Aggravation of diabetes mellitus has been reported. Possible mechanisms include atypical antipsychotic-induced insulin resistance or direct beta-cell inhibition.
    Zonisamide: (Moderate) Carbonic anhydrase inhibitors such as zonisamide frequently cause a decrease in serum bicarbonate and induce non-anion gap, hyperchloremic metabolic acidosis. Use of zonisamide with metformin may increase the risk for lactic acidosis; consider more frequent monitoring. Carbonic anhydrase inhibitors may also alter blood sugar; both hyperglycemia and hypoglycemia have been described. Monitor blood glucose and for changes in glycemic control and be alert for evidence of an interaction.

    PREGNANCY AND LACTATION

    Pregnancy

    The effects of pioglitazone; metformin on the nursing infant are unknown and therefore, the developmental and health benefits of breast-feeding should be considered along with the mother's clinical need for pioglitazone; metformin and any potential adverse effects on the nursing infant from pioglitazone; metformin or from the underlying maternal condition. Animal data suggest that pioglitazone may be excreted in milk, however, it is unknown if pioglitazone or its metabolites are excreted in human milk. Animal data show that metformin is excreted into breast milk and reaches levels similar to those in plasma. Small studies indicate that metformin is excreted in human breast milk. However, adverse effects on infant plasma glucose have not been reported in human studies. Furthermore, the use of metformin 2,550 mg/day by mothers breast-feeding their infants for 6 months does not affect growth, motor, or social development; the effects beyond 6 months are not known. In all of these studies, the estimated weight-adjusted infant exposure to metformin ranged from 0.11% to 1.08% of the mother's dose. If blood glucose is not controlled on diet and exercise alone, insulin therapy should be considered; insulin is considered by experts to be compatible with breast-feeding. Other oral hypoglycemics may also be considered as possible alternatives in some patients. Because acarbose has limited systemic absorption, which results in minimal maternal plasma concentrations, clinically significant exposure via breast milk is not expected. Metformin monotherapy can also be a consideration. Tolbutamide is usually considered compatible with breast-feeding. Glyburide may be a suitable alternative since it was not detected in the breast milk of lactating women who received single and multiple doses of glyburide. If any oral hypoglycemics are used during breast-feeding, the nursing infant should be monitored for signs of hypoglycemia, such as increased fussiness or somnolence.

    MECHANISM OF ACTION

    Pioglitazone; metformin combines 2 antidiabetic agents with different mechanisms to improve glycemic control in patients with type 2 diabetes mellitus (DM). Metformin acts primarily by decreasing endogenous hepatic glucose production; pioglitazone is an insulin sensitizer that acts by enhancing peripheral glucose utilization.
    Pioglitazone: Pioglitazone's primary action is enhancement of insulin sensitivity in adipose tissue, skeletal muscle, and the liver. Clinically, pioglitazone decreases plasma glucose concentrations, insulin concentrations, and glycosylated hemoglobin. Additional favorable metabolic effects include decreased hepatic glucose output, lower free fatty acid concentrations, and improved lipid profiles. In addition, preliminary evidence suggests that the thiazolidinediones may preserve beta cell function, a key component in the development of type 2 DM in patients with insulin resistance. Unlike oral sulfonylureas, pioglitazone does not stimulate insulin secretion. All oral agents used in the management of type 2 DM, including pioglitazone, are ineffective in patients with insulin deficiency (i.e., type 1 DM). Pioglitazone is a highly selective and potent agonist for the peroxisome proliferator activated receptor (PPAR-gamma) that regulates the transcription of a number of insulin responsive genes. PPAR receptors can be found in key targets for insulin action including adipose tissue, skeletal muscle, and the liver. Activation of the PPAR-gamma receptor enhances insulin sensitivity through several mechanisms. First, expression of the glucose transporter GLUT4 is increased in adipose tissue resulting in improved glucose utilization in skeletal muscle and the liver. Second, insulin sensitivity is enhanced by the lowering of plasma free fatty acid concentrations and shifting the storage of free fatty acids from non-adipose cells to adipocytes. Finally, the release of adipocytokines such as tumor necrosis factor alfa, resistin, and adiponectin is regulated to promote insulin sensitivity. Furthermore, thiazolidinedione-mediated receptor activation promotes adipogenesis and the differentiation of adipocytes causing a favorable redistribution of fat from visceral to subcutaneous stores. Subcutaneous adipocytes tend to be less lipolytic and more insulin sensitive. These effects contribute to the overall improved metabolic effects associated with thiazolidinedione use including insulin sensitivity peripherally.
    Metformin: Metformin is an antihyperglycemic agent that improves glucose tolerance, lowering both basal and postprandial plasma glucose with mechanisms different from other classes of oral antidiabetic agents. Metformin decreases hepatic gluconeogenesis production, decreases intestinal absorption of glucose, and improves insulin sensitivity by increasing peripheral glucose uptake and utilization. With metformin therapy, insulin secretion remains unchanged while fasting insulin levels and day-long plasma insulin response may actually decrease. Metformin improve glucose utilization in skeletal muscle and adipose tissue by increasing cell membrane glucose transport. This effect may be due to improved binding of insulin to insulin receptors since metformin is not effective in diabetics without some residual functioning pancreatic islet cells. Unlike the sulfonylureas, metformin rarely causes hypoglycemia since it does not significantly change insulin concentrations. An important distinction is that sulfonylureas increase insulin secretion thus making them useful in non-obese patients with type 2 diabetes mellitus (DM) while metformin improves insulin resistance, a common pathophysiologic finding in obese patients with type 2 DM. Metformin causes a 10% to 20% decrease in fatty-acid oxidation and a slight increase in glucose oxidation. Unlike phenformin, metformin does not inhibit the mitochondrial oxidation of lactate unless plasma concentrations of metformin become excessive (i.e., in patients with renal failure) and/or hypoxia is present. Clinically, metformin lowers fasting and postprandial hyperglycemia. The decrease in fasting plasma glucose is approximately 25% to 30%. Unlike oral sulfonylureas, metformin rarely causes hypoglycemia. Thus, metformin demonstrates more of an antihyperglycemic action than a hypoglycemic action. Metformin does not cause weight gain and in fact, may cause a modest weight loss due to drug-induced anorexia. Metformin also decreases plasma VLDL triglycerides resulting in modest decreases in plasma triglycerides and total cholesterol. Patients receiving metformin show a significant improvement in A1C, and a tendency toward improvement in the lipid profile, especially when baseline values are abnormally elevated.

    PHARMACOKINETICS

    Pioglitazone; metformin combination products are administered orally.[50311]
    Pioglitazone: Protein binding is extensive (more than 99%), primarily to serum albumin. Binding also occurs to other serum proteins, but with lower affinity. Pioglitazone is extensively metabolized by hydroxylation and oxidation. Pioglitazone is primarily metabolized by CYP2C8 and to a lesser extent, CYP3A4 with contributions from a variety of other isoforms including the mainly extrahepatic CYP1A1 enzyme. In animal models of type 2 diabetes, metabolites M2 and M4 (hydroxy derivatives of pioglitazone) and M3 (keto derivative of pioglitazone) are pharmacologically active. Metabolites M3 and M4 are the principal drug-related species found in human serum following multiple dosing. At steady state, serum concentrations of metabolites M3 and M4 are equal to or greater than serum concentrations of pioglitazone. In both healthy volunteers and patients with type 2 diabetes, pioglitazone comprises approximately 30% to 50% of the total peak serum concentrations and 20% to 25% of the total AUC at steady state. Approximately 15% to 30% of the total dose is recovered in the urine. Renal elimination is negligible, and the drug is excreted primarily as metabolites and their conjugates. Most of an oral dose is presumed to be excreted into the bile either unchanged or as metabolites and eliminated in the feces. The mean serum half-lives of pioglitazone and its metabolites is 3 to 7 hours and 16 to 24 hours, respectively.[50311]
    Metformin: Metformin is distributed rapidly into peripheral body tissues and fluids and appears to distribute slowly into erythrocytes and to a deep tissue compartment (most likely GI tissues). The highest concentrations of metformin are found in the GI tract (10 times the concentrations in the plasma) and lower concentrations in the kidney, liver, and salivary gland tissue. Metformin is negligibly bound to plasma proteins. The apparent volume of distribution (V/F) of metformin following a single, 850 mg dose is 654 +/- 358 L. Steady-state concentrations of metformin are reached within 1 to 2 days and are generally less than 1 mcg/mL. Metformin is not metabolized by the liver, and this fact may explain why the risk of lactic acidosis is much less for metformin than for phenformin (i.e., approximately 10% of patients have an inherited defect in the ability to metabolize phenformin).[24568] The drug is excreted by the kidneys, largely unchanged, through an active tubular process; tubular secretion may be altered by many cationic drugs. Approximately 10% of an oral dose is excreted in the feces, presumably as unabsorbed metformin, and about 90% of a dose is excreted by the kidneys within 24 hours. Biliary excretion does not occur. Although the average elimination half-life in the plasma is 6.2 hours in patients with normal renal function, metformin accumulates in red blood cells, which leads to a much longer elimination half-life in the blood (17.6 hours).[28550] [42826] [50311]
     
    Affected cytochrome P450 (CYP450) isoenzymes and drug transporters: Organic cationic transporter-2 (OCT2), multidrug and toxin extrusion (MATE1 and MATE2k), CYP2C8
    Pioglitazone: Pioglitazone is primarily metabolized by CYP2C8 and to a lesser extent, CYP3A4 with contributions from a variety of other isoforms including the mainly extrahepatic CYP1A1 enzyme. Clinically significant interactions may occur when administered with drugs that inhibit or induce CYP2C8. If given with a strong CYP2C8 inhibitor, do not exceed pioglitazone 15 mg daily. Urinary 6-beta-hydroxycortisol/cortisol ratios measured in patients treated with the drug showed that pioglitazone is not a strong CYP3A4 enzyme inducer.[28109] [50311]
    Metformin: Drugs that interfere with common renal tubular transport systems involved in the renal elimination of metformin (e.g., organic cationic transporter-2 [OCT2]/multidrug and toxin extrusion [MATE1 and MATE2k] inhibitors such as ranolazine, vandetanib, dolutegravir, and cimetidine) could increase systemic exposure to metformin.[28550] [56579] An interaction between metformin and oral cimetidine has been observed, with a 60% increase in peak metformin plasma and whole blood concentrations and a 40% increase in plasma and whole blood metformin AUC, but no change in metformin elimination half-life. Careful patient monitoring and dose adjustment of metformin and/or the potentially interfering drug is recommended with concurrent use.[28550] [50311]

    Oral Route

    Bioequivalence between the separate tablets and the combination products pioglitazone; metformin tablets (Actoplus Met) and pioglitazone; metformin extended-release tablets (Actoplus Met XR) has been demonstrated. In the Actoplus Met XR formulation, single-composition osmotic technology (SCOT) allows metformin to be released at a constant rate from an osmotically active tablet core surrounded by a semi-permeable membrane and coated with a pioglitazone drug layer.
    Pioglitazone: Following oral administration, serum concentrations of pioglitazone are first measurable within 30 minutes. Peak serum concentrations occur within 2 hours. Food slightly delays the time to peak serum concentration to 3 to 4 hours, but does not alter the extent of absorption. Steady-state serum concentrations are achieved within 7 days.
    Metformin: The bioavailability of metformin is 50% to 60%. Food decreases the extent and slightly delays the absorption of conventional metformin, however, it is recommended to be taken with meals. When Actoplus Met XR is administered with food, the extent of absorption of metformin is increased by approximately 60%; Cmax is increased by 30%, and Tmax is increased to 6.1 hours (vs. 4 hours with conventional metformin).