Demerol injection for severe pain, anesthesia support, and obstetrical analgesia

Demerol is an injectable opioid medication containing meperidine hydrochloride. It is used primarily to manage pain severe enough to require opioid analgesics when other treatments are inadequate, as well as for preoperative medication, anesthesia support, and obstetrical analgesia. Demerol injection is administered subcutaneously, intramuscularly, or intravenously under careful medical supervision due to its potent effects and associated risks.

Demerol injection is approved for:

• Management of pain that is severe enough to need opioid analgesics when alternative treatments are insufficient.
• Preoperative medication to prepare patients before surgery.
• Support of anesthesia during surgical procedures.
• Obstetrical analgesia to relieve pain during childbirth.

Use should be reserved for patients who cannot adequately manage pain with other treatment options because of the risks of addiction, abuse, misuse, overdose, and death.

meperidine hydrochloride

Demerol works by binding to specific opioid receptors in the brain and spinal cord, altering the perception and response to pain. This action decreases the sensation of pain and produces sedation, making it effective for severe pain management and anesthesia support.

General Guidance

• Use the lowest effective dose for the shortest duration consistent with treatment goals.
• Start dosing individually based on pain severity, prior analgesic response, and addiction risk factors.
• Risk of life-threatening respiratory depression requires cautious titration and close monitoring, especially at therapy initiation or dose increases.
• Inspect injection solution for discoloration or particulates before use; do not use if discolored or precipitated.

Adults

• Relief of pain: 50 to 150 mg intramuscularly (IM) or subcutaneously (SC) every 3 to 4 hours as needed.
• Preoperative medication: 50 to 100 mg IM or SC, 30 to 90 minutes before anesthesia.
• Obstetrical analgesia: 50 to 100 mg IM or SC, may be repeated every 1 to 3 hours.
• For intravenous (IV) administration, reduce the dose and inject slowly, preferably diluted.

Children

• 0.5 mg/lb to 0.8 mg/lb IM or SC every 3 to 4 hours for pain relief, not exceeding adult doses.
• 0.5 mg/lb to 1 mg/lb IM or SC for preoperative medication, 30 to 90 minutes before anesthesia, up to adult dosing.

Titration and Maintenance

• Doses should be titrated based on individual patient response and adverse reactions.
• Frequent reassessment is important to balance pain control and side effects.
• If pain increases after stabilization, identify causes before dose increases.
• Adjust doses carefully, decreasing if opioid-related adverse effects worsen.

Discontinuation

• Do not abruptly stop or rapidly reduce dose in physically-dependent patients.
• Taper dosage by 25% to 50% every 2 to 4 days while monitoring withdrawal symptoms.
• If withdrawal occurs, raise dose to previous level and taper more slowly.

Special Populations

• Elderly patients should receive the lower end of dosing ranges and be observed carefully.

Interactions Affecting Dosing

• Reduce dose by 25% to 50% when given with phenothiazines or many tranquilizers due to potentiation.

• Significant respiratory depression
• Acute or severe bronchial asthma in unmonitored settings or absence of resuscitative equipment
• Concurrent use of monoamine oxidase inhibitors (MAOIs) or use within last 14 days
• Known or suspected gastrointestinal obstruction, including paralytic ileus
• Hypersensitivity to meperidine or any ingredients of the product

Boxed Warning Risks

• Addiction, abuse, misuse: Opioid use can lead to these risks which may cause overdose and death. Assess all patients for these risks before and during treatment.
• Life-threatening respiratory depression: Can occur especially at therapy start or after dose increases. Proper dosing and slow titration are crucial.
• Concomitant CNS depressants: Using Demerol with benzodiazepines, alcohol, or other CNS depressants can lead to profound sedation, coma, respiratory depression, and death. Concomitant use should be reserved for patients lacking alternatives.
• Neonatal opioid withdrawal syndrome: Pregnant women using opioids chronically risk this serious condition in newborns; management by neonatology experts is necessary.
• CYP3A4 enzyme interactions: CYP3A4 inhibitors can raise meperidine levels causing potentially fatal respiratory depression; inducers' discontinuation can have similar effects. Close monitoring is required.
• Monoamine oxidase inhibitors (MAOIs): Concomitant use or use within 14 days is contraindicated due to severe, potentially fatal reactions including coma and respiratory depression.

Other Important Warnings

• Monitor for opioid-induced hyperalgesia, where increased pain sensitivity paradoxically occurs.
• Be vigilant for serotonin syndrome when combined with serotonergic drugs; discontinue if suspected.
• Patients with chronic pulmonary disease, elderly, cachectic or debilitated are at higher risk of respiratory depression; monitor closely.
• Use caution in patients with adrenal insufficiency, severe hypotension, increased intracranial pressure, brain tumors, or impaired consciousness.
• Demerol may cause severe hypotension and should be avoided in circulatory shock.
• Seizure risk increases, especially with accumulation of metabolite normeperidine in prolonged use.
• Avoid mixed agonist/antagonist or partial agonist opioids concurrently due to reduced analgesic effects or precipitated withdrawal.
• Warn patients about impairment of mental or physical abilities such as driving until effects are known.

Common Side Effects

• Lightheadedness, dizziness, sedation
• Nausea, vomiting
• Sweating

Other Adverse Reactions

• Nervous system: mood changes (euphoria, dysphoria), headache, agitation, tremor, muscle twitches, myoclonus, seizures, hallucinations, confusion, delirium, visual disturbances
• Injection site reactions: pain, local irritation, induration, sensory-motor paralysis (usually transient)
• Gastrointestinal: dry mouth, constipation, biliary tract spasm
• Cardiovascular: flushing, tachycardia, bradycardia, palpitations, hypotension, syncope, phlebitis (IV injection)
• Genitourinary: urinary retention
• Allergic: pruritus, urticaria, skin rashes, wheal and flare at IV site, hypersensitivity reactions, anaphylaxis
• Histamine release symptoms: hypotension, flushing, tachycardia, sweating, pruritus
• Other: antidiuretic effect
• Serotonin syndrome symptoms with serotonergic drug use (agitation, hyperthermia, diarrhea, tremors, altered consciousness)
• Adrenal insufficiency symptoms (nausea, fatigue, dizziness, hypotension)
• Opioid-induced hyperalgesia and allodynia
• Hypoglycemia in some patients, especially those with risk factors
• Opioid-induced esophageal dysfunction (dysphagia, regurgitation, chest pain)

• CNS depressants (benzodiazepines, alcohol, sedatives, muscle relaxants, antipsychotics, gabapentinoids, other opioids): May cause profound sedation, respiratory depression, coma, death. Reserve concomitant use for patients without alternatives and use lowest effective doses.
• MAO inhibitors: Contraindicated within 14 days due to risk of severe, life-threatening reactions.
• CYP3A4 inhibitors (macrolides, azole antifungals, protease inhibitors): Increase meperidine plasma concentration, risking fatal respiratory depression; monitor and consider dose reduction.
• CYP3A4 inducers (rifampin, carbamazepine, phenytoin): May reduce meperidine levels; discontinuation may increase levels causing adverse reactions; monitor and adjust dose accordingly.
• Serotonergic drugs (SSRIs, SNRIs, TCAs, triptans, certain muscle relaxants, tramadol): May increase risk of serotonin syndrome; discontinue Demerol if suspected.
• Phenothiazines and tranquilizers: May potentiate effects; reduce Demerol dose by 25-50% when used concurrently.

Pregnancy:

Use of Demerol during pregnancy, especially prolonged use, can result in neonatal opioid withdrawal syndrome (NOWS), which can be life-threatening if not recognized and treated. Arrange for appropriate neonatology management at delivery and monitor newborns for NOWS signs.

Lactation:

No specific information provided in the label.

Overdose of Demerol can cause severe respiratory depression, respiratory arrest, shock, cardiac arrest, and death. Management includes immediate supportive measures, close observation, and administration of opioid overdose reversal agents such as naloxone or nalmefene based on clinical status.