Meperidine

12.1 Mechanism of Action Meperidine is an opioid agonist with multiple actions qualitatively similar to those of morphine; the most prominent of these involve the central nervous system and organs composed of smooth muscle. The principal actions of therapeutic value are analgesia and sedation.

1 INDICATIONS AND USAGE Meperidine Hydrochloride Tablets and Oral Solution are indicated for the management of acute pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate. Limitations of Use Because of the risks of addiction, abuse, misuse, overdose, and death, which can occur at any dosage or duration and persist over the course of therapy [see Warnings and Precautions ( 5.2 )], reserve opioid analgesics, including Meperidine Hydrochloride Tablets and Oral Solution, for use in patients for whom alternative treatment options are ineffective, not tolerated, or would be otherwise inadequate to provide sufficient management of pain. Meperidine Hydrochloride Tablets or Oral Solution should not be used for the treatment of chronic pain. Use of Meperidine Hydrochloride Tablets or Oral Solution for an extended period of time may increase the risk of toxicity (e.g. seizures) from the accumulation of the meperidine metabolite, normeperidine. Meperidine Hydrochloride Tablets and Oral Solution are opioid agonists indicated for the management of pain, severe enough to require an opioid analgesic and for which alternative treatments are inadequate. ( 1 ) Limitations of Use: • Because of the risks of addiction, abuse, misuse, overdose, and death, which can occur at any dosage or duration and persist over the course of therapy, reserve opioid analgesics, including Meperidine Hydrochloride Tablets and Oral Solution, for use in patients for whom alternative treatment options are ineffective, not tolerated, or would be otherwise inadequate to provide sufficient management of pain. ( 1 , 5.2 ) Meperidine Hydrochloride Tablets and Oral Solution should not be used for the treatment of chronic pain. Use of Meperidine Hydrochloride Tablets and Oral Solution for an extended period of time may increase the risk of toxicity (e.g., seizures) from the accumulation of the meperidine metabolite, normeperidine.

2 DOSAGE AND ADMINISTRATION • Meperidine Hydrochloride Tablets and Oral Solution should be prescribed only by healthcare professionals who are knowledgeable about the use of opioids and how to mitigate the associated risks. ( 2.1 ) • Use the lowest effective dosage for the shortest duration of time consistent with individual patient treatment goals. Reserve titration to higher doses of Meperidine Hydrochloride Tablets and Oral Solution for patients in whom lower doses are insufficiently effective and in whom the expected benefits of using a higher dose opioid clearly outweigh the substantial risks. ( 2.1 , 5 ) • Many acute pain conditions (e.g., the pain that occurs with a number of surgical procedures or acute musculoskeletal injuries) require no more than a few days of an opioid analgesic. Clinical guidelines on opioid prescribing for some acute pain conditions are available. ( 2.1 ) • Initiate the dosing regimen for each patient individually, taking into account the patient’s underlying cause and severity of pain, prior analgesic treatment and response, and risk factors for addiction, abuse, and misuse. ( 2.1 , 5.2 ) • Respiratory depression can occur at any time during opioid therapy, especially when initiating and following dosage increases with Meperidine Hydrochloride Tablets and Oral Solution. Consider this risk when selecting an initial dose and when making dose adjustments. ( 2.1 , 5.3 ) • Discuss opioid overdose reversal agents and options for acquiring them with the patient and/or caregiver, both when initiating and renewing treatment with Meperidine Hydrochloride Tablets and Oral Solution, especially if the patient has additional risk factors for overdose, or close contacts at risk for exposure and overdose. ( 2.2 , 5.2 , 5.3 , 5.4 ) • Adult Patients : Initiate treatment in adults with 50 mg to 150 mg orally, every 3 to 4 hours as needed for pain, at the lowest dose necessary to achieve adequate analgesia ( 2.3 ). Titrate the dose based upon the individual patient’s response to their initial dose of Meperidine Hydrochloride Tablets and Oral Solution. • Pediatric Patients : Initiate treatment in pediatric patients with 1.1 mg/kg to 1.8 mg/kg orally, up to the adult dose, every 3 to 4 hours as needed, at the lowest dose necessary to achieve adequate analgesia ( 2.3 ). Titrate the dose based upon the individual patient’s response to their initial dose of Meperidine Hydrochloride Tablets and Oral Solution. • Periodically reassess patients receiving Meperidine Hydrochloride Tablets or Oral Solution to evaluate the continued need for opioid analgesics to maintain pain control, for the signs or symptoms of adverse reactions, and for the development of addiction, abuse, or misuse . ( 2.5 ) • Do not rapidly reduce or abruptly discontinue Meperidine Hydrochloride Tablets and Oral Solution in a physically dependent patient because rapid reduction or abrupt discontinuation of opioid analgesics has resulted in serious withdrawal symptoms, uncontrolled pain, and suicide. ( 2.6 , 5.17 ) 2.1 Important Dosage and Administration Instructions Meperidine Hydrochloride Oral Solution Ensure accuracy when prescribing, dispensing, and administering Meperidine Hydrochloride Oral Solution to avoid dosing errors due to confusion between mg and mL, and with other meperidine solutions of different concentrations, which could result in accidental overdose and death. Ensure the proper dose is communicated and dispensed. When writing prescriptions, include both the total dose in mg and the total dose in volume. Instruct patients and caregivers on how to accurately measure and take or administer the correct dose of Meperidine Hydrochloride Oral Solution. Strongly advise patients and caregivers to always use a graduated oral syringe or measuring cup, with metric units of measurements (i.e., mL), to correctly measure the prescribed amount of medication. Inform patients and caregivers that oral dosing devices may be obtained from their pharmacy and to never use household teaspoons or tablespoons to measure Meperidine Hydrochloride Oral Solution. Meperidine Hydrochloride Tablets and Oral Solution Meperidine Hydrochloride Tablets and Oral Solution should be prescribed only by healthcare professionals who are knowledgeable about the use of opioids and how to mitigate the associated risks. Use the lowest effective dosage for the shortest duration of time consistent with individual patient treatment goals [see Warnings and Precautions ( 5 )]. Because the risk of overdose increases as opioid doses increase, reserve titration to higher doses of Meperidine Hydrochloride Tablets and Oral Solution for patients in whom lower doses are insufficiently effective and in whom the expected benefits of using a higher dose opioid clearly outweigh the substantial risks. Many acute pain conditions (e.g., the pain that occurs with a number of surgical procedures or acute musculoskeletal injuries) require no more than a few days of an opioid analgesic.

6 ADVERSE REACTIONS The following serious adverse reactions are described, or described in greater detail, in other sections: • Addiction, Abuse, and Misuse [see Warnings and Precautions ( 5.2 )] • Life-Threatening Respiratory Depression [see Warnings and Precautions ( 5.3 )] • Interactions with Benzodiazepines or Other CNS Depressants [see Warnings and Precautions ( 5.4 )] • Neonatal Opioid Withdrawal Syndrome [see Warnings and Precautions ( 5.5 )] • Opioid-Induced Hyperalgesia and Allodynia [see Warnings and Precautions ( 5.9 )] • Serotonin Syndrome [see Warnings and Precautions ( 5.10 )] • Adrenal Insufficiency [see Warnings and Precautions ( 5.12 )] • Severe Hypotension [see Warnings and Precautions ( 5.13 )] • Gastrointestinal Adverse Reactions [see Warnings and Precautions ( 5.15 )] • Seizures [see Warnings and Precautions ( 5.16 )] • Withdrawal [see Warnings and Precautions ( 5.17 )] The following adverse reactions associated with the use of meperidine were identified in clinical studies or postmarketing reports. Because some of these reactions were reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. The major hazards of meperidine, as with other opioid analgesics, are respiratory depression and, to a lesser degree, circulatory depression, respiratory arrest, shock, and cardiac arrest. The most frequently observed adverse reactions included lightheadedness, dizziness, sedation, nausea, vomiting, and sweating. These effects seem to be more prominent in ambulatory patients and in those who are not experiencing severe pain. In such individuals, lower doses are advisable. Some adverse reactions in ambulatory patients may be alleviated if the patient lies down. Other adverse reactions include: Nervous System: Mood changes (e.g., euphoria, dysphoria), weakness, headache, agitation, tremor, involuntary muscle movements (e.g., muscle twitches, myoclonus), severe convulsions, seizures , transient hallucinations and disorientation, confusion, delirium, visual disturbances. Gastrointestinal: Dry mouth, constipation, biliary tract spasm. Cardiovascular: Flushing of the face, tachycardia, bradycardia, palpitation, hypotension [see Warnings and Precautions ( 5.4 )], syncope. Genitourinary: Urinary retention. Allergic: Pruritus, urticaria, other skin rashes, wheal and flare over the vein with intravenous injection. Hypersensitivity reactions, anaphylaxis. Histamine release leading to hypotension and/or tachycardia, flushing, sweating, and pruritus. Serotonin Syndrome: Cases of serotonin syndrome, a potentially life-threatening condition, have been reported during concomitant use of opioids with serotonergic drugs. Adrenal Insufficiency: Cases of adrenal insufficiency have been reported with opioid use, more often following greater than one month of use. Androgen Deficiency: Cases of androgen deficiency have occurred with use of opioids for an extended period of time. Hyperalgesia and Allodynia: Cases of hyperalgesia and allodynia have been reported with opioid therapy of any duration [see Warnings and Precautions ( 5.9 )]. Hypoglycemia: Case of hypoglycemia have been reported in patients taking opioids. Most reports were in patients with at least one predisposing risk factor (e.g., diabetes). Opioid-induced esophageal dysfunction (OIED): Cases of OIED have been reported in patients taking opioids and may occur more frequently in patients taking higher doses of opioids, and/or in patients taking opioids longer term [see Warnings and Precautions ( 5.15 )]. Adverse Reactions from Observational Studies A prospective, observational cohort study estimated the risks of addiction, abuse, and misuse in patients initiating long-term use of Schedule II opioid analgesics between 2017 and 2021. Study participants included in one or more analyses had been enrolled in selected insurance plans or health systems for at least one year, were free of at least one outcome at baseline, completed a minimum number of follow-up assessments, and either: 1) filled multiple extended-release/long-acting opioid analgesic prescriptions during a 90-day period (n=978); or 2) filled any Schedule II opioid analgesic prescriptions covering at least 70 of 90 days (n=1,244). Those included also had no dispensing of the qualifying opioids in the previous 6 months. Over 12 months: • approximately 1% to 6% of participants across the two cohorts newly met criteria for addiction, as assessed with two validated interview-based measures of moderate-to-severe opioid use disorder based on Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) criteria, and • approximately 9% and 22% of participants across the two cohorts newly met criteria for prescription opioid abuse and misuse [defined in Drug Abuse and Dependence ( 9.2 )], respectively, as measured with a validated self-reported instrument. A retrospective, observat

7 DRUG INTERACTIONS Table 1 includes clinically significant drug interactions with meperidine. Table 1: Clinically Significant Drug Interactions with Meperidine Hydrochloride Tablets and Oral Solution Monoamine Oxidase Inhibitors (MAOIs) Clinical Impact: Meperidine is contraindicated in patients who are receiving monoamine oxidase inhibitors (MAOIs) or those who have recently received such agents. Therapeutic doses of meperidine have occasionally precipitated unpredictable, severe, and occasionally fatal reactions in patients who have received such agents within 14 days. The mechanism of these reactions is unclear, but may be related to a preexisting hyperphenylalaninemia. Some have been characterized by coma, severe respiratory depression, cyanosis, and hypotension, and have resembled the syndrome of acute narcotic overdose. Serotonin syndrome with agitation, hyperthermia, diarrhea, tachycardia, sweating, tremors and impaired consciousness may also occur. In other reactions the predominant manifestations have been hyperexcitability, convulsions, tachycardia, hyperpyrexia, and hypertension. Intervention: Do not use Meperidine Hydrochloride Tablets or Oral Solution in patients taking MAOIs or within 14 days of stopping such treatment. Intravenous hydrocortisone or prednisolone have been used to treat severe reactions, with the addition of intravenous chlorpromazine in those cases exhibiting hypertension and hyperpyrexia. The usefulness and safety of narcotic antagonists in the treatment of these reactions is unknown. Examples: Phenelzine, tranylcypromine, linezolid. Inhibitors of CYP3A4 and CYP2B6 Clinical Impact: The concomitant use of meperidine and CYP3A4 or CYP2B6 inhibitors can increase the plasma concentration of meperidine, resulting in increased or prolonged opioid effects. These effects could be more pronounced with concomitant use of meperidine and CYP2B6 and CYP3A4 inhibitors, particularly when an inhibitor is added after a stable dose of meperidine is achieved [see Warnings and Precautions ( 5.7 )]. After stopping a CYP3A4 or CYP2B6 inhibitor, as the effects of the inhibitor decline, the meperidine plasma concentration will decrease [see Clinical Pharmacology ( 12.3 )], resulting in decreased opioid efficacy or a withdrawal syndrome in patients who had developed physical dependence to meperidine. Intervention: If concomitant use is necessary, consider dosage reduction of Meperidine Hydrochloride Tablets or Oral Solution until stable drug effects are achieved. Evaluate patients at frequent intervals for respiratory depression and sedation. If a CYP3A4 or CYP2B6 inhibitor is discontinued, consider increasing the meperidine dosage until stable drug effects are achieved. Evaluate for signs of opioid withdrawal. Examples: Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconazole), protease inhibitors (e.g., ritonavir). CYP3A4 and CYP2B6 Inducers Clinical Impact: The concomitant use of meperidine and CYP3A4 or CYP2B6 inducers can decrease the plasma concentration of meperidine [see Clinical Pharmacology ( 12.3 )], resulting in decreased efficacy or onset of a withdrawal syndrome in patients who have developed physical dependence to meperidine [see Warnings and Precautions ( 5.7 )]. After stopping a CYP3A4 or CYP2B6 inducer, as the effects of the inducer decline, the meperidine plasma concentration will increase [see Clinical Pharmacology ( 12.3 )], which could increase or prolong both the therapeutic effects and adverse reactions, and may cause serious respiratory depression. Intervention: If concomitant use is necessary, consider increasing the Meperidine Hydrochloride Tablets or Oral Solution dosage until stable drug effects are achieved. Evaluate for signs of opioid withdrawal. If a CYP3A4 or CYP2B6 inducer is discontinued, consider meperidine dosage reduction and evaluate patients at frequent intervals for signs of respiratory depression and sedation. Examples: Rifampin, carbamazepine, phenytoin. Benzodiazepines and Other Central Nervous System (CNS) Depressants Clinical Impact: Due to additive pharmacologic effect, the concomitant use of benzodiazepines or other CNS depressants, including alcohol, can increase the risk of hypotension, respiratory depression, profound sedation, coma, and death. Intervention: Reserve concomitant prescribing of these drugs for use in patients for whom alternative treatment options are inadequate. Limit dosages and durations to the minimum required. Inform patients and caregivers of this potential interaction and educate them on the signs and symptoms of respiratory depression (including sedation). If concomitant use is warranted, consider recommending or prescribing an opioid overdose reversal agent [see Dosage and Administration ( 2.3 ), Warnings and Precautions ( 5.2 , 5.3 , 5.4 )]. Examples: Benzodiazepines and other sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, gabapentinoids