Demerol

Opioid Agonists

Oral Administration

Storage: Keep meperidine secured in a location not accessible by others.
Disposal: Flush unused meperidine down the toilet when it is no longer needed if a drug take-back option is not readily available.

Oral Liquid Formulations

Dilute oral solution in one-half glass of water prior to administration to avoid topical anesthesia of mucous membranes.

Injectable Administration

Visually inspect parenteral products for particulate matter and discoloration prior to administration whenever solution and container permit.
When meperidine is given parenterally, the patient should be lying down.

Intravenous Administration

Do not administer IV unless an opioid antagonist and the facilities for assisted or controlled respiration are immediately available.
 
Intravenous injection:
Inject IV slowly, preferably as a diluted solution.
 
Continuous intravenous infusion:
Dilute solution (e.g., 1 mg/mL) for continuous IV infusion.

Intramuscular Administration

IM administration is preferred when repeated doses are required.
Inject into a large muscle mass.

Subcutaneous Administration

Subcutaneous administration is suitable for occasional use only.

Severe

respiratory arrest / Rapid / Incidence not known
apnea / Delayed / Incidence not known
visual impairment / Early / Incidence not known
muscle paralysis / Delayed / Incidence not known
seizures / Delayed / Incidence not known
neonatal opioid withdrawal syndrome / Delayed / Incidence not known
bradycardia / Rapid / Incidence not known
anaphylactoid reactions / Rapid / Incidence not known
SIADH / Delayed / Incidence not known
serotonin syndrome / Delayed / Incidence not known

Moderate

tolerance / Delayed / Incidence not known
respiratory depression / Rapid / Incidence not known
myoclonia / Delayed / Incidence not known
dysphoria / Early / Incidence not known
delirium / Early / Incidence not known
confusion / Early / Incidence not known
hallucinations / Early / Incidence not known
euphoria / Early / Incidence not known
constipation / Delayed / Incidence not known
psychological dependence / Delayed / Incidence not known
physiological dependence / Delayed / Incidence not known
withdrawal / Early / Incidence not known
hyperamylasemia / Delayed / Incidence not known
hypotension / Rapid / Incidence not known
palpitations / Early / Incidence not known
hypertension / Early / Incidence not known
orthostatic hypotension / Delayed / Incidence not known
sinus tachycardia / Rapid / Incidence not known
urinary retention / Early / Incidence not known
phlebitis / Rapid / Incidence not known
hyponatremia / Delayed / Incidence not known
impotence (erectile dysfunction) / Delayed / Incidence not known
infertility / Delayed / Incidence not known
adrenocortical insufficiency / Delayed / Incidence not known
hyperalgesia / Delayed / Incidence not known

Mild

dizziness / Early / Incidence not known
headache / Early / Incidence not known
weakness / Early / Incidence not known
drowsiness / Early / Incidence not known
agitation / Early / Incidence not known
tremor / Early / Incidence not known
vomiting / Early / Incidence not known
nausea / Early / Incidence not known
flushing / Rapid / Incidence not known
syncope / Early / Incidence not known
diaphoresis / Early / Incidence not known
xerostomia / Early / Incidence not known
pruritus / Rapid / Incidence not known
urticaria / Rapid / Incidence not known
injection site reaction / Rapid / Incidence not known
rash / Early / Incidence not known
libido decrease / Delayed / Incidence not known
amenorrhea / Delayed / Incidence not known
gonadal suppression / Delayed / Incidence not known

Asthma, chronic obstructive pulmonary disease (COPD), coadministration with other CNS depressants, cor pulmonale, hypoxemia, respiratory depression, respiratory insufficiency, sleep apnea

Meperidine is contraindicated in persons with significant respiratory depression and those with acute or severe asthma in an unmonitored setting or in the absence of resuscitative equipment. Avoid coadministration with other CNS depressants when possible, as this significantly increases the risk for profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs for use in persons for whom alternative treatment options are inadequate; if concurrent use is necessary, use the lowest effective dosages and minimum treatment durations needed. Monitor closely for signs or symptoms of respiratory depression and sedation. [61143] Persons with chronic obstructive pulmonary disease (COPD), cor pulmonale, respiratory insufficiency, hypoxemia, hypercapnia, or preexisting respiratory depression are at increased risk of decreased respiratory drive even at recommended doses. Persons with advanced age, cachexia, or debilitation are also at an increased risk for opioid-induced respiratory depression. Monitor such persons closely, particularly when initiating and titrating the opioid; consider the use of non-opioid analgesics. Opioids increase the risk of central sleep apnea (CSA) and sleep-related hypoxemia in a dose-dependent fashion. Consider decreasing the opioid dosage in persons with CSA. Respiratory depression, if left untreated, may cause respiratory arrest and death. Carbon dioxide retention from respiratory depression may also worsen opioid sedating effects. Careful monitoring is required, particularly when CYP450 3A4 inhibitors or inducers are used concomitantly; concurrent use of a CYP3A4 inhibitor or discontinuation of a concurrently used CYP3A4 inducer may increase plasma meperidine concentrations and potentiate the risk of fatal respiratory depression. Management of respiratory depression may include observation, necessary supportive measures, and opioid antagonist use when indicated.

MAOI therapy

Meperidine is contraindicated in patients who are receiving monoamine oxidase inhibitors (MAOIs) or those who have received MAOI therapy within the past 14 days. Therapeutic doses of meperidine have occasionally precipitated unpredictable, severe, and occasionally fatal reactions in patients who received MAOIs within 14 days. The exact mechanism of the reaction is unknown; however, it may be due to preexisting hyperphenylalaninemia. The reactions have been characterized by coma, severe respiratory depression, cyanosis, and hypotension, and have resembled the syndrome of acute narcotic overdose. Serotonin syndrome may occur. In other reactions, the predominant manifestations have been hyperexcitability, convulsions, tachycardia, hyperpyrexia, and hypertension. Intravenous hydrocortisone or prednisolone has been used to treat severe reactions. Intravenous chlorpromazine may be added in cases exhibiting hypertension and hyperpyrexia. The safety and efficacy of opioid antagonists for the treatment of these reactions are unknown.

Accidental exposure, alcoholism, depression, opioid overdose, opioid use disorder, potential for overdose or poisoning, requires an experienced clinician, substance abuse

Opioid use requires an experienced clinician who is knowledgeable about the use of opioids and how to mitigate the associated risks. Opioids expose users to the risks of addiction, abuse, and misuse, which can occur at any dosage or duration. Although the risk of addiction in any individual is unknown, it can occur in persons appropriately prescribed an opioid. Addiction can occur at recommended dosages and if the drug is misused or abused. Assess each individual's risk for opioid addiction, abuse, or misuse before prescribing an opioid, and monitor for the development of these behaviors or conditions. Risks are increased in persons with a personal or family history of substance abuse (including alcoholism) or mental illness (e.g., major depression). The potential for these risks should not prevent the proper management of pain in any given individual. Persons at increased risk may be prescribed opioids but use in such persons necessitates intensive counseling about the risks and proper use of the opioid along with intensive monitoring for signs of addiction, abuse, and misuse. Abuse and addiction are separate and distinct from physical dependence and tolerance; persons with addiction may not exhibit tolerance and symptoms of physical dependence. Opioids are sought by drug abusers and persons with addiction disorders and are subject to criminal diversion. Abuse of opioids has the potential for overdose or poisoning and death. Consider these risks when prescribing or dispensing opioids. Strategies to reduce these risks include prescribing the drug in the smallest appropriate quantity. Dosing errors may result from confusion between mg and mL when prescribing, dispensing, and administering meperidine oral solution. Ensure that the dose is communicated clearly and dispensed accurately. Instruct patients on how to measure the dose and to use a calibrated oral dosing device. Keep opioids out of the reach of pediatric patients, others for whom the drug was not prescribed, and pets as accidental exposure or improper use may cause respiratory failure and a fatal overdose. Accidental exposure of even a single dose of an opioid, especially by younger persons, can result in a fatal overdose. Because the risk of overdose increases as opioid doses increase, reserve titration to higher doses of an opioid for persons in whom lower doses are insufficiently effective and in whom the expected benefits of using a higher dose opioid clearly outweigh the substantial risks. Do not use immediate-release opioids for an extended period unless the pain remains severe enough to require an opioid and for which alternative treatment options continue to be inadequate. Many acute pain conditions (e.g., pain occurring with surgical procedures or acute musculoskeletal injuries) require no more than a few days of an opioid. Clinical guidelines on opioid prescribing for some acute pain conditions are available. Discuss the availability of naloxone with all patients and consider prescribing it in persons who are at increased risk of opioid overdose, such as those who are also using other CNS depressants, who have a history of opioid use disorder (OUD), who have experienced a previous opioid overdose, or who have household members or other close contacts at risk for accidental exposure or opioid overdose.

Labor, neonatal opioid withdrawal syndrome, obstetric delivery, pregnancy

Available data with meperidine use during pregnancy are insufficient to inform a drug-associated risk for major birth defects and miscarriage. Animal reproduction studies have not been conducted with meperidine. Neural tube defects have been reported in hamsters given a single dose of meperidine during organogenesis at doses 0.85 and 1.5 times the total human daily dose of 1,200 mg. Opioids cross the placenta. Meperidine is not recommended for use during and immediately before labor when other analgesic techniques are more appropriate. Opioids can prolong labor and obstetric delivery by temporarily reducing the strength, duration, and frequency of uterine contractions. This effect is not consistent and may be offset by an increased rate of cervical dilatation, which may shorten labor. Opioids cross the placenta and may produce respiratory depression and psycho-physiologic effects in the neonate. Monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression. An opioid antagonist (e.g., naloxone) should be available for reversal of opioid-induced respiratory depression in the neonate. Further, prolonged maternal use of opioids during pregnancy may result in neonatal opioid withdrawal syndrome (NOWS). Monitor the exposed neonate for withdrawal symptoms, including irritability, hyperactivity and abnormal sleep pattern, high-pitched cry, tremor, vomiting, diarrhea, and failure to gain weight, and manage accordingly. Onset, duration, and severity of opioid withdrawal may vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination by the newborn. Guidelines recommend early universal screening of pregnant patients for opioid use and opioid use disorder at the first prenatal visit. Obtain a thorough history of substance use and review the Prescription Drug Monitoring Program to determine if patients have received prior prescriptions for opioids or other high-risk drugs such as benzodiazepines. Discuss the risks and benefits of opioid use during pregnancy, including the risk of becoming physiologically dependent on opioids, the possibility for NOWS, and how long-term opioid use may affect care during a future pregnancy.[64838] [64909] In women undergoing uncomplicated normal spontaneous vaginal birth, consider opioid therapy only if expected benefits for both pain and function are anticipated to outweigh risks to the patient. If opioids are used, use in combination with nonpharmacologic therapy and nonopioid pharmacologic therapy, as appropriate. Use immediate-release opioids instead of extended-release or long-acting opioids; order the lowest effective dosage and prescribe no greater quantity of opioids than needed for the expected duration of such pain severe enough to require opioids.[64909] For women using opioids for chronic pain, consider strategies to avoid or minimize the use of opioids, including alternative pain therapies (i.e., nonpharmacologic) and nonopioid pharmacologic treatments. Opioid agonist pharmacotherapy (e.g., methadone or buprenorphine) is preferable to medically supervised withdrawal in pregnant women with opioid use disorder.[64838]

Demerol, Meperitab

Rx, schedule II

Phenylpiperidine opiate agonist
Used for relief of moderate to severe acute pain, postoperative shivering, and chills due to amphotericin B
May cause seizures with high or repeated doses, especially in patients with renal impairment

For the treatment of severe pain where treatment with an opioid is appropriate and for which alternative treatments are inadequate. For obstetric analgesia during labor and delivery. Intramuscular or Subcutaneous dosage Adults

50 to 100 mg IM or subcutaneously every 1 to 3 hours as needed.

Intramuscular, Intravenous, or Subcutaneous dosage Adults

50 to 150 mg IM or subcutaneously every 3 to 4 hours as needed. IM administration is preferred for repeated doses; subcutaneous administration is suitable for occasional use. If IV administration is required, decrease the dose. Use lower doses and close observation in geriatric patients.

Adolescents and Children

1.1 to 1.8 mg/kg (Max: 150 mg/dose) IM or subcutaneously every 3 to 4 hours as needed. IM administration is preferred for repeated doses; subcutaneous administration is suitable for occasional use. If IV administration is required, decrease the dose.

Oral dosage Adults

50 to 150 mg PO every 3 to 4 hours as needed. Use lower doses and close observation in geriatric patients.

Adolescents and Children

1.1 to 1.8 mg/kg (Max: 150 mg/dose) PO every 3 to 4 hours as needed.

For preoperative procedural sedation. Intramuscular or Subcutaneous dosage Adults

50 to 100 mg IM or subcutaneously 30 to 90 minutes before the beginning of anesthesia. Use lower doses and close observation in geriatric patients.

Adolescents and Children

1.1 to 2.2 mg/kg (Max:100 mg/dose) IM or subcutaneously 30 to 90 minutes before the beginning of anesthesia.

For general anesthesia maintenance. Intravenous dosage Adults

Use repeated slow IV injection of fractional doses (e.g., 10 mg/mL) or dilute solution (e.g., 1 mg/mL) continuous IV infusion. Titrate dosage to the needs of the patient, dependent upon premedication and anesthesia used and nature and duration of procedure. Use lower doses and close observation in geriatric patients.

For the treatment of shaking chills† induced by intravenous infusions of amphotericin B or for postoperative shivering†. Intravenous dosage Adults

25 to 50 mg IV as a single dose.

Children and Adolescents

Limited data suggest a dose of 0.35 to 1 mg/kg IV. The adult dose of 25 to 50 mg IV should not be exceeded. The lower end of the dosage range (i.e., 0.35 mg/kg) has been recommended by authors describing meperidine's use for postoperative shivering. Doses up to 1 mg/kg IV have been reported for the management of rigors and shaking chills associated with the administration of amphotericin B products.

†Indicates off-label use

Hepatic Impairment

Specific guidelines for dosage adjustments in hepatic impairment are not available; it appears that no dosage adjustments are needed. Titrate dosage slowly in patients with hepatic impairment, and monitor closely for signs of central nervous system and respiratory depression.

Renal Impairment

Specific guidelines for dosage adjustments in renal impairment are not available; it appears that no dosage adjustments are needed. Titrate dosage slowly in patients with renal impairment, and monitor closely for signs of central nervous system and respiratory depression.

Acetaminophen; Aspirin; Diphenhydramine: (Major) Reserve concomitant use of opioids and diphenhydramine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Acetaminophen; Caffeine; Pyrilamine: (Moderate) Concomitant use of opioid agonists with pyrilamine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with pyrilamine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Acetaminophen; Chlorpheniramine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Acetaminophen; Chlorpheniramine; Dextromethorphan: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Acetaminophen; Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Acetaminophen; Chlorpheniramine; Phenylephrine : (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Acetaminophen; Dextromethorphan; Doxylamine: (Major) Reserve concomitant use of opioids and doxylamine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Acetaminophen; Diphenhydramine: (Major) Reserve concomitant use of opioids and diphenhydramine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Acetaminophen; Hydrocodone: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression.
Acetaminophen; Oxycodone: (Major) Concomitant use of oxycodone with other opiate agonists may lead to additive respiratory and/or CNS depression. Hypotension, profound sedation, coma, respiratory depression, or death may occur. Prior to concurrent use of oxycodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. If a CNS depressant is used concurrently with oxycodone, a reduced dosage of oxycodone and/or the CNS depressant is recommended; use an initial dose of oxycodone at 1/3 to 1/2 the usual dosage. Monitor for sedation and respiratory depression.
Acetaminophen; Pamabrom; Pyrilamine: (Moderate) Concomitant use of opioid agonists with pyrilamine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with pyrilamine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Acrivastine; Pseudoephedrine: (Major) Avoid coadministration of opioid agonists with acrivastine due to the risk of additive CNS depression.
Adagrasib: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of adagrasib is necessary. If adagrasib is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A and adagrasib is a strong CYP3A inhibitor. Concomitant use with adagrasib can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Aldesleukin, IL-2: (Moderate) Aldesleukin, IL-2 may affect CNS function significantly. Therefore, psychotropic pharmacodynamic interactions could occur following concomitant administration of drugs with significant CNS or psychotropic activity such as opiate agonists. In addition, aldesleukin, IL-2, is a CYP3A4 inhibitor and may increase oxycodone plasma concentrations and related toxicities including potentially fatal respiratory depression. If therapy with both agents is necessary, monitor patients for an extended period and adjust oxycodone dosage as necessary.
Aliskiren; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Alosetron: (Major) Patients taking medications that decrease GI motility may be at greater risk for serious complications from alosetron, like constipation, via a pharmacodynamic interaction. Constipation is the most frequently reported adverse effect with alosetron. Alosetron, if used with drugs such as opiate agonists, may seriously worsen constipation, leading to events such as GI obstruction/impaction or paralytic ileus.
Alprazolam: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Alvimopan: (Moderate) Patients should not take alvimopan if they have received therapeutic doses of opiate agonists for more than seven consecutive days immediately before initiation of alvimopan therapy. Patients recently exposed to opioids are expected to be more sensitive to the effects of mu-opioid receptor antagonists and may experience adverse effects localized to the gastrointestinal tract such as abdominal pain, nausea, vomiting, and diarrhea.
Amide local anesthetics: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Amiloride: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when amiloride is administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Amiloride; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when amiloride is administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Amitriptyline: (Major) Concomitant use of meperidine with tricyclic antidepressants (TCAs) may cause excessive sedation and somnolence. Limit the use of opioid pain medications with TCAs to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome or signs of urinary retention or reduced gastric motility. 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. The concomitant use of anticholinergic drugs may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Amlodipine; Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Amobarbital: (Major) Concomitant use of meperidine with a barbiturate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a barbiturate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concurrent use of meperidine with a barbiturate may decrease meperidine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to opioid agonists. Monitor for signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of increased opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; meperidine is a CYP3A4 substrate.
Amoxapine: (Moderate) Concomitant use of mepridine with amoxapine may cause additive sedation and somnolence. Limit the use of opioid pain medications to patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression. Monitor for other additive effects, such as constipation or urinary retention.
Amphetamine: (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.
Amphetamine; Dextroamphetamine: (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.
Amphetamines: (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.
Anticholinergics: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Apomorphine: (Major) Concomitant use of opioid agonists with apomorphine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with apomorphine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression. Dopaminergic agents like apomorphine have also been associated with sudden sleep onset during activities of daily living such as driving, which has resulted in accidents in some cases. Prescribers should re-assess patients for drowsiness or sleepiness regularly throughout treatment, especially since events may occur well after the start of treatment.
Apraclonidine: (Minor) Theoretically, apraclonidine might potentiate the effects of CNS depressant drugs such as opiate agonists. Although no specific drug interactions were identified with systemic agents and apraclonidine during clinical trials, apraclonidine can cause dizziness and somnolence.
Aripiprazole: (Moderate) Concomitant use of opioid agonists with aripiprazole may cause excessive sedation and somnolence. Limit the use of opioid pain medications with aripiprazole to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Articaine; Epinephrine: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Asciminib: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of asciminib is necessary. If asciminib is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A and asciminib is a weak CYP3A inhibitor. Concomitant use with asciminib can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Asenapine: (Moderate) Concomitant use of opioid agonists with asenapine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with asenapine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Aspirin, ASA; Butalbital; Caffeine: (Major) Concomitant use of meperidine with a barbiturate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a barbiturate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concurrent use of meperidine with a barbiturate may decrease meperidine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to opioid agonists. Monitor for signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of increased opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; meperidine is a CYP3A4 substrate.
Aspirin, ASA; Caffeine; Orphenadrine: (Major) Concomitant use of opioid agonists with orphenadrine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with orphenadrine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations.
Aspirin, ASA; Carisoprodol: (Major) Concomitant use of opioid agonists with carisoprodol may cause excessive sedation and somnolence. Limit the use of opioid pain medications with carisoprodol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations.
Aspirin, ASA; Carisoprodol; Codeine: (Major) Concomitant use of opioid agonists with carisoprodol may cause excessive sedation and somnolence. Limit the use of opioid pain medications with carisoprodol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations.
Aspirin, ASA; Oxycodone: (Major) Concomitant use of oxycodone with other opiate agonists may lead to additive respiratory and/or CNS depression. Hypotension, profound sedation, coma, respiratory depression, or death may occur. Prior to concurrent use of oxycodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. If a CNS depressant is used concurrently with oxycodone, a reduced dosage of oxycodone and/or the CNS depressant is recommended; use an initial dose of oxycodone at 1/3 to 1/2 the usual dosage. Monitor for sedation and respiratory depression.
Atenolol; Chlorthalidone: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Atropine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Atropine; Difenoxin: (Moderate) Concurrent administration of diphenoxylate/difenoxin with other opiate agonists can potentiate the CNS-depressant effects of diphenoxylate/difenoxin. Use caution during coadministration. In addition, diphenoxylate/difenoxin use may cause constipation; cases of severe GI reactions including toxic megacolon and adynamic ileus have been reported. Reduced GI motility when combined with opiate agonists may increase the risk of serious GI related adverse events. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Avacopan: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of avacopan is necessary. If avacopan is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A and avacopan is a weak CYP3A inhibitor. Concomitant use with avacopan can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Azelastine: (Major) Concomitant use of opioid agonists with azelastine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with azelastine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Azelastine; Fluticasone: (Major) Concomitant use of opioid agonists with azelastine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with azelastine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Azilsartan; Chlorthalidone: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Baclofen: (Major) Concomitant use of opioid agonists with baclofen may cause excessive sedation and somnolence. Limit the use of opioid pain medications with baclofen to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations.
Barbiturates: (Major) Concomitant use of meperidine with a barbiturate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a barbiturate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concurrent use of meperidine with a barbiturate may decrease meperidine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to opioid agonists. Monitor for signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of increased opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; meperidine is a CYP3A4 substrate.
Belladonna; Opium: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Belumosudil: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of belumosudil is necessary. If belumosudil is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A and belumosudil is a weak CYP3A inhibitor. Concomitant use with belumosudil can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Belzutifan: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal if coadministration with belzutifan is necessary. Consider increasing the dose of meperidine as needed. If belzutifan is discontinued, consider a dose reduction of meperidine and frequently monitor for signs of respiratory depression and sedation. Meperidine is a substrate of CYP3A; belzutifan is a weak CYP3A inducer. Concomitant use can decrease meperidine exposure resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Benazepril; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Benzhydrocodone; Acetaminophen: (Major) Concomitant use of opioid agonists with benzhydrocodone may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of benzhydrocodone with opioid agonists to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If benzhydrocodone is initiated in a patient taking meperidine, reduce initial dosage and titrate to clinical response. If meperidine is prescribed in a patient taking benzhydrocodone, use a lower initial dose of meperidine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. Careful monitoring, particularly during treatment initiation and dose adjustment, is recommended during coadministration of benzhydrocodone and meperidine because of the potential risk of serotonin syndrome. Discontinue benzhydrocodone if serotonin syndrome is suspected. Serotonin syndrome is characterized by rapid development of hyperthermia, hypertension, myoclonus, rigidity, autonomic instability, mental status changes (e.g., delirium or coma), and in rare cases, death. Serotonin syndrome, in its most severe form, can resemble neuroleptic malignant syndrome.
Benzoic Acid; Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate: (Contraindicated) Meperidine use in patients taking methylene blue or within 14 days of stopping such treatment is contraindicated due to the risk of serotonin syndrome or precipitation of other unpredictable, severe, and occasionally fatal reactions, possibly related to preexisting hyperphenylalaninemia. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Benzphetamine: (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.
Benztropine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Berotralstat: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of berotralstat is necessary. If berotralstat is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A4 and berotralstat is a moderate CYP3A4 inhibitor. Concomitant use with berotralstat can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Bethanechol: (Moderate) Bethanechol facilitates intestinal and bladder function via parasympathomimetic actions. Opiate agonists impair the peristaltic activity of the intestine. Thus, these drugs can antagonize the beneficial actions of bethanechol on GI motility.
Bismuth Subcitrate Potassium; Metronidazole; Tetracycline: (Moderate) Additive constipation may be seen with concurrent use of opiate agonists and antidiarrheals. Opioids increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Bismuth Subsalicylate: (Moderate) Additive constipation may be seen with concurrent use of opiate agonists and antidiarrheals. Opioids increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Bismuth Subsalicylate; Metronidazole; Tetracycline: (Moderate) Additive constipation may be seen with concurrent use of opiate agonists and antidiarrheals. Opioids increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Bisoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Brexanolone: (Moderate) Concomitant use of brexanolone with CNS depressants like the opiate agonists may increase the likelihood or severity of adverse reactions related to sedation and additive CNS depression. Monitor for excessive sedation, dizziness, and a potential for loss of consciousness during brexanolone use.
Brexpiprazole: (Major) Concomitant use of opioid agonists with brexpiprazole may cause excessive sedation and somnolence. Limit the use of opioid pain medications with brexpiprazole to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Brigatinib: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal if coadministration with brigatinib is necessary. Consider increasing the dose of meperidine as needed. If brigatinib is discontinued, consider a dose reduction of meperidine and frequently monitor for signs of respiratory depression and sedation. Meperidine is a substrate of CYP3A; brigatinib is a weak CYP3A inducer. Concomitant use can decrease meperidine exposure resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Brimonidine: (Moderate) Based on the sedative effects of brimonidine in individual patients, brimonidine administration has potential to enhance the CNS depressants effects of opiate agonists.
Brimonidine; Brinzolamide: (Moderate) Based on the sedative effects of brimonidine in individual patients, brimonidine administration has potential to enhance the CNS depressants effects of opiate agonists.
Brimonidine; Timolol: (Moderate) Based on the sedative effects of brimonidine in individual patients, brimonidine administration has potential to enhance the CNS depressants effects of opiate agonists.
Brompheniramine: (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with brompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Brompheniramine; Dextromethorphan; Phenylephrine: (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with brompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Brompheniramine; Phenylephrine: (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with brompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Brompheniramine; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with brompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Brompheniramine; Pseudoephedrine; Dextromethorphan: (Moderate) Concomitant use of opioid agonists with brompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with brompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Budesonide; Glycopyrrolate; Formoterol: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Bumetanide: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when loop diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Bupivacaine Liposomal: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Bupivacaine: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Bupivacaine; Epinephrine: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Bupivacaine; Lidocaine: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Bupivacaine; Meloxicam: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Buprenorphine: (Major) Buprenorphine is a mixed opiate agonist/antagonist with strong affinity for the mu-receptor that may partially block the effects of full mu-receptor opiate agonists and reduce analgesic effects. In some cases of acute pain, trauma, or during surgical management, opiate-dependent patients receiving buprenorphine maintenance therapy may require concurrent treatment with opiate agonists, such as meperidine. In these cases, health care professionals must exercise caution in opiate agonist dose selection, as higher doses of an opiate agonist may be required to compete with buprenorphine at the mu-receptor. Management strategies may include adding a short-acting opiate agonist to achieve analgesia in the presence of buprenorphine, discontinuation of buprenorphine and use of an opiate agonist to avoid withdrawal and achieve analgesia, or conversion of buprenorphine to methadone while using additional opiate agonists if needed. Closely monitor patients for CNS or respiratory depression. When buprenorphine is used for analgesia, avoid co-use with opiate agonists. Buprenorphine may cause withdrawal symptoms in patients receiving chronic opiate agonists as well as possibly potentiate CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Buprenorphine; Naloxone: (Major) Buprenorphine is a mixed opiate agonist/antagonist with strong affinity for the mu-receptor that may partially block the effects of full mu-receptor opiate agonists and reduce analgesic effects. In some cases of acute pain, trauma, or during surgical management, opiate-dependent patients receiving buprenorphine maintenance therapy may require concurrent treatment with opiate agonists, such as meperidine. In these cases, health care professionals must exercise caution in opiate agonist dose selection, as higher doses of an opiate agonist may be required to compete with buprenorphine at the mu-receptor. Management strategies may include adding a short-acting opiate agonist to achieve analgesia in the presence of buprenorphine, discontinuation of buprenorphine and use of an opiate agonist to avoid withdrawal and achieve analgesia, or conversion of buprenorphine to methadone while using additional opiate agonists if needed. Closely monitor patients for CNS or respiratory depression. When buprenorphine is used for analgesia, avoid co-use with opiate agonists. Buprenorphine may cause withdrawal symptoms in patients receiving chronic opiate agonists as well as possibly potentiate CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Bupropion: (Moderate) Excessive use of opioid agonists (e.g., opiate addiction) is associated with an increased seizure risk; seizures may be more likely to occur during concurrent use of bupropion in these patients since bupropion is associated with a dose-related risk of seizures.
Bupropion; Naltrexone: (Major) When naltrexone is used as adjuvant treatment of opiate or alcohol dependence, use is contraindicated in patients currently receiving opiate agonists. Naltrexone will antagonize the therapeutic benefits of opiate agonists and will induce a withdrawal reaction in patients with physical dependence to opioids. Also, patients should be opiate-free for at least 7-10 days prior to initiating naltrexone therapy. If there is any question of opioid use in the past 7-10 days and the patient is not experiencing opioid withdrawal symptoms and/or the urine is negative for opioids, a naloxone challenge test needs to be performed. If a patient receives naltrexone, and an opiate agonist is needed for an emergency situation, large doses of opiate agonists may ultimately overwhelm naltrexone antagonism of opiate receptors. Immediately following administration of exogenous opiate agonists, the opiate plasma concentration may be sufficient to overcome naltrexone competitive blockade, but the patient may experience deeper and more prolonged respiratory depression and thus, may be in danger of respiratory arrest and circulatory collapse. Non-receptor mediated actions like facial swelling, itching, generalized erythema, or bronchoconstriction may occur presumably due to histamine release. A rapidly acting opiate agonist is preferred as the duration of respiratory depression will be shorter. Patients receiving naltrexone may also experience opiate side effects with low doses of opiate agonists. If the opiate agonist is taken in such a way that high concentrations remain in the body beyond the time naltrexone exerts its therapeutic effects, serious side effects may occur. (Moderate) Excessive use of opioid agonists (e.g., opiate addiction) is associated with an increased seizure risk; seizures may be more likely to occur during concurrent use of bupropion in these patients since bupropion is associated with a dose-related risk of seizures.
Buspirone: (Moderate) Concomitant use of CNS depressants, such as buspirone, can potentiate the effects of meperidine, which may potentially lead to respiratory depression, CNS depression, sedation, or hypotensive responses. If concurrent use of codeine and buspirone is imperative, reduce the dose of one or both drugs.
Butabarbital: (Major) Concomitant use of meperidine with a barbiturate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a barbiturate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concurrent use of meperidine with a barbiturate may decrease meperidine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to opioid agonists. Monitor for signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of increased opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; meperidine is a CYP3A4 substrate.
Butalbital; Acetaminophen: (Major) Concomitant use of meperidine with a barbiturate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a barbiturate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concurrent use of meperidine with a barbiturate may decrease meperidine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to opioid agonists. Monitor for signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of increased opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; meperidine is a CYP3A4 substrate.
Butalbital; Acetaminophen; Caffeine: (Major) Concomitant use of meperidine with a barbiturate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a barbiturate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concurrent use of meperidine with a barbiturate may decrease meperidine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to opioid agonists. Monitor for signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of increased opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; meperidine is a CYP3A4 substrate.
Butalbital; Acetaminophen; Caffeine; Codeine: (Major) Concomitant use of meperidine with a barbiturate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a barbiturate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concurrent use of meperidine with a barbiturate may decrease meperidine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to opioid agonists. Monitor for signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of increased opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; meperidine is a CYP3A4 substrate.
Butalbital; Aspirin; Caffeine; Codeine: (Major) Concomitant use of meperidine with a barbiturate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a barbiturate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concurrent use of meperidine with a barbiturate may decrease meperidine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to opioid agonists. Monitor for signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of increased opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; meperidine is a CYP3A4 substrate.
Butorphanol: (Major) Avoid the concomitant use of butorphanol and opiate agonists, such as meperidine. Butorphanol is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects. Butorphanol may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of butorphanol with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Calcium, Magnesium, Potassium, Sodium Oxybates: (Major) Concomitant use of opioid agonists with sodium oxybate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medication with sodium oxybate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also 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.
Candesartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Cannabidiol: (Moderate) Concomitant use of opioid agonists with cannabidiol may cause excessive sedation and somnolence. Limit the use of opioid pain medications with cannabidiol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Capsaicin; Metaxalone: (Major) Concomitant use of opioid agonists with metaxalone may cause respiratory depression, profound sedation, and death. Limit the use of opioid pain medication with metaxalone to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose. Concomitant use of metaxalone and opioid agonists increases the risk for serotonin syndrome. Avoid concomitant use if possible and monitor for serotonin syndrome if use is necessary.
Captopril; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Carbinoxamine: (Moderate) Concomitant use of opioid agonists with carbinoxamine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with carbinoxamine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Cariprazine: (Moderate) Concomitant use of opioid agonists like meperidine with cariprazine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with cariprazine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Carisoprodol: (Major) Concomitant use of opioid agonists with carisoprodol may cause excessive sedation and somnolence. Limit the use of opioid pain medications with carisoprodol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations.
Celecoxib; Tramadol: (Major) Concomitant use of tramadol increases the seizure risk in patients taking opiate agonists. Also, tramadol can cause additive CNS depression and respiratory depression when used with opiate agonists; avoid concurrent use whenever possible. If used together, extreme caution is needed, and a reduced tramadol dose is recommended.
Cenobamate: (Moderate) Concomitant use of meperidine with cenobamate may cause excessive sedation and somnolence. Limit the use of meperidine with cenobamate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Cetirizine: (Major) Reserve concomitant use of opioids and cetirizine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Cetirizine; Pseudoephedrine: (Major) Reserve concomitant use of opioids and cetirizine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emerge

ncy treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Chlophedianol; Dexbrompheniramine: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlophedianol; Dexchlorpheniramine; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with dexchlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexchlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorcyclizine: (Moderate) Concomitant use of opioid agonists with chlorcyclizine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorcyclizine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlordiazepoxide: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Chlordiazepoxide; Amitriptyline: (Major) Concomitant use of meperidine with tricyclic antidepressants (TCAs) may cause excessive sedation and somnolence. Limit the use of opioid pain medications with TCAs to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome or signs of urinary retention or reduced gastric motility. 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. The concomitant use of anticholinergic drugs may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Chlordiazepoxide; Clidinium: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Chloroprocaine: (Minor) Due to the CNS depression potential of all local anesthetics, they should be used with caution with other agents that can cause respiratory depression, such as opiate agonists.
Chlorothiazide: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Chlorpheniramine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Codeine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Dextromethorphan: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Dextromethorphan; Phenylephrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Dihydrocodeine; Phenylephrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Hydrocodone: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression. (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Ibuprofen; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Phenylephrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpheniramine; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with chlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with chlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Chlorpromazine: (Major) Additive CNS depression or hypotensive effects are possible during concurrent use of phenothiazines and meperidine. In addition, an increased risk of seizures is possible due to phenothiazine-induced decreases in the seizure threshold, particularly during routine use. If meperidine is used with a phenothiazine, the meperidine dosage is recommended to be reduced by 25% to 50%. Further dose adjustments may be needed.
Chlorthalidone: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Chlorthalidone; Clonidine: (Major) Concomitant use of opioid agonists with clonidine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with clonidine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Chlorzoxazone: (Major) Concomitant use of opioid agonists with chlorzoxazone may cause excessive sedation and somnolence. Limit the use of opioid pain medications with chlorzoxazone to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations.
Cimetidine: (Minor) Excessive sedation and respiratory depression may occur if meperidine is used with cimetidine. When used in high doses (i.e., more than 600 mg/day), cimetidine has decreased the metabolism of certain opiate agonists leading to increased serum opiate concentrations and toxicity in some patients. In healthy subjects, cimetidine reduced the clearance and volume of distribution of meperidine.
Citalopram: (Moderate) If concomitant use of meperidine and citalopram 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.
Clemastine: (Moderate) Concomitant use of opioid agonists with clemastine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with clemastine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Clobazam: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Clomipramine: (Major) Concomitant use of meperidine with tricyclic antidepressants (TCAs) may cause excessive sedation and somnolence. Limit the use of opioid pain medications with TCAs to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome or signs of urinary retention or reduced gastric motility. 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. The concomitant use of anticholinergic drugs may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Clonazepam: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Clonidine: (Major) Concomitant use of opioid agonists with clonidine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with clonidine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Clopidogrel: (Moderate) Coadministration of opioid agonists, such as meperidine, delay and reduce the absorption of clopidogrel resulting in reduced exposure to active metabolites and diminished inhibition of platelet aggregation. Consider the use of a parenteral antiplatelet agent in acute coronary syndrome patients requiring an opioid agonist. Coadministration of intravenous morphine decreased the Cmax and AUC of clopidogrel's active metabolites by 34%. Time required for maximal inhibition of platelet aggregation (median 3 hours vs. 1.25 hours) was significantly delayed; times up to 5 hours were reported. Inhibition of platelet plug formation was delayed and residual platelet aggregation was significantly greater 1 to 4 hours after morphine administration.
Clorazepate: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Clozapine: (Moderate) Meperidine should be combined cautiously with clozapine due to the potential for additive depressant effects, respiratory depression, or hypotension. Combining clozapine with opiate agonists may also lead to reduced intestinal motility or bladder function.
COMT inhibitors: (Major) Concomitant use of opioid agonists with COMT inhibitors may cause excessive sedation and somnolence. Limit the use of opioid pain medications with COMT inhibitors to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression. COMT inhibitors have also been associated with sudden sleep onset during activities of daily living such as driving, which has resulted in accidents in some cases. Prescribers should re-assess patients for drowsiness or sleepiness regularly throughout treatment, especially since events may occur well after the start of treatment.
Conivaptan: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of conivaptan is necessary. If conivaptan is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A and conivaptan is a moderate CYP3A inhibitor. Concomitant use with conivaptan can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Crofelemer: (Moderate) Pharmacodynamic interactions between crofelemer and opiate agonists are theoretically possible. Crofelemer does not affect GI motility mechanisms, but does have antidiarrheal effects. Patients taking medications that decrease GI motility, such as opiate agonists, may be at greater risk for serious complications from crofelemer, such as constipation with chronic use. Use caution and monitor GI symptoms during coadministration.
Cyclizine: (Moderate) Concomitant use of opioid agonists with cyclizine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with cyclizine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Cyclobenzaprine: (Major) Concomitant use of opioid agonists with cyclobenzaprine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with cyclobenzaprine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also 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.
Cyproheptadine: (Moderate) Concomitant use of opioid agonists with cyproheptadine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with cyproheptadine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Dantrolene: (Major) Concomitant use of opioid agonists with dantrolene may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid agonists with dantrolene to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations.
Daridorexant: (Major) Concomitant use of opiate agonists with daridorexant may cause excessive sedation and somnolence. Limit the use of opiates with daridorexant to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression. Avoid prescribing cough medicines that contain opiates in patients taking daridorexant.
Darifenacin: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when darifenacin, an anticholinergic drug for overactive bladder, is used with opiate agonists. The concomitant use of these drugs together may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect. Both agents may also cause drowsiness or blurred vision, and patients should use care in driving or performing other hazardous tasks until the effects of the drugs are known.
Delavirdine: (Major) Due the potential for increased formation of neurotoxic metabolites, concurrent use of delavirdine and meperidine is not recommended. Delavirdine is a potent inhibitor of CYP3A4 and an inhibitor (in vitro) of CYP2D6, CYP2C9, and CYP2C19. Therefore, delavirdine may alter the response to various opiate agonists. Increased concentrations of the CYP substrates alfentanil, fentanyl, hydrocodone, morphine, sufentanil, and oxycodone may be noted.
Desflurane: (Moderate) Concurrent use with opiate agonists can decrease the minimum alveolar concentration (MAC) of desflurane needed to produce anesthesia.
Desipramine: (Major) Concomitant use of meperidine with tricyclic antidepressants (TCAs) may cause excessive sedation and somnolence. Limit the use of opioid pain medications with TCAs to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome or signs of urinary retention or reduced gastric motility. 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. The concomitant use of anticholinergic drugs may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Desmopressin: (Major) Additive hyponatremic effects may be seen in patients treated with desmopressin and drugs associated with water intoxication, hyponatremia, or SIADH including opiate agonists. Use combination with caution, and monitor patients for signs and symptoms of hyponatremia.
Deutetrabenazine: (Major) Concomitant use of opiate agonists with deutetrabenazine may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with deutetrabenazine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking deutetrabenazine, use a lower initial dose of the opiate and titrate to clinical response. If deutetrabenazine is prescribed for a patient taking an opiate agonist, use a lower initial dose of deutetrabenazine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Dexamethasone: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal if coadministration with dexamethasone is necessary. Consider increasing the dose of meperidine as needed. If dexamethasone is discontinued, consider a dose reduction of meperidine and frequently monitor for signs of respiratory depression and sedation. Meperidine is a substrate of CYP3A; dexamethasone is a weak CYP3A inducer. Concomitant use can decrease meperidine exposure resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Dexbrompheniramine: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Dexbrompheniramine; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with dexbrompheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexbrompheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Dexchlorpheniramine: (Moderate) Concomitant use of opioid agonists with dexchlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexchlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Dexchlorpheniramine; Dextromethorphan; Pseudoephedrine: (Moderate) Concomitant use of opioid agonists with dexchlorpheniramine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dexchlorpheniramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Dexmedetomidine: (Moderate) Concomitant use of opioid agonists with dexmedetomidine may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medication with dexmedetomidine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Dexmethylphenidate: (Moderate) If concomitant use of meperidine and methylphenidate derivatives 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.
Dextroamphetamine: (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.
Dextromethorphan; Bupropion: (Moderate) Excessive use of opioid agonists (e.g., opiate addiction) is associated with an increased seizure risk; seizures may be more likely to occur during concurrent use of bupropion in these patients since bupropion is associated with a dose-related risk of seizures.
Dextromethorphan; Diphenhydramine; Phenylephrine: (Major) Reserve concomitant use of opioids and diphenhydramine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Diazepam: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If parental diazepam is used with an opiate agonist, reduce the opiate agonist dosage by at least 1/3. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Dicyclomine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Difelikefalin: (Major) Avoid concomitant use of opioids and other CNS depressants, such as difelikefalin. Concomitant use can increase the risk of respiratory depression, hypotension, profound sedation, and death. If alternate treatment options are inadequate and coadministration is necessary, limit dosages and durations to the minimum required, monitor patients closely for respiratory depression and sedation, and consider prescribing naloxone for the emergency treatment of opioid overdose.
Dimenhydrinate: (Moderate) Concomitant use of opioid agonists with dimenhydrinate may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dimenhydrinate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Diphenhydramine: (Major) Reserve concomitant use of opioids and diphenhydramine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Diphenhydramine; Ibuprofen: (Major) Reserve concomitant use of opioids and diphenhydramine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Diphenhydramine; Naproxen: (Major) Reserve concomitant use of opioids and diphenhydramine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Diphenhydramine; Phenylephrine: (Major) Reserve concomitant use of opioids and diphenhydramine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Diphenoxylate; Atropine: (Moderate) Concurrent administration of diphenoxylate/difenoxin with other opiate agonists can potentiate the CNS-depressant effects of diphenoxylate/difenoxin. Use caution during coadministration. In addition, diphenoxylate/difenoxin use may cause constipation; cases of severe GI reactions including toxic megacolon and adynamic ileus have been reported. Reduced GI motility when combined with opiate agonists may increase the risk of serious GI related adverse events. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Dolasetron: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering meperidine with serotonin-receptor antagonists. The development of serotonin syndrome has been reported with 5-HT3 receptor antagonists, mostly when used in combination with other serotonergic medications. 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.
Doxepin: (Major) Concomitant use of meperidine with tricyclic antidepressants (TCAs) may cause excessive sedation and somnolence. Limit the use of opioid pain medications with TCAs to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome or signs of urinary retention or reduced gastric motility. 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. The concomitant use of anticholinergic drugs may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Doxylamine: (Major) Reserve concomitant use of opioids and doxylamine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Doxylamine; Pyridoxine: (Major) Reserve concomitant use of opioids and doxylamine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Dronabinol: (Moderate) Concomitant use of opioid agonists with dronabinol may cause excessive sedation and somnolence. Limit the use of opioid pain medication with dronabinol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Droperidol: (Major) Concomitant use of opioid agonists with droperidol may cause excessive sedation and somnolence. Limit the use of opioid pain medications with droperidol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Eluxadoline: (Major) Avoid use of eluxadoline with medications that may cause constipation, such as meperidine. Opioids increase the tone and decrease the propulsive contractions of the smooth muscle within the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect. Closely monitor for increased side effects if these drugs are administered together.
Enalapril; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Enzalutamide: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal if coadministration with enzalutamide is necessary. Consider increasing the dose of meperidine as needed. If enzalutamide is discontinued, consider a dose reduction of meperidine and frequently monitor for signs of respiratory depression and sedation. Meperidine is a substrate of CYP3A; enzalutamide is a strong CYP3A inducer. Concomitant use can decrease meperidine exposure resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Eprosartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Escitalopram: (Moderate) If concomitant use of meperidine and escitalopram 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.
Esketamine: (Major) Concomitant use of opioid agonists with esketamine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with esketamine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Patients who have received a dose of esketamine should be instructed not to drive or engage in other activities requiring complete mental alertness until the next day after a restful sleep. Educate patients about the risks and symptoms of excessive CNS depression.
Estazolam: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Eszopiclone: (Moderate) Concomitant use of opioid agonists with eszopiclone may cause excessive sedation, somnolence, and complex sleep-related behaviors (e.g., driving, talking, eating, or performing other activities while not fully awake). Limit the use of opioid pain medications with eszopiclone to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Instruct patients to contact their provider immediately if sleep-related symptoms or behaviors occur. Educate patients about the risks and symptoms of excessive CNS depression.
Ethacrynic Acid: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when loop diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Ethanol: (Major) Advise patients to avoid alcohol consumption while taking opioids. Alcohol consumption may result in additive CNS depression and may increase the risk for opioid overdose. Consider the patient's use of alcohol when prescribing opioid medications. If the patient is unlikely to be compliant with avoiding alcohol, consider prescribing naloxone especially if additional risk factors for opioid overdose are present.
Ethotoin: (Major) The coadministration of phenytoin, fosphenytoin, or ethotoin with meperidine may result in reduced analgesic efficacy of meperidine and increased meperidine/normeperidine related CNS adverse effects. Phenytoin may stimulate the metabolism of meperidine to its more toxic metabolite normeperidine. While the clinical relevance of this interaction is uncertain, concurrent use should be undertaken with care.
Etomidate: (Major) Concomitant use of meperidine with a general anesthetic may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a general anesthetic to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
Fenfluramine: (Moderate) Concomitant use of opioid agonists with fenfluramine may cause excessive sedation and somnolence. Limit the use of opioid agonists with fenfluramine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Also monitor patients for the emergence of serotonin syndrome. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Fesoterodine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when fesoterodine, an anticholinergic drug for overactive bladder is used with opiate agonists. The concomitant use of these drugs together may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect. Both agents may also cause drowsiness or blurred vision, and patients should use care in driving or performing other hazardous tasks until the effects of the drugs are known.
Flavoxate: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Flibanserin: (Moderate) Concomitant use of opioid agonists with flibanserin may cause excessive sedation and somnolence. Limit the use of opioid pain medication with flibanserin to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Fluoxetine: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of fluoxetine is necessary; if fluoxetine is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A4, and fluoxetine and its metabolite, norfluoxetine, are weak and moderate CYP3A4 inhibitors, respectively. Concomitant use with fluoxetine can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine. Also 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.
Fluphenazine: (Major) Phenothiazines can potentiate the CNS-depressant action of other drugs such as meperidine. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Flurazepam: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Fluvoxamine: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of fluvoxamine is necessary; if fluvoxamine is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A4, and fluvoxamine is a moderate CYP3A4 inhibitor. Concomitant use with fluvoxamine can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine. Also 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.
Food: (Major) Advise patients to avoid cannabis use while taking CNS depressants due to the risk for additive CNS depression and potential for other cognitive adverse reactions.
Fosamprenavir: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of fosamprenavir is necessary. If fosamprenavir is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A and fosamprenavir is a moderate CYP3A inhibitor. Concomitant use with fosamprenavir can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Fosinopril; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Fosphenytoin: (Major) The coadministration of phenytoin, fosphenytoin, or ethotoin with meperidine may result in reduced analgesic efficacy of meperidine and increased meperidine/normeperidine related CNS adverse effects. Phenytoin may stimulate the metabolism of meperidine to its more toxic metabolite normeperidine. While the clinical relevance of this interaction is uncertain, concurrent use should be undertaken with care.
Furosemide: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when loop diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Gabapentin: (Major) Concomitant use of opioid agonists with gabapentin may cause excessive sedation, somnolence, and respiratory depression. Limit the use of opioid pain medications with gabapentin to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, initiate gabapentin at the lowest recommended dose and monitor patients for symptoms of respiratory depression and sedation. Use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression and respiratory depression.
General anesthetics: (Major) Concomitant use of meperidine with a general anesthetic may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a general anesthetic to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
Glycerol Phenylbutyrate: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal if coadministration with glycerol phenylbutyrate is necessary. Consider increasing the dose of meperidine as needed. If glycerol phenylbutyrate is discontinued, consider a dose reduction of meperidine and frequently monitor for signs of respiratory depression and sedation. Meperidine is a substrate of CYP3A; glycerol phenylbutyrate is a weak CYP3A inducer. Concomitant use can decrease meperidine exposure resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Glycopyrrolate: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Glycopyrrolate; Formoterol: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Granisetron: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering meperidine with serotonin-receptor antagonists. The development of serotonin syndrome has been reported with 5-HT3 receptor antagonists, mostly when used in combination with other serotonergic medications. 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.
Guaifenesin; Hydrocodone: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression.
Guanfacine: (Moderate) Concomitant use of opioid agonists with guanfacine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with guanfacine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Haloperidol: (Moderate) Haloperidol can potentiate the actions of other CNS depressants such as opiate agonists. Dose reduction of one or both drugs is necessary.
Homatropine; Hydrocodone: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Hydantoins: (Major) The coadministration of phenytoin, fosphenytoin, or ethotoin with meperidine may result in reduced analgesic efficacy of meperidine and increased meperidine/normeperidine related CNS adverse effects. Phenytoin may stimulate the metabolism of meperidine to its more toxic metabolite normeperidine. While the clinical relevance of this interaction is uncertain, concurrent use should be undertaken with care.
Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Hydrochlorothiazide, HCTZ; Methyldopa: (Moderate) Concomitant use of opioid agonists with methyldopa may cause excessive sedation and somnolence. Limit the use of opioid pain medication with methyldopa to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Hydrochlorothiazi de, HCTZ; Moexipril: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Hydrocodone: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression.
Hydrocodone; Ibuprofen: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression.
Hydrocodone; Pseudoephedrine: (Major) Concomitant use of hydrocodone with other CNS depressants may lead to hypotension, profound sedation, coma, respiratory depression and death. Prior to concurrent use of hydrocodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Hydrocodone should be used in reduced dosages if used concurrently with a CNS depressant; initiate hydrocodone at 20 to 30% of the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression.
Hydromorphone: (Major) Concomitant use of hydromorphone with other central nervous system (CNS) depressants, such as other opiate agonists, can potentiate the effects of hydromorphone and may lead to additive CNS or respiratory depression, profound sedation, or coma. Prior to concurrent use of hydromorphone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. If hydromorphone is used concurrently with a CNS depressant, a reduced dosage of hydromorphone and/or the CNS depressant is recommended; start with one-third to one-half of the estimated hydromorphone starting dose when using hydromorphone extended-release tablets. Carefully monitor the patient for hypotension, CNS depression, and respiratory depression. Carbon dioxide retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids.
Hydroxyzine: (Major) Concomitant use of opioid agonists with hydroxyzine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with hydroxyzine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Hyoscyamine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Hyoscyamine; Methenamine; Methylene Blue; Phenyl Salicylate; Sodium Biphosphate: (Contraindicated) Meperidine use in patients taking methylene blue or within 14 days of stopping such treatment is contraindicated due to the risk of serotonin syndrome or precipitation of other unpredictable, severe, and occasionally fatal reactions, possibly related to preexisting hyperphenylalaninemia. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Ibuprofen; Oxycodone: (Major) Concomitant use of oxycodone with other opiate agonists may lead to additive respiratory and/or CNS depression. Hypotension, profound sedation, coma, respiratory depression, or death may occur. Prior to concurrent use of oxycodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. If a CNS depressant is used concurrently with oxycodone, a reduced dosage of oxycodone and/or the CNS depressant is recommended; use an initial dose of oxycodone at 1/3 to 1/2 the usual dosage. Monitor for sedation and respiratory depression.
Iloperidone: (Moderate) Concomitant use of iloperidone with other centrally-acting medications such as opiate agonists, may increase both the frequency and the intensity of adverse effects including drowsiness, sedation, and dizziness.
Imipramine: (Major) Concomitant use of meperidine with tricyclic antidepressants (TCAs) may cause excessive sedation and somnolence. Limit the use of opioid pain medications with TCAs to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome or signs of urinary retention or reduced gastric motility. 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. The concomitant use of anticholinergic drugs may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Indacaterol; Glycopyrrolate: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Indapamide: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when indapamide is administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Irbesartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Isoflurane: (Major) Concomitant use of meperidine with a general anesthetic may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a general anesthetic to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
Isoniazid, INH: (Major) Isoniazid, INH has been shown to have some non-selective MAO-inhibiting properties. Because meperidine possesses serotonergic properties and the combination of serotonergic agents and MAO-inhibitors has resulted in the development of serotonin syndrome, meperidine should be used cautiously in patients receiving isoniazid, INH.
Isoniazid, INH; Pyrazinamide, PZA; Rifampin: (Major) Isoniazid, INH has been shown to have some non-selective MAO-inhibiting properties. Because meperidine possesses serotonergic properties and the combination of serotonergic agents and MAO-inhibitors has resulted in the development of serotonin syndrome, meperidine should be used cautiously in patients receiving isoniazid, INH.
Isoniazid, INH; Rifampin: (Major) Isoniazid, INH has been shown to have some non-selective MAO-inhibiting properties. Because meperidine possesses serotonergic properties and the combination of serotonergic agents and MAO-inhibitors has resulted in the development of serotonin syndrome, meperidine should be used cautiously in patients receiving isoniazid, INH.
Ketamine: (Major) Concomitant use of meperidine with a general anesthetic may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a general anesthetic to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
Lasmiditan: (Moderate) Concomitant use of meperidine with lasmiditan may cause excessive sedation, somnolence, and serotonin syndrome. Limit the use of meperidine with lasmiditan to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression and serotonin syndrome.
Lemborexant: (Moderate) Concomitant use of meperidine with lemborexant may cause excessive sedation and somnolence. Limit the use of meperidine with lemborexant to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Lenacapavir: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of lenacapavir is necessary. If lenacapavir is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A and lenacapavir is a moderate CYP3A inhibitor. Concomitant use with lenacapavir can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Levocetirizine: (Major) Reserve concomitant use of opioids and cetirizine for patients in whom alternate treatment options are inadequate. Limit dosages and durations to the minimum required and monitor patients closely for respiratory depression and sedation. If concomitant use is necessary, consider prescribing naloxone for the emergency treatment of opioid overdose and monitor for signs of urinary retention or reduced gastric motility. Concomitant use can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death as well as urinary retention and/or severe constipation, which may lead to paralytic ileus.
Lidocaine: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Lidocaine; Epinephrine: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Lidocaine; Prilocaine: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Linezolid: (Contraindicated) Meperidine use in patients taking linezolid or within 14 days of stopping such treatment is contraindicated due to the risk of serotonin syndrome or precipitation of other unpredictable, severe, and occasionally fatal reactions, possibly related to preexisting hyperphenylalaninemia.
Lisdexamfetamine: (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.
Lisinopril; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Lithium: (Moderate) If concomitant use of meperidine and lithium 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.
Lofexidine: (Moderate) Monitor for excessive hypotension and sedation during coadministration of lofexidine and meperidine. Lofexidine can potentiate the effects of CNS depressants.
Lonafarnib: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of lonafarnib is necessary. If lonafarnib is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A4 and lonafarnib is a strong CYP3A4 inhibitor. Concomitant use with lonafarnib can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Loop diuretics: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when loop diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Lopinavir; Ritonavir: (Contraindicated) Concomitant use of high-dose, long-term meperidine therapy with ritonavir is not recommended due the increased concentration of the neurotoxic metabolite of meperidine, normeperidine. Ritonavir is associated with a 62% decrease in meperidine AUC thought to be due to increased meperidine metabolism. The AUC and Cmax of normeperidine, the toxic metabolite of meperidine, increased 47% and 87%, respectively, with concurrent administration of ritonavir.
Lorazepam: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Lorcaserin: (Moderate) If concomitant use of meperidine and lorcaserin 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.
Losartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Loxapine: (Moderate) Concomitant use of opioid agonists, such as meperidine, with loxapine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with loxapine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Lumateperone: (Moderate) Concomitant use of opioid agonists like meperidine with lumateperone may cause excessive sedation and somnolence. Limit the use of opioid pain medication with lumateperone to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Lurasidone: (Moderate) Concomitant use of opioid agonists like meperidine with lurasidone may cause excessive sedation and somnolence. Limit the use of opioid pain medication with lurasidone to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Maprotiline: (Major) Concomitant use of opioid agonists with maprotiline may cause excessive sedation and somnolence. Limit the use of opioid pain medications with maprotiline to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Maribavir: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of maribavir is necessary. If maribavir is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A and maribavir is a weak CYP3A inhibitor. Concomitant use with maribavir can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Mavacamten: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal if coadministration with mavacamten is necessary. Consider increasing the dose of meperidine as needed. If mavacamten is discontinued, consider a dose reduction of meperidine and frequently monitor for signs of respiratory depression and sedation. Meperidine is a substrate of CYP3A; mavacamten is a moderate CYP3A inducer. Concomitant use can decrease meperidine exposure resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Melatonin: (Moderate) Concomitant use of opioid agonists with melatonin may cause excessive sedation and somnolence. Limit the use of opioid pain medications with melatonin to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Mepivacaine: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Meprobamate: (Moderate) Concomitant use of meprobamate and meperidine can potentiate the effects of meperidine, which may potentially lead to respiratory depression, CNS depression, sedation, or hypotensive responses. If these drugs are used together, reduce the dose of one or both drugs.
Metaxalone: (Major) Concomitant use of opioid agonists with metaxalone may cause respiratory depression, profound sedation, and death. Limit the use of opioid pain medication with metaxalone to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Consider prescribing naloxone for the emergency treatment of opioid overdose. Concomitant use of metaxalone and opioid agonists increases the risk for serotonin syndrome. Avoid concomitant use if possible and monitor for serotonin syndrome if use is necessary.
Methadone: (Major) Concomitant use of methadone with another CNS depressant can lead to additive respiratory depression, hypotension, profound sedation, or coma. Prior to concurrent use of methadone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Methadone should be used with caution and in reduced dosages if used concurrently with a CNS depressant; also consider a using a lower dose of the CNS depressant. Monitor patients for sedation and respiratory depression.
Methamphetamine: (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.
Methenamine; Sodium Acid Phosphate; Methylene Blue; Hyoscyamine: (Contraindicated) Meperidine use in patients taking methylene blue or within 14 days of stopping such treatment is contraindicated due to the risk of serotonin syndrome or precipitation of other unpredictable, severe, and occasionally fatal reactions, possibly related to preexisting hyperphenylalaninemia. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Methocarbamol: (Major) Concomitant use of opioid agonists with methocarbamol may cause excessive sedation and somnolence. Limit the use of opioid pain medications with methocarbamol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations.
Methohexital: (Major) Concomitant use of meperidine with a barbiturate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a barbiturate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concurrent use of meperidine with a barbiturate may decrease meperidine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to opioid agonists. Monitor for signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of increased opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; meperidine is a CYP3A4 substrate.
Methscopolamine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Methyclothiazide: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Methyldopa: (Moderate) Concomitant use of opioid agonists with methyldopa may cause excessive sedation and somnolence. Limit the use of opioid pain medication with methyldopa to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Methylene Blue: (Contraindicated) Meperidine use in patients taking methylene blue or within 14 days of stopping such treatment is contraindicated due to the risk of serotonin syndrome or precipitation of other unpredictable, severe, and occasionally fatal reactions, possibly related to preexisting hyperphenylalaninemia.
Methylphenidate Derivatives: (Moderate) If concomitant use of meperidine and methylphenidate derivatives 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.
Methylphenidate: (Moderate) If concomitant use of meperidine and methylphenidate derivatives 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.
Metoclopramide: (Moderate) The effects of metoclopramide on gastrointestinal motility are antagonized by narcotic analgesics. Concomitant use of opioid agonists with metoclopramide may also cause excessive sedation and somnolence. Limit the use of opioid pain medications with metoclopramide to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Metolazone: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Metoprolol; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Metyrosine: (Moderate) The concomitant administration of metyrosine with opiate agonists can result in additive sedative effects.
Midazolam: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Midostaurin: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal if coadministration with midostaurin is necessary. Consider increasing the dose of meperidine as needed. If midostaurin is discontinued, consider a dose reduction of meperidine and frequently monitor for signs of respiratory depression and sedation. Meperidine is a substrate of CYP2B6; midostaurin is a weak CYP2B6 inducer. Concomitant use can decrease meperidine exposure resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Minocycline: (Minor) Injectable minocycline contains magnesium sulfate heptahydrate. Because of the CNS-depressant effects of magnesium sulfate, additive central-depressant effects can occur following concurrent administration with CNS depressants such as opiate agonists. Caution should be exercised when using these agents concurrently.
Mirtazapine: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering meperidine with mirtazapine. Limit the use of opiod pain medications with mirtazapine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Mitapivat: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal if coadministration with mitapivat is necessary; these effects may be more pronounced with mitapivat as it can induce multiple CYP enzymes. Consider increasing the dose of meperidine as needed. If mitapivat is discontinued, consider a dose reduction of meperidine and frequently monitor for signs of respiratory depression and sedation. Meperidine is a substrate of CYP3A and CYP2B6; mitapivat is a dual CYP3A and CYP2B6 inducer. Concomitant use can decrease meperidine exposure resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Mobocertinib: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal if coadministration with mobocertinib is necessary. Consider increasing the dose of meperidine as needed. If mobocertinib is discontinued, consider a dose reduction of meperidine and frequently monitor for signs of respiratory depression and sedation. Meperidine is a substrate of CYP3A; mobocertinib is a weak CYP3A inducer. Concomitant use can decrease meperidine exposure resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Molindone: (Moderate) Concomitant use of opioid agonists like meperidine with molindone may cause excessive sedation and somnolence. Limit the use of opioid pain medication with molindone to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Monoamine oxidase inhibitors: (Contraindicated) The use of meperidine is contraindicated in patients who have received a monoamine oxidase inhibitor (MAOI) within 14 days due to a risk for serotonin syndrome or opioid toxicity, including respiratory depression. The combination is also contraindicated due to serious effects that have been reported following a single dose of meperidine in patients receiving MAOI therapy including excitation, seizures, delirium, hyperpyrexia, circulatory collapse, coma, and death. If urgent use of an opioid is necessary, use test doses and frequent titration of small doses of alternate opioids to treat pain while closely monitoring blood pressure and signs and symptoms of CNS and respiratory depression.
Nabilone: (Major) Avoid coadministration of opioid agonists with nabilone due to the risk of additive CNS depression.
Nalbuphine: (Major) Avoid the concomitant use of nalbuphine and opiate agonists, such as meperidine. Nalbuphine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects. Nalbuphine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of nalbuphine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Naltrexone: (Major) When naltrexone is used as adjuvant treatment of opiate or alcohol dependence, use is contraindicated in patients currently receiving opiate agonists. Naltrexone will antagonize the therapeutic benefits of opiate agonists and will induce a withdrawal reaction in patients with physical dependence to opioids. Also, patients should be opiate-free for at least 7-10 days prior to initiating naltrexone therapy. If there is any question of opioid use in the past 7-10 days and the patient is not experiencing opioid withdrawal symptoms and/or the urine is negative for opioids, a naloxone challenge test needs to be performed. If a patient receives naltrexone, and an opiate agonist is needed for an emergency situation, large doses of opiate agonists may ultimately overwhelm naltrexone antagonism of opiate receptors. Immediately following administration of exogenous opiate agonists, the opiate plasma concentration may be sufficient to overcome naltrexone competitive blockade, but the patient may experience deeper and more prolonged respiratory depression and thus, may be in danger of respiratory arrest and circulatory collapse. Non-receptor mediated actions like facial swelling, itching, generalized erythema, or bronchoconstriction may occur presumably due to histamine release. A rapidly acting opiate agonist is preferred as the duration of respiratory depression will be shorter. Patients receiving naltrexone may also experience opiate side effects with low doses of opiate agonists. If the opiate agonist is taken in such a way that high concentrations remain in the body beyond the time naltrexone exerts its therapeutic effects, serious side effects may occur.
Nefazodone: (Major) Concomitant use of meperidine with nefazodone may cause excessive sedation and somnolence. Limit the use of meperidine with nefazodone to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Monitor patients closely for respiratory depression and sedation at frequent intervals and base subsequent doses on the patient's severity of pain and response to treatment if concomitant administration of meperidine and nefazodone is necessary; less frequent dosing of meperidine may be required. Concomitant use of meperidine and nefazodone may increase the plasma concentration of meperidine, resulting in increased or prolonged opioid effects. If nefazodone is discontinued, consider increasing the meperidine dose until stable drug effects are achieved and monitor for evidence of opioid withdrawal. Meperidine is a CYP3A4 substrate and nefazodone is a strong CYP3A4 inhibitor. Also 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.
Neostigmine; Glycopyrrolate: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Nesiritide, BNP: (Major) The potential for hypotension may be increased when coadministering nesiritide with opiate agonists.
Nevirapine: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal if coadministration with nevirapine is necessary. Consider increasing the dose of meperidine as needed. If nevirapine is discontinued, consider a dose reduction of meperidine and frequently monitor for signs of respiratory depression and sedation. Meperidine is a substrate of CYP3A; nevirapine is a weak CYP3A inducer. Concomitant use can decrease meperidine exposure resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Nirmatrelvir; Ritonavir: (Contraindicated) Concomitant use of high-dose, long-term meperidine therapy with ritonavir is not recommended due the increased concentration of the neurotoxic metabolite of meperidine, normeperidine. Ritonavir is associated with a 62% decrease in meperidine AUC thought to be due to increased meperidine metabolism. The AUC and Cmax of normeperidine, the toxic metabolite of meperidine, increased 47% and 87%, respectively, with concurrent administration of ritonavir. (Major) Consider withholding meperidine, if clinically appropriate, during receipt of ritonavir-boosted nirmatrelvir. If this is not feasible, consider using an alternative COVID-19 therapy or reducing the meperidine dose. Coadministration may increase meperidine exposure resulting in increased toxicity, including potentially fatal respiratory depression. Meperidine is a CYP3A substrate and nirmatrelvir is a CYP3A inhibitor.
Nitroglycerin: (Minor) Nitroglycerin can cause hypotension. This action may be additive with other agents that can cause hypotension such as opiate agonists. Patients should be monitored more closely for hypotension if nitroglycerin is used concurrently with opiate agonists.
Nortriptyline: (Major) Concomitant use of meperidine with tricyclic antidepressants (TCAs) may cause excessive sedation and somnolence. Limit the use of opioid pain medications with TCAs to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome or signs of urinary retention or reduced gastric motility. 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. The concomitant use of anticholinergic drugs may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Odevixibat: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal if coadministration with odevixibat is necessary. Consider increasing the dose of meperidine as needed. If odevixibat is discontinued, consider a dose reduction of meperidine and frequently monitor for signs of respiratory depression and sedation. Meperidine is a substrate of CYP3A; odevixibat is a weak CYP3A inducer. Concomitant use can decrease meperidine exposure resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Olanzapine: (Major) Concomitant use of opioid agonists with olanzapine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with olanzapine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also 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.
Olanzapine; Fluoxetine: (Major) Concomitant use of opioid agonists with olanzapine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with olanzapine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also 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. (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of fluoxetine is necessary; if fluoxetine is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A4, and fluoxetine and its metabolite, norfluoxetine, are weak and moderate CYP3A4 inhibitors, respectively. Concomitant use with fluoxetine can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine. Also 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.
Olanzapine; Samidorphan: (Contraindicated) Salmidorphan is contraindicated in patients who are using opiate agonists or undergoing acute opioid withdrawal. Salmidorphan increases the risk of precipitating acute opioid withdrawal in patients dependent on opioids. Before initiating salmidorphan, there should be at least a 7-day opioid-free interval from the last use of short-acting opioids, and at least a 14-day opioid-free interval from the last use of long-acting opioids. In emergency situations, if a salmidorphan-treated patient requires opiates for anesthesia or analgesia, discontinue salmidorphan. The opiate agonist should be administered by properly trained individual(s), and the patient properly monitored in a setting equipped and staffed for cardiopulmonary resuscitation. In non-emergency situations, if a salmidorphan-treated patient requires opiate agonist treatment (e.g., for analgesia) discontinue salmidorphan at least 5 days before opioid treatment. Salmidorphan, as an opioid antagonist, may cause opioid treatment to be less effective or ineffective shortly after salmidorphan discontinuation. (Major) Concomitant use of opioid agonists with olanzapine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with olanzapine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also 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.
Oliceridine: (Major) Concomitant use of oliceridine with meperidine may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of oliceridine with meperidine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also 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: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Olmesartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Olutasidenib: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal if coadministration with olutasidenib is necessary. Consider increasing the dose of meperidine as needed. If olutasidenib is discontinued, consider a dose reduction of meperidine and frequently monitor for signs of respiratory depression and sedation. Meperidine is a substrate of CYP3A; olutasidenib is a weak CYP3A inducer. Concomitant use can decrease meperidine exposure resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Omaveloxolone: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal if coadministration with omaveloxolone is necessary. Consider increasing the dose of meperidine as needed. If omaveloxolone is discontinued, consider a dose reduction of meperidine and frequently monitor for signs of respiratory depression and sedation. Meperidine is a substrate of CYP3A; omaveloxolone is a weak CYP3A inducer. Concomitant use can decrease meperidine exposure resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Ondansetron: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering meperidine with serotonin-receptor antagonists. The development of serotonin syndrome has been reported with 5-HT3 receptor antagonists, mostly when used in combination with other serotonergic medications. 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.
Orphenadrine: (Major) Concomitant use of opioid agonists with orphenadrine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with orphenadrine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations.
Oxazepam: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Oxybutynin: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Oxycodone: (Major) Concomitant use of oxycodone with other opiate agonists may lead to additive respiratory and/or CNS depression. Hypotension, profound sedation, coma, respiratory depression, or death may occur. Prior to concurrent use of oxycodone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. If a CNS depressant is used concurrently with oxycodone, a reduced dosage of oxycodone and/or the CNS depressant is recommended; use an initial dose of oxycodone at 1/3 to 1/2 the usual dosage. Monitor for sedation and respiratory depression.
Oxymorphone: (Major) Concomitant use of oxymorphone with other CNS depressants may produce additive CNS depressant effects. Respiratory depression, hypotension, profound sedation, or coma may result from combination therapy. Prior to concurrent use of oxymorphone in patients taking a CNS depressant, assess the level of tolerance to CNS depression that has developed, the duration of use, and the patient's overall response to treatment. Consider the patient's use of alcohol or illicit drugs. Oxymorphone should be used in reduced dosages if used concurrently with a CNS depressant; initiate oxymorphone at one-third to one-half the usual dosage in patients that are concurrently receiving another CNS depressant. Also consider a using a lower dose of the CNS depressant. Slowly titrate the dose as necessary for adequate pain relief and monitor for sedation or respiratory depression.
Ozanimod: (Contraindicated) Do not use meperidine in patients taking MAOIs or within 14 days of stopping them. An active metabolite of ozanimod inhibits MAO-B. MAO inhibitor interactions with meperidine may manifest as serotonin syndrome, hypertensive crisis, or opioid toxicity (e.g., respiratory depression, coma). Although a small number of patients treated with ozanimod were concomitantly exposed to opioids, this exposure was not adequate to rule out the possibility of an adverse reaction from coadministration.
Pacritinib: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of pacritinib is necessary. If pacritinib is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A and pacritinib is a weak CYP3A inhibitor. Concomitant use with pacritinib can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Paliperidone: (Moderate) Drugs that can cause CNS depression such as opiate agonists, if used concomitantly with paliperidone, can increase both the frequency and the intensity of adverse effects such as drowsiness, sedation, and dizziness. Monitor for signs and symptoms of CNS depression during coadministration of paliperidone and meperidine and advise patients to avoid driving or engaging in other activities requiring mental alertness until they know how this combination affects them.
Palonosetron: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering meperidine with serotonin-receptor antagonists. The development of serotonin syndrome has been reported with 5-HT3 receptor antagonists, mostly when used in combination with other serotonergic medications. 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.
Paroxetine: (Moderate) If concomitant use of meperidine and paroxetine 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.
Pegvisomant: (Moderate) In clinical trials, patients taking opiate agonists often required higher serum pegvisomant concentrations to achieve appropriate IGF-I suppression compared with patients not receiving opiate agonists. The mechanism of this interaction is unknown.
Pentazocine: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as meperidine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of meperidine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Pentazocine; Naloxone: (Major) Avoid the concomitant use of pentazocine and opiate agonists, such as meperidine. Pentazocine is a mixed opiate agonist/antagonist that may block the effects of opiate agonists and reduce analgesic effects of meperidine. Pentazocine may cause withdrawal symptoms in patients receiving chronic opiate agonists. Concurrent use of pentazocine with other opiate agonists can cause additive CNS, respiratory, and hypotensive effects. The additive or antagonistic effects are dependent upon the dose of the opiate agonist used; antagonistic effects are more common at low to moderate doses of the opiate agonist.
Pentobarbital: (Major) Concomitant use of meperidine with a barbiturate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a barbiturate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concurrent use of meperidine with a barbiturate may decrease meperidine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to opioid agonists. Monitor for signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of increased opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; meperidine is a CYP3A4 substrate.
Perampanel: (Moderate) Concomitant use of opioid agonists with perampanel may cause excessive sedation and somnolence. Limit the use of opioid pain medications with perampanel to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Perphenazine: (Major) Phenothiazines can potentiate the CNS-depressant action of ot her drugs such as meperidine. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Perphenazine; Amitriptyline: (Major) Concomitant use of meperidine with tricyclic antidepressants (TCAs) may cause excessive sedation and somnolence. Limit the use of opioid pain medications with TCAs to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome or signs of urinary retention or reduced gastric motility. 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. The concomitant use of anticholinergic drugs may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. (Major) Phenothiazines can potentiate the CNS-depressant action of other drugs such as meperidine. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Phenobarbital: (Major) Concomitant use of meperidine with a barbiturate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a barbiturate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concurrent use of meperidine with a barbiturate may decrease meperidine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to opioid agonists. Monitor for signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of increased opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; meperidine is a CYP3A4 substrate.
Phenobarbital; Hyoscyamine; Atropine; Scopolamine: (Major) Concomitant use of meperidine with a barbiturate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a barbiturate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concurrent use of meperidine with a barbiturate may decrease meperidine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to opioid agonists. Monitor for signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of increased opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; meperidine is a CYP3A4 substrate. (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Phenytoin: (Major) The coadministration of phenytoin, fosphenytoin, or ethotoin with meperidine may result in reduced analgesic efficacy of meperidine and increased meperidine/normeperidine related CNS adverse effects. Phenytoin may stimulate the metabolism of meperidine to its more toxic metabolite normeperidine. While the clinical relevance of this interaction is uncertain, concurrent use should be undertaken with care.
Pimozide: (Moderate) Concomitant use of other central nervous system (CNS) depressants, such as pimozide, can potentiate the effects of meperidine and may lead to additive CNS or respiratory depression, hypotension, or profound sedation. If these agents are used together, a reduced initial dosage of meperidine is recommended. Carefully monitor the patient for hypotension, CNS depression, and respiratory depression. Carbon dioxide retention from opioid-induced respiratory depression can exacerbate the sedating effects of opioids.
Pirtobrutinib: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of pirtobrutinib is necessary. If pirtobrutinib is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A and pirtobrutinib is a weak CYP3A inhibitor. Concomitant use with pirtobrutinib can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Pramipexole: (Major) Concomitant use of opioid agonists with pramipexole may cause excessive sedation and somnolence. Limit the use of opioid pain medications with pramipexole to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression. Dopaminergic agents like pramipexole have also been associated with sudden sleep onset during activities of daily living such as driving, which has resulted in accidents in some cases. Prescribers should re-assess patients for drowsiness or sleepiness regularly throughout treatment, especially since events may occur well after the start of treatment.
Pramlintide: (Major) Pramlintide slows gastric emptying and the rate of nutrient delivery to the small intestine. Medications with the potential to slow GI motility, such as opiate agonists, should be used with caution, if at all, with pramlintide until more data are available from the manufacturer. Monitor blood glucose.
Prasugrel: (Moderate) Consider the use of a parenteral anti-platelet agent for patients with acute coronary syndrome who require concomitant opioid agonists. Coadministration of opioid agonists with prasugrel delays and reduces the absorption of prasugrel's active metabolite due to slowed gastric emptying.
Pregabalin: (Major) Concomitant use of opioid agonists with pregabalin may cause excessive sedation, somnolence, and respiratory depression. Limit the use of opioid pain medications with pregabalin to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, initiate pregabalin at the lowest recommended dose and monitor patients for symptoms of respiratory depression and sedation. Use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression and respiratory depression.
Prilocaine: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Prilocaine; Epinephrine: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Primidone: (Major) Concomitant use of meperidine with a barbiturate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a barbiturate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concurrent use of meperidine with a barbiturate may decrease meperidine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to opioid agonists. Monitor for signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of increased opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; meperidine is a CYP3A4 substrate.
Procarbazine: (Contraindicated) Meperidine is contraindicated in patients receiving or who have received procarbazine, a weak monoamine oxidase inhibitor (MAOI), in the preceding 2 to 3 weeks. Severe reactions, such as excitation; agitation; sweating; hyperthermia; rigidity; hypertension; severe respiratory depression; coma; and vasculatory collapse, possibly resulting in death, can occur. These reactions may stem from accumulation of serotonin; meperidine blocks the neuronal reuptake of serotonin.
Prochlorperazine: (Major) Phenothiazines can potentiate the CNS-depressant action of other drugs such as meperidine. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Propantheline: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Propofol: (Major) Concomitant use of meperidine with a general anesthetic may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a general anesthetic to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
Propranolol; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Protriptyline: (Major) Concomitant use of meperidine with tricyclic antidepressants (TCAs) may cause excessive sedation and somnolence. Limit the use of opioid pain medications with TCAs to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome or signs of urinary retention or reduced gastric motility. 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. The concomitant use of anticholinergic drugs may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Pseudoephedrine; Triprolidine: (Moderate) Concomitant use of opioid agonists with triprolidine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with triprolidine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Pyrilamine: (Moderate) Concomitant use of opioid agonists with pyrilamine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with pyrilamine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Quazepam: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Quetiapine: (Major) Concomitant use of opioid agonists with quetiapine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with quetiapine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also 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.
Quinapril; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Quinine: (Moderate) Quinine inhibits CYP2D6 and may theoretically increase concentrations of drugs metabolized by this enzyme, such as meperidine. Because large increases in serum concentrations of meperidine may be associated with severe adverse reactions, caution is recommended during coadministration with quinine.
Ramelteon: (Moderate) Concomitant use of opioid agonists with ramelteon may cause excessive sedation and somnolence. Limit the use of opioid pain medications with ramelteon to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Rasagiline: (Contraindicated) Meperidine use in patients taking rasagiline or within 14 days of stopping such treatment is contraindicated due to the risk of serotonin syndrome.
Remimazolam: (Major) Concomitant use of opioid agonists with remimazolam may cause respiratory depression, hypotension, profound sedation, and death. Titrate the dose of remimazolam to the desired clinical response and continuously monitor sedated patients for hypotension, airway obstruction, hypoventilation, apnea, and oxygen desaturation.
Risperidone: (Moderate) Due to the primary CNS effects of risperidone, caution should be used when risperidone is given in combination with other centrally acting medications including meperidine. Hypotension, respiratory and/or CNS depression can be additive if meperidine is used concomitantly with risperidone.
Ritlecitinib: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of ritlecitinib is necessary. If ritlecitinib is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A and ritlecitinib is a moderate CYP3A inhibitor. Concomitant use with ritlecitinib can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Ritonavir: (Contraindicated) Concomitant use of high-dose, long-term meperidine therapy with ritonavir is not recommended due the increased concentration of the neurotoxic metabolite of meperidine, normeperidine. Ritonavir is associated with a 62% decrease in meperidine AUC thought to be due to increased meperidine metabolism. The AUC and Cmax of normeperidine, the toxic metabolite of meperidine, increased 47% and 87%, respectively, with concurrent administration of ritonavir.
Ropinirole: (Major) Concomitant use of opioid agonists with ropinirole may cause excessive sedation and somnolence. Limit the use of opioid pain medication with ropinirole to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Dopaminergic agents have also been associated with sudden sleep onset during activities of daily living such as driving, which has resulted in accidents in some cases. Reassess patients for drowsiness or sleepiness regularly throughout treatment, especially since events may occur well after the start of treatment.
Ropivacaine: (Moderate) The use of these drugs together must be approached with caution. Although commonly used together for additive analgesic effects, the patient must be monitored for respiratory depression, hypotension, and excessive sedation due to additive effects on the CNS and blood pressure. In rare instances, serious morbidity and mortality has occurred. Limit the use of opiate pain medications with local anesthetics to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. The use of the local anesthetic will allow for the use a lower initial dose of the opiate and then the doses can be titrated to proper clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Rotigotine: (Major) Concomitant use of opioid agonists with rotigotine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with rotigotine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression. Dopaminergic agents like rotigotine have also been associated with sudden sleep onset during activities of daily living such as driving, which has resulted in accidents in some cases. Prescribers should re-assess patients for drowsiness or sleepiness regularly throughout treatment, especially since events may occur well after the start of treatment.
Safinamide: (Contraindicated) Concomitant use of safinamide with opioids is contraindicated due to the risk of serotonin syndrome. Allow at least 14 days between discontinuation of safinamide and initiation of treatment with opioids.
Scopolamine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Secobarbital: (Major) Concomitant use of meperidine with a barbiturate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a barbiturate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation. Additionally, concurrent use of meperidine with a barbiturate may decrease meperidine plasma concentrations, decrease opioid efficacy, and potentially lead to a withdrawal syndrome in those with physical dependence to opioid agonists. Monitor for signs of opioid withdrawal. Discontinuation of a barbiturate may increase the risk of increased opioid-related adverse reactions, such as fatal respiratory depression. Barbiturates induce CYP3A4; meperidine is a CYP3A4 substrate.
Selegiline: (Contraindicated) Coadministration of meperidine and selegiline is contraindicated due to a risk for serotonin syndrome. At least 14 days should elapse between discontinuation of selegiline and initiation of treatment with meperidine. After stopping treatment with meperidine, a time period equal to 4 to 5 half-lives of meperidine or any active metabolite should elapse before starting therapy with selegiline. Therapeutic doses of meperidine have occasionally precipitated unpredictable, severe, and occasionally fatal reactions in patients who have received MAO inhibiting agents within the past 14 days, and may increase the risk for serotonin syndrome or opioid toxicity, including respiratory depression. If urgent use of an opioid is necessary, use test doses and frequent titration of small doses of alternate opioids to treat pain while closely monitoring blood pressure and signs and symptoms of CNS and respiratory depression.
Serdexmethylphenidate; Dexmethylphenidate: (Moderate) If concomitant use of meperidine and methylphenidate derivatives 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.
Serotonin norepinephrine reuptake inhibitors: (Moderate) If concomitant use of meperidine and serotonin norepinephrine reuptake inhibitors 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.
Serotonin-Receptor Agonists: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering meperidine with serotonin-receptor 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 adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Serotonin-Receptor Antagonists: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering meperidine with serotonin-receptor antagonists. The development of serotonin syndrome has been reported with 5-HT3 receptor antagonists, mostly when used in combination with other serotonergic medications. 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.
Sertraline: (Moderate) If concomitant use of meperidine and sertraline 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.
Sevoflurane: (Major) Concomitant use of meperidine with a general anesthetic may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medications with a general anesthetic to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Educate patients about the risks and symptoms of respiratory depression and sedation.
Sodium Oxybate: (Major) Concomitant use of opioid agonists with sodium oxybate may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opioid pain medication with sodium oxybate to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also 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.
Sodium Phenylbutyrate; Taurursodiol: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal and/or increased toxicity if coadministration with taurursodiol is necessary. Consider adjusting the dose of meperidine as needed. Concomitant use may alter meperidine exposure. If taurursodiol is discontinued, frequently monitor for signs of respiratory depression and sedation or withdrawal syndrome. Meperidine is a substrate of CYP2B6 and CYP3A; taurursodiol is a weak CYP2B6 and CYP3A inducer and weak CYP2B6 inhibitor. The net effect on meperidine exposure is unknown.
Solifenacin: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug, such as solifenacin. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Sotorasib: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal if coadministration with sotorasib is necessary. Consider increasing the dose of meperidine as needed. If sotorasib is discontinued, consider a dose reduction of meperidine and frequently monitor for signs of respiratory depression and sedation. Meperidine is a substrate of CYP3A4; sotorasib is a moderate CYP3A4 inducer. Concomitant use can decrease meperidine exposure resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Sparsentan: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal if coadministration with sparsentan is necessary. Consider increasing the dose of meperidine as needed. If sparsentan is discontinued, consider a dose reduction of meperidine and frequently monitor for signs of respiratory depression and sedation. Meperidine is a substrate of CYP2B6; sparsentan is a weak CYP2B6 inducer. Concomitant use can decrease meperidine exposure resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence.
Spironolactone: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. If spironolactone is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A4 and spironolactone is a weak CYP3A4 inhibitor. Concomitant use with spironolactone can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Spironolactone; Hydrochlorothiazide, HCTZ: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of spironolactone is necessary. If spironolactone is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A4 and spironolactone is a weak CYP3A4 inhibitor. Concomitant use with spironolactone can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine. Additionally, monitor for decreased diuretic efficacy and additive orthostatic hypotension when spironolactone is administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
St. John's Wort, Hypericum perforatum: (Moderate) Monitor for reduced efficacy of meperidine and signs of opioid withdrawal if coadministration with St. John's Wort is necessary; these effects may be more pronounced with St. John's Wort as it can induce multiple CYP enzymes. Consider increasing the dose of meperidine as needed. If St. John's Wort is discontinued, consider a dose reduction of meperidine and frequently monitor for signs of respiratory depression and sedation. Meperidine is a substrate of CYP3A4 and CYP2B6; St. John's Wort is a CYP3A4 and CYP2B6 inducer. Concomitant use can decrease meperidine exposure resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence. Also 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.
Stiripentol: (Moderate) Concomitant use of opioid agonists with stiripentol may cause excessive sedation and somnolence. Limit the use of opioid pain medications with stiripentol to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Suvorexant: (Moderate) Concomitant use of opioid agonists with suvorexant may cause excessive sedation and somnolence. Limit the use of opioid pain medications with suvorexant to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Tapentadol: (Major) Concomitant use of tapentadol with meperidine may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of tapentadol with meperidine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also 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.
Tasimelteon: (Moderate) Concomitant use of opioid agonists with tasimelteon may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tasimelteon to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Tedizolid: (Contraindicated) Meperidine use in patients taking tedizolid or within 14 days of stopping such treatment is contraindicated due to the risk of serotonin syndrome or precipitation of other unpredictable, severe, and occasionally fatal reactions, possibly related to preexisting hyperphenylalaninemia.
Telmisartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Temazepam: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Terbinafine: (Moderate) In vitro studies have shown systemic terbinafine to inhibit hepatic isoenzyme CYP2D6, and thus may inhibit the clearance of drugs metabolized by this isoenzyme, such as meperidine.
Tetrabenazine: (Moderate) Additive effects are possible when tetrabenazine is combined with other drugs that cause CNS depression. Concurrent use of tetrabenazine and drugs that can cause CNS depression, such as opiate agonists, can increase both the frequency and the intensity of adverse effects such as drowsiness, sedation, dizziness, and orthostatic hypotension.
Tetracaine: (Major) Due to the central nervous system depression potential of local anesthetics, they should be used with caution with other agents that can cause respiratory depression, such as opiate agonists. Excitation or depression of the CNS may be the first manifestation of CNS toxicity. Restlessness, anxiety, tinnitus, dizziness, blurred vision, tremors, depression, or drowsiness may be early warning signs of CNS toxicity. After each local anesthetic injection, careful and constant monitoring of ventilation adequacy, cardiovascular vital signs, and the patient's state of consciousness is advised.
Thalidomide: (Major) Avoid coadministration of opioid agonists with thalidomide due to the risk of additive CNS depression.
Thiazide diuretics: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Thioridazine: (Major) Hypotension, respiratory and/or CNS depression may occur if meperidine is used concomitantly with CNS depressants, including thioridazine. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Thiothixene: (Moderate) Concomitant use of opioid agonists like meperidine with thiothixene may cause excessive sedation and somnolence. Limit the use of opioid pain medication with thiothixene to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Ticagrelor: (Moderate) Coadministration of opioid agonists, such as meperidine, may delay and reduce the absorption of ticagrelor resulting in reduced exposure and diminished inhibition of platelet aggregation. Consider the use of a parenteral antiplatelet agent in acute coronary syndrome patients requiring an opioid agonist. Mean ticagrelor exposure decreased up to 36% in ACS patients undergoing PCI when intravenous morphine was administered with a loading dose of ticagrelor; mean platelet aggregation was higher up to 3 hours post loading dose. Similar effects on ticagrelor exposure and platelet inhibition were observed when fentanyl was administered with a ticagrelor loading dose in ACS patients undergoing PCI. Although exposure to ticagrelor was decreased up to 25% in healthy adults administered intravenous morphine with a loading dose of ticagrelor, platelet inhibition was not delayed or decreased in this population.
Tipranavir: (Moderate) Coadministration of tipranavir with meperidine should be avoided when possible. Tipranavir increases the metabolism of meperidine resulting in decreased pain control but elevated concentrations of the neurotoxic metabolite, normeperidine. Meperidine dosage increase or long-term use is not recommended.
Tizanidine: (Major) Concomitant use of opioid agonists with tizanidine may cause excessive sedation and somnolence. Limit the use of opioid pain medications with tizanidine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations.
Tolterodine: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug, such as tolterodine. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Torsemide: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when loop diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Tramadol: (Major) Concomitant use of tramadol increases the seizure risk in patients taking opiate agonists. Also, tramadol can cause additive CNS depression and respiratory depression when used with opiate agonists; avoid concurrent use whenever possible. If used together, extreme caution is needed, and a reduced tramadol dose is recommended.
Tramadol; Acetaminophen: (Major) Concomitant use of tramadol increases the seizure risk in patients taking opiate agonists. Also, tramadol can cause additive CNS depression and respiratory depression when used with opiate agonists; avoid concurrent use whenever possible. If used together, extreme caution is needed, and a reduced tramadol dose is recommended.
Trazodone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering meperidine with trazodone. Limit the use of meperidine with trazodone to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Triamterene: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when triamterene is administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Triamterene; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone. (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when triamterene is administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Triazolam: (Major) Concomitant use of opiate agonists with benzodiazepines may cause respiratory depression, hypotension, profound sedation, and death. Limit the use of opiate pain medications with benzodiazepines to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. If an opiate agonist is initiated in a patient taking a benzodiazepine, use a lower initial dose of the opiate and titrate to clinical response. If a benzodiazepine is prescribed for an indication other than epilepsy in a patient taking an opiate agonist, use a lower initial dose of the benzodiazepine and titrate to clinical response. Educate patients about the risks and symptoms of respiratory depression and sedation.
Tricyclic antidepressants: (Major) Concomitant use of meperidine with tricyclic antidepressants (TCAs) may cause excessive sedation and somnolence. Limit the use of opioid pain medications with TCAs to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome or signs of urinary retention or reduced gastric motility. 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. The concomitant use of anticholinergic drugs may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Trifluoperazine: (Major) Phenothiazines can potentiate the CNS-depressant action of other drugs such as meperidine. Caution should be exercised during simultaneous use of these agents due to potential excessive CNS effects or additive hypotension.
Trihexyphenidyl: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when meperidine is used concomitantly with an anticholinergic drug. The concomitant use of meperidine and anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect.
Trimethobenzamide: (Moderate) The concurrent use of trimethobenzamide with other medications that cause CNS depression, like opiate agonists, may potentiate the effects of either trimethobenzamide or the opiate agonist.
Trimipramine: (Major) Concomitant use of meperidine with tricyclic antidepressants (TCAs) may cause excessive sedation and somnolence. Limit the use of opioid pain medications with TCAs to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, reduce initial dosage and titrate to clinical response; use the lowest effective doses and minimum treatment durations. Also monitor patients for the emergence of serotonin syndrome or signs of urinary retention or reduced gastric motility. 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. The concomitant use of anticholinergic drugs may increase the risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.
Triprolidine: (Moderate) Concomitant use of opioid agonists with triprolidine may cause excessive sedation and somnolence. Limit the use of opioid pain medication with triprolidine to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Trofinetide: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of trofinetide is necessary. If trofinetide is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A and trofinetide is a weak CYP3A inhibitor. Concomitant use with trofinetide can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Trospium: (Moderate) Monitor patients for signs of urinary retention or reduced gastric motility when trospium, an anticholinergic drug for overactive bladder, is used with opiate agonists. The concomitant use of these drugs together may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Opiates increase the tone and decrease the propulsive contractions of the smooth muscle of the gastrointestinal tract. Prolongation of the gastrointestinal transit time may be the mechanism of the constipating effect. Both agents may also cause drowsiness or blurred vision, and patients should use care in driving or performing other hazardous tasks until the effects of the drugs are known.
Valerian, Valeriana officinalis: (Moderate) Concomitant use of opioid agonists with valerian may cause excessive sedation and somnolence. Limit the use of opioid pain medication with valerian to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect.
Valproic Acid, Divalproex Sodium: (Moderate) Concomitant use of opioid agonists with valproic acid may cause excessive sedation and somnolence. Limit the use of opioid pain medications with valproic acid to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Educate patients about the risks and symptoms of excessive CNS depression.
Valsartan; Hydrochlorothiazide, HCTZ: (Moderate) Monitor for decreased diuretic efficacy and additive orthostatic hypotension when thiazide diuretics are administered with meperidine. Adjustments to diuretic therapy may be needed in some patients. The efficacy of diuretics may be reduced due to opioid-induced release of antidiuretic hormone.
Vigabatrin: (Moderate) Vigabatrin may cause somnolence and fatigue. Drugs that can cause CNS depression, if used concomitantly with vigabatrin, may increase both the frequency and the intensity of adverse effects such as drowsiness, sedation, and dizziness. Caution should be used when vigabatrin is given with opiate agonists.
Vilazodone: (Moderate) Because of the potential risk and severity of excessive sedation, somnolence, and serotonin syndrome, caution should be observed when administering meperidine with vilazodone. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Inform patients taking this combination of the possible increased risks and monitor for the emergence of excessive CNS depression and serotonin syndrome, particularly during treatment initiation and dose adjustment. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Viloxazine: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of viloxazine is necessary. If viloxazine is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A4 and viloxazine is a weak CYP3A4 inhibitor. Concomitant use with viloxazine can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Vonoprazan; Amoxicillin: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of vonoprazan is necessary. If vonoprazan is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A and vonoprazan is a weak CYP3A inhibitor. Concomitant use with vonoprazan can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Vonoprazan; Amoxicillin; Clarithromycin: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of vonoprazan is necessary. If vonoprazan is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A and vonoprazan is a weak CYP3A inhibitor. Concomitant use with vonoprazan can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Vortioxetine: (Moderate) Because of the potential risk and severity of serotonin syndrome, caution should be observed when administering meperidine with vortioxetine. 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.
Voxelotor: (Moderate) Consider a reduced dose of meperidine with frequent monitoring for respiratory depression and sedation if concurrent use of voxelotor is necessary. If voxelotor is discontinued, meperidine plasma concentrations can decrease resulting in reduced efficacy and potential withdrawal syndrome in a patient who has developed physical dependence to meperidine. Meperidine is a substrate of CYP3A and voxelotor is a moderate CYP3A inhibitor. Concomitant use with voxelotor can increase meperidine exposure resulting in increased or prolonged opioid effects including fatal respiratory depression, particularly when an inhibitor is added to a stable dose of meperidine.
Zaleplon: (Major) Concomitant use of opioid agonists with zaleplon may cause excessive sedation, somnolence, and complex sleep-related behaviors (e.g., driving, talking, eating, or performing other activities while not fully awake). Limit the use of opioid pain medications with zaleplon to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Instruct patients to contact their provider immediately if sleep-related symptoms or behaviors occur. Educate patients about the risks and symptoms of excessive CNS depression.
Ziconotide: (Moderate) Concurrent use of ziconotide and opiate agonists may result in an increased incidence of dizziness and confusion. Ziconotide neither interacts with opiate receptors nor potentiates opiate-induced respiratory depression. However, in animal models, ziconotide did potentiate gastrointestinal motility reduction by opioid agonists.
Ziprasidone: (Moderate) Because of the potential for additive sedation and CNS depression, caution should be observed when administering meperidine with ziprasidone. The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome. There are case reports of serotonin syndrome with use of ziprasidone postmarketing but causality is not established. Discontinue all serotonergic agents and initiate symptomatic treatment if serotonin syndrome occurs.
Zolpidem: (Major) Concomitant use of opioid agonists with zolpidem may cause excessive sedation, somnolence, and complex sleep-related behaviors (e.g., driving, talking, eating, or performing other activities while not fully awake). Limit the use of opioid pain medications with zolpidem to only patients for whom alternative treatment options are inadequate. If concurrent use is necessary, use the lowest effective doses and minimum treatment durations needed to achieve the desired clinical effect. Instruct patients to contact their provider immediately if sleep-related symptoms or behaviors occur. Educate patients about the risks and symptoms of excessive CNS depression. For Intermezzo brand of sublingual zolpidem tablets, reduce the dose to 1.75 mg/night.

Demerol/Meperidine Hydrochloride Intramuscular Inj Sol: 1mL, 25mg, 50mg, 75mg, 100mg
Demerol/Meperidine Hydrochloride Intravenous Inj Sol: 1mL, 10mg, 25mg, 50mg, 75mg, 100mg
Demerol/Meperidine Hydrochloride Oral Sol: 5mL, 50mg
Demerol/Meperidine Hydrochloride Subcutaneous Inj Sol: 1mL, 25mg, 50mg, 75mg, 100mg
Demerol/Meperidine Hydrochloride/Meperitab Oral Tab: 50mg, 100mg

Adults

150 mg/dose PO, IV, IM, or subcutaneously for pain; 100 mg/dose IM or subcutaneously for preoperative procedural sedation.

Geriatric

150 mg/dose PO, IV, IM, or subcutaneously for pain; 100 mg/dose IM or subcutaneously for preoperative procedural sedation.

Adolescents

1.8 mg/kg/dose (Max: 150 mg/dose) PO, IV, IM, or subcutaneously for pain; 2.2 mg/kg/dose (Max: 100 mg/dose) IM or subcutaneously for preoperative procedural sedation.

Children

1.8 mg/kg/dose (Max: 150 mg/dose) PO, IV, IM, or subcutaneously for pain; 2.2 mg/kg/dose (Max: 100 mg/dose) IM or subcutaneously for preoperative procedural sedation.

Infants

Safety and efficacy have not been established.

Neonates

Safety and efficacy have not been established.

Meperidine is a mu- and kappa-opiate receptor agonist that also has local anesthetic effects. Meperidine has more affinity for the kappa-receptor than morphine. Opiate receptors have been reclassified by an International Union of Pharmacology subcommittee as OP1 (delta), OP2 (kappa), and OP3 (mu). These receptors are coupled with G-protein (guanine-nucleotide-binding protein) receptors and function as modulators, both positive and negative, of synaptic transmission via G-proteins that activate effector proteins. Opioid-G-protein systems include adenylyl cyclase-cyclic adenosine monophosphate (cAMP) and phospholipase3 C (PLC)-inositol 1,4,5 triphosphate (Ins(1,4,5)P3)-Ca2).
 
Opiates do not alter the pain threshold of afferent nerve endings to noxious stimuli, nor do they affect the conductance of impulses along peripheral nerves. Analgesia is mediated through changes in the perception of pain at the spinal cord (mu2-, delta-, kappa-receptors) and higher levels in the CNS (mu1- and kappa3 receptors). There is no ceiling effect of analgesia for opiates. The emotional response to pain is also altered. Opiates close N-type voltage-operated calcium channels (kappa-receptor agonist) and open calcium-dependent inwardly rectifying potassium channels (mu and delta receptor agonist) resulting in hyperpolarization and reduced neuronal excitability. Binding of the opiate stimulates the exchange of guanosine triphosphate (GTP) for guanosine diphosphate (GDP) on the G-protein complex. Binding of GTP leads to a release of the G-protein subunit, which acts on the effector system. In this case of opioid-induced analgesia, the effector system is adenylate cyclase and cAMP located at the inner surface of the plasma membrane. Thus, opiates decrease intracellular cAMP by inhibiting adenylate cyclase that modulates the release of nociceptive neurotransmitters such as substance P, GABA, dopamine, acetylcholine and norepinephrine. Opiates also modulate the endocrine and immune systems. Opiates inhibit the release of vasopressin, somatostatin, insulin and glucagon.
 
The stimulatory effects of opiates are the result of 'disinhibition' as the release of inhibitory neurotransmitters such as GABA and acetylcholine is blocked. The exact mechanism how opioid agonists cause both inhibitory and stimulatory processes is not well understood. Possible mechanisms including differential susceptibility of the opioid receptor to desensitization or activation of more than one G-protein system or subunit (one excitatory and one inhibitory) by an opioid receptor.
 
Clinically, stimulation of mu-receptors produces analgesia, euphoria, respiratory depression, miosis, decreased gastrointestinal motility, and physical dependence. Kappa-receptor stimulation also produces analgesia, miosis, respiratory depression, as well as, dysphoria and some psychomimetic effects (i.e., disorientation and/or depersonalization). Meperidine's superiority over other opioid agonists in the treatment of post-operative shivering is probably related to its kappa-receptor activity. Miosis is produced by an excitatory action on the autonomic segment of the nucleus of the oculomotor nerve. Respiratory depression is caused by direct action of opiate agonists on respiratory centers in the brain stem. Opiate agonists increase smooth muscle tone in the antral portion of the stomach, the small intestine (especially the duodenum), the large intestine, and the sphincters. Opiate agonists also decrease secretions from the stomach, pancreas, and biliary tract. The combination of effects of opiate agonists on the GI tract results in constipation and delayed digestion. Urinary smooth muscle tone is also increased by opiate agonists. The tone of the bladder detrusor muscle, ureters, and vesical sphincter is increased, which sometimes causes urinary retention.
 
Several other clinical effects occur with opiate agonists including cough suppression, hypotension, and nausea/vomiting. The antitussive effects of opiate agonists are mediated through direct action on receptors in the cough center of the medulla. Cough suppression with meperidine occurs at doses necessary for analgesia. Hypotension is possibly due to an increase in histamine release and/or depression of the vasomotor center in the medulla. Intravenous meperidine results in more histamine release than equipotent doses of morphine, fentanyl or sufentanil. Induction of nausea and vomiting possibly occurs from direct stimulation of the vestibular system and/or the chemoreceptor trigger zone.

Meperidine is administered via the oral, intravenous, intramuscular, and subcutaneous routes. Protein binding is 65% to 75%, primarily to albumin and alpha-1-acid glycoprotein. Meperidine is distributed widely, crossing the placenta and distributing into breast milk. Meperidine is metabolized in the liver by hydrolysis to meperidinic acid followed by partial conjugation with glucuronic acid. Meperidine also undergoes N-demethylation to normeperidine, which then undergoes hydrolysis and partial conjugation. Normeperidine, an active metabolite of meperidine, is about half as potent as meperidine, but it has twice the CNS stimulation effects. Individuals with normal urine pH excrete about 30% as the active metabolite and about 5% as unchanged parent drug. Acidification of the urine greatly enhances excretion of both meperidine and normeperidine. The half-life of meperidine 2 to 5 hours. The half-life of normeperidine is 15 to 30 hours.
 
Affected cytochrome P450 isoenzymes and drug transporters: CYP3A4, CYP2B6
Meperidine is metabolized to normeperidine in liver by CYP3A4 and CYP2B6.

Oral Route

When administered orally, meperidine undergoes extensive first-pass metabolism. Oral bioavailability of meperidine is 50%. After oral administration the onset of analgesia is within 15 minutes and peak effects occur in 60 to 90 minutes.

Intravenous Route

When given intravenously, the onset of analgesia of meperidine is noted within 1 minute and the time to peak effects is 5 to 7 minutes. The duration of meperidine-induced analgesia is 2 to 4 hours but this decreases with chronic dosing.

Intramuscular Route

When given intramuscuarly, the onset of analgesia of meperidine occurs within 10 to 15 minutes and peak effects occur within 1 hour.

Subcutaneous Route

Following subcutaneous administration of meperidine, onset of analgesia occurs within 10 to 15 minutes and peak effects occur within 1 hour.

Pregnancy

Available data with meperidine use during pregnancy are insufficient to inform a drug-associated risk for major birth defects and miscarriage. Animal reproduction studies have not been conducted with meperidine. Neural tube defects have been reported in hamsters given a single dose of meperidine during organogenesis at doses 0.85 and 1.5 times the total human daily dose of 1,200 mg. Opioids cross the placenta. Meperidine is not recommended for use during and immediately before labor when other analgesic techniques are more appropriate. Opioids can prolong labor and obstetric delivery by temporarily reducing the strength, duration, and frequency of uterine contractions. This effect is not consistent and may be offset by an increased rate of cervical dilatation, which may shorten labor. Opioids cross the placenta and may produce respiratory depression and psycho-physiologic effects in the neonate. Monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression. An opioid antagonist (e.g., naloxone) should be available for reversal of opioid-induced respiratory depression in the neonate. Further, prolonged maternal use of opioids during pregnancy may result in neonatal opioid withdrawal syndrome (NOWS). Monitor the exposed neonate for withdrawal symptoms, including irritability, hyperactivity and abnormal sleep pattern, high-pitched cry, tremor, vomiting, diarrhea, and failure to gain weight, and manage accordingly. Onset, duration, and severity of opioid withdrawal may vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination by the newborn. Guidelines recommend early universal screening of pregnant patients for opioid use and opioid use disorder at the first prenatal visit. Obtain a thorough history of substance use and review the Prescription Drug Monitoring Program to determine if patients have received prior prescriptions for opioids or other high-risk drugs such as benzodiazepines. Discuss the risks and benefits of opioid use during pregnancy, including the risk of becoming physiologically dependent on opioids, the possibility for NOWS, and how long-term opioid use may affect care during a future pregnancy.[64838] [64909] In women undergoing uncomplicated normal spontaneous vaginal birth, consider opioid therapy only if expected benefits for both pain and function are anticipated to outweigh risks to the patient. If opioids are used, use in combination with nonpharmacologic therapy and nonopioid pharmacologic therapy, as appropriate. Use immediate-release opioids instead of extended-release or long-acting opioids; order the lowest effective dosage and prescribe no greater quantity of opioids than needed for the expected duration of such pain severe enough to require opioids.[64909] For women using opioids for chronic pain, consider strategies to avoid or minimize the use of opioids, including alternative pain therapies (i.e., nonpharmacologic) and nonopioid pharmacologic treatments. Opioid agonist pharmacotherapy (e.g., methadone or buprenorphine) is preferable to medically supervised withdrawal in pregnant women with opioid use disorder.[64838]