Regimex

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Regimex

Classes

Adrenergic Agonists for Obesity

Administration
Oral Administration

Subsequent doses during the day, if given, should be administered at least 6 hours before bedtime to avoid interference with sleep.

Adverse Reactions
Severe

cardiomyopathy / Delayed / Incidence not known
bradycardia / Rapid / Incidence not known
pulmonary hypertension / Delayed / Incidence not known
seizures / Delayed / Incidence not known
toxic epidermal necrolysis / Delayed / Incidence not known
anaphylactoid reactions / Rapid / Incidence not known
angioedema / Rapid / Incidence not known
Stevens-Johnson syndrome / Delayed / Incidence not known
serotonin syndrome / Delayed / Incidence not known
rhabdomyolysis / Delayed / Incidence not known

Moderate

psychosis / Early / 0-1.0
euphoria / Early / 0-1.0
hypertension / Early / Incidence not known
peripheral edema / Delayed / Incidence not known
dyspnea / Early / Incidence not known
sinus tachycardia / Rapid / Incidence not known
palpitations / Early / Incidence not known
hallucinations / Early / Incidence not known
mania / Early / Incidence not known
impotence (erectile dysfunction) / Delayed / Incidence not known
delirium / Early / Incidence not known
hyperthermia / Delayed / Incidence not known
growth inhibition / Delayed / Incidence not known
physiological dependence / Delayed / Incidence not known
withdrawal / Early / Incidence not known
psychological dependence / Delayed / Incidence not known
tolerance / Delayed / Incidence not known

Mild

dyspepsia / Early / 1.0-10.0
nausea / Early / 1.0-10.0
dysgeusia / Early / 1.0-10.0
xerostomia / Early / 1.0-10.0
insomnia / Early / 1.0-10.0
headache / Early / 1.0-10.0
dizziness / Early / 1.0-10.0
abdominal pain / Early / 0-1.0
vomiting / Early / 0-1.0
diarrhea / Early / 0-1.0
emotional lability / Early / 0-1.0
anxiety / Delayed / 0-1.0
anorexia / Delayed / 10.0
restlessness / Early / 10.0
syncope / Early / Incidence not known
tremor / Early / Incidence not known
fatigue / Early / Incidence not known
photosensitivity / Delayed / Incidence not known
rash / Early / Incidence not known
alopecia / Delayed / Incidence not known
urticaria / Rapid / Incidence not known
hyperhidrosis / Delayed / Incidence not known
libido increase / Delayed / Incidence not known
libido decrease / Delayed / Incidence not known
paranoia / Early / Incidence not known

Common Brand Names

Didrex, Regimex

Dea Class

Rx, schedule III

Description

Oral, indirect-acting sympathomimetic amine; metabolized to amphetamine and methamphetamine
Used as an anorectic agent in the short-term (8 to 12 weeks) exogenous treatment of obesity
Potential for abuse and addiction; not generally recommended by guidelines due to lack of longer-term health benefits

Dosage And Indications
For the short-term (i.e., 8 to 12 weeks) treatment of exogenous obesity. Oral dosage Adults

Initially, 25 to 50 mg PO once daily, preferably at mid-morning or mid-afternoon. Increase according to patient response, up to 50 mg PO 3 times daily. Max: 150 mg/day PO. Continue only if the patient has satisfactory weight loss within the first 4 weeks of treatment (i.e., weight loss of at least 4 pounds, or as determined by the physician). When tolerance to the anorectic effect develops, do not exceed the recommended dose in an attempt to increase the effect; instead, the drug should be discontinued. Use for short-term (8 to 12 weeks) only.[28456] INTENDED USE: Use as monotherapy only. Not recommended for patients who used any other anorectic agents within the prior year. Use is for patients with an initial body mass index (BMI) of 30 kg/m2 or more who have not responded to diet and exercise alone. The limited usefulness of agents of this class should be weighed against possible risks inherent in their use.[28456] According to the American Association of Clinical Endocrinologists and American College of Endocrinology (AACE/ACE) Obesity Clinical Practice Guidelines, short-term pharmacotherapy, such as with the amphetamine anorectics, has not been shown to produce longer-term health benefits in obese and overweight patients and cannot be generally recommended; these drugs should not be used for weight management long-term. Weight gain usually resumes after drug discontinuation.[62881]

Children and Adolescents 12 years and older

Initially, 25 to 50 mg PO once daily, preferably at mid-morning or mid-afternoon. Increase according to patient response, up to 50 mg PO 3 times daily. Max: 150 mg/day PO. Continue only if the patient has satisfactory weight loss within the first 4 weeks of treatment (i.e., weight loss of at least 4 pounds, or as determined by the physician). When tolerance to the anorectic effect develops, do not exceed the recommended dose in an attempt to increase the effect; instead, the drug should be discontinued. Use for short-term (8 to 12 weeks) only.[28456] INTENDED USE: Use as monotherapy only. Not recommended for patients who used any other anorectic agents within the prior year. Use is for patients with an initial body mass index (BMI) of 30 kg/m2 or more who have not responded to diet and exercise alone. The limited usefulness of agents of this class should be weighed against possible risks inherent in their use.[28456] Guidelines state that short-term pharmacotherapy, such as with the amphetamine anorectics, has not been shown to produce longer-term health benefits in pediatric patients and cannot be generally recommended. In general, children with a BMI below the 95th percentile should not be treated with antiobesity drugs. Pharmacotherapy for overweight children (BMI of at least 85th but less than 95th percentile) should be reserved for those with significant, severe comorbidities who have not responded to lifestyle modification.

Dosing Considerations
Hepatic Impairment

Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed.

Renal Impairment

Specific guidelines for dosage adjustments in renal impairment are not available; it appears that no dosage adjustments are needed.

Drug Interactions

Acarbose: (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.
Acebutolol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Acetaminophen; Aspirin, ASA; Caffeine: (Moderate) Avoid excessive caffeine intake during use of benzphetamine. Caffeine is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants. Excessive caffeine ingestion (via medicines, foods like chocolate, dietary supplements, or beverages including coffee, green tea, other teas, colas) may contribute to side effects like nervousness, irritability, nausea, insomnia, or tremor. Patients should avoid medications and dietary supplements which contain high amounts of caffeine.
Acetaminophen; Aspirin; Diphenhydramine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Acetaminophen; Caffeine: (Moderate) Avoid excessive caffeine intake during use of benzphetamine. Caffeine is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants. Excessive caffeine ingestion (via medicines, foods like chocolate, dietary supplements, or beverages including coffee, green tea, other teas, colas) may contribute to side effects like nervousness, irritability, nausea, insomnia, or tremor. Patients should avoid medications and dietary supplements which contain high amounts of caffeine.
Acetaminophen; Caffeine; Dihydrocodeine: (Moderate) Avoid excessive caffeine intake during use of benzphetamine. Caffeine is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants. Excessive caffeine ingestion (via medicines, foods like chocolate, dietary supplements, or beverages including coffee, green tea, other teas, colas) may contribute to side effects like nervousness, irritability, nausea, insomnia, or tremor. Patients should avoid medications and dietary supplements which contain high amounts of caffeine.
Acetaminophen; Caffeine; Pyrilamine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine. (Moderate) Avoid excessive caffeine intake during use of benzphetamine. Caffeine is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants. Excessive caffeine ingestion (via medicines, foods like chocolate, dietary supplements, or beverages including coffee, green tea, other teas, colas) may contribute to side effects like nervousness, irritability, nausea, insomnia, or tremor. Patients should avoid medications and dietary supplements which contain high amounts of caffeine.
Acetaminophen; Chlorpheniramine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Acetaminophen; Chlorpheniramine; Dextromethorphan: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Acetaminophen; Chlorpheniramine; Phenylephrine : (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Acetaminophen; Codeine: (Moderate) If concomitant use of codeine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Acetaminophen; Dextromethorphan; Doxylamine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Acetaminophen; Diphenhydramine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Acetaminophen; Hydrocodone: (Moderate) If concomitant use of hydrocodone and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Acetaminophen; Oxycodone: (Moderate) If concomitant use of oxycodone and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Acetaminophen; Pamabrom; Pyrilamine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Acetazolamide: (Moderate) Urinary alkalinizers, such as acetazolamide, result in decreased renal excretion of amphetamines. Monitor for amphetamine-related side effects. Avoid concomitant use in amphetamine overdose situations. Urinary alkalinizers increase the proportion of non-ionized metabolites of the amphetamine molecule, resulting in decreased renal excretion of these compounds. Alkaline urine will significantly increase the half-life of benzphetamine.
Aclidinium; Formoterol: (Moderate) Caution and close observation should be used when formoterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
Acrivastine; Pseudoephedrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Albuterol: (Moderate) Caution and close observation should be used when albuterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
Albuterol; Budesonide: (Moderate) Caution and close observation should be used when albuterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
Alfentanil: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering alfentanil with amphetamines. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Aliskiren; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Alkalinizing Agents: (Moderate) Monitor for an increase in the incidence and severity of amphetamine-related adverse effects during concomitant use of urinary alkalinizing agents. Increasing urine pH may increase amphetamine exposure by reducing urinary excretion of amphetamine. A urine pH more than 7.5 has been observed to increase the half-life of amphetamine from 8 to 10.5 hours to 16 to 31 hours when compared to a pH less than 6. Additionally, a urine pH more than 8 has been observed to reduce the amount of amphetamine excreted in the urine over 16 hours to less than 3% of the original dose; a 5-fold reduction compared to controls.
Alogliptin; Metformin: (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.
Alogliptin; Pioglitazone: (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.
Alpha-glucosidase Inhibitors: (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.
Aluminum Hydroxide: (Minor) Monitor for an increase in amphetamine-related adverse effects during concomitant antacid use. Increasing gastric or urine pH may increase amphetamine exposure and the risk for side effects in some patients. As antacids have rarely been observed to increase gastric or urinary pH above 6.5, antacid-related pH changes may be insufficient to warrant clinical concern in most patients.
Aluminum Hydroxide; Magnesium Carbonate: (Minor) Monitor for an increase in amphetamine-related adverse effects during concomitant antacid use. Increasing gastric or urine pH may increase amphetamine exposure and the risk for side effects in some patients. As antacids have rarely been observed to increase gastric or urinary pH above 6.5, antacid-related pH changes may be insufficient to warrant clinical concern in most patients.
Aluminum Hydroxide; Magnesium Hydroxide: (Minor) Monitor for an increase in amphetamine-related adverse effects during concomitant antacid use. Increasing gastric or urine pH may increase amphetamine exposure and the risk for side effects in some patients. As antacids have rarely been observed to increase gastric or urinary pH above 6.5, antacid-related pH changes may be insufficient to warrant clinical concern in most patients.
Aluminum Hydroxide; Magnesium Hydroxide; Simethicone: (Minor) Monitor for an increase in amphetamine-related adverse effects during concomitant antacid use. Increasing gastric or urine pH may increase amphetamine exposure and the risk for side effects in some patients. As antacids have rarely been observed to increase gastric or urinary pH above 6.5, antacid-related pH changes may be insufficient to warrant clinical concern in most patients.
Aluminum Hydroxide; Magnesium Trisilicate: (Minor) Monitor for an increase in amphetamine-related adverse effects during concomitant antacid use. Increasing gastric or urine pH may increase amphetamine exposure and the risk for side effects in some patients. As antacids have rarely been observed to increase gastric or urinary pH above 6.5, antacid-related pH changes may be insufficient to warrant clinical concern in most patients.
Amantadine: (Moderate) Careful observation is required when amantadine is administered concurrently with central nervous system (CNS) stimulants. An increase in stimulant effects, such as nervousness, irritability, insomnia, tremor, seizures, or cardiac arrhythmias may occur.
Ambrisentan: (Minor) Sympathomimetics such as benzphetamine can antagonize the effects of vasodilators when administered concomitantly. Patients should be monitored for reduced efficacy of ambrisentan.
Amifampridine: (Major) Carefully consider the need for concomitant treatment with benzphetamine and amifampridine, as coadministration may increase the risk of seizures. If coadministration occurs, closely monitor patients for seizure activity. Seizures have been observed in patients without a history of seizures taking amifampridine at recommended doses. Benzphetamine may increase the risk of seizures.
Amiloride: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like potassium-sparing diuretics. Close monitoring of blood pressure is advised.
Amiloride; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH. (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like potassium-sparing diuretics. Close monitoring of blood pressure is advised.
Amlodipine: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Amlodipine; Atorvastatin: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Amlodipine; Benazepril: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised. (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Amlodipine; Celecoxib: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Amlodipine; Olmesartan: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Amlodipine; Valsartan: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Amlodipine; Valsartan; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH. (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Amoxapine: (Major) Concomitant use of amoxapine with sympathomimetics should be avoided whenever possible; use with caution when concurrent use cannot be avoided. One drug information reference suggests that cyclic antidepressants potentiate the pharmacologic effects of indirect-acting sympathomimetics, such as amphetamine, however, the data are not consistent.
Angiotensin II receptor antagonists: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, such as angiotensin II receptor antagonists. Close monitoring of blood pressure is advised.
Angiotensin-converting enzyme inhibitors: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Antacids: (Minor) Monitor for an increase in amphetamine-related adverse effects during concomitant antacid use. Increasing gastric or urine pH may increase amphetamine exposure and the risk for side effects in some patients. As antacids have rarely been observed to increase gastric or urinary pH above 6.5, antacid-related pH changes may be insufficient to warrant clinical concern in most patients.
Arformoterol: (Moderate) Caution and close observation should be used when arformoterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
Armodafinil: (Moderate) The use of armodafinil with other psychostimulants, including amphetamines, (e.g., dextroamphetamine, lisdexamfetamine, amphetamine) has not been studied. In a single-dose study of dextroamphetamine combined with modafinil, a racemic compound containing armodafinil, no pharmacokinetic interactions occurred but a slight increase in stimulant-associated side effects was noted. Patients receiving combination therapy of armodafinil with other psychostimulants should be closely observed for signs of nervousness, irritability, insomnia, arrhythmias, or other stimulant-related side effects.
Articaine; Epinephrine: (Moderate) Monitor blood pressure and heart rate during concomitant amphetamine and epinephrine use. Amphetamines may potentiate the pressor effects of epinephrine.
Ascorbic Acid, Vitamin C: (Moderate) Concurrent use of amphetamines and gastrointestinal acidifying agents, such as ascorbic acid, vitamin C, should be used with caution. Vitamin C lowers the absorption of amphetamines, resulting in reduced efficacy. It may be advisable to separate times of administration. In addition, ascorbic acid acts as a urinary acidifier, which reduces the renal tubular reabsorption of amphetamines, accelerating amphetamine clearance and reducing the duration of effect. If combined use is necessary, the amphetamine dose should be adjusted according to clinical response as needed.
Aspirin, ASA; Butalbital; Caffeine: (Moderate) Avoid excessive caffeine intake during use of benzphetamine. Caffeine is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants. Excessive caffeine ingestion (via medicines, foods like chocolate, dietary supplements, or beverages including coffee, green tea, other teas, colas) may contribute to side effects like nervousness, irritability, nausea, insomnia, or tremor. Patients should avoid medications and dietary supplements which contain high amounts of caffeine.
Aspirin, ASA; Caffeine: (Moderate) Avoid excessive caffeine intake during use of benzphetamine. Caffeine is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants. Excessive caffeine ingestion (via medicines, foods like chocolate, dietary supplements, or beverages including coffee, green tea, other teas, colas) may contribute to side effects like nervousness, irritability, nausea, insomnia, or tremor. Patients should avoid medications and dietary supplements which contain high amounts of caffeine.
Aspirin, ASA; Caffeine; Orphenadrine: (Moderate) Avoid excessive caffeine intake during use of benzphetamine. Caffeine is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants. Excessive caffeine ingestion (via medicines, foods like chocolate, dietary supplements, or beverages including coffee, green tea, other teas, colas) may contribute to side effects like nervousness, irritability, nausea, insomnia, or tremor. Patients should avoid medications and dietary supplements which contain high amounts of caffeine.
Aspirin, ASA; Carisoprodol; Codeine: (Moderate) If concomitant use of codeine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Aspirin, ASA; Citric Acid; Sodium Bicarbonate: (Moderate) Monitor for an increase in the incidence and severity of amphetamine-related adverse effects during concomitant use of urinary alkalinizing agents. Increasing urine pH may increase amphetamine exposure by reducing urinary excretion of amphetamine. A urine pH more than 7.5 has been observed to increase the half-life of amphetamine from 8 to 10.5 hours to 16 to 31 hours when compared to a pH less than 6. Additionally, a urine pH more than 8 has been observed to reduce the amount of amphetamine excreted in the urine over 16 hours to less than 3% of the original dose; a 5-fold reduction compared to controls.
Aspirin, ASA; Oxycodone: (Moderate) If concomitant use of oxycodone and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Atenolol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Atenolol; Chlorthalidone: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug. (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Atomoxetine: (Moderate) Amphetamines increase both systolic and diastolic blood pressure; atomoxetine has been reported to also increase blood pressure and heart rate, probably via inhibition of norepinephrine reuptake. Due to an additive pharmacodynamic effect, amphetamines and atomoxetine should be used together cautiously, particularly in patients with a history of cardiac disease. Consider monitoring heart rate and blood pressure at baseline and regularly throughout treatment if these agents must be used together.
Azilsartan; Chlorthalidone: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Benazepril: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Benazepril; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH. (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Contraindicated) Amphetamines should not be administered during or within 14 days after the use of methylene blue. Methylene blue is a potent, reversible monoamine oxidase inhibitor (MAOI) which can prolong and intensify the cardiac stimulation and vasopressor effects of amphetamines, potentially resulting in hypertensive crisis. Methylene blue also has the potential to interact with serotonergic agents, such as amphetamines, which may increase the risk for serotonin syndrome. Serotonin syndrome is characterized by mental status changes (e.g., agitation, hallucinations, delirium, and coma), autonomic instability (e.g., tachycardia, labile blood pressure, dizziness, diaphoresis, flushing, hyperthermia), neuromuscular symptoms (e.g., tremor, rigidity, myoclonus, hyperreflexia, incoordination), seizures, gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea), and in rare instances, death. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving selective serotonin reuptake inhibitors, serotonin/norepinephrine reuptake inhibitors, or clomipramine. It is not known if patients receiving other serotonergic psychiatric agents, such as amphetamines, with intravenous methylene blue are at a comparable risk or if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. Published interaction reports between intravenously administered methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma. (Major) Urinary acidifying agents, such as ammonium chloride, phosphorus salts, and methenamine salts (e.g., methenamine; sodium acid phosphate), reduce the tubular reabsorption of amphetamines. As a result, amphetamine clearance is accelerated and the duration of effect is reduced. Combination therapy should be avoided if possible.
Beta-blockers: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Betaxolol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Bethanechol: (Moderate) Bethanechol offsets the effects of sympathomimetics at sites where sympathomimetic and cholinergic receptors have opposite effects.
Bisoprolol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Bisoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug. (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Bretylium: (Moderate) Monitor blood pressure and heart rate closely when sympathomimetics are administered with bretylium. The pressor and arrhythmogenic effects of catecholamines are enhanced by bretylium.
Brimonidine; Timolol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Bromocriptine: (Moderate) Concurrent use of bromocriptine and some sympathomimetics such as amphetamines should be approached with caution. One case report documented worsening headache, hypertension, premature ventricular complexes, and ventricular tachycardia in a post-partum patient receiving bromocriptine for lactation suppression who was subsequently prescribed an isometheptene-containing medication for a headache. A second case involved a post-partum patient receiving bromocriptine who was later prescribed a phenylpropanolamine-expectorant combination and subsequently developed hypertension, tachycardia, seizures, and cerebral vasospasm.
Brompheniramine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Brompheniramine; Dextromethorphan; Phenylephrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Brompheniramine; Phenylephrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Brompheniramine; Pseudoephedrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Brompheniramine; Pseudoephedrine; Dextromethorphan: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Budesonide; Formoterol: (Moderate) Caution and close observation should be used when formoterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
Budesonide; Glycopyrrolate; Formoterol: (Moderate) Caution and close observation should be used when formoterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
Bumetanide: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, such as loop diuretics. Close monitoring of blood pressure is advised.
Bupivacaine; Epinephrine: (Moderate) Monitor blood pressure and heart rate during concomitant amphetamine and epinephrine use. Amphetamines may potentiate the pressor effects of epinephrine.
Buprenorphine: (Moderate) If concomitant use of buprenorphine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Buprenorphine; Naloxone: (Moderate) If concomitant use of buprenorphine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Bupropion: (Major) The risk of seizures from the use of bupropion may be increased with concomitant use of CNS stimulants and anorectics that may induce seizures, including benzphetamine. Concurrent use is not recommended. Extreme caution and close clinical monitoring is recommended if these agents must be used together.
Bupropion; Naltrexone: (Major) The risk of seizures from the use of bupropion may be increased with concomitant use of CNS stimulants and anorectics that may induce seizures, including benzphetamine. Concurrent use is not recommended. Extreme caution and close clinical monitoring is recommended if these agents must be used together.
Buspirone: (Moderate) Coadministration of buspirone with amphetamines may increase the risk of serotonin syndrome. At high doses, amphetamines can increase serotonin release and act as serotonin agonists. Buspirone has some serotonergic properties. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome, particularly during treatment initiation and dose increases. If serotonin syndrome occurs, all serotonergic drugs should be discontinued and appropriate medical treatment should be initiated.
Butalbital; Acetaminophen; Caffeine: (Moderate) Avoid excessive caffeine intake during use of benzphetamine. Caffeine is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants. Excessive caffeine ingestion (via medicines, foods like chocolate, dietary supplements, or beverages including coffee, green tea, other teas, colas) may contribute to side effects like nervousness, irritability, nausea, insomnia, or tremor. Patients should avoid medications and dietary supplements which contain high amounts of caffeine.
Butalbital; Acetaminophen; Caffeine; Codeine: (Moderate) Avoid excessive caffeine intake during use of benzphetamine. Caffeine is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants. Excessive caffeine ingestion (via medicines, foods like chocolate, dietary supplements, or beverages including coffee, green tea, other teas, colas) may contribute to side effects like nervousness, irritability, nausea, insomnia, or tremor. Patients should avoid medications and dietary supplements which contain high amounts of caffeine. (Moderate) If concomitant use of codeine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Butalbital; Aspirin; Caffeine; Codeine: (Moderate) Avoid excessive caffeine intake during use of benzphetamine. Caffeine is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants. Excessive caffeine ingestion (via medicines, foods like chocolate, dietary supplements, or beverages including coffee, green tea, other teas, colas) may contribute to side effects like nervousness, irritability, nausea, insomnia, or tremor. Patients should avoid medications and dietary supplements which contain high amounts of caffeine. (Moderate) If concomitant use of codeine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Caffeine: (Moderate) Avoid excessive caffeine intake during use of benzphetamine. Caffeine is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants. Excessive caffeine ingestion (via medicines, foods like chocolate, dietary supplements, or beverages including coffee, green tea, other teas, colas) may contribute to side effects like nervousness, irritability, nausea, insomnia, or tremor. Patients should avoid medications and dietary supplements which contain high amounts of caffeine. (Moderate) CNS-stimulating actions of caffeine can be additive with other CNS stimulants. Patients may need to reduce, limit, or avoid caffeine intake. Excessive caffeine ingestion (via medicines, supplements or beverages including coffee, green tea, other teas, guarana, colas) may contribute to side effects like nervousness, irritability, insomnia, or tremor.
Caffeine; Sodium Benzoate: (Moderate) Avoid excessive caffeine intake during use of benzphetamine. Caffeine is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants. Excessive caffeine ingestion (via medicines, foods like chocolate, dietary supplements, or beverages including coffee, green tea, other teas, colas) may contribute to side effects like nervousness, irritability, nausea, insomnia, or tremor. Patients should avoid medications and dietary supplements which contain high amounts of caffeine.
Calcium Carbonate: (Minor) Monitor for an increase in amphetamine-related adverse effects during concomitant antacid use. Increasing gastric or urine pH may increase amphetamine exposure and the risk for side effects in some patients. As antacids have rarely been observed to increase gastric or urinary pH above 6.5, antacid-related pH changes may be insufficient to warrant clinical concern in most patients.
Calcium Carbonate; Famotidine; Magnesium Hydroxide: (Minor) Monitor for an increase in amphetamine-related adverse effects during concomitant antacid use. Increasing gastric or urine pH may increase amphetamine exposure and the risk for side effects in some patients. As antacids have rarely been observed to increase gastric or urinary pH above 6.5, antacid-related pH changes may be insufficient to warrant clinical concern in most patients.
Calcium Carbonate; Magnesium Hydroxide: (Minor) Monitor for an increase in amphetamine-related adverse effects during concomitant antacid use. Increasing gastric or urine pH may increase amphetamine exposure and the risk for side effects in some patients. As antacids have rarely been observed to increase gastric or urinary pH above 6.5, antacid-related pH changes may be insufficient to warrant clinical concern in most patients.
Calcium Carbonate; Magnesium Hydroxide; Simethicone: (Minor) Monitor for an increase in amphetamine-related adverse effects during concomitant antacid use. Increasing gastric or urine pH may increase amphetamine exposure and the risk for side effects in some patients. As antacids have rarely been observed to increase gastric or urinary pH above 6.5, antacid-related pH changes may be insufficient to warrant clinical concern in most patients.
Calcium Carbonate; Simethicone: (Minor) Monitor for an increase in amphetamine-related adverse effects during concomitant antacid use. Increasing gastric or urine pH may increase amphetamine exposure and the risk for side effects in some patients. As antacids have rarely been observed to increase gastric or urinary pH above 6.5, antacid-related pH changes may be insufficient to warrant clinical concern in most patients.
Calcium, Magnesium, Potassium, Sodium Oxybates: (Moderate) Sodium oxybate has the potential to induce seizures; it has been speculated that this effect may be mediated through the action of sodium oxybate at GABA receptors. Although convulsant effects occur primarily at high dosages, sodium oxybate should be used cautiously with psychostimulants that are known to lower seizure threshold such as the amphetamines. Note that CNS stimulants, including the amphetamines, methylphenidate, and modafinil are frequently used in the treatment of narcolepsy, and clinical trials involving the use of psychostimulants with sodium oxybate have not found the combinations to be unsafe. Pharmacodynamic interactions cannot be ruled out, however.
Calcium; Vitamin D: (Minor) Monitor for an increase in amphetamine-related adverse effects during concomitant antacid use. Increasing gastric or urine pH may increase amphetamine exposure and the risk for side effects in some patients. As antacids have rarely been observed to increase gastric or urinary pH above 6.5, antacid-related pH changes may be insufficient to warrant clinical concern in most patients.
Calcium-channel blockers: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Canagliflozin: (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 SGLT2 inhibitors. 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.
Canagliflozin; Metformin: (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. (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 SGLT2 inhibitors. 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.
Candesartan; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Captopril: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Captopril; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH. (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Carbidopa; Levodopa: (Major) Levodopa, due to its conversion to dopamine, may increase the risk of developing amphetamine-induced cardiac arrhythmias; dosage reductions or discontinuation of benzphetamine is recommended if the two agents are used concurrently.
Carbidopa; Levodopa; Entacapone: (Major) Levodopa, due to its conversion to dopamine, may increase the risk of developing amphetamine-induced cardiac arrhythmias; dosage reductions or discontinuation of benzphetamine is recommended if the two agents are used concurrently.
Carbinoxamine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Carteolol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Carvedilol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Celecoxib; Tramadol: (Moderate) Serotonin syndrome may occur during coadministration of serotonergic drugs such as amphetamines and tramadol. At high doses, amphetamines can increase serotonin release, as well as act as serotonin agonists. An additive risk of seizures is also possible. Inform patients taking this combination of the possible increased risk of serotonin syndrome and seizures and monitor for adverse effects particularly after a dose increase or the addition of interacting medications. Discontinue all serotonergic agents if serotonin syndrome occurs and implement appropriate medical management.
Chlophedianol; Dexbrompheniramine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Chlophedianol; Dexchlorpheniramine; Pseudoephedrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Chlorcyclizine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Chlorothiazide: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Chlorpheniramine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Chlorpheniramine; Codeine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine. (Moderate) If concomitant use of codeine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Chlorpheniramine; Dextromethorphan: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Chlorpheniramine; Dihydrocodeine; Phenylephrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Chlorpheniramine; Hydrocodone: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine. (Moderate) If concomitant use of hydrocodone and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Chlorpheniramine; Ibuprofen; Pseudoephedrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Chlorpheniramine; Phenylephrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Chlorpheniramine; Pseudoephedrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Chlorthalidone: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Chlorthalidone; Clonidine: (Major) Benzphetamine can increase both systolic and diastolic blood pressure and may counteract the activity of clonidine. This represents a pharmacodynamic, and not a pharmacokinetic, interaction. Close monitoring of blood pressure, especially in patients who are taking antihypertensive agents, may be needed. (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Citalopram: (Moderate) Coadministration of selective serotonin reuptake inhibitors (SSRIs) like citalopram with amphetamines may increase the risk of serotonin syndrome. At high doses, amphetamines can increase serotonin release and act as serotonin agonists. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome, particularly during treatment initiation and dose increases. If serotonin syndrome occurs, serotonergic drugs should be discontinued and appropriate medical treatment should be initiated.
Citric Acid; Potassium Citrate; Sodium Citrate: (Major) Urinary alkalinizers, such as potassium citrate diminish the urinary excretion of benzphetamine. These medications increase the proportion of non-ionized amphetamines, resulting in increased renal tubular reabsorption of these compounds. The half-life and therapeutic actions of benzphetamine will be prolonged in the presence of potassium citrate. This combination should be avoided. (Moderate) Monitor for an increase in the incidence and severity of amphetamine-related adverse effects during concomitant use of urinary alkalinizing agents. Increasing urine pH may increase amphetamine exposure by reducing urinary excretion of amphetamine. A urine pH more than 7.5 has been observed to increase the half-life of amphetamine from 8 to 10.5 hours to 16 to 31 hours when compared to a pH less than 6. Additionally, a urine pH more than 8 has been observed to reduce the amount of amphetamine excreted in the urine over 16 hours to less than 3% of the original dose; a 5-fold reduction compared to controls.
Clemastine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.

>Clevidipine: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Clonidine: (Major) Benzphetamine can increase both systolic and diastolic blood pressure and may counteract the activity of clonidine. This represents a pharmacodynamic, and not a pharmacokinetic, interaction. Close monitoring of blood pressure, especially in patients who are taking antihypertensive agents, may be needed.
Cocaine: (Major) Avoid concomitant use of additional vasoconstrictor agents with cocaine. If unavoidable, prolonged vital sign and ECG monitoring may be required. Myocardial ischemia, myocardial infarction, and ventricular arrhythmias have been reported after concomitant administration of topical intranasal cocaine and vasoconstrictor agents during nasal and sinus surgery. The risk for nervousness, irritability, convulsions, and other cardiac arrhythmias may increase during coadministration.
Codeine: (Moderate) If concomitant use of codeine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Codeine; Guaifenesin: (Moderate) If concomitant use of codeine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Codeine; Guaifenesin; Pseudoephedrine: (Moderate) If concomitant use of codeine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Codeine; Phenylephrine; Promethazine: (Moderate) If concomitant use of codeine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Codeine; Promethazine: (Moderate) If concomitant use of codeine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Colchicine: (Minor) The response to sympathomimetics may be enhanced by colchicine.
Cyclizine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Cyproheptadine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Dacomitinib: (Moderate) Warn patients that the risk of amphetamine toxicity, including serotonin syndrome, may be increased during concurrent use with dacomitinib. Concurrent use of dacomitinib, a strong CYP2D6 inhibitor, may increase exposure to the amphetamine increasing the risk for serotonin syndrome. If serotonin syndrome occurs, both the amphetamine and dacomitinib should be discontinued and appropriate medical treatment should be implemented.
Dapagliflozin: (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 SGLT2 inhibitors. 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.
Dapagliflozin; Metformin: (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. (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 SGLT2 inhibitors. 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.
Dapagliflozin; Saxagliptin: (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 SGLT2 inhibitors. 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.
Delavirdine: (Moderate) Warn patients that there are potentially serious drug interactions between delavirdine and prescription amphetamine therapy or illicit amphetamine use. The risk of amphetamine toxicity may be increased during concurrent use of potent CYP2D6 inhibitors such as delavirdine. Amphetamines are partially metabolized by CYP2D6 and have serotonergic properties; inhibition of amphetamine metabolism may increase the risk of serotonin syndrome or other toxicity. If serotonin syndrome occurs, both the amphetamine and CYP2D6 inhibitor should be discontinued and appropriate medical treatment should be implemented.
Dexbrompheniramine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Dexbrompheniramine; Pseudoephedrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Dexchlorpheniramine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Dextromethorphan; Bupropion: (Major) The risk of seizures from the use of bupropion may be increased with concomitant use of CNS stimulants and anorectics that may induce seizures, including benzphetamine. Concurrent use is not recommended. Extreme caution and close clinical monitoring is recommended if these agents must be used together.
Dextromethorphan; Diphenhydramine; Phenylephrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Dextromethorphan; Quinidine: (Moderate) Warn patients that the risk of amphetamine toxicity may be increased during concurrent use of quinidine, a strong CYP2D6 inhibitor. Amphetamines are partially metabolized by CYP2D6 and have serotonergic properties; inhibition of amphetamine metabolism may increase the risk of serotonin syndrome or other toxicity. If serotonin syndrome occurs, both the amphetamine and CYP2D6 inhibitor should be discontinued and appropriate medical treatment should be implemented.
Diltiazem: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Dimenhydrinate: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Dipeptidyl Peptidase-4 Inhibitors: (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 dipeptidyl peptidase-4 (DPP-4) inhibitors. 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.
Diphenhydramine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Diphenhydramine; Ibuprofen: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Diphenhydramine; Naproxen: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Diphenhydramine; Phenylephrine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Dorzolamide; Timolol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Doxazosin: (Minor) Close monitoring of blood pressure or the selection of alternative therapeutic agents may be needed in patients receiving doxazosin and amphetamines. Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, such as doxazosin.
Doxylamine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Doxylamine; Pyridoxine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Dronabinol: (Moderate) Concurrent use of dronabinol, THC with sympathomimetics may result in additive hypertension, tachycardia, and possibly cardiotoxicity. Dronabinol, THC has been associated with occasional hypotension, hypertension, syncope, and tachycardia. In a study of 7 adult males, combinations of IV cocaine and smoked marijuana, 1 g marijuana cigarette, 0 to 2.7% delta-9-THC, increased the heart rate above levels seen with either agent alone, with increases plateauing at 50 bpm.
Dulaglutide: (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 incretin mimetics. 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.
Empagliflozin: (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 SGLT2 inhibitors. 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.
Empagliflozin; Linagliptin: (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 SGLT2 inhibitors. 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.
Empagliflozin; Linagliptin; Metformin: (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. (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 SGLT2 inhibitors. 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.
Empagliflozin; Metformin: (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. (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 SGLT2 inhibitors. 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.
Enalapril, Enalaprilat: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Enalapril; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH. (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Epinephrine: (Moderate) Monitor blood pressure and heart rate during concomitant amphetamine and epinephrine use. Amphetamines may potentiate the pressor effects of epinephrine.
Eplerenone: (Major) Benzphetamine can increase both systolic and diastolic blood pressure and may counteract the activity of eplerenone. This represents a pharmacodynamic, and not a pharmacokinetic, interaction. Close monitoring of blood pressure, especially in patients who are taking antihypertensive agents, may be needed.
Epoprostenol: (Major) Avoid use of sympathomimetic agents with epoprostenol. Sympathomimetics counteract the medications used to stabilize pulmonary hypertension, including epoprostenol. Sympathomimetics can increase blood pressure, increase heart rate, and may cause vasoconstriction resulting in chest pain and shortness of breath in these patients. Patients should be advised to avoid amphetamine drugs, decongestants (including nasal decongestants) and sympathomimetic anorexiants for weight loss, including dietary supplements. Intravenous vasopressors may be used in the emergency management of pulmonary hypertension patients when needed, but hemodynamic monitoring and careful monitoring of cardiac status are needed to avoid ischemia and other complications.
Eprosartan; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Ergot alkaloids: (Major) Amphetamines, which increase catecholamine release, can increase blood pressure; this effect may be additive with the prolonged vasoconstriction caused by ergot alkaloids. Monitoring for cardiac effects during concurrent use of ergot alkaloids with amphetamines may be advisable.
Ergotamine; Caffeine: (Moderate) Avoid excessive caffeine intake during use of benzphetamine. Caffeine is a CNS-stimulant and such actions are expected to be additive when coadministered with other CNS stimulants or psychostimulants. Excessive caffeine ingestion (via medicines, foods like chocolate, dietary supplements, or beverages including coffee, green tea, other teas, colas) may contribute to side effects like nervousness, irritability, nausea, insomnia, or tremor. Patients should avoid medications and dietary supplements which contain high amounts of caffeine.
Ertugliflozin: (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 SGLT2 inhibitors. 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.
Ertugliflozin; Metformin: (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. (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 SGLT2 inhibitors. 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.
Ertugliflozin; Sitagliptin: (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 SGLT2 inhibitors. 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.
Escitalopram: (Moderate) Coadministration of selective serotonin reuptake inhibitors (SSRIs) like escitalopram with amphetamines may increase the risk of serotonin syndrome. At high doses, amphetamines can increase serotonin release and act as serotonin agonists. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome, particularly during treatment initiation and dose increases. If serotonin syndrome occurs, serotonergic drugs should be discontinued and appropriate medical treatment should be initiated.
Esketamine: (Major) Closely monitor blood pressure during concomitant use of esketamine and an amphetamine. Coadministration of psychostimulants, such as amphetamines, with esketamine may increase blood pressure, including the possibility of hypertensive crisis.
Eslicarbazepine: (Moderate) Patients who are taking anticonvulsants for epilepsy/seizure control should use amphetamines with caution. Amphetamines may decrease the seizure threshold and may increase the risk of seizures. If seizures occur, amphetamine discontinuation may be necessary. Additionally, amphetamines may delay the intestinal absorption of ethosuximide, ethotoin (hydantoin), phenobarbital, and phenytoin, the extent of absorption of these seizure medications is not known to be affected.
Esmolol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Ethacrynic Acid: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, such as loop diuretics. Close monitoring of blood pressure is advised.
Ethiodized Oil: (Major) Sympathomimetics lower the seizure threshold and should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Ethosuximide: (Major) Patients who are taking anticonvulsants for epilepsy/seizure control should use benzphetamine with caution. Amphetamines may decrease the seizure threshold and increase the risk of seizures. If seizures occur, amphetamine discontinuation may be necessary. Additionally, the amphetamines may delay the intestinal absorption of ethosuximide; the extent of absorption of these seizure medications is not known to be affected.
Etomidate: (Major) Inhalational general anesthetics may sensitize the myocardium to the effects of sympathomimetics. Dosages of sympathomimetics should be substantially reduced prior to surgery, and caution should be observed with concurrent use of anesthetics.
Exenatide: (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 incretin mimetics. 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.
Felodipine: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Fenfluramine: (Moderate) Use fenfluramine and amphetamines with caution due to an increased risk of serotonin syndrome. Monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Fentanyl: (Moderate) If concomitant use of fentanyl and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Fluoxetine: (Moderate) Monitor for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant amphetamine and fluoxetine use. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for serotonin syndrome.
Fluticasone; Salmeterol: (Moderate) Caution and close observation should also be used when salmeterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
Fluticasone; Umeclidinium; Vilanterol: (Moderate) Administer sympathomimetics with caution with beta-agonists such as vilanterol. The cardiovascular effects of beta-2 agonists may be potentiated by concomitant use. Monitor the patient for tremors, nervousness, increased heart rate, or other additive side effects.
Fluticasone; Vilanterol: (Moderate) Administer sympathomimetics with caution with beta-agonists such as vilanterol. The cardiovascular effects of beta-2 agonists may be potentiated by concomitant use. Monitor the patient for tremors, nervousness, increased heart rate, or other additive side effects.
Fluvoxamine: (Moderate) Coadministration of selective serotonin reuptake inhibitors (SSRIs) like fluvoxamine with amphetamines may increase the risk of serotonin syndrome. At high doses, amphetamines can increase serotonin release and act as serotonin agonists. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome, particularly during treatment initiation and dose increases. If serotonin syndrome occurs, serotonergic drugs should be discontinued and appropriate medical treatment should be initiated.
Food: (Moderate) Foods that acidify the urine may increase benzphetamine renal excretion. Conversely, foods that alkalinize the urine may slightly slow urinary excretion of amphetamines. Patients should not significantly alter their diets, however, as these changes are not expected to be clinically significant. (Moderate) In general, food does not significantly interact with the amphetamine stimulants, a dose may be taken with or without food. However, certain gastrointestinal acidifying agents (e.g., certain fruit juices, etc.) can lower the oral absorption of amphetamines. To ensure proper absorption, it may be prudent for the patient to avoid citrus fruits and citrus juices 1 hour before a dose, at the time of dosing, and for the 1 hour following a dose. In addition, the excretion of amphetamines is increased in acidic urine and decreased in alkaline urine. Foods that acidify the urine, such as cranberry juice, orange juice, or those that contain vitamin C (ascorbic acid) may increase amphetamine renal excretion. Conversely, foods that alkalinize the urine, such as beets, dairy products, kale, spinach may slightly slow urinary excretion of amphetamines. Patients should not significantly alter their diets, however, as these changes in urinary pH from foods are not expected to be clinically significant for most patients.
Formoterol: (Moderate) Caution and close observation should be used when formoterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
Formoterol; Mometasone: (Moderate) Caution and close observation should be used when formoterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
Fosinopril: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Fosinopril; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH. (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Furosemide: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, such as loop diuretics. Close monitoring of blood pressure is advised.
Glipizide; Metformin: (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.
Glyburide; Metformin: (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.
Glycopyrrolate; Formoterol: (Moderate) Caution and close observation should be used when formoterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
Green Tea: (Major) Some, but not all, green tea products contain caffeine. Additive CNS stimulant effects are likely to occur when caffeine is coadministered with other CNS stimulants or psychostimulants. Caffeine should be avoided or used cautiously with benzphetamine.
Guaifenesin; Hydrocodone: (Moderate) If concomitant use of hydrocodone and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Guanfacine: (Moderate) Sympathomimetic agents, such as amphetamines, may increase blood pressure and reduce the antihypertensive effects of antihypertensive agents, such as guanfacine. Monitor blood pressure and heart rate periodically when prescribed together. Guanfacine may be used adjunctively to psychostimulants such as amphetamines in the treatment of attention deficit hyperactivity disorder (ADHD). Pharmacokinetic studies reveal that guanfacine does not influence lisdexamfetamine pharmacokinetics and lisdexamfetamine does not affect guanfacine pharmacokinetics. No dosage adjustments are required when guanfacine and amphetamines are used together for ADHD. Monitor heart rate, blood pressure and for sedation during ADHD treatment.
Homatropine; Hydrocodone: (Moderate) If concomitant use of hydrocodone and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Hydrochlorothiazide, HCTZ; Methyldopa: (Major) Benzphetamine can increase both systolic and diastolic blood pressure and may counteract the activity of methyldopa. This represents a pharmacodynamic, and not a pharmacokinetic, interaction. Close monitoring of blood pressure, especially in patients who are taking antihypertensive agents, may be needed. (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Hydrochlorothiazide, HCTZ; Moexipril: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH. (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Hydrocodone: (Moderate) If concomitant use of hydrocodone and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Hydrocodone; Ibuprofen: (Moderate) If concomitant use of hydrocodone and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Hydrocodone; Pseudoephedrine: (Moderate) If concomitant use of hydrocodone and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Hydromorphone: (Moderate) If concomitant use of hydromorphone and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Hydroxyzine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate; Sodium Biphosphate: (Contraindicated) Amphetamines should not be administered during or within 14 days after the use of methylene blue. Methylene blue is a potent, reversible monoamine oxidase inhibitor (MAOI) which can prolong and intensify the cardiac stimulation and vasopressor effects of amphetamines, potentially resulting in hypertensive crisis. Methylene blue also has the potential to interact with serotonergic agents, such as amphetamines, which may increase the risk for serotonin syndrome. Serotonin syndrome is characterized by mental status changes (e.g., agitation, hallucinations, delirium, and coma), autonomic instability (e.g., tachycardia, labile blood pressure, dizziness, diaphoresis, flushing, hyperthermia), neuromuscular symptoms (e.g., tremor, rigidity, myoclonus, hyperreflexia, incoordination), seizures, gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea), and in rare instances, death. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving selective serotonin reuptake inhibitors, serotonin/norepinephrine reuptake inhibitors, or clomipramine. It is not known if patients receiving other serotonergic psychiatric agents, such as amphetamines, with intravenous methylene blue are at a comparable risk or if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. Published interaction reports between intravenously administered methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma. (Major) Urinary acidifying agents, such as ammonium chloride, phosphorus salts, and methenamine salts (e.g., methenamine; sodium acid phosphate), reduce the tubular reabsorption of amphetamines. As a result, amphetamine clearance is accelerated and the duration of effect is reduced. Combination therapy should be avoided if possible.
Ibritumomab Tiuxetan: (Moderate) Monitor for an increase in the incidence and severity of amphetamine-related adverse effects during concomitant use of urinary alkalinizing agents. Increasing urine pH may increase amphetamine exposure by reducing urinary excretion of amphetamine. A urine pH more than 7.5 has been observed to increase the half-life of amphetamine from 8 to 10.5 hours to 16 to 31 hours when compared to a pH less than 6. Additionally, a urine pH more than 8 has been observed to reduce the amount of amphetamine excreted in the urine over 16 hours to less than 3% of the original dose; a 5-fold reduction compared to controls.
Ibuprofen; Oxycodone: (Moderate) If concomitant use of oxycodone and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Iloprost: (Major) Avoid use of sympathomimetic agents with iloprost. Sympathomimetics counteract the medications used to stabilize pulmonary hypertension, including iloprost. Sympathomimetics can increase blood pressure, increase heart rate, and may cause vasoconstriction resulting in chest pain and shortness of breath in these patients. Patients should be advised to avoid amphetamine drugs, decongestants (including nasal decongestants) and sympathomimetic anorexiants for weight loss, including dietary supplements. Intravenous vasopressors may be used in the emergency management of pulmonary hypertension patients when needed, but hemodynamic monitoring and careful monitoring of cardiac status are needed to avoid ischemia and other complications.
Incretin Mimetics: (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 incretin mimetics. 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.
Indacaterol: (Moderate) Administer sympathomimetics with caution with beta-agonists such as indacaterol. The cardiovascular effects of beta-2 agonists may be potentiated by concomitant use. Monitor the patient for tremors, nervousness, increased heart rate, or other additive side effects.
Indacaterol; Glycopyrrolate: (Moderate) Administer sympathomimetics with caution with beta-agonists such as indacaterol. The cardiovascular effects of beta-2 agonists may be potentiated by concomitant use. Monitor the patient for tremors, nervousness, increased heart rate, or other additive side effects.
Indapamide: (Moderate) Indapamide may increase blood levels and therefore potentiate the actions of amphetamines. Thiazide diuretics and related drugs like indapamide may increase urinary pH, acting as a urinary alkalinizer, thus reducing urinary excretion and increasing blood concentrations of the amphetamine. Co-administration of amphetamines and urinary alkalinizing agents should be avoided if possible. If needed, monitor for common amphetamine side effects, including decreased appetite, anxiety, dizziness, dry mouth, irritability, insomnia, nausea, increased blood pressure or increased heart rate.
Insulin Degludec; Liraglutide: (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 incretin mimetics. 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.
Insulin Glargine; Lixisenatide: (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 incretin mimetics. 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.
Insulins: (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 insulin. 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.
Iobenguane I 131: (Major) Discontinue sympathomimetics for at least 5 half-lives before the administration of the dosimetry dose or a therapeutic dose of iobenguane I-131. Do not restart sympathomimetics until at least 7 days after each iobenguane I-131 dose. Drugs that reduce catecholamine uptake or deplete catecholamine stores, such as sympathomimetics, may interfere with iobenguane I-131 uptake into cells and interfere with dosimetry calculations resulting in altered iobenguane I-131 efficacy.
Iodixanol: (Major) Sympathomimetics lower the seizure threshold and should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Iohexol: (Major) Sympathomimetics lower the seizure threshold and should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Iomeprol: (Major) Sympathomimetics lower the seizure threshold and should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Iopamidol: (Major) Sympathomimetics lower the seizure threshold and should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Iopromide: (Major) Sympathomimetics lower the seizure threshold and should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Ioversol: (Major) Sympathomimetics lower the seizure threshold and should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Ipratropium; Albuterol: (Moderate) Caution and close observation should be used when albuterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
Irbesartan; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Isocarboxazid: (Contraindicated) In general, sympathomimetics should be avoided in patients receiving MAOIs due to an increased risk of hypertensive crisis. This applies to sympathomimetics including stimulants for ADHD, narcolepsy or weight loss, nasal, oral, and ophthalmic decongestants and cold products, and respiratory sympathomimetics (e.g., beta agonist drugs). Some local anesthetics also contain a sympathomimetic (e.g., epinephrine). In general, medicines containing sympathomimetic agents should not be used concurrently with MAOIs or within 14 days before or after their use.
Isosulfan Blue: (Major) Sympathomimetics lower the seizure threshold and should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Isradipine: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Ketamine: (Moderate) Closely monitor vital signs when ketamine and benzphetamine are coadministered; consider dose adjustment individualized to the patient's clinical situation. Benzphetamine may enhance the sympathomimetic effects of ketamine.
Labetalol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Lasmiditan: (Moderate) Serotonin syndrome may occur during coadministration of lasmiditan and amphetamines. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly after a dose increase or the addition of other serotonergic medications to an existing regimen. Discontinue all serotonergic agents if serotonin syndrome occurs and implement appropriate medical management.
Levalbuterol: (Moderate) Caution and close observation should be used when albuterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
Levamlodipine: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Levobunolol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Levodopa: (Major) Levodopa, due to its conversion to dopamine, may increase the risk of developing amphetamine-induced cardiac arrhythmias; dosage reductions or discontinuation of benzphetamine is recommended if the two agents are used concurrently.
Levorphanol: (Moderate) If concomitant use of levorphanol and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Levothyroxine: (Moderate) Monitor hemodynamic parameters during concomitant sympathomimetic agent and thyroid hormone use; dosage adjustments may be necessary. Concomitant use may increase the effects of sympathomimetics or thyroid hormone.
Levothyroxine; Liothyronine (Porcine): (Moderate) Monitor hemodynamic parameters during concomitant sympathomimetic agent and thyroid hormone use; dosage adjustments may be necessary. Concomitant use may increase the effects of sympathomimetics or thyroid hormone.
Levothyroxine; Liothyronine (Synthetic): (Moderate) Monitor hemodynamic parameters during concomitant sympathomimetic agent and thyroid hormone use; dosage adjustments may be necessary. Concomitant use may increase the effects of sympathomimetics or thyroid hormone.
Lidocaine; Epinephrine: (Moderate) Monitor blood pressure and heart rate during concomitant amphetamine and epinephrine use. Amphetamines may potentiate the pressor effects of epinephrine.
Linagliptin; Metformin: (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.
Linezolid: (Contraindicated) Amphetamines should not be administered during or within 14 days after the use of linezolid. Linezolid possesses MAO-inhibiting activity and can prolong and intensify the cardiac stimulation and vasopressor effects of the amphetamines, potentially resulting in hypertensive crisis. Linezolid also has the potential to interact with serotonergic agents, such as amphetamines, which may increase the risk for serotonin syndrome. Serotonin syndrome is characterized by mental status changes (e.g., agitation, hallucinations, delirium, and coma), autonomic instability (e.g., tachycardia, labile blood pressure, dizziness, diaphoresis, flushing, hyperthermia), neuromuscular symptoms (e.g., tremor, rigidity, myoclonus, hyperreflexia, incoordination), seizures, gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea), and in rare instances, death. If serotonin syndrome occurs, discontinue serotonergic drugs and institute appropriate medical management.
Liothyronine: (Moderate) Monitor hemodynamic parameters during concomitant sympathomimetic agent and thyroid hormone use; dosage adjustments may be necessary. Concomitant use may increase the effects of sympathomimetics or thyroid hormone.
Liraglutide: (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 incretin mimetics. 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.
Lisinopril: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Lisinopril; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH. (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Lithium: (Moderate) Coadministration of amphetamines and lithium may increase the risk of serotonin syndrome. At high doses, amphetamines can increase serotonin release, as well as act as serotonin agonists. Lithium has central serotonergic effects. Inform patients of the possible increased risk and monitor for serotonin syndrome, particularly during treatment initiation, after a dose increase, or the addition of other serotonergic medications. Discontinue all serotonergic agents if serotonin syndrome occurs and implement appropriate medical management.
Lixisenatide: (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 incretin mimetics. 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.
Loop diuretics: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, such as loop diuretics. Close monitoring of blood pressure is advised.
Lopinavir; Ritonavir: (Moderate) Warn patients that the risk of amphetamine toxicity may be increased during concurrent use of ritonavir, a strong CYP2D6 inhibitor. Amphetamines are partially metabolized by CYP2D6 and have serotonergic properties; inhibition of amphetamine metabolism may increase the risk of serotonin syndrome or other toxicity. If serotonin syndrome occurs, both the amphetamine and CYP2D6 inhibitor should be discontinued and appropriate medical treatment should be implemented.
Lorcaserin: (Moderate) Serotonin syndrome may occur during coadministration of serotonergic drugs such as amphetamines and lorcaserin. At high doses, amphetamines can increase serotonin release, as well as act as serotonin agonists. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly after a dose increase or the addition of other serotonergic medications to an existing regimen. Discontinue all serotonergic agents if serotonin syndrome oc curs and implement appropriate medical management. Also, the safety and efficacy of coadministration of lorcaserin with other products for weight loss, including amphetamines, have not been established.
Losartan; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Loxapine: (Major) Concurrent use of antipsychotics and amphetamines should generally be avoided. Antipsychotics and amphetamines may interact pharmacodynamically to diminish the therapeutic effects of either agent through opposing effects on dopamine. Amphetamines are thought to block central dopamine reuptake, which has the potential to exacerbate psychosis, and antipsychotics, which are central dopamine antagonists, may diminish the effectiveness of amphetamines.
Lurasidone: (Major) Concurrent use of antipsychotics and amphetamines should generally be avoided. Antipsychotics and amphetamines may interact pharmacodynamically to diminish the therapeutic effects of either agent through opposing effects on dopamine. Amphetamines are thought to block central dopamine reuptake, which has the potential to exacerbate psychosis, and antipsychotics, which are central dopamine antagonists, may diminish the effectiveness of amphetamines.
Macitentan: (Major) Avoid use of sympathomimetic agents with macitentan. Sympathomimetics counteract the medications used to stabilize pulmonary hypertension, including macitentan. Sympathomimetics can increase blood pressure, increase heart rate, and may cause vasoconstriction resulting in chest pain and shortness of breath in these patients. Patients should be advised to avoid amphetamine drugs, decongestants (including nasal decongestants) and sympathomimetic anorexiants for weight loss, including dietary supplements. Intravenous vasopressors may be used in the emergency management of pulmonary hypertension patients when needed, but hemodynamic monitoring and careful monitoring of cardiac status are needed to avoid ischemia and other complications.
Magnesium Hydroxide: (Minor) Monitor for an increase in amphetamine-related adverse effects during concomitant antacid use. Increasing gastric or urine pH may increase amphetamine exposure and the risk for side effects in some patients. As antacids have rarely been observed to increase gastric or urinary pH above 6.5, antacid-related pH changes may be insufficient to warrant clinical concern in most patients.
Maprotiline: (Moderate) Use maprotiline and sympathomimetics together with caution and close clinical monitoring. Regularly assess blood pressure, heart rate, the efficacy of treatment, and the emergence of sympathomimetic/adrenergic adverse events. Carefully adjust dosages as clinically indicated. Maprotiline has pharmacologic activity similar to tricyclic antidepressant agents and may cause additive sympathomimetic effects when combined with agents with adrenergic/sympathomimetic activity.
Mecamylamine: (Major) The cardiovascular effects of sympathomimetics may reduce the antihypertensive effects produced by mecamylamine. Close monitoring of blood pressure or the selection of alternative therapeutic agents may be needed.
Meclizine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Meglitinides: (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.
Meperidine: (Moderate) If concomitant use of meperidine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Metaproterenol: (Major) Caution and close observation should also be used when metaproterenol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
Metformin: (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.
Metformin; Repaglinide: (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.
Metformin; Rosiglitazone: (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. (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.
Metformin; Saxagliptin: (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.
Metformin; Sitagliptin: (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.
Methadone: (Moderate) If concomitant use of methadone and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Methazolamide: (Moderate) Urinary alkalinizers, such as methazolamide, result in decreased renal excretion of amphetamines. Monitor for amphetamine-related side effects. Avoid concomitant use in amphetamine overdose situations.
Methenamine: (Major) Urinary acidifying agents, such as ammonium chloride, phosphorus salts, and methenamine salts (e.g., methenamine; sodium acid phosphate), reduce the tubular reabsorption of amphetamines. As a result, amphetamine clearance is accelerated and the duration of effect is reduced. Combination therapy should be avoided if possible.
Methenamine; Sodium Acid Phosphate: (Major) Urinary acidifying agents, such as ammonium chloride, phosphorus salts, and methenamine salts (e.g., methenamine; sodium acid phosphate), reduce the tubular reabsorption of amphetamines. As a result, amphetamine clearance is accelerated and the duration of effect is reduced. Combination therapy should be avoided if possible.
Methenamine; Sodium Acid Phosphate; Methylene Blue; Hyoscyamine: (Contraindicated) Amphetamines should not be administered during or within 14 days after the use of methylene blue. Methylene blue is a potent, reversible monoamine oxidase inhibitor (MAOI) which can prolong and intensify the cardiac stimulation and vasopressor effects of amphetamines, potentially resulting in hypertensive crisis. Methylene blue also has the potential to interact with serotonergic agents, such as amphetamines, which may increase the risk for serotonin syndrome. Serotonin syndrome is characterized by mental status changes (e.g., agitation, hallucinations, delirium, and coma), autonomic instability (e.g., tachycardia, labile blood pressure, dizziness, diaphoresis, flushing, hyperthermia), neuromuscular symptoms (e.g., tremor, rigidity, myoclonus, hyperreflexia, incoordination), seizures, gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea), and in rare instances, death. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving selective serotonin reuptake inhibitors, serotonin/norepinephrine reuptake inhibitors, or clomipramine. It is not known if patients receiving other serotonergic psychiatric agents, such as amphetamines, with intravenous methylene blue are at a comparable risk or if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. Published interaction reports between intravenously administered methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma. (Major) Urinary acidifying agents, such as ammonium chloride, phosphorus salts, and methenamine salts (e.g., methenamine; sodium acid phosphate), reduce the tubular reabsorption of amphetamines. As a result, amphetamine clearance is accelerated and the duration of effect is reduced. Combination therapy should be avoided if possible.
Methenamine; Sodium Salicylate: (Major) Urinary acidifying agents, such as ammonium chloride, phosphorus salts, and methenamine salts (e.g., methenamine; sodium acid phosphate), reduce the tubular reabsorption of amphetamines. As a result, amphetamine clearance is accelerated and the duration of effect is reduced. Combination therapy should be avoided if possible.
Methohexital: (Major) Inhalational general anesthetics may sensitize the myocardium to the effects of sympathomimetics. Dosages of sympathomimetics should be substantially reduced prior to surgery, and caution should be observed with concurrent use of anesthetics.
Methyclothiazide: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Methyldopa: (Major) Benzphetamine can increase both systolic and diastolic blood pressure and may counteract the activity of methyldopa. This represents a pharmacodynamic, and not a pharmacokinetic, interaction. Close monitoring of blood pressure, especially in patients who are taking antihypertensive agents, may be needed.
Methylene Blue: (Contraindicated) Amphetamines should not be administered during or within 14 days after the use of methylene blue. Methylene blue is a potent, reversible monoamine oxidase inhibitor (MAOI) which can prolong and intensify the cardiac stimulation and vasopressor effects of amphetamines, potentially resulting in hypertensive crisis. Methylene blue also has the potential to interact with serotonergic agents, such as amphetamines, which may increase the risk for serotonin syndrome. Serotonin syndrome is characterized by mental status changes (e.g., agitation, hallucinations, delirium, and coma), autonomic instability (e.g., tachycardia, labile blood pressure, dizziness, diaphoresis, flushing, hyperthermia), neuromuscular symptoms (e.g., tremor, rigidity, myoclonus, hyperreflexia, incoordination), seizures, gastrointestinal symptoms (e.g., nausea, vomiting, diarrhea), and in rare instances, death. Cases of serotonin syndrome have been reported, primarily following administration of standard infusions of methylene blue (1 to 8 mg/kg) as a visualizing agent in parathyroid surgery, in patients receiving selective serotonin reuptake inhibitors, serotonin/norepinephrine reuptake inhibitors, or clomipramine. It is not known if patients receiving other serotonergic psychiatric agents, such as amphetamines, with intravenous methylene blue are at a comparable risk or if methylene blue administered by other routes (e.g., orally, local injection) or in doses less than 1 mg/kg IV can produce a similar outcome. Published interaction reports between intravenously administered methylene blue and serotonergic psychiatric agents have documented symptoms including lethargy, confusion, delirium, agitation, aggression, obtundation, myoclonus, expressive aphasia, hypertonia, pyrexia, elevated blood pressure, seizures, and/or coma.
Metolazone: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Metoprolol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Metoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug. (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Miglitol: (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.
Mirtazapine: (Moderate) Serotonin syndrome may occur during coadministration of serotonergic drugs such as amphetamines and mirtazapine. At high doses, amphetamines can increase serotonin release, as well as act as serotonin agonists. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly after a dose increase or the addition of other serotonergic medications to an existing regimen. Discontinue all serotonergic agents if serotonin syndrome occurs and implement appropriate medical management.
Modafinil: (Moderate) The use of modafinil with other psychostimulants, including amphetamines (e.g., amphetamine, dextroamphetamine, lisdexamfetamine), has not been extensively studied. Patients receiving combination therapy of modafinil with other psychostimulants should be closely observed for signs of nervousness, irritability, insomnia, arrhythmias, or other CNS stimulant-related side effects. In single-dose studies of dextroamphetamine combined with modafinil, no significant pharmacokinetic interactions occurred, but a slight increase in stimulant-associated side effects was noted.
Moexipril: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Molindone: (Major) Concurrent use of antipsychotics and amphetamines should generally be avoided. Antipsychotics and amphetamines may interact pharmacodynamically to diminish the therapeutic effects of either agent through opposing effects on dopamine. Amphetamines are thought to block central dopamine reuptake, which has the potential to exacerbate psychosis, and antipsychotics, which are central dopamine antagonists, may diminish the effectiveness of amphetamines.
Monoamine oxidase inhibitors: (Contraindicated) In general, sympathomimetics should be avoided in patients receiving MAOIs due to an increased risk of hypertensive crisis. This applies to sympathomimetics including stimulants for ADHD, narcolepsy or weight loss, nasal, oral, and ophthalmic decongestants and cold products, and respiratory sympathomimetics (e.g., beta agonist drugs). Some local anesthetics also contain a sympathomimetic (e.g., epinephrine). In general, medicines containing sympathomimetic agents should not be used concurrently with MAOIs or within 14 days before or after their use.
Morphine: (Moderate) If concomitant use of morphine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Morphine; Naltrexone: (Moderate) If concomitant use of morphine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Nabilone: (Moderate) Concurrent use of nabilone with sympathomimetics (e.g., amphetamine or cocaine) may result in additive hypertension, tachycardia, and possibly cardiotoxicity. In a study of 7 adult males, combinations of cocaine (IV) and smoked marijuana (1 g marijuana cigarette, 0 to 2.7% delta-9-THC) increased the heart rate above levels seen with either agent alone, with increases reaching a plateau at 50 bpm.
Nadolol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Nalbuphine: (Moderate) If concomitant use of nalbuphine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Nebivolol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Nebivolol; Valsartan: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Nefazodone: (Moderate) Serotonin syndrome may occur during coadministration of serotonergic drugs such as amphetamines and nefazodone. At high doses, amphetamines can increase serotonin release, as well as act as serotonin agonists. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly after a dose increase or the addition of other serotonergic medications to an existing regimen. Discontinue all serotonergic agents if serotonin syndrome occurs and implement appropriate medical management.
Nicardipine: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Nicotine: (Moderate) Nicotine use may potentiate the effects of the adrenergic agonists and the ergot alkaloids. If significant changes in nicotine intake occur, the dosages of these drugs may need adjustment.
Nifedipine: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Nimodipine: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Nirmatrelvir; Ritonavir: (Moderate) Warn patients that the risk of amphetamine toxicity may be increased during concurrent use of ritonavir, a strong CYP2D6 inhibitor. Amphetamines are partially metabolized by CYP2D6 and have serotonergic properties; inhibition of amphetamine metabolism may increase the risk of serotonin syndrome or other toxicity. If serotonin syndrome occurs, both the amphetamine and CYP2D6 inhibitor should be discontinued and appropriate medical treatment should be implemented.
Nisoldipine: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Nitrates: (Moderate) Sympathomimetics can antagonize the antianginal effects of nitrates, and can increase blood pressure and/or heart rate. Anginal pain may be induced when coronary insufficiency is present.
Non-Ionic Contrast Media: (Major) Sympathomimetics lower the seizure threshold and should be discontinued at least 48 hours before myelography and should not be resumed for at least 24 hours postprocedure.
Olanzapine; Fluoxetine: (Moderate) Monitor for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant amphetamine and fluoxetine use. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for serotonin syndrome.
Oliceridine: (Moderate) If concomitant use of oliceridine and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Olmesartan; Amlodipine; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH. (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Olmesartan; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Omeprazole; Sodium Bicarbonate: (Moderate) Monitor for an increase in the incidence and severity of amphetamine-related adverse effects during concomitant use of urinary alkalinizing agents. Increasing urine pH may increase amphetamine exposure by reducing urinary excretion of amphetamine. A urine pH more than 7.5 has been observed to increase the half-life of amphetamine from 8 to 10.5 hours to 16 to 31 hours when compared to a pH less than 6. Additionally, a urine pH more than 8 has been observed to reduce the amount of amphetamine excreted in the urine over 16 hours to less than 3% of the original dose; a 5-fold reduction compared to controls.
Oxycodone: (Moderate) If concomitant use of oxycodone and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Oxymorphone: (Moderate) If concomitant use of oxymorphone and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Ozanimod: (Major) Avoid concurrent use of ozanimod and amphetamines when possible as this combination may increase the risk for serious adverse reactions such as hypertensive crisis. If use is necessary, monitor for hypertension. Amphetamines may increase blood pressure by increasing norepinephrine and serotonin concentrations and monoamine oxidase inhibitors (MAOIs) are known to potentiate these effects. An active metabolite of ozanimod inhibits MAO-B in vitro. Sympathomimetics are contraindicated for use with non-selective MAOIs, however the risk for hypertensive reactions may be lower with selective MAO-B inhibitors.
Paroxetine: (Moderate) Monitor for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant amphetamine and paroxetine use. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for serotonin syndrome.
Perindopril: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Perindopril; Amlodipine: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised. (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Phenelzine: (Contraindicated) In general, sympathomimetics should be avoided in patients receiving MAOIs due to an increased risk of hypertensive crisis. This applies to sympathomimetics including stimulants for ADHD, narcolepsy or weight loss, nasal, oral, and ophthalmic decongestants and cold products, and respiratory sympathomimetics (e.g., beta agonist drugs). Some local anesthetics also contain a sympathomimetic (e.g., epinephrine). In general, medicines containing sympathomimetic agents should not be used concurrently with MAOIs or within 14 days before or after their use.
Phenobarbital: (Major) Patients who are taking anticonvulsants for epilepsy/seizure control should use benzphetamine with caution. Amphetamines may decrease the seizure threshold and increase the risk of seizures. If seizures occur, amphetamine discontinuation may be necessary. Additionally, the amphetamines may delay the intestinal absorption of phenobarbital; the extent of absorption of these seizure medications is not known to be affected.
Phenobarbital; Hyoscyamine; Atropine; Scopolamine: (Major) Patients who are taking anticonvulsants for epilepsy/seizure control should use benzphetamine with caution. Amphetamines may decrease the seizure threshold and increase the risk of seizures. If seizures occur, amphetamine discontinuation may be necessary. Additionally, the amphetamines may delay the intestinal absorption of phenobarbital; the extent of absorption of these seizure medications is not known to be affected.
Phenoxybenzamine: (Major) Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents. Due to the risk of unopposed alpha-adrenergic activity, amphetamines should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. In particular, amphetamines can inhibit the antihypertensive response to guanadrel, an adrenergic antagonist that causes depletion of norepinephrine in the synapse. Close monitoring of blood pressure or the selection of alternative therapeutic agents may be needed.
Phentermine: (Major) Avoid coadministration of phentermine and other medications for weight loss, such as amphetamines. The safety and efficacy of combination therapy have not been established.
Phentermine; Topiramate: (Major) Avoid coadministration of phentermine and other medications for weight loss, such as amphetamines. The safety and efficacy of combination therapy have not been established. (Moderate) Monitor for amphetamine-related adverse events if coadministered with topiramate. Concurrent use may increase amphetamine concentrations, resulting in potentiation of the action of amphetamines.
Phentolamine: (Major) Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents. Due to the risk of unopposed alpha-adrenergic activity, amphetamines should be used cautiously with beta-blockers. Increased blood pressure, bradycardia, or heart block may occur due to excessive alpha-adrenergic receptor stimulation. Phentolamine may decrease, but not completely reverse, the pressor response of amphetamine overdose. Close monitoring of blood pressure or the selection of alternative therapeutic agents may be needed.
Phenytoin: (Major) Patients who are taking anticonvulsants for epilepsy/seizure control should use benzphetamine with caution. Amphetamines may decrease the seizure threshold and increase the risk of seizures. If seizures occur, amphetamine discontinuation may be necessary. Additionally, the amphetamines may delay the intestinal absorption of phenytoin; the extent of absorption of these seizure medications is not known to be affected.
Pindolol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Pioglitazone: (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.
Pioglitazone; Glimepiride: (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.
Pioglitazone; Metformin: (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. (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.
Potassium Bicarbonate: (Major) Urinary alkalinizers, such as potassium citrate diminish the urinary excretion of benzphetamine. These medications increase the proportion of non-ionized amphetamines, resulting in increased renal tubular reabsorption of these compounds. The half-life and therapeutic actions of benzphetamine will be prolonged in the presence of potassium citrate. This combination should be avoided. (Moderate) Monitor for an increase in the incidence and severity of amphetamine-related adverse effects during concomitant use of urinary alkalinizing agents. Increasing urine pH may increase amphetamine exposure by reducing urinary excretion of amphetamine. A urine pH more than 7.5 has been observed to increase the half-life of amphetamine from 8 to 10.5 hours to 16 to 31 hours when compared to a pH less than 6. Additionally, a urine pH more than 8 has been observed to reduce the amount of amphetamine excreted in the urine over 16 hours to less than 3% of the original dose; a 5-fold reduction compared to controls.
Potassium Chloride: (Major) Urinary alkalinizers, such as potassium citrate diminish the urinary excretion of benzphetamine. These medications increase the proportion of non-ionized amphetamines, resulting in increased renal tubular reabsorption of these compounds. The half-life and therapeutic actions of benzphetamine will be prolonged in the presence of potassium citrate. This combination should be avoided.
Potassium Citrate: (Major) Urinary alkalinizers, such as potassium citrate diminish the urinary excretion of benzphetamine. These medications increase the proportion of non-ionized amphetamines, resulting in increased renal tubular reabsorption of these compounds. The half-life and therapeutic actions of benzphetamine will be prolonged in the presence of potassium citrate. This combination should be avoided. (Moderate) Monitor for an increase in the incidence and severity of amphetamine-related adverse effects during concomitant use of urinary alkalinizing agents. Increasing urine pH may increase amphetamine exposure by reducing urinary excretion of amphetamine. A urine pH more than 7.5 has been observed to increase the half-life of amphetamine from 8 to 10.5 hours to 16 to 31 hours when compared to a pH less than 6. Additionally, a urine pH more than 8 has been observed to reduce the amount of amphetamine excreted in the urine over 16 hours to less than 3% of the original dose; a 5-fold reduction compared to controls.
Potassium Citrate; Citric Acid: (Major) Urinary alkalinizers, such as potassium citrate diminish the urinary excretion of benzphetamine. These medications increase the proportion of non-ionized amphetamines, resulting in increased renal tubular reabsorption of these compounds. The half-life and therapeutic actions of benzphetamine will be prolonged in the presence of potassium citrate. This combination should be avoided. (Moderate) Monitor for an increase in the incidence and severity of amphetamine-related adverse effects during concomitant use of urinary alkalinizing agents. Increasing urine pH may increase amphetamine exposure by reducing urinary excretion of amphetamine. A urine pH more than 7.5 has been observed to increase the half-life of amphetamine from 8 to 10.5 hours to 16 to 31 hours when compared to a pH less than 6. Additionally, a urine pH more than 8 has been observed to reduce the amount of amphetamine excreted in the urine over 16 hours to less than 3% of the original dose; a 5-fold reduction compared to controls.
Potassium-sparing diuretics: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like potassium-sparing diuretics. Close monitoring of blood pressure is advised.
Pramlintide: (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.
Prazosin: (Minor) Close monitoring of blood pressure or the selection of alternative therapeutic agents may be needed in patients receiving prazosin and amphetamines. Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, such as prazosin.
Prilocaine; Epinephrine: (Moderate) Monitor blood pressure and heart rate during concomitant amphetamine and epinephrine use. Amphetamines may potentiate the pressor effects of epinephrine.
Probenecid; Colchicine: (Minor) The response to sympathomimetics may be enhanced by colchicine.
Procarbazine: (Major) Because procarbazine exhibits some monoamine oxidase inhibitory (MAOI) activity, sympathomimetic drugs should be avoided. As with MAOIs, the use of a sympathomimetic drug with procarbazine may precipitate hypertensive crisis or other serious side effects. In the presence of MAOIs, drugs that cause release of norepinephrine induce severe cardiovascular and cerebrovascular responses. In general, do not use a sympathomimetic drug unless clinically necessary (e.g., medical emergencies, agents like dopamine) within the 14 days prior, during or 14 days after procarbazine therapy. If use is necessary within 2 weeks of the MAOI drug, in general the initial dose of the sympathomimetic agent must be greatly reduced. Patients should be counseled to avoid non-prescription (OTC) decongestants and other drug products, weight loss products, and energy supplements that contain sympathomimetic agents.
Propofol: (Major) Inhalational general anesthetics may sensitize the myocardium to the effects of sympathomimetics. Dosages of sympathomimetics should be substantially reduced prior to surgery, and caution should be observed with concurrent use of anesthetics.
Propranolol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Propranolol; Hydrochlorothiazide, HCTZ: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug. (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Pseudoephedrine; Triprolidine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Pyrilamine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Quinapril: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Quinapril; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH. (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Quinidine: (Moderate) Warn patients that the risk of amphetamine toxicity may be increased during concurrent use of quinidine, a strong CYP2D6 inhibitor. Amphetamines are partially metabolized by CYP2D6 and have serotonergic properties; inhibition of amphetamine metabolism may increase the risk of serotonin syndrome or other toxicity. If serotonin syndrome occurs, both the amphetamine and CYP2D6 inhibitor should be discontinued and appropriate medical treatment should be implemented.
Racepinephrine: (Major) Racepinephrine is a sympathomimetic drug with agonist actions at both the alpha and beta receptors. Patients using racepinephrine inhalation are advised to avoid other non-prescription products containing sympathomimetics since additive adverse effects on the cardiovascular and nervous system are possible, some which may be undesirable. Side effects such as nausea, tremor, nervousness, difficulty with sleep, and increased heart rate or blood pressure may be additive. Patients should avoid use of non-prescription decongestants, such as phenylephrine and pseudoephedrine, while using racepinephrine inhalations. Patients should avoid dietary supplements containing ingredients that are reported or claimed to have a stimulant or weight-loss effect, such as ephedrine and ephedra, Ma huang, and phenylpropanolamine. Patients taking prescription sympathomimetic or stimulant medications (including amphetamines, methylphenidate, dexmethylphenidate, isometheptane, epinephrine) should seek health care professional advice prior to the use of racepinephrine inhalations; consider therapeutic alternatives to racepinephrine for these patients.
Ramipril: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Rasagiline: (Moderate) The concomitant use of rasagiline and sympathomimetics was not allowed in clinical studies; therefore, caution is advised during concurrent use of rasagiline and sympathomimetics including stimulants for ADHD and weight loss, non-prescription nasal, oral, and ophthalmic decongestants, and weight loss dietary supplements containing Ephedra. Although sympathomimetics are contraindicated for use with other non-selective monoamine oxidase inhibitors (MAOIs), hypertensive reactions generally are not expected to occur during concurrent use with rasagiline because of the selective monoamine oxidase-B (MAO-B) inhibition of rasagiline at manufacturer recommended doses. One case of elevated blood pressure has been reported in a patient during concurrent use of the recommended dose of rasagiline and ophthalmic tetrahydrozoline. One case of hypertensive crisis has been reported in a patient taking the recommended dose of another MAO-B inhibitor, selegiline, in combination with ephedrine. It should be noted that the MAO-B selectivity of rasagiline decreases in a dose-related manner as increases are made above the recommended daily dose and interactions with sympathomimetics may be more likely to occur at these higher doses.
Remifentanil: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering remifentanil with amphetamines. Inform patients taking this combination of the possible increased risks and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Riociguat: (Major) Avoid use of sympathomimetic agents with riociguat. Sympathomimetics counteract the medications used to stabilize pulmonary hypertension, including riociguat. Sympathomimetics can increase blood pressure, increase heart rate, and may cause vasoconstriction resulting in chest pain and shortness of breath in these patients. Patients should be advised to avoid amphetamine drugs, decongestants (including nasal decongestants) and sympathomimetic anorexiants for weight loss, including dietary supplements. Intravenous vasopressors may be used in the emergency management of pulmonary hypertension patients when needed, but hemodynamic monitoring and careful monitoring of cardiac status are needed to avoid ischemia and other complications.
Ritonavir: (Moderate) Warn patients that the risk of amphetamine toxicity may be increased during concurrent use of ritonavir, a strong CYP2D6 inhibitor. Amphetamines are partially metabolized by CYP2D6 and have serotonergic properties; inhibition of amphetamine metabolism may increase the risk of serotonin syndrome or other toxicity. If serotonin syndrome occurs, both the amphetamine and CYP2D6 inhibitor should be discontinued and appropriate medical treatment should be implemented.
Rosiglitazone: (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.
Safinamide: (Contraindicated) Safinamide, a selective monoamine oxidase-B inhibitor, is contraindicated for use with amphetamines due to the risk of serotonin syndrome or hypertensive crisis. The manufacturer of safinamide recommends that a period of at least 14 days elapse between the discontinuation of safinamide and the initiation of serotonergic agents. Hypertensive crisis has been reported in patients taking recommended doses of selective MAO-B inhibitors and sympathomimetic medications, such as amphetamines. Safinamide can cause hypertension or exacerbate existing hypertension, particularly at daily dosages exceeding those recommended by the manufacturer.
Salmeterol: (Moderate) Caution and close observation should also be used when salmeterol is used concurrently with other adrenergic sympathomimetics, administered by any route, to avoid potential for increased cardiovascular effects.
Sedating H1-blockers: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Selegiline: (Contraindicated) The product labels for amphetamines contraindicate use with monoamine oxidase inhibitors (MAOIs), including selegiline, due to the risk of hypertensive crisis or serotonin syndrome. Amphetamines should not be used concurrently with MAOIs or within 14 days before or after their use. The manufacturers of selegiline products recommend caution and monitoring of blood pressure during concurrent use with sympathomimetics.
Selexipag: (Major) Avoid use of sympathomimetic agents with selexipag. Sympathomimetics counteract the medications used to stabilize pulmonary hypertension, including selexipag. Sympathomimetics can increase blood pressure, increase heart rate, and may cause vasoconstriction resulting in chest pain and shortness of breath in these patients. Patients should be advised to avoid amphetamine drugs, decongestants (including nasal decongestants) and sympathomimetic anorexiants for weight loss, including dietary supplements. Intravenous vasopressors may be used in the emergency management of pulmonary hypertension patients when needed, but hemodynamic monitoring and careful monitoring of cardiac status are needed to avoid ischemia and other complications.
Semaglutide: (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 incretin mimetics. 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.
Serotonin norepinephrine reuptake inhibitors: (Moderate) Serotonin syndrome may occur during coadministration of serotonergic drugs such as amphetamines and serotonin norepinephrine reuptake inhibitors. At high doses, amphetamines can increase serotonin release, as well as act as serotonin agonists. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly after a dose increase or the addition of other serotonergic medications to an existing regimen. Discontinue all serotonergic agents if serotonin syndrome occurs and implement appropriate medical management.
Serotonin-Receptor Agonists: (Moderate) Serotonin syndrome may occur during coadministration of serotonergic drugs such as amphetamines and serotonin-receptor agonists. At high doses, amphetamines can increase serotonin release, as well as act as serotonin agonists. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome particularly after a dose increase or the addition of other serotonergic medications to an existing regimen. Discontinue all serotonergic agents if serotonin syndrome occurs and implement appropriate medical management.
Sertraline: (Moderate) Coadministration of selective serotonin reuptake inhibitors (SSRIs) like sertraline with amphetamines may increase the risk of serotonin syndrome. At high doses, amphetamines can increase serotonin release and act as serotonin agonists. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome, particularly during treatment initiation and dose increases. If serotonin syndrome occurs, serotonergic drugs should be discontinued and appropriate medical treatment should be initiated.
SGLT2 Inhibitors: (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 SGLT2 inhibitors. 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.
Sodium Acetate: (Moderate) Monitor for an increase in the incidence and severity of amphetamine-related adverse effects during concomitant use of urinary alkalinizing agents. Increasing urine pH may increase amphetamine exposure by reducing urinary excretion of amphetamine. A urine pH more than 7.5 has been observed to increase the half-life of amphetamine from 8 to 10.5 hours to 16 to 31 hours when compared to a pH less than 6. Additionally, a urine pH more than 8 has been observed to reduce the amount of amphetamine excreted in the urine over 16 hours to less than 3% of the original dose; a 5-fold reduction compared to controls.
Sodium Bicarbonate: (Moderate) Monitor for an increase in the incidence and severity of amphetamine-related adverse effects during concomitant use of urinary alkalinizing agents. Increasing urine pH may increase amphetamine exposure by reducing urinary excretion of amphetamine. A urine pH more than 7.5 has been observed to increase the half-life of amphetamine from 8 to 10.5 hours to 16 to 31 hours when compared to a pH less than 6. Additionally, a urine pH more than 8 has been observed to reduce the amount of amphetamine excreted in the urine over 16 hours to less than 3% of the original dose; a 5-fold reduction compared to controls.
Sodium Citrate; Citric Acid: (Moderate) Monitor for an increase in the incidence and severity of amphetamine-related adverse effects during concomitant use of urinary alkalinizing agents. Increasing urine pH may increase amphetamine exposure by reducing urinary excretion of amphetamine. A urine pH more than 7.5 has been observed to increase the half-life of amphetamine from 8 to 10.5 hours to 16 to 31 hours when compared to a pH less than 6. Additionally, a urine pH more than 8 has been observed to reduce the amount of amphetamine excreted in the urine over 16 hours to less than 3% of the original dose; a 5-fold reduction compared to controls.
Sodium Lactate: (Moderate) Monitor for an increase in the incidence and severity of amphetamine-related adverse effects during concomitant use of urinary alkalinizing agents. Increasing urine pH may increase amphetamine exposure by reducing urinary excretion of amphetamine. A urine pH more than 7.5 has been observed to increase the half-life of amphetamine from 8 to 10.5 hours to 16 to 31 hours when compared to a pH less than 6. Additionally, a urine pH more than 8 has been observed to reduce the amount of amphetamine excreted in the urine over 16 hours to less than 3% of the original dose; a 5-fold reduction compared to controls.
Sodium Oxybate: (Moderate) Sodium oxybate has the potential to induce seizures; it has been speculated that this effect may be mediated through the action of sodium oxybate at GABA receptors. Although convulsant effects occur primarily at high dosages, sodium oxybate should be used cautiously with psychostimulants that are known to lower seizure threshold such as the amphetamines. Note that CNS stimulants, including the amphetamines, methylphenidate, and modafinil are frequently used in the treatment of narcolepsy, and clinical trials involving the use of psychostimulants with sodium oxybate have not found the combinations to be unsafe. Pharmacodynamic interactions cannot be ruled out, however.
Solriamfetol: (Moderate) Monitor blood pressure and heart rate during coadministration of solriamfetol, a norepinephrine and dopamine reuptake inhibitor, and amphetamines, which are CNS stimulants. Concurrent use of solriamfetol and other medications that increase blood pressure and/or heart rate may increase the risk of such effects. Coadministration of solriamfetol with other drugs that increase blood pressure or heart rate has not been evaluated.
Sotagliflozin: (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 SGLT2 inhibitors. 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.
Sotalol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Spironolactone: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like potassium-sparing diuretics. Close monitoring of blood pressure is advised.
Spironolactone; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH. (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like potassium-sparing diuretics. Close monitoring of blood pressure is advised.
St. John's Wort, Hypericum perforatum: (Moderate) Coadministration of St. John's Wort with amphetamines may increase the risk of serotonin syndrome. At high doses, amphetamines can increase serotonin release, as well as act as serotonin agonists. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome, particularly at initiation of treatment, after a dose increase, or the addition of other serotonergic medications. Discontinue serotonergic agents if serotonin syndrome occurs and implement appropriate medical management.
Sufentanil: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering sufentanil with amphetamines. Inform patients taking this combination of the possible increa sed risks and monitor for the emergence of serotonin syndrome particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Sulfonylureas: (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 sulfonylureas. 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.
Tapentadol: (Moderate) If concomitant use of tapentadol and amphetamines is warranted, monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome.
Tedizolid: (Minor) Theoretically, drugs that possess MAO-inhibiting activity, such as tedizolid, can prolong and intensify the cardiac stimulation and vasopressor effects of amphetamines. Serious CNS reactions, such as serotonin syndrome, have been reported during the concurrent use of linezolid, which is structurally similar to tedizolid, and psychiatric medications that enhance central serotonergic activity; therefore, caution is warranted with concomitant use of other agents with serotonergic activity, including amphetamines.
Telmisartan; Amlodipine: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Telmisartan; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Terazosin: (Minor) Close monitoring of blood pressure or the selection of alternative therapeutic agents may be needed in patients receiving terazosin and amphetamines. Amphetamines increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, such as terazosin.
Terbutaline: (Major) Concomitant use of sympathomimetics with beta-agonists might result in additive cardiovascular effects such as increased blood pressure and heart rate.
Theophylline, Aminophylline: (Moderate) Concurrent administration of theophylline or aminophylline with some sympathomimetics can produce excessive stimulation and effects such as nervousness, irritability, or insomnia. Seizures or cardiac arrhythmias are also possible. (Moderate) Concurrent administration of theophylline or aminophylline with sympathomimetics can produce excessive stimulation manifested by skeletal muscle activity, agitation, and hyperactivity.
Thiazide diuretics: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Thiazolidinediones: (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.
Thiothixene: (Major) Concurrent use of antipsychotics, such as thiothixene, and amphetamines should generally be avoided. Antipsychotics and amphetamines may interact pharmacodynamically to diminish the therapeutic effects of either agent through opposing effects on dopamine. Amphetamines are thought to block central dopamine reuptake, which has the potential to exacerbate psychosis, and antipsychotics, which are central dopamine antagonists, may diminish the effectiveness of amphetamines.
Thyroid hormones: (Moderate) Monitor hemodynamic parameters during concomitant sympathomimetic agent and thyroid hormone use; dosage adjustments may be necessary. Concomitant use may increase the effects of sympathomimetics or thyroid hormone.
Timolol: (Moderate) Monitor hemodynamic parameters and for loss of efficacy during concomitant sympathomimetic agent and beta-blocker use; dosage adjustments may be necessary. Concomitant use may antagonize the cardiovascular effects of either drug.
Tipranavir: (Moderate) Warn patients that there are potentially serious drug interactions between tipranavir and prescription amphetamine therapy or illicit amphetamine use. The risk of amphetamine toxicity may be increased during concurrent use of potent CYP2D6 inhibitors such as tipranavir. Amphetamines are partially metabolized by CYP2D6 and have serotonergic properties; inhibition of amphetamine metabolism may increase the risk of serotonin syndrome or other toxicity. If serotonin syndrome occurs, discontinue both the amphetamine and CYP2D6 inhibitor and initiate appropriate medical treatment.
Tirzepatide: (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 incretin mimetics. 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.
Topiramate: (Moderate) Monitor for amphetamine-related adverse events if coadministered with topiramate. Concurrent use may increase amphetamine concentrations, resulting in potentiation of the action of amphetamines.
Torsemide: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, such as loop diuretics. Close monitoring of blood pressure is advised.
Tramadol: (Moderate) Serotonin syndrome may occur during coadministration of serotonergic drugs such as amphetamines and tramadol. At high doses, amphetamines can increase serotonin release, as well as act as serotonin agonists. An additive risk of seizures is also possible. Inform patients taking this combination of the possible increased risk of serotonin syndrome and seizures and monitor for adverse effects particularly after a dose increase or the addition of interacting medications. Discontinue all serotonergic agents if serotonin syndrome occurs and implement appropriate medical management.
Tramadol; Acetaminophen: (Moderate) Serotonin syndrome may occur during coadministration of serotonergic drugs such as amphetamines and tramadol. At high doses, amphetamines can increase serotonin release, as well as act as serotonin agonists. An additive risk of seizures is also possible. Inform patients taking this combination of the possible increased risk of serotonin syndrome and seizures and monitor for adverse effects particularly after a dose increase or the addition of interacting medications. Discontinue all serotonergic agents if serotonin syndrome occurs and implement appropriate medical management.
Trandolapril: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised.
Trandolapril; Verapamil: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like angiotensin-converting enzyme inhibitors (ACE inhibitors). Close monitoring of blood pressure is advised. (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Tranylcypromine: (Contraindicated) In general, sympathomimetics should be avoided in patients receiving MAOIs due to an increased risk of hypertensive crisis. This applies to sympathomimetics including stimulants for ADHD, narcolepsy or weight loss, nasal, oral, and ophthalmic decongestants and cold products, and respiratory sympathomimetics (e.g., beta agonist drugs). Some local anesthetics also contain a sympathomimetic (e.g., epinephrine). In general, medicines containing sympathomimetic agents should not be used concurrently with MAOIs or within 14 days before or after their use.
Trazodone: (Moderate) Coadministration of trazodone and amphetamines may increase the risk of serotonin syndrome. Serotonin syndrome has been reported with both drugs when taken alone, but especially when coadministered with other serotonergic agents. The MAOI activity of amphetamines may also be of concern with trazodone. Inform patients taking this combination of the possible increased risk and monitor for the emergence of serotonin syndrome. Serotonergic agents should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
Treprostinil: (Major) Avoid use of sympathomimetic agents with treprostinil. Sympathomimetics counteract the medications used to stabilize pulmonary hypertension, including treprostinil. Sympathomimetics can increase blood pressure, increase heart rate, and may cause vasoconstriction resulting in chest pain and shortness of breath in these patients. Patients should be advised to avoid amphetamine drugs, decongestants (including nasal decongestants) and sympathomimetic anorexiants for weight loss, including dietary supplements. Intravenous vasopressors may be used in the emergency management of pulmonary hypertension patients when needed, but hemodynamic monitoring and careful monitoring of cardiac status are needed to avoid ischemia and other complications.
Triamterene: (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like potassium-sparing diuretics. Close monitoring of blood pressure is advised.
Triamterene; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH. (Minor) Benzphetamine may increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like potassium-sparing diuretics. Close monitoring of blood pressure is advised.
Tricyclic antidepressants: (Moderate) Monitor blood pressure, heart rate, and for signs and symptoms of serotonin syndrome, particularly during treatment initiation and dosage increase, during concomitant amphetamine and tricyclic antidepressant use. Adjust doses or use alternative therapy based on clinical response. If serotonin syndrome occurs, discontinue therapy. Concomitant use increases the risk for potentiation of cardiovascular effects and serotonin syndrome. Amphetamines may enhance the activity of tricyclic antidepressants causing significant and sustained increases in amphetamine concentrations in the brain.
Triprolidine: (Moderate) Amphetamines may pharmacodynamically counteract the sedative properties of some antihistamines, such as the sedating H1-blockers. This effect may be clinically important if a patient is receiving an antihistamine agent for treatment of insomnia. Alternatively, if a patient is receiving an amphetamine for treatment of narcolepsy, the combination with a sedating antihistamine may reverse the action of the amphetamine.
Tromethamine: (Moderate) Monitor for an increase in the incidence and severity of amphetamine-related adverse effects during concomitant use of urinary alkalinizing agents. Increasing urine pH may increase amphetamine exposure by reducing urinary excretion of amphetamine. A urine pH more than 7.5 has been observed to increase the half-life of amphetamine from 8 to 10.5 hours to 16 to 31 hours when compared to a pH less than 6. Additionally, a urine pH more than 8 has been observed to reduce the amount of amphetamine excreted in the urine over 16 hours to less than 3% of the original dose; a 5-fold reduction compared to controls.
Tryptophan, 5-Hydroxytryptophan: (Major) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering amphetamines with other drugs that have serotonergic properties such as tryptophan. Serotonin syndrome is characterized by the rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Further study is needed to fully elucidate the severity and frequency of adverse effects that may occur from concomitant administration of amphetamines and tryptophan. Patients receiving tryptophan and an amphetamine should be monitored for the emergence of serotonin syndrome, particularly during treatment initiation and during dosage increases. The amphetamine and tryptophan should be discontinued if serotonin syndrome occurs and supportive symptomatic treatment should be initiated.
Umeclidinium; Vilanterol: (Moderate) Administer sympathomimetics with caution with beta-agonists such as vilanterol. The cardiovascular effects of beta-2 agonists may be potentiated by concomitant use. Monitor the patient for tremors, nervousness, increased heart rate, or other additive side effects.
Valsartan; Hydrochlorothiazide, HCTZ: (Minor) Amphetamines may counteract the activity of some antihypertensive agents, such as thiazide diuretics. Close monitoring of blood pressure is advised. Thiazide diuretics may also increase and prolong the actions of amphetamines by increasing the urinary pH.
Vasodilators: (Moderate) Use sympathomimetic agents with caution in patients receiving therapy for hypertension. Patients should be monitored to confirm that the desired antihypertensive effect is achieved. Sympathomimetics can increase blood pressure and heart rate, and antagonize the antihypertensive effects of vasodilators when administered concomitantly. Anginal pain may be induced when coronary insufficiency is present.
Verapamil: (Minor) Benzphetamine might increase both systolic and diastolic blood pressure and may counteract the activity of some antihypertensive agents, like calcium-channel blockers. Close monitoring of blood pressure is advised.
Vilazodone: (Moderate) Serotonin syndrome may occur during coadministration of serotonergic drugs such as amphetamines and vilazodone. At high doses, amphetamines can increase serotonin release and act as serotonin agonists. Monitor for the emergence of serotonin syndrome particularly after a dose increase or the addition of other serotonergic medications. Discontinue all serotonergic agents if serotonin syndrome occurs and implement appropriate medical management.
Vortioxetine: (Moderate) Serotonin syndrome may occur during coadministration of serotonergic drugs such as amphetamines and vortioxetine. At high doses, amphetamines can increase serotonin release and act as serotonin agonists. Monitor for the emergence of serotonin syndrome particularly after a dose increase or the addition of other serotonergic medications to an existing regimen. Discontinue all serotonergic agents if serotonin syndrome occurs and implement appropriate medical management.
Ziprasidone: (Minor) Serotonin syndrome has been reported during the combined use of amphetamine stimulants and other medications with serotonergic properties. Serotonin syndrome has been reported during postmarketing use of ziprasidone; however, a causal relationship has not been established.
Zonisamide: (Moderate) Patients who are taking anticonvulsants for epilepsy/seizure control should use amphetamines with caution. Amphetamines may decrease the seizure threshold and increase the risk of seizures. If seizures occur, amphetamine discontinuation may be necessary.

How Supplied

Benzphetamine/Benzphetamine Hydrochloride/Didrex/Regimex Oral Tab: 25mg, 50mg

Maximum Dosage
Adults

150 mg/day PO.

Elderly

150 mg/day PO.

Adolescents

150 mg/day PO.

Children

Safety and efficacy have not been established.

Mechanism Of Action

Benzphetamine is an anorectic agent that stimulates the central nervous system (CNS) and causes appetite suppression. The predominant mechanism of benzphetamine's CNS effect is to stimulate the release of several biogenic amines from storage sites in the nerve terminal. Benzphetamine is metabolized to amphetamine, and therefore has actions as both an indirect-acting sympathomimetic and a direct adrenergic agonist. At typical doses, benzphetamine stimulates the release of norepinephrine. At higher doses, dopamine is released from its storage sites accounting for some of the behavioral changes seen with sympathomimetics. The release of dopamine is thought to be responsible for the reinforcing properties of amphetamines. At still higher doses, the release of serotonin (5-hydroxytryptamine or 5-HT) is stimulated. Serotonin is this neurotransmitter that is thought to explain the overt psychotic behavior associated with amphetamine excess. The metabolite amphetamine may also act as a direct agonist on central 5-HT receptors. Indirect agonists are associated with tachyphylaxis due to the ever-decreasing supply of endogenous neurotransmitter that can be displaced from the nerve ending. Amphetamine may also inhibit monoamine oxidase (MAO), but this is a minor action. Amphetamine-induced CNS stimulation produces a decreased sense of fatigue, an increase in motor activity and mental alertness, and mild euphoria. These effects are believed to be due to stimulation of norepinephrine release from central noradrenergic neurons. The primary sites of activity in the CNS appear to be in the cerebral cortex and the reticular activating system. Benzphetamine's action in the treatment of obesity may result from mechanisms besides appetite suppression at the lateral hypothalamic feeding center. The anorectic effect is postulated to be secondary to CNS stimulation and a decrease in the acuity of smell and taste. Benzphetamine does not seem to alter the basal metabolic rate or nitrogen excretion. It is unknown if other CNS actions or metabolic effects may be involved in the promotion of weight loss with amphetamines.
 
In the periphery, benzphetamine and its metabolite amphetamine are believed to stimulate the release of norepinephrine from the adrenergic nerve terminals, by direct action on alpha- and beta-receptors. Amphetamines increase systolic and diastolic blood pressure and cause respiratory stimulation and weak bronchodilation. Heart rate reflexively decreases in response to increased blood pressure. At higher doses and in overdose, heart rate may increase or cardiac arrhythmias may occur. Benzphetamine and amphetamine may produce mydriasis and contraction of the bladder sphincter. Benzphetamine's effect on GI tract motility is unpredictable.

Pharmacokinetics

Benzphetamine is administered orally. It is widely distributed throughout the body, including the CNS. Benzphetamine is metabolized in the liver to amphetamine and methamphetamine, as well as other metabolites. Urinary elimination may be affected by agents that acidify or alkalinize the urine (see Drug Interactions). For amphetamines in general, every 1 unit increase in urinary pH corresponds with a 7-hour increase in amphetamine half-life. Conversely, acidification of the urine speeds benzphetamine elimination.

Oral Route

The onset of action of benzphetamine occurs within 30—60 minutes after oral administration.

Pregnancy And Lactation
Pregnancy

Women taking amphetamines, including benzphetamine, should refrain from breast-feeding. Amphetamines are excreted in human milk. The American Academy of Pediatrics (AAP) previously considered amphetamines, when used as drugs of abuse, to be contraindicated in breast-feeding due to concerns of irritability and poor sleeping pattern in the infant. If breast-feeding cannot be avoided during administration of a stimulant, the nursing infant should be monitored for signs of central nervous system hyperactivity, including decreased appetite, insomnia, and irritability. If possible, long-term infant exposure to stimulants through breast milk should be avoided since the consequences of such exposure are unknown. Consider the benefits of breast-feeding, the risk of potential infant drug exposure, and the risk of an untreated or inadequately treated condition.