This site is intended for healthcare professionals
Abstract digital waveforms in blue and purple
  • Home
  • /
  • Drugs
  • /
  • D
  • /
  • DEMEROL
  • /
  • DEMEROL MEPERIDINE HYDROCHLORIDE 25 mg/mL Hospira, Inc.
FDA Drug information

DEMEROL

Read time: 1 mins
Marketing start date: 12 Jan 2025

Summary of product characteristics


Indications And Usage

1 INDICATIONS AND USAGE DEMEROL Injection is indicated for preoperative medication, support of anesthesia, and obstetrical analgesia. DEMEROL Injection is indicated for the management of pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate. DEMEROL Injection is indicated for preoperative medication, support of anesthesia, for obstetrical analgesia, and for the management of pain severe enough to require an opioid analgesic and for which alternative treatments are inadequate. ( 1 ) Limitations of Use ( 1 ) Because of the risks of addiction, abuse, and misuse with opioids, which can occur at any dosage or duration ( 5.1 ), reserve DEMEROL Injection for use in patients for whom alternative treatment options [e.g., non-opioid analgesics or opioid combination products]: • Have not been tolerated or are not expected to be tolerated, • Have not provided adequate analgesia or are not expected to provide adequate analgesia. DEMEROL Injection should not be used for an extended period of time unless the ‎pain remains severe enough to require an opioid analgesic and for which ‎alternative treatment options continue to be inadequate.‎ Use of ‎DEMEROL Injection for an extended period of time may increase the risk of ‎toxicity (e.g., seizures) from the accumulation of the meperidine metabolite, ‎normeperidine.‎ Limitations of Use: Because of the risks of addiction, abuse, and misuse with opioids, which can occur at any dosage or duration [see Warnings and Precautions (5.1) ] , reserve DEMEROL Injection for use in patients for whom alternative treatment options (e.g., non-opioid analgesics or opioid combination products): • Have not been tolerated or are not expected to be tolerated, • Have not provided adequate analgesia or are not expected to provide adequate analgesia. DEMEROL Injection should not be used for an extended period of time unless the ‎pain remains severe enough to require an opioid analgesic and for which ‎alternative treatment options continue to be inadequate.‎ Use of DEMEROL Injection for an extended period of time may increase the risk of toxicity (e.g ., seizures) from the accumulation of the meperidine metabolite, normeperidine.

Adverse Reactions

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 (5.1) ] • Life-Threatening Respiratory Depression [see Warnings and Precautions (5.2) ] • Interactions with Benzodiazepines or Other CNS Depressants [see Warnings and Precautions (5.3) ] • Neonatal Opioid Withdrawal Syndrome [see Warnings and Precautions (5.4) ] • Opioid-Induced Hyperalgesia and Allodynia [see Warnings and Precautions (5.7) ]‎ • Serotonin Syndrome with Concomitant Use of Serotonergic Drugs [see Warnings and Precautions (5.8) ] • Adrenal Insufficiency [see Warnings and Precautions (5.10) ] • Severe Hypotension [see Warnings and Precautions (5.11) ] • Gastrointestinal Adverse Reactions [see Warnings and Precautions (5.13) ] • Seizures [see Warnings and Precautions (5.14) ] • Withdrawal [see Warnings and Precautions (5.15) ] 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 have occurred. The most frequently observed adverse reactions include 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, transient hallucinations and disorientation, confusion, delirium, visual disturbances. Inadvertent injection about a nerve trunk may result in sensory-motor paralysis which is usually, though not always, transitory. Gastrointestinal: Dry mouth, constipation, biliary tract spasm. Cardiovascular: Flushing of the face, tachycardia, bradycardia, palpitation, hypotension [see Warnings and Precautions (5.18) ] , syncope, phlebitis following intravenous injection. 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. Other: Pain at injection site; local tissue irritation and induration following subcutaneous injection, particularly when repeated; antidiuretic effect. 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 [see Clinical Pharmacology (12.2) ] . Hyperalgesia and Allodynia : Cases of hyperalgesia and allodynia have been ‎reported with opioid therapy of any duration [see Warnings and Precautions ‎‎(5.7) ]‎ . Hypoglycemia : Cases of hypoglycemia have been reported in patients ‎taking opioids. Most reports were in patients with at least one ‎predisposing risk factor (e.g., diabetes).‎ Most common adverse reactions were lightheadedness, dizziness, sedation, nausea, vomiting and sweating. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Hospira, Inc. at 1-800-441-4100, or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch .

Contraindications

4 CONTRAINDICATIONS DEMEROL Injection is contraindicated in patients with: • Significant respiratory depression [see Warnings and Precautions (5.2) ] • Acute or severe bronchial asthma in an unmonitored setting or in the absence of resuscitative equipment [see Warnings and Precautions (5.9) ] • Concurrent use of monoamine oxidase inhibitors (MAOIs) or use of MAOIs within the last 14 days [see Warnings and Precautions (5.6) , Drug Interactions (7) ] • Known or suspected gastrointestinal obstruction, including paralytic ileus [see Warnings and Precautions (5.13) ] • Hypersensitivity to meperidine (e.g., anaphylaxis) [see Adverse Reactions (6) ] • Significant respiratory depression. ( 4 ) • Acute or severe bronchial asthma in an unmonitored setting or in absence of resuscitative equipment. ( 4 ) • Concurrent use of monoamine oxidase inhibitors (MAOIs) or use of MAOIs within the last 14 days. ( 7 ) • Known or suspected gastrointestinal obstruction, including paralytic ileus. ( 4 ) • Hypersensitivity to meperidine or to any other ingredients of the product. ( 4 )

Description

11 DESCRIPTION DEMEROL (meperidine hydrochloride injection) is an opioid agonist available as a sterile aqueous solution, for intramuscular, intravenous, or subcutaneous administration. It contains meperidine hydrochloride as the active pharmaceutical ingredient. Meperidine hydrochloride chemical name is 4‑Piperidinecarboxylic acid, 1‑methyl-4-phenyl-,ethyl ester, hydrochloride. The molecular weight is 283.79 g/mol. Its molecular formula is C 15 H 21 NO 2 ·HCl, and it has the following chemical structure. Meperidine hydrochloride is a white crystalline substance with a melting point of 186° C to 189° C, and it is readily soluble in water. DEMEROL (meperidine hydrochloride injection) is available as: Single-dose Carpuject cartridge with Luer Lock for the Carpuject Syringe System: 25 mg/mL, 50 mg/mL, 75 mg/mL, and 100 mg/mL. Each mL of Single-dose cartridge contains 25 mg, 50 mg, 75 mg or 100 mg of meperidine hydrochloride USP (equivalent to 21.79 mg, 43.58 mg, 65.36 mg or 87.15 mg of meperidine), respectively, and sodium hydroxide NF, and hydrochloric acid NF as pH adjusters, in water for injection. Only the 25 mg strength contains 3.8 mg of sodium chloride USP as isotonicity agent. Multiple-dose vials: 1,500 mg/30 mL (50 mg/mL) strength. Each mL of vial contains 50 mg of meperidine hydrochloride USP (equivalent to 43.58 mg of meperidine), 1 mg of meta-cresol USP, as a preservative, and sodium hydroxide NF, and hydrochloric acid NF as pH adjusters, in water for injection. Single-dose NexJect™ Prefilled Syringe with Luer Lock: 25 mg/mL and 50 mg/mL strengths. Each mL contains 25 mg or 50 mg of meperidine hydrochloride USP (equivalent to 21.79 mg or 43.58 mg of meperidine), respectively, and sodium hydroxide NF, and hydrochloric acid NF as pH adjusters, in water for injection. Only the 25 mg strength contains 3.8 mg of sodium chloride USP as isotonicity agent. The pH of DEMEROL (meperidine hydrochloride injection) solutions is between 3.5 and 6.0. DEMEROL (meperidine hydrochloride injection) 5 percent solution has a specific gravity of 1.0086 at 20°C, and the 10 percent solution has a specific gravity of 1.0165 at 20°C. Chemical Structure

Dosage And Administration

2 DOSAGE AND ADMINISTRATION • DEMEROL Injection 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 DEMEROL ‎Injection 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 DEMEROL Injection. Consider this risk ‎when selecting an initial dose and when making dose ‎adjustments. ( 2.2 , 5.3 )‎ • For Relief of Pain: Titrate the dose based upon the individual patient’s response to their ‎initial dose of DEMEROL Injection. ( 2.2 , 5 )‎ Adults: 50 mg to 150 mg intramuscularly or subcutaneously every 3 to 4 hours. ( 2.2 ) Children: 0.5 mg/lb to 0.8 mg/lb intramuscularly or subcutaneously up to the adult dose every 3 to 4 hours. ( 2.2 ) • Preoperative Medication: Adults: 50 mg to 100 mg intramuscularly or subcutaneously, 30 to 90 minutes before beginning anesthesia. ( 2.3 ) Children: 0.5 mg/lb to 1 mg/lb intramuscularly or subcutaneously up to the adult dose, 30 to 90 minutes before beginning anesthesia. ( 2.3 ) • Obstetrical Analgesia: 50 mg to 100 mg intramuscularly or subcutaneously; may be repeated at 1 to 3 hour intervals. ( 2.4 ) • Do not abruptly discontinue DEMEROL Injection in a physically‑dependent patient. ( 2.2 ) 2.1 Important Dosage and Administration Instructions • DEMEROL Injection 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 DEMEROL Injection 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. Clinical guidelines on opioid prescribing for some acute ‎pain conditions are available.‎ • There is variability in the opioid analgesic dose and duration needed to ‎adequately manage pain due both to the cause of pain and to individual patient ‎factors. ‎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 [see Warnings and Precautions (5.1) ] . • Respiratory depression can occur at any time during opioid therapy, especially ‎when initiating and following dosage increases with DEMEROL Injection.‎ Consider this risk when selecting an initial dose and when making dose ‎adjustments [see Warnings and Precautions (5) ] . • Inspect DEMEROL Injection for particulate matter and discoloration prior to administration. Do not use if color is darker than pale yellow, if it is discolored in any other way, or if it contains a ‎precipitate.‎ 2.2 For Management of Pain Initial Dosage Dosage should be adjusted according to the severity of the pain and the response of the patient. While subcutaneous administration is suitable for occasional use, intramuscular administration is preferred when repeated doses are required. If intravenous administration is required, dosage should be decreased and the injection made very slowly, preferably utilizing a diluted solution. Adults: Initiate treatment in a dosing range of 50 mg to 150 mg intramuscularly or subcutaneously every 3 to 4 hours as needed for pain , and at the lowest dose necessary to achieve adequate analgesia . Elderly patients should usually be given meperidine at the lower end of the dose range and observed closely. Children: Initiate treatment in a dosing range of 0.5 mg/lb to 0.8 mg/lb intramuscularly or subcutaneously up to the adult dose, every 3 to 4 hours as necessary , and at the lowest dose necessary to achieve adequate analgesia. Titration and Maintenance of Therapy Titrate the dose based upon the individual patient’s response to their initial dose of DEMEROL Injection. Individually titrate DEMEROL Injection to a dose that provides adequate analgesia and minimizes adverse reactions. Continually reevaluate patients receiving DEMEROL Injection to assess the maintenance of pain control , signs and symptoms of opioid withdrawal, and other adverse reactions, as well as to reassess for the development of addiction, abuse, or misuse [see Warnings and Precautions (5.1 , 5.15) ] . Frequent communication is important among the prescriber, other members of the health and care team, the patient, and the caregiver/family during periods of changing analgesic requirements, including initial titration. If the level of pain increases after dosage stabilization, attempt to identify the source of increased pain before increasing the DEMEROL Injection dosage. If after increasing the dosage, unacceptable opioid-related adverse reactions are observed (including an increase in pain after a dosage increase) , consider reducing the dosage [see Warnings and Precautions ‎‎(5) ] . Adjust the dosage to obtain an appropriate balance between management of pain and opioid-related adverse reactions. Discontinuation of DEMEROL Injection When a patient who has been taking DEMEROL Injection regularly and may be physically-dependent no longer requires therapy with DEMEROL Injection, taper the dose gradually, by 25% to 50% every 2 to 4 days, while monitoring carefully for signs and symptoms of withdrawal. If the patient develops these signs or symptoms, raise the dose to the previous level and taper more slowly, either by increasing the interval between decreases, decreasing the amount of change in dose, or both. Do not abruptly discontinue DEMEROL Injection in a physically-dependent patient [see Warnings and Precautions (5.15) , Drug Abuse and Dependence (9.3) ] . 2.3 For Preoperative Medication Adults: The usual dosage is 50 mg to 100 mg intramuscularly or subcutaneously, 30 to 90 minutes before the beginning of anesthesia. Elderly patients should usually be given meperidine at the lower end of the dose range and observed closely. Children: The usual dosage is 0.5 mg/lb to 1 mg/lb intramuscularly or subcutaneously up to the adult dose, 30 to 90 minutes before the beginning of anesthesia. 2.4 For Support of Anesthesia Repeated slow intravenous Injections of fractional doses (e.g., 10 mg/mL) or continuous intravenous infusion of a more dilute solution (e.g., 1 mg/mL) should be used. The dose should be titrated to the needs of the patient and will depend on the premedication and type of anesthesia being employed, the characteristics of the particular patient, and the nature and duration of the operative procedure. Elderly patients should usually be given meperidine at the lower end of the dose range and observed closely. 2.5 For Obstetrical Analgesia The usual dosage is 50 mg to 100 mg intramuscularly or subcutaneously when pain becomes regular, and may be repeated at 1- to 3-hour intervals. 2.6 Dosage Modifications with Concomitant Phenothiazines The dose of DEMEROL Injection should be proportionately reduced (usually by 25 to 50 percent) when administered concomitantly with phenothiazines and many other tranquilizers since they potentiate the action of DEMEROL Injection.

Abuse

9.2 Abuse DEMEROL Injection contains meperidine, a substance with high potential for misuse and abuse, which can lead to the development of substance use disorder, including addiction [see Warnings and Precautions (5.1) ]. Misuse is the intentional use, for therapeutic purposes, of a drug by an ‎individual in a way other than prescribed by a healthcare provider or for ‎whom it was not prescribed.‎ Abuse is the intentional, non-therapeutic use of a drug, even once, for its desirable psychological or physiological effects. Drug addiction is a cluster of behavioral, cognitive, and physiological phenomena that may include a strong desire to take the drug, difficulties in controlling ‎drug use (e.g., continuing drug use despite harmful consequences, giving ‎a higher priority to drug use than other activities and obligations), and ‎possible tolerance or physical dependence.‎ Misuse and abuse of DEMEROL Injection increases risk of overdose, ‎which may lead to central nervous system and respiratory depression, ‎hypotension, seizures, and death. The risk is increased with concurrent ‎abuse of DEMEROL Injection with alcohol and/or other CNS depressants. Abuse of and addiction to opioids in some ‎individuals may not be accompanied by concurrent tolerance and ‎symptoms of physical dependence. In addition, abuse of opioids can occur ‎in the absence of addiction.‎ All patients treated with opioids require careful and frequent reevaluation for signs of misuse, abuse and addiction, because use of opioid analgesic products carries the risk of addiction even under appropriate medical use. ‎Patients at high risk of DEMEROL Injection abuse include those with a ‎history of prolonged use of any opioid, including products containing meperidine, those with a history of drug or alcohol abuse, or those who use DEMEROL Injection in ‎combination with other abused drugs. “Drug-seeking” behavior is very common in persons with substance use disorders. Drug-seeking tactics include emergency calls or visits near the end of office hours, refusal to undergo appropriate examination, testing, or referral, repeated “loss” of prescriptions, tampering with prescriptions, and reluctance to provide prior medical records or contact information for other treating healthcare provider(s). “Doctor shopping” (visiting multiple prescribers to obtain additional prescriptions) is common among people who abuse drugs and people with substance use disorder. Preoccupation with achieving adequate pain relief can be appropriate behavior in a patient with inadequate pain control. DEMEROL Injection, like other opioids, can be diverted for nonmedical use into illicit channels of distribution. Careful record-keeping of prescribing information, including quantity, frequency, and renewal requests, as required by state and federal law, is strongly advised. Proper assessment of the patient, proper prescribing practices, periodic reevaluation of therapy, and proper dispensing and storage are appropriate measures that help to limit abuse of opioid drugs. Risks Specific to Abuse of DEMEROL Injection Abuse of DEMEROL Injection poses a risk of overdose and death. The risk is increased with concurrent abuse of DEMEROL Injection with alcohol and/or other CNS depressants. Parenteral drug abuse is commonly associated with transmission of infectious diseases such as hepatitis and HIV.

Controlled Substance

9.1 Controlled Substance DEMEROL Injection contains meperidine, a Schedule II controlled substance.

Dependence

9.3 Dependence Both tolerance and physical dependence can develop during use of opioid therapy. Tolerance is a physiological state characterized by a reduced response to a drug after repeated administration (i.e., a higher dose of a drug is required to produce the same effect that was once obtained at a lower dose). Physical dependence is a state that develops as a result of a physiological adaptation in response to repeated drug use, manifested by withdrawal signs and symptoms after abrupt discontinuation or a significant dose reduction of a drug. Withdrawal may be precipitated through the administration of drugs with opioid antagonist activity (e.g., naloxone), mixed agonist/antagonist analgesics (e.g., pentazocine, butorphanol, nalbuphine), or partial agonists (e.g., buprenorphine). Physical dependence may not occur to a clinically significant degree until after several days to weeks of continued use. DEMEROL Injection should not be abruptly discontinued in a physically-dependent patient [see Dosage and Administration (2.4) ] . If DEMEROL Injection is abruptly discontinued in a physically-dependent patient, a withdrawal syndrome may occur, typically characterized by restlessness, lacrimation, rhinorrhea, perspiration, chills, myalgia, and mydriasis. Other signs and symptoms also may develop, including irritability, anxiety, backache, joint pain, weakness, abdominal cramps, insomnia, nausea, anorexia, vomiting, diarrhea, or increased blood pressure, respiratory rate, or heart rate. Infants born to mothers physically-dependent on opioids will also be physically-dependent and may exhibit respiratory difficulties and withdrawal signs [see Use in Specific Populations (8.1) ] .

Drug Abuse And Dependence

9 DRUG ABUSE AND DEPENDENCE 9.1 Controlled Substance DEMEROL Injection contains meperidine, a Schedule II controlled substance. 9.2 Abuse DEMEROL Injection contains meperidine, a substance with high potential for misuse and abuse, which can lead to the development of substance use disorder, including addiction [see Warnings and Precautions (5.1) ]. Misuse is the intentional use, for therapeutic purposes, of a drug by an ‎individual in a way other than prescribed by a healthcare provider or for ‎whom it was not prescribed.‎ Abuse is the intentional, non-therapeutic use of a drug, even once, for its desirable psychological or physiological effects. Drug addiction is a cluster of behavioral, cognitive, and physiological phenomena that may include a strong desire to take the drug, difficulties in controlling ‎drug use (e.g., continuing drug use despite harmful consequences, giving ‎a higher priority to drug use than other activities and obligations), and ‎possible tolerance or physical dependence.‎ Misuse and abuse of DEMEROL Injection increases risk of overdose, ‎which may lead to central nervous system and respiratory depression, ‎hypotension, seizures, and death. The risk is increased with concurrent ‎abuse of DEMEROL Injection with alcohol and/or other CNS depressants. Abuse of and addiction to opioids in some ‎individuals may not be accompanied by concurrent tolerance and ‎symptoms of physical dependence. In addition, abuse of opioids can occur ‎in the absence of addiction.‎ All patients treated with opioids require careful and frequent reevaluation for signs of misuse, abuse and addiction, because use of opioid analgesic products carries the risk of addiction even under appropriate medical use. ‎Patients at high risk of DEMEROL Injection abuse include those with a ‎history of prolonged use of any opioid, including products containing meperidine, those with a history of drug or alcohol abuse, or those who use DEMEROL Injection in ‎combination with other abused drugs. “Drug-seeking” behavior is very common in persons with substance use disorders. Drug-seeking tactics include emergency calls or visits near the end of office hours, refusal to undergo appropriate examination, testing, or referral, repeated “loss” of prescriptions, tampering with prescriptions, and reluctance to provide prior medical records or contact information for other treating healthcare provider(s). “Doctor shopping” (visiting multiple prescribers to obtain additional prescriptions) is common among people who abuse drugs and people with substance use disorder. Preoccupation with achieving adequate pain relief can be appropriate behavior in a patient with inadequate pain control. DEMEROL Injection, like other opioids, can be diverted for nonmedical use into illicit channels of distribution. Careful record-keeping of prescribing information, including quantity, frequency, and renewal requests, as required by state and federal law, is strongly advised. Proper assessment of the patient, proper prescribing practices, periodic reevaluation of therapy, and proper dispensing and storage are appropriate measures that help to limit abuse of opioid drugs. Risks Specific to Abuse of DEMEROL Injection Abuse of DEMEROL Injection poses a risk of overdose and death. The risk is increased with concurrent abuse of DEMEROL Injection with alcohol and/or other CNS depressants. Parenteral drug abuse is commonly associated with transmission of infectious diseases such as hepatitis and HIV. 9.3 Dependence Both tolerance and physical dependence can develop during use of opioid therapy. Tolerance is a physiological state characterized by a reduced response to a drug after repeated administration (i.e., a higher dose of a drug is required to produce the same effect that was once obtained at a lower dose). Physical dependence is a state that develops as a result of a physiological adaptation in response to repeated drug use, manifested by withdrawal signs and symptoms after abrupt discontinuation or a significant dose reduction of a drug. Withdrawal may be precipitated through the administration of drugs with opioid antagonist activity (e.g., naloxone), mixed agonist/antagonist analgesics (e.g., pentazocine, butorphanol, nalbuphine), or partial agonists (e.g., buprenorphine). Physical dependence may not occur to a clinically significant degree until after several days to weeks of continued use. DEMEROL Injection should not be abruptly discontinued in a physically-dependent patient [see Dosage and Administration (2.4) ] . If DEMEROL Injection is abruptly discontinued in a physically-dependent patient, a withdrawal syndrome may occur, typically characterized by restlessness, lacrimation, rhinorrhea, perspiration, chills, myalgia, and mydriasis. Other signs and symptoms also may develop, including irritability, anxiety, backache, joint pain, weakness, abdominal cramps, insomnia, nausea, anorexia, vomiting, diarrhea, or increased blood pressure, respiratory rate, or heart rate. Infants born to mothers physically-dependent on opioids will also be physically-dependent and may exhibit respiratory difficulties and withdrawal signs [see Use in Specific Populations (8.1) ] .

Overdosage

10 OVERDOSAGE Clinical Presentation Acute overdose with meperidine can be manifested by respiratory depression, somnolence progressing to stupor or coma, skeletal muscle flaccidity, cold and clammy skin, constricted pupils, and, in some cases, pulmonary edema, bradycardia, hypotension, hypoglycemia, partial or complete airway obstruction, atypical snoring, and death. Marked mydriasis rather than miosis may be seen with hypoxia in overdose situations [see Clinical Pharmacology (12.2) ] . In severe overdose, particularly by the intravenous route, apnea, circulatory collapse, cardiac arrest, and death may occur. Accumulation of normeperidine as in chronic use or possibly following introduction of a concomitant CYP3A4 inducer presents as excitatory syndrome including hallucinations, tremors, muscle twitches, dilated pupils, hyperactive reflexes, and convulsions. Treatment of Overdose In case of overdose, priorities are the reestablishment of a patent and protected airway and institution of assisted or controlled ventilation, if needed. Employ other supportive measures (including oxygen and vasopressors) in the management of circulatory shock and pulmonary edema as indicated. Cardiac arrest or arrhythmias will require advanced life-support measures. Opioid antagonists, such as naloxone, are specific antidotes to respiratory depression resulting from opioid overdose. For clinically significant respiratory or circulatory depression secondary to meperidine overdose, administer an opioid antagonist. Because the duration of opioid reversal is expected to be less than the duration of action of meperidine in DEMEROL Injection, carefully monitor the patient until spontaneous respiration is reliably re-established. If the response to an opioid antagonist is suboptimal or only brief in nature, administer additional antagonist as directed by the product's prescribing information. In an individual physically dependent on opioids, administration of the recommended usual dosage of the antagonist will precipitate an acute withdrawal syndrome. The severity of the withdrawal symptoms experienced will depend on the degree of physical dependence and the dose of the antagonist administered. If a decision is made to treat serious respiratory depression in the physically-dependent patient, administration of the antagonist should be begun with care and by titration with smaller than usual doses of the antagonist.

Drug Interactions

7 DRUG INTERACTIONS Table 1 includes clinically significant drug interactions with DEMEROL Injection. Table 1: Clinically Significant Drug Interactions with DEMEROL Injection Monoamine Oxidase Inhibitors (MAOIs) Clinical Impact: Meperidine is contraindicated in patients who are receiving monoamine oxidase (MAO) inhibitors 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 [see Warnings and Precautions (5.6) ]‎ . Intervention: Do not use DEMEROL Injection 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 DEMEROL Injection 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 DEMEROL Injection and CYP2B6 and CYP3A4 inhibitors, particularly when an inhibitor is added after a stable dose of DEMEROL Injection is achieved [see Warnings and Precautions (5.5) ] . After stopping a CYP3A4 inhibitor, as the effects of the inhibitor decline, the meperidine plasma concentration will decrease [see Clinical Pharmacology (12.3) ] , potentially 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 DEMEROL Injection until stable drug effects are achieved. Monitor patients for respiratory depression and sedation at frequent intervals. If a CYP3A4 or CYP2B6 inhibitor is discontinued, consider increasing the DEMEROL Injection dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal. Examples: Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconizole), protease inhibitors (e.g., ritonavir) CYP3A4 and CYP2B6 Inducers Clinical Impact: The concomitant use of DEMEROL Injection and CYP3A4 inducers 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 (5.5) ] . 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 DEMEROL Injection dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal. If a CYP3A4 or CYP2B6 inducer is discontinued, consider DEMEROL Injection dosage reduction and monitor for signs of respiratory depression. 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 [see Warnings and Precautions (5.3) ] . 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. Monitor patients closely for signs of respiratory depression and sedation. Examples: Benzodiazepines and other sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, other opioids, alcohol. Serotonergic Drugs Clinical Impact: The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome [see Warnings and Precautions (5.8) ]. Intervention: If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment. Discontinue DEMEROL Injection if serotonin syndrome is suspected. Examples: Selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that affect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), certain muscle relaxants (i.e., cyclobenzaprine, metaxalone), monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue). Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics Clinical Impact: May reduce the analgesic effect of DEMEROL Injection and/or precipitate withdrawal symptoms. Intervention: Avoid concomitant use. Examples: Butorphanol, nalbuphine, pentazocine, buprenorphine. Muscle Relaxants Clinical Impact: Meperidine may enhance the neuromuscular blocking action of skeletal muscle relaxants and produce an increased degree of respiratory depression. Intervention: Monitor patients for signs of respiratory depression that may be greater than otherwise expected and decrease the dosage of DEMEROL Injection and/or the muscle relaxant as necessary. Diuretics Clinical Impact: Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone. Intervention: Monitor patients for signs of diminished diuresis and/or effects on blood pressure and increase the dosage of the diuretic as needed. Anticholinergic Drugs Clinical Impact: The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus. Intervention: Monitor patients for signs of urinary retention or reduced gastric motility when DEMEROL Injection is used concomitantly with anticholinergic drugs. Acyclovir Clinical Impact: The concomitant use of acyclovir may increase the plasma concentrations of meperidine and its metabolite, normeperidine. Intervention: If concomitant use of acyclovir and DEMEROL Injection is necessary, monitor patients for respiratory depression and sedation at frequent intervals. Cimetidine Clinical Impact: The concomitant use of cimetidine may reduce the clearance and volume of distribution of meperidine also the formation of the metabolite, normeperidine, in healthy subjects Intervention: If concomitant use cimetidine and DEMEROL Injection is necessary, monitor patients for respiratory depression and sedation at frequent intervals. Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics : Avoid use with DEMEROL Injection because they may reduce analgesic effect of DEMEROL Injection or precipitate withdrawal symptoms. ( 7 )

Drug Interactions Table

Table 1: Clinically Significant Drug Interactions with DEMEROL Injection

Monoamine Oxidase Inhibitors (MAOIs)

Clinical Impact:

Meperidine is contraindicated in patients who are receiving monoamine oxidase (MAO) inhibitors 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 [see Warnings and Precautions (5.6)]‎.

Intervention:

Do not use DEMEROL Injection 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 DEMEROL Injection 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 DEMEROL Injection and CYP2B6 and CYP3A4 inhibitors, particularly when an inhibitor is added after a stable dose of DEMEROL Injection is achieved [see Warnings and Precautions (5.5)].

After stopping a CYP3A4 inhibitor, as the effects of the inhibitor decline, the meperidine plasma concentration will decrease [see Clinical Pharmacology (12.3)], potentially 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 DEMEROL Injection until stable drug effects are achieved. Monitor patients for respiratory depression and sedation at frequent intervals.

If a CYP3A4 or CYP2B6 inhibitor is discontinued, consider increasing the DEMEROL Injection dosage until stable drug effects are achieved.

Monitor for signs of opioid withdrawal.

Examples:

Macrolide antibiotics (e.g., erythromycin), azole-antifungal agents (e.g., ketoconizole), protease inhibitors (e.g., ritonavir)

CYP3A4 and CYP2B6 Inducers

Clinical Impact:

The concomitant use of DEMEROL Injection and CYP3A4 inducers 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 (5.5)].

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 DEMEROL Injection dosage until stable drug effects are achieved. Monitor for signs of opioid withdrawal. If a CYP3A4 or CYP2B6 inducer is discontinued, consider DEMEROL Injection dosage reduction and monitor for signs of respiratory depression.

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 [see Warnings and Precautions (5.3)].

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. Monitor patients closely for signs of respiratory depression and sedation.

Examples:

Benzodiazepines and other sedatives/hypnotics, anxiolytics, tranquilizers, muscle relaxants, general anesthetics, antipsychotics, other opioids, alcohol.

Serotonergic Drugs

Clinical Impact:

The concomitant use of opioids with other drugs that affect the serotonergic neurotransmitter system has resulted in serotonin syndrome [see Warnings and Precautions (5.8)].

Intervention:

If concomitant use is warranted, carefully observe the patient, particularly during treatment initiation and dose adjustment. Discontinue DEMEROL Injection if serotonin syndrome is suspected.

Examples:

Selective serotonin reuptake inhibitors (SSRIs), serotonin and norepinephrine reuptake inhibitors (SNRIs), tricyclic antidepressants (TCAs), triptans, 5-HT3 receptor antagonists, drugs that affect the serotonin neurotransmitter system (e.g., mirtazapine, trazodone, tramadol), certain muscle relaxants (i.e., cyclobenzaprine, metaxalone), monoamine oxidase (MAO) inhibitors (those intended to treat psychiatric disorders and also others, such as linezolid and intravenous methylene blue).

Mixed Agonist/Antagonist and Partial Agonist Opioid Analgesics

Clinical Impact:

May reduce the analgesic effect of DEMEROL Injection and/or precipitate withdrawal symptoms.

Intervention:

Avoid concomitant use.

Examples:

Butorphanol, nalbuphine, pentazocine, buprenorphine.

Muscle Relaxants

Clinical Impact:

Meperidine may enhance the neuromuscular blocking action of skeletal muscle relaxants and produce an increased degree of respiratory depression.

Intervention:

Monitor patients for signs of respiratory depression that may be greater than otherwise expected and decrease the dosage of DEMEROL Injection and/or the muscle relaxant as necessary.

Diuretics

Clinical Impact:

Opioids can reduce the efficacy of diuretics by inducing the release of antidiuretic hormone.

Intervention:

Monitor patients for signs of diminished diuresis and/or effects on blood pressure and increase the dosage of the diuretic as needed.

Anticholinergic Drugs

Clinical Impact:

The concomitant use of anticholinergic drugs may increase risk of urinary retention and/or severe constipation, which may lead to paralytic ileus.

Intervention:

Monitor patients for signs of urinary retention or reduced gastric motility when DEMEROL Injection is used concomitantly with anticholinergic drugs.

Acyclovir

Clinical Impact:

The concomitant use of acyclovir may increase the plasma concentrations of meperidine and its metabolite, normeperidine.

Intervention:

If concomitant use of acyclovir and DEMEROL Injection is necessary, monitor patients for respiratory depression and sedation at frequent intervals.

Cimetidine

Clinical Impact:

The concomitant use of cimetidine may reduce the clearance and volume of distribution of meperidine also the formation of the metabolite, normeperidine, in healthy subjects

Intervention:

If concomitant use cimetidine and DEMEROL Injection is necessary, monitor patients for respiratory depression and sedation at frequent intervals.

Clinical Pharmacology

12 CLINICAL PHARMACOLOGY 12.1 Mechanism of Action Meperidine hydrochloride 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. 12.2 Pharmacodynamics Effects on the Central Nervous System Meperidine produces respiratory depression by direct action on brain stem respiratory centers. The respiratory depression involves a reduction in the responsiveness of the brain stem respiratory centers to both increases in carbon dioxide tension and electrical stimulation. Meperidine causes miosis, even in total darkness. Pinpoint pupils are a sign of opioid overdose but are not pathognomonic (e.g., pontine lesions of hemorrhagic or ischemic origins may produce similar findings). Marked mydriasis rather than miosis may be seen due to hypoxia in overdose situations. Effects on the Gastrointestinal Tract and Other Smooth Muscle Meperidine causes a reduction in motility associated with an increase in smooth muscle tone in the antrum of the stomach duodenum. Digestion of food in the small intestine is delayed and propulsive contractions are decreased. Propulsive peristaltic waves in the colon are decreased, while tone may be increased to the point of spasm, resulting in constipation. Other opioid-induced effects may include a reduction in biliary and pancreatic secretions, spasm of sphincter of Oddi, and transient elevations in serum amylase. Effects of the Cardiovascular System Meperidine produces peripheral vasodilation which may result in orthostatic hypotension or syncope. Manifestations of histamine release and/or peripheral vasodilation may include pruritus, flushing, red eyes, and sweating and/or orthostatic hypotension. Effects on the Endocrine System Opioids inhibit the secretion of adrenocorticotropic hormone (ACTH), cortisol, and luteinizing hormones (LH) in humans [see Adverse Reactions (6) ] . They also stimulate prolactin, growth hormone (GH) secretion, and pancreatic secretion of insulin and glucagon. Use of opioids for an extended period of time may influence the hypothalamic-pituitary-gonadal axis, leading to androgen deficiency that may manifest as low libido, impotence, erectile dysfunction, amenorrhea, or infertility. The causal role of opioids in the clinical syndrome of hypogonadism is unknown because the various medical, physical, lifestyle, and psychological stressors that may influence gonadal hormone levels have not been adequately controlled for in studies conducted to date [see Adverse Reactions (6) ] . Effects on the Immune System Opioids have been shown to have a variety of effects on components of the immune system in in vitro and animal models. The clinical significance of these findings is unknown. Overall, the effects of opioids appear to be modestly immunosuppressive. Concentration–Efficacy Relationships The minimum effective analgesic concentration will vary widely among patients, especially among patients who have been previously treated with opioid agonists. The minimum effective analgesic concentration of meperidine for any individual patient may increase over time due to an increase in pain, the development of a new pain syndrome and/or the development of analgesic tolerance [see Dosage and Administration (2.1 , 2.2) ] . Meperidine, in 60 mg to 80 mg parenteral doses, is approximately equivalent in analgesic effect to 10 mg of morphine. The onset of action is slightly more rapid than with morphine, and the duration of action is slightly shorter. Meperidine is significantly less effective by the oral than by the parenteral route, but the exact ratio of oral to parenteral effectiveness is unknown. Concentration–Adverse Reaction Relationships There is a relationship between increasing meperidine plasma concentration and increasing frequency of dose-related opioid adverse reactions such as nausea, vomiting, CNS effects, and respiratory depression. In opioid-tolerant patients, the situation may be altered by the development of tolerance to opioid-related adverse reactions [see Dosage and Administration (2.1 , 2.2) ] . 12.3 Pharmacokinetics Elimination The half-life of meperidine is 2 to 5 hours, and the half-life of normeperidine is 15 to 30 hours. Metabolism Meperidine is metabolized through biotransformation. In vitro data show meperidine is metabolized to normeperidine in liver mainly by CYP3A4 and CYP2B6. Excretion Meperidine and normeperidine are excreted by kidneys. Specific Population Hepatic Impairment The elimination half-life is 3 to 8 hours in healthy volunteers and is 1.3 to 2 times greater in post‑operative or cirrhotic patients. Age In clinical studies reported in the literature, changes in several pharmacokinetic parameters with increasing age have been observed. The initial volume of distribution and steady-state volume of distribution may be higher in elderly patients than in younger patients. The free fraction of meperidine in plasma may be higher in patients over 45 years of age than in younger patients. Drug Interactions Studies Phenytoin: The hepatic metabolism of meperidine may be enhanced by phenytoin. Concomitant administration resulted in reduced half-life and bioavailability with increased clearance of meperidine in healthy subjects; however, blood concentrations of normeperidine were increased [see Drug Interactions (7) ] . Ritonavir: Plasma concentrations of the active metabolite normeperidine may be increased by ritonavir [see Drug Interactions (7) ] . Acyclovir: Plasma concentrations of meperidine and its metabolite, normeperidine, may be increased by acyclovir [see Drug Interactions (7) ] . Cimetidine: Cimetidine reduced the clearance and volume of distribution of meperidine and also the formation of the metabolite, normeperidine, in healthy subjects [see Drug Interactions (7) ] .

Mechanism Of Action

12.1 Mechanism of Action Meperidine hydrochloride 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.

Pharmacodynamics

12.2 Pharmacodynamics Effects on the Central Nervous System Meperidine produces respiratory depression by direct action on brain stem respiratory centers. The respiratory depression involves a reduction in the responsiveness of the brain stem respiratory centers to both increases in carbon dioxide tension and electrical stimulation. Meperidine causes miosis, even in total darkness. Pinpoint pupils are a sign of opioid overdose but are not pathognomonic (e.g., pontine lesions of hemorrhagic or ischemic origins may produce similar findings). Marked mydriasis rather than miosis may be seen due to hypoxia in overdose situations. Effects on the Gastrointestinal Tract and Other Smooth Muscle Meperidine causes a reduction in motility associated with an increase in smooth muscle tone in the antrum of the stomach duodenum. Digestion of food in the small intestine is delayed and propulsive contractions are decreased. Propulsive peristaltic waves in the colon are decreased, while tone may be increased to the point of spasm, resulting in constipation. Other opioid-induced effects may include a reduction in biliary and pancreatic secretions, spasm of sphincter of Oddi, and transient elevations in serum amylase. Effects of the Cardiovascular System Meperidine produces peripheral vasodilation which may result in orthostatic hypotension or syncope. Manifestations of histamine release and/or peripheral vasodilation may include pruritus, flushing, red eyes, and sweating and/or orthostatic hypotension. Effects on the Endocrine System Opioids inhibit the secretion of adrenocorticotropic hormone (ACTH), cortisol, and luteinizing hormones (LH) in humans [see Adverse Reactions (6) ] . They also stimulate prolactin, growth hormone (GH) secretion, and pancreatic secretion of insulin and glucagon. Use of opioids for an extended period of time may influence the hypothalamic-pituitary-gonadal axis, leading to androgen deficiency that may manifest as low libido, impotence, erectile dysfunction, amenorrhea, or infertility. The causal role of opioids in the clinical syndrome of hypogonadism is unknown because the various medical, physical, lifestyle, and psychological stressors that may influence gonadal hormone levels have not been adequately controlled for in studies conducted to date [see Adverse Reactions (6) ] . Effects on the Immune System Opioids have been shown to have a variety of effects on components of the immune system in in vitro and animal models. The clinical significance of these findings is unknown. Overall, the effects of opioids appear to be modestly immunosuppressive. Concentration–Efficacy Relationships The minimum effective analgesic concentration will vary widely among patients, especially among patients who have been previously treated with opioid agonists. The minimum effective analgesic concentration of meperidine for any individual patient may increase over time due to an increase in pain, the development of a new pain syndrome and/or the development of analgesic tolerance [see Dosage and Administration (2.1 , 2.2) ] . Meperidine, in 60 mg to 80 mg parenteral doses, is approximately equivalent in analgesic effect to 10 mg of morphine. The onset of action is slightly more rapid than with morphine, and the duration of action is slightly shorter. Meperidine is significantly less effective by the oral than by the parenteral route, but the exact ratio of oral to parenteral effectiveness is unknown. Concentration–Adverse Reaction Relationships There is a relationship between increasing meperidine plasma concentration and increasing frequency of dose-related opioid adverse reactions such as nausea, vomiting, CNS effects, and respiratory depression. In opioid-tolerant patients, the situation may be altered by the development of tolerance to opioid-related adverse reactions [see Dosage and Administration (2.1 , 2.2) ] .

Pharmacokinetics

12.3 Pharmacokinetics Elimination The half-life of meperidine is 2 to 5 hours, and the half-life of normeperidine is 15 to 30 hours. Metabolism Meperidine is metabolized through biotransformation. In vitro data show meperidine is metabolized to normeperidine in liver mainly by CYP3A4 and CYP2B6. Excretion Meperidine and normeperidine are excreted by kidneys. Specific Population Hepatic Impairment The elimination half-life is 3 to 8 hours in healthy volunteers and is 1.3 to 2 times greater in post‑operative or cirrhotic patients. Age In clinical studies reported in the literature, changes in several pharmacokinetic parameters with increasing age have been observed. The initial volume of distribution and steady-state volume of distribution may be higher in elderly patients than in younger patients. The free fraction of meperidine in plasma may be higher in patients over 45 years of age than in younger patients. Drug Interactions Studies Phenytoin: The hepatic metabolism of meperidine may be enhanced by phenytoin. Concomitant administration resulted in reduced half-life and bioavailability with increased clearance of meperidine in healthy subjects; however, blood concentrations of normeperidine were increased [see Drug Interactions (7) ] . Ritonavir: Plasma concentrations of the active metabolite normeperidine may be increased by ritonavir [see Drug Interactions (7) ] . Acyclovir: Plasma concentrations of meperidine and its metabolite, normeperidine, may be increased by acyclovir [see Drug Interactions (7) ] . Cimetidine: Cimetidine reduced the clearance and volume of distribution of meperidine and also the formation of the metabolite, normeperidine, in healthy subjects [see Drug Interactions (7) ] .

Effective Time

20241004

Version

34

Dosage Forms And Strengths

3 DOSAGE FORMS AND STRENGTHS DEMEROL Injection is a clear, colorless, sterile aqueous solution, available in the following dosage forms and strengths: • Single-dose Carpuject‎™‎ cartridge with Luer Lock for the Carpuject Syringe System, ONLY to be used with Carpuject‎™‎ Holder, and available in the following strengths: 25 mg/mL, 50 mg/mL, 75 mg/mL, and 100 mg/mL. • Multiple-dose vials containing 0.1% metacresol as a preservative, available in the following strength: 1,500 mg/30 mL (50 mg/mL). • Single-dose NexJect TM Prefilled Syringe with Luer Lock, available in the following strengths: 25 mg/mL and 50 mg/mL. • Injectable, Carpuject™ Single-Dose cartridge with Luer Lock for the Carpuject Syringe System, to be used ONLY with Carpuject™ Holder: 25 mg/mL, 50 mg/mL, 75 mg/mL, and 100 mg/mL. ( 3 ) • Injectable, Multiple-dose vials: 1,500 mg/30 mL (50 mg/mL). ( 3 ) • Injectable, NexJect™ Single-dose Prefilled Syringe with Luer Lock: 25 mg/mL and 50 mg/mL. ( 3 )

Spl Product Data Elements

DEMEROL MEPERIDINE HYDROCHLORIDE MEPERIDINE HYDROCHLORIDE MEPERIDINE SODIUM HYDROXIDE HYDROCHLORIC ACID METACRESOL WATER DEMEROL MEPERIDINE HYDROCHLORIDE MEPERIDINE HYDROCHLORIDE MEPERIDINE SODIUM HYDROXIDE HYDROCHLORIC ACID SODIUM CHLORIDE WATER DEMEROL MEPERIDINE HYDROCHLORIDE MEPERIDINE HYDROCHLORIDE MEPERIDINE SODIUM HYDROXIDE HYDROCHLORIC ACID WATER DEMEROL MEPERIDINE HYDROCHLORIDE MEPERIDINE HYDROCHLORIDE MEPERIDINE SODIUM HYDROXIDE HYDROCHLORIC ACID WATER DEMEROL MEPERIDINE HYDROCHLORIDE MEPERIDINE HYDROCHLORIDE MEPERIDINE SODIUM HYDROXIDE HYDROCHLORIC ACID WATER DEMEROL MEPERIDINE HYDROCHLORIDE MEPERIDINE HYDROCHLORIDE MEPERIDINE SODIUM HYDROXIDE HYDROCHLORIC ACID SODIUM CHLORIDE WATER DEMEROL MEPERIDINE HYDROCHLORIDE MEPERIDINE HYDROCHLORIDE MEPERIDINE SODIUM HYDROXIDE HYDROCHLORIC ACID WATER

Carcinogenesis And Mutagenesis And Impairment Of Fertility

13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenesis Long-term studies in animals to evaluate the carcinogenic potential of meperidine have not been conducted. Mutagenesis Studies in animals to evaluate the mutagenic potential of meperidine have not been conducted. Impairment of Fertility Studies to determine the effect of meperidine on fertility have not been conducted.

Nonclinical Toxicology

13 NONCLINICAL TOXICOLOGY 13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility Carcinogenesis Long-term studies in animals to evaluate the carcinogenic potential of meperidine have not been conducted. Mutagenesis Studies in animals to evaluate the mutagenic potential of meperidine have not been conducted. Impairment of Fertility Studies to determine the effect of meperidine on fertility have not been conducted.

Application Number

NDA021171

Brand Name

DEMEROL

Generic Name

MEPERIDINE HYDROCHLORIDE

Product Ndc

0409-1362

Product Type

HUMAN PRESCRIPTION DRUG

Route

INTRAMUSCULAR,INTRAVENOUS,SUBCUTANEOUS

Package Label Principal Display Panel

PRINCIPAL DISPLAY PANEL - 25 mg/mL Cartridge Label 1 mL Single-dose Carpuject™ Sterile Cartridge Unit with Luer Lock Rx only NDC 0409-1176-03 Demerol™ meperidine HCl injection, USP 25 mg/mL CII Dist. by Hospira, Inc., Lake Forest, IL 60045 USA Hospira PAA198797 #####AA DMMMYYYY PRINCIPAL DISPLAY PANEL - 25 mg/mL Cartridge Label

Recent Major Changes

Boxed Warning 12/2023 Indications and Usage ( 1 ) 12/2023 Dosage and Administration ( 2.1 , 2.2 )‎ 12/2023 Warnings and Precautions ( 5.7 )‎ 12/2023

Recent Major Changes Table

Boxed Warning

12/2023

Indications and Usage (1)

12/2023

Dosage and Administration (2.1, 2.2)‎

12/2023

Warnings and Precautions (5.7)‎

12/2023

Spl Unclassified Section

Distributed by Hospira, Inc., Lake Forest, IL 60045 USA For Medical Information about DEMEROL Injection, please visit www.pfizermedinfo.com or call 1‑800‑438‑1985. LAB-0846-11.0 Logo

Information For Patients

17 PATIENT COUNSELING INFORMATION Addiction, Abuse, and Misuse Inform patients that the use of DEMEROL Injection, even when taken as recommended, can result in addiction, abuse, and misuse, which can lead to overdose and death [see Warnings and Precautions (5.1) ] . Instruct patients not to share DEMEROL Injection with others and to take steps to protect DEMEROL Injection from theft or misuse. Life-Threatening Respiratory Depression Inform patients of the risk of life-threatening respiratory depression, including information that the risk is greatest when DEMEROL Injection or when the dosage is increased, and that it can occur even at recommended dosages [see Warnings and Precautions (5.2) ] . Hyperalgesia and Allodynia Advise patients to inform their healthcare provider if they experience symptoms of hyperalgesia, including worsening pain, increased sensitivity to pain, or new pain [see Warnings and Precautions (5.7) , Adverse Reactions (6) ] . Serotonin Syndrome Inform patients that opioids could cause a rare but potentially life-threatening condition called serotonin syndrome resulting from concomitant administration of serotonergic drugs. Warn patients of the symptoms of serotonin syndrome and to seek medical attention right away if symptoms develop after discharge from the hospital. Instruct patients to inform their healthcare provider if they are taking, or plan to take serotonergic medications [see Warnings and Precautions (5.8) , Drug Interactions (7) ] . Constipation Advise patients of the potential for severe constipation, including management instructions and when to seek medical attention [see Adverse Reactions (6) , Clinical Pharmacology (12.1) ] .

Instructions For Use

INSTRUCTIONS FOR USE Parenteral drug products should be inspected visually for particulate matter and discoloration prior to ‎administration, whenever solution and container permit. Do not use if color is darker than pale yellow, if it ‎is discolored in any other way, or if it contains a precipitate. Instructions for use - Carpuject™ Single-dose Cartridge Carpuject™ Single-dose cartridges with Luer Lock are packaged in a Slim-Pak™ tamper detection package. Note that a needle is not included. Before use, read all instructions for using the Carpuject™ Syringe, which are contained in the product insert for‎ the reusable Carpuject™ Holder before use. Carpuject™ Single-dose cartridges are to be used ONLY with Carpuject™ Holders. NOTE: To prevent needlestick injuries, do not recap, purposely bend, or break by hand used ‎needles. Do not recap, purposely bend, or break by hand blunt Cannulas. Instructions for use - NexJect™ Single-dose Prefilled Syringe NOTE : To prevent needlestick injuries, do not recap, purposely bend, or break by hand used ‎needles. Do not recap, purposely bend, or break by ‎hand blunt Cannulas. Distributed by Hospira, Inc., Lake Forest, IL 60045 USA LAB-1387-2.0 Revised: 12/2023 Image Image Image Image

Geriatric Use

8.5 Geriatric Use Elderly patients (aged 65 years or older) may have increased sensitivity to meperidine. In general, use caution when selecting a dosage for an elderly patient, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function and of concomitant disease or other drug therapy. Respiratory depression is the chief risk for elderly patients treated with opioids, and has occurred after large initial doses were administered to patients who were not opioid-tolerant or when opioids were co-administered with other agents that depress respiration. Titrate the dosage of DEMEROL Injection slowly in geriatric patients and monitor closely for signs of central nervous system and respiratory depression [see Warnings and Precautions (5.2) ] . Meperidine is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function.

Pediatric Use

8.4 Pediatric Use The safety and efficacy of DEMEROL Injection in patients less than 18 years of age have not been established. The safety and effectiveness of meperidine in pediatric patients has not been established. Literature reports indicate that meperidine has a slower elimination rate in neonates and young infants compared to older children and adults. Neonates and young infants may also be more susceptible to the effects, especially the respiratory depressant effects. If meperidine use is contemplated in neonates or young infants, any potential benefits of the drug need to be weighed against the relative risk of the patient.

Pregnancy

8.1 Pregnancy Risk Summary Use of opioid analgesics for an extended period of time during pregnancy may cause neonatal opioid withdrawal syndrome [see Warnings and Precautions (5.4) ] . Available data with DEMEROL Injection are insufficient to inform a drug-associated risk for major birth defects and miscarriage or adverse maternal outcomes. There are adverse outcomes reported with fetal exposure to opioid analgesics (see Clinical Considerations ) . Formal animal reproduction studies have not been conducted with meperidine. Neural tube defects (exencephaly and cranioschisis) have been reported in hamsters administered a single bolus dose of meperidine during a critical period of organogenesis at 0.85 and 1.5 times the total human daily dose of 1200 mg [see Data ] . The background risk of major birth defects and miscarriage for the indicated population is unknown. All ‎‎pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Clinical Considerations Fetal/Neonatal Adverse Reactions Use of opioid analgesics for an extended period of time during pregnancy for medical or nonmedical purposes can result in physical dependence in the neonate and neonatal opioid withdrawal syndrome shortly after birth. Neonatal opioid withdrawal syndrome presents as irritability, hyperactivity and abnormal sleep pattern, high pitched cry, tremor, vomiting, diarrhea, and failure to gain weight. The onset, duration, and severity of neonatal opioid withdrawal syndrome vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination of the drug by the newborn. Observe newborns for symptoms of neonatal opioid withdrawal syndrome and manage accordingly [see Warnings and Precautions (5.4) ] . Labor or Delivery Opioids cross the placenta and may produce respiratory depression and psycho-physiologic effects in neonates. An opioid antagonist, such as naloxone, must be available for reversal of opioid-induced respiratory depression in the neonate. DEMEROL Injection is not recommended for use in pregnant women during or immediately prior to labor, when other analgesic techniques are more appropriate. Opioid analgesics, including DEMEROL Injection, can prolong labor through actions which temporarily reduce the strength, duration, and frequency of uterine contractions. However, this effect is not consistent and may be offset by an increased rate of cervical dilation, which tends to shorten labor. Monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression. Data Animal Data Formal reproductive and developmental toxicology studies for meperidine have not been completed. In a published study, neural tube defects (exencephaly and cranioschisis) were noted following subcutaneous administration of meperidine hydrochloride (127 and 218 mg/kg, respectively) on Gestation Day 8 to pregnant hamsters (0.85 and 1.5 times the total daily dose of 1200 mg/day based on body surface area). The findings cannot be clearly attributed to maternal toxicity.

Use In Specific Populations

8 USE IN SPECIFIC POPULATIONS • Pregnancy: May cause fetal harm. ( 8.1 ) • Geriatric Patients: Use caution during dose selection, starting at the low ‎end of the dosing range while carefully monitoring for side effects. ‎‎( 8.5 )‎ 8.1 Pregnancy Risk Summary Use of opioid analgesics for an extended period of time during pregnancy may cause neonatal opioid withdrawal syndrome [see Warnings and Precautions (5.4) ] . Available data with DEMEROL Injection are insufficient to inform a drug-associated risk for major birth defects and miscarriage or adverse maternal outcomes. There are adverse outcomes reported with fetal exposure to opioid analgesics (see Clinical Considerations ) . Formal animal reproduction studies have not been conducted with meperidine. Neural tube defects (exencephaly and cranioschisis) have been reported in hamsters administered a single bolus dose of meperidine during a critical period of organogenesis at 0.85 and 1.5 times the total human daily dose of 1200 mg [see Data ] . The background risk of major birth defects and miscarriage for the indicated population is unknown. All ‎‎pregnancies have a background risk of birth defect, loss, or other adverse outcomes. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Clinical Considerations Fetal/Neonatal Adverse Reactions Use of opioid analgesics for an extended period of time during pregnancy for medical or nonmedical purposes can result in physical dependence in the neonate and neonatal opioid withdrawal syndrome shortly after birth. Neonatal opioid withdrawal syndrome presents as irritability, hyperactivity and abnormal sleep pattern, high pitched cry, tremor, vomiting, diarrhea, and failure to gain weight. The onset, duration, and severity of neonatal opioid withdrawal syndrome vary based on the specific opioid used, duration of use, timing and amount of last maternal use, and rate of elimination of the drug by the newborn. Observe newborns for symptoms of neonatal opioid withdrawal syndrome and manage accordingly [see Warnings and Precautions (5.4) ] . Labor or Delivery Opioids cross the placenta and may produce respiratory depression and psycho-physiologic effects in neonates. An opioid antagonist, such as naloxone, must be available for reversal of opioid-induced respiratory depression in the neonate. DEMEROL Injection is not recommended for use in pregnant women during or immediately prior to labor, when other analgesic techniques are more appropriate. Opioid analgesics, including DEMEROL Injection, can prolong labor through actions which temporarily reduce the strength, duration, and frequency of uterine contractions. However, this effect is not consistent and may be offset by an increased rate of cervical dilation, which tends to shorten labor. Monitor neonates exposed to opioid analgesics during labor for signs of excess sedation and respiratory depression. Data Animal Data Formal reproductive and developmental toxicology studies for meperidine have not been completed. In a published study, neural tube defects (exencephaly and cranioschisis) were noted following subcutaneous administration of meperidine hydrochloride (127 and 218 mg/kg, respectively) on Gestation Day 8 to pregnant hamsters (0.85 and 1.5 times the total daily dose of 1200 mg/day based on body surface area). The findings cannot be clearly attributed to maternal toxicity. 8.2 Lactation Risk Summary Meperidine appears in the milk of nursing mothers receiving the drug. The developmental and health benefits of breastfeeding should be considered along with the mother's clinical need for DEMEROL Injection and any potential adverse effects on the breastfed infant from DEMEROL Injection or from the underlying maternal condition. Clinical Considerations Monitor infants exposed to DEMEROL Injection through breast milk for excess sedation and respiratory depression. Withdrawal symptoms can occur in breastfed infants when maternal administration of an opioid analgesic is stopped, or when breastfeeding is stopped. 8.3 Females and Males of Reproductive Potential Infertility Use of opioids for an extended period of time may cause reduced fertility in females and males of reproductive potential. It is not known whether these effects on fertility are reversible [see Adverse Reactions (6) , Clinical Pharmacology (12.2) , Nonclinical Pharmacology (13.1) ]. 8.4 Pediatric Use The safety and efficacy of DEMEROL Injection in patients less than 18 years of age have not been established. The safety and effectiveness of meperidine in pediatric patients has not been established. Literature reports indicate that meperidine has a slower elimination rate in neonates and young infants compared to older children and adults. Neonates and young infants may also be more susceptible to the effects, especially the respiratory depressant effects. If meperidine use is contemplated in neonates or young infants, any potential benefits of the drug need to be weighed against the relative risk of the patient. 8.5 Geriatric Use Elderly patients (aged 65 years or older) may have increased sensitivity to meperidine. In general, use caution when selecting a dosage for an elderly patient, usually starting at the low end of the dosing range, reflecting the greater frequency of decreased hepatic, renal, or cardiac function and of concomitant disease or other drug therapy. Respiratory depression is the chief risk for elderly patients treated with opioids, and has occurred after large initial doses were administered to patients who were not opioid-tolerant or when opioids were co-administered with other agents that depress respiration. Titrate the dosage of DEMEROL Injection slowly in geriatric patients and monitor closely for signs of central nervous system and respiratory depression [see Warnings and Precautions (5.2) ] . Meperidine is known to be substantially excreted by the kidney, and the risk of adverse reactions to this drug may be greater in patients with impaired renal function. Because elderly patients are more likely to have decreased renal function, care should be taken in dose selection, and it may be useful to monitor renal function. 8.6 Hepatic Impairment Accumulation of meperidine and/or its active metabolite, normeperidine, can also occur in patients with hepatic impairment. Elevated serum levels have been reported to cause central nervous system excitatory effects. Meperidine should therefore be used with caution in patients with hepatic impairment. Titrate the dosage of DEMEROL Injection slowly in patients with hepatic impairment and monitor closely for signs of central nervous system and respiratory depression. 8.7 Renal Impairment Accumulation of meperidine and/or its active metabolite, normeperidine, can occur in patients with renal impairment. Meperidine should therefore be used with caution in patients with renal impairment. Titrate the dosage of DEMEROL Injection slowly in patients with renal impairment and monitor closely for signs of central nervous system and respiratory depression.

How Supplied

16 HOW SUPPLIED/STORAGE AND HANDLING For Parenteral Use DEMEROL (meperidine hydrochloride injection) is clear and colorless. DEMEROL (meperidine hydrochloride injection) is supplied as a sterile solution in a multiple-dose vial, single-dose Carpuject™ cartridges for use ONLY with the Carpuject™ Holders and NexJect™ prefilled syringes for subcutaneous, intramuscular, and intravenous administration, and available as follows: Unit of Sale Concentration (per total volume) NDC 0409-1181-30 Carton of 1 30 mL fill in 30 mL Multiple-dose Vial 1,500 mg/30 mL (50 mg/mL) NDC 0409-1176-30 Carton of 10 1 mL fill in 2.5 mL Carpuject™ Single-dose cartridge with Luer Lock 25 mg/mL NDC 0409-1178-30 Carton of 10 1 mL fill in 2.5 mL Carpuject™ Single-dose cartridge with Luer Lock 50 mg/mL NDC 0409-1179-30 Carton of 10 1 mL fill in 2.5 mL Carpuject™ Single-dose cartridge with Luer Lock 75 mg/mL NDC 0409-1180-69 Carton of 10 1 mL fill in 2.5 mL Carpuject™ Single-dose cartridge with Luer Lock 100 mg/mL NDC 0409-1362-01 Clamshell of 10 1 mL fill in 1.5 mL NexJect™ Single-dose Prefilled Syringe with Luer Lock 25 mg/mL NDC 0409-1418-01 Clamshell of 10 1 mL fill in 1.5 mL NexJect™ Single-dose Prefilled Syringe with Luer Lock 50 mg/mL Carpuject™ Single-dose cartridges are packaged in a Slim-Pak tamper detection package. Note that a needle is not included with Carpuject™ Single-dose cartridges and Nexject™ Single-dose Prefilled Syringes. Carpuject and NexJect TM Single-dose products: Discard unused portion. Multiple-dose vials: Discard unused portion after 28 days. Store at 20°C to 25°C (68°F to 77°F), excursions permitted between 15°C to 30°C (59°F to 86°F). [See USP Controlled Room Temperature.]

How Supplied Table

Unit of SaleConcentration (per total volume)

NDC 0409-1181-30 Carton of 1 30 mL fill in 30 mL Multiple-dose Vial

1,500 mg/30 mL (50 mg/mL)

NDC 0409-1176-30 Carton of 10 1 mL fill in 2.5 mL Carpuject™ Single-dose cartridge with Luer Lock

25 mg/mL

NDC 0409-1178-30 Carton of 10 1 mL fill in 2.5 mL Carpuject™ Single-dose cartridge with Luer Lock

50 mg/mL

NDC 0409-1179-30 Carton of 10 1 mL fill in 2.5 mL Carpuject™ Single-dose cartridge with Luer Lock

75 mg/mL

NDC 0409-1180-69 Carton of 10 1 mL fill in 2.5 mL Carpuject™ Single-dose cartridge with Luer Lock

100 mg/mL

NDC 0409-1362-01 Clamshell of 10 1 mL fill in 1.5 mL NexJect™ Single-dose Prefilled Syringe with Luer Lock

25 mg/mL

NDC 0409-1418-01 Clamshell of 10 1 mL fill in 1.5 mL NexJect™ Single-dose Prefilled Syringe with Luer Lock

50 mg/mL

Storage And Handling

Store at 20°C to 25°C (68°F to 77°F), excursions permitted between 15°C to 30°C (59°F to 86°F). [See USP Controlled Room Temperature.]

Boxed Warning

WARNING: SERIOUS AND LIFE-THREATENING RISKS FROM USE OF DEMEROL Addiction, Abuse, and Misuse Because the use of DEMEROL Injection exposes patients and other users to the risks of opioid addiction, abuse, and misuse, which can lead to overdose and death , a ssess each patient’s risk prior to prescribing and reassess all patients regularly for the development of these behaviors and conditions [see Warnings and Precautions (5.1) ] . Life-Threatening Respiratory Depression Serious, life-threatening, or fatal respiratory depression may occur with use of DEMEROL Injection, especially during initiation or following a dosage increase . To reduce the risk of respiratory depression, ‎proper dosing and titration of DEMEROL Injection are essential [see Warnings and Precautions (5.2) ] . Risks from Concomitant Use with Benzodiazepines or Other CNS Depressants Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of DEMEROL Injection and benzodiazepines or other CNS depressants for use in patients for whom alternative treatment options are inadequate [see Warnings and Precautions (5.3) , Drug Interactions (7) ] . Neonatal Opioid Withdrawal Syndrome (NOWS) If opioid use is required for an extended period of time in a pregnant woman, advise the patient of the risk of N eonatal O pioid W ithdrawal S yndrome , which may be life-threatening if not recognized and treated. Ensure that management by neonatology experts will be available at delivery [ see Warnings and Precautions (5.4) ] . Cytochrome P450 3A4 Interaction The concomitant use of DEMEROL Injection with all cytochrome P450 3A4 inhibitors may result in an increase in meperidine plasma concentrations, which could increase or prolong adverse reactions and may cause potentially fatal respiratory depression. In addition, discontinuation of a concomitantly used cytochrome P450 3A4 inducer may result in an increase in meperidine plasma concentration. Monitor patients receiving DEMEROL Injection and any CYP3A4 inhibitor or inducer [ see Warnings and Precautions (5.5) , Drug Interactions (7) ] . Concomitant Use of DEMEROL Injection with Monoamine Oxidase (MAO) Inhibitors Concomitant use of DEMEROL Injection with monoamine oxidase (MAO) inhibitors can result in coma, severe respiratory depression, cyanosis, and hypotension. Use of DEMEROL Injection with MAO inhibitors within last 14 days is contraindicated [see Contraindications (4) , Warnings and Precautions (5.6) , Drug Interactions (7) ] . WARNING: SERIOUS AND LIFE-THREATENING RISKS FROM USE OF DEMEROL ‎INJECTION See full prescribing information for complete boxed warning. • DEMEROL Injection exposes users to risks of addiction, abuse, and misuse, which can lead to overdose and death. Assess patient’s risk before prescribing and reassess regularly for these behaviors and conditions. ( 5.1 ) • Serious, life-threatening, or fatal respiratory depression may occur with use of DEMEROL Injection, especially during initiation or following a dosage increase. To reduce the risk of respiratory depression, proper dosing and titration of ‎DEMEROL Injection are essential.‎ ( 5.2 ) • Concomitant use of opioids with benzodiazepines or other central nervous system (CNS) depressants, including alcohol, may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing for use in patients for whom alternative treatment options are inadequate. ( 5.3 , 7 ) • If opioid use is required for an extended period of time in a pregnant woman, ‎advise the patient of the risk of Neonatal Opioid Withdrawal Syndrome, which may be life-threatening if not ‎recognized and treated. Ensure that management by neonatology experts will be ‎available at delivery. ( 5.4 ) • Concomitant use with CYP3A4 inhibitors (or discontinuation of CYP3A4 inducers) can result in a fatal overdose of meperidine. ( 5.5 , 7 ) • Concomitant use of DEMEROL Injection with Monoamine oxidase (MAO) inhibitors can result in coma, severe respiratory depression, cyanosis and hypotension. Use of DEMEROL Injection with MAO inhibitors is contraindicated. ( 4 , 5.6 , 7 )

Learning Zones

The Learning Zones are an educational resource for healthcare professionals that provide medical information on the epidemiology, pathophysiology and burden of disease, as well as diagnostic techniques and treatment regimens.

Disclaimer

The drug Prescribing Information (PI), including indications, contra-indications, interactions, etc, has been developed using the U.S. Food & Drug Administration (FDA) as a source (www.fda.gov).

Medthority offers the whole library of PI documents from the FDA. Medthority will not be held liable for explicit or implicit errors, or missing data.

Drugs appearing in this section are approved by the FDA. For regions outside of the United States, this content is for informational purposes only and may not be aligned with local regulatory approvals or guidance.