Pronunciation: me-PER-i-deen HYE-droe-KLOR-ide
Class: Opioid analgesic

Trade Names

Demerol
- Tablets, oral 50 mg
- Tablets, oral 100 mg
- Injection, solution 25 mg/mL
- Injection, solution 50 mg/mL
- Injection, solution 75 mg/mL
- Injection, solution 100 mg/mL

Meperidine Hydrochloride
- Solution, oral 50 mg per 5 mL
- Injection, solution 10 mg/mL

Pharmacology

Relieves pain by stimulating opiate receptors in the CNS; also causes respiratory depression and peripheral vasodilation.

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Pharmacokinetics

Absorption

After oral absorption, about 50% of the dose reaches the systemic circulation; T _max is 1 to 2 h.

Distribution

Meperidine protein binding is high (60% to 80%). Meperidine and its active metabolite, normeperidine, both appear in the CSF; meperidine also crosses the placenta.

Metabolism

Undergoes hepatic metabolism; active metabolite is normeperidine.

Elimination

The half-life of the parent drug is 3 to 6 (oral) or 8 (injection) h. The half-life for normeperidine is 20 h.

Special Populations

Renal Function Impairment

Accumulation of meperidine and/or normeperidine may occur.

Hepatic Function Impairment

Accumulation of meperidine and/or normeperidine may occur. Half-life is 1.3 to 2 times greater in cirrhotic patients.

Elderly

Elderly patients have a slower elimination rate.

Children

Meperidine has a slower elimination rate in neonates and young infants.

Postoperative patients

The half-life is 1.3 to 2 times greater in these patients.

Indications and Usage

Oral and parenteral

Relief of moderate to severe pain.

Parenteral (excluding products for patient-controlled analgesia [PCA] pumps)

Preoperative sedation; support of anesthesia; obstetrical analgesia.

Contraindications

Patients who are receiving or who have recently received an MAOI; hypersensitivity to meperidine or any components of the product; severe respiratory insufficiency; solutions of meperidine and barbiturates.

Dosage and Administration

Pain
Adults

IM/Subcutaneous/PO 50 to 150 mg every 3 to 4 h as needed. If IV administration is required, reduce dose and administer slowly. For use in a PCA pump, administer 10 mg IV with a range of 1 to 5 mg per incremental dose; for continuous infusion, the usual dose is 15 to 35 mg/h IV, as required.

Children

IM/Subcutaneous/PO 1 to 1.8 mg/kg (max, 50 to 150 mg per dose) every 3 to 4 h as needed.

Preoperative Sedation
Adults

IM/Subcutaneous 50 to 100 mg 30 to 90 min before anesthetic. To support anesthesia, administer fractional doses (eg, 10 mg/mL) slowly by IV injection or by a continuous IV infusion of a more dilute solution (eg, 1 mg/mL).

Children

IM/Subcutaneous 1.1 to 2.2 mg/kg (max, 50 to 100 mg per dose), 30 to 90 min before beginning anesthesia. To support anesthesia, administer fractional doses (eg, 10 mg/mL) slowly by IV injection or by a continuous IV infusion of a more dilute solution (eg, 1 mg/mL).

Support of Anesthesia
Adults

IV Repeated doses diluted to 10 mg/mL by slow injection or by continuous infusion diluted to 1 mg/mL.

Hepatic Function Impairment
Adults

IM/Subcutaneous/PO Use with caution and reduce the initial dose.

Renal Function Impairment
Adults

IM/Subcutaneous/PO Use with caution and reduce the initial dose.

Obstetrical Analgesia
Adults

IM/Subcutaneous 50 to 100 mg every 1 to 3 h as needed when pain becomes regular.

Elderly

IM/Subcutaneous/PO Use with caution and reduce the initial and total daily dose.

General Advice

• Adjust dosage according to the severity of pain and the response of the patient.
• IM administration is preferred over subcutaneous administration when repeated doses are required.
• Subcutaneous administration is suitable for occasional use.
• If IV administration is required, decrease dosage and inject very slowly, preferably utilizing a diluted solution.
• Proportionately reduce the dose (usually by 25% to 50%) when coadministering with phenothiazines or other tranquilizers. A reduced dose is indicated in patients receiving other CNS depressants.
• The 10 mg/mL vials or syringes are for use with a compatible PCA pump.
• If used long-term, dosage should be tapered to prevent withdrawal symptoms.
• Dilute each dose of the oral solution in ½ glass of water.

Storage/Stability

Store at 59° to 86°F. Protect from light.

Drug Interactions

Acyclovir

Plasma concentrations of meperidine and its active metabolite, normeperidine, may be elevated, increasing the pharmacologic effects and risk of adverse reactions. Coadminister with caution.

Cimetidine

Monitor for increased respiratory and CNS depression.

CNS depressants (eg, alcohol, barbiturates, general anesthetics, hypnotics, other opioids, phenothiazines, sedatives, tranquilizers)

Additive CNS and respiratory depression. Coadminister with caution and with a reduced starting meperidine dose.

Furazolidone, MAOIs (eg, phenelzine)

Potentially fatal reactions can occur if meperidine is used concurrently with MAOIs or furazolidone.

Mixed agonist/antagonist opioid analgesics (eg, buprenorphine, butorphanol, nalbuphine, pentazocine)

The analgesic effect of meperidine may be reduced and/or withdrawal symptoms may be precipitated. Coadminister with caution. Close clinical monitoring for withdrawal symptoms or reduced efficacy is warranted.

Naltrexone

The analgesic effect of meperidine may be reduced and/or withdrawal symptoms may be precipitated. Close clinical monitoring for withdrawal symptoms or reduced efficacy is warranted. Opioid-dependent patients should be detoxified before treatment with naltrexone.

Phenytoin

Meperidine metabolism may be increased, resulting in reduced half-life and bioavailability. However, normeperidine concentrations may be increased. Coadminister with caution.

Ritonavir

Plasma concentrations of the active meperidine metabolite, normeperidine, may be increased. Avoid coadministration.

Serotonin reuptake inhibitors (eg, fluoxetine)

The risk of serotonin syndrome may be increased. Close clinical monitoring for signs of serotonin syndrome is warranted.

Sibutramine

The risk of serotonin syndrome may be increased. Coadministration is not recommended.

Skeletal muscle relaxants (eg, cyclobenzaprine)

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

Sodium oxybate

Effects of coadministration may be additive, increasing sleep duration and the risk of CNS depression. Coadministration is contraindicated.

Incompatibility

Do not co-infuse with solutions of soluble barbiturates, aminophylline, heparin, morphine, methicillin, phenytoin, sodium bicarbonate, iodine, sulfadiazine, or sulfisoxazole.

Adverse Reactions

Cardiovascular

Bradycardia; flushing of the face; hypotension; orthostatic hypotension; palpitation; syncope; tachycardia.

CNS

Agitation; confusion; delirium; disorientation; dizziness; headache; incoordination; involuntary muscle movements (eg, muscle twitches, myoclonus); light-headedness; mood changes (eg, dysphoria, euphoria); sedation; seizures; sensory-motor paralysis (from injection near a nerve; usually temporary); transient hallucinations; tremor; weakness.

Dermatologic

Pruritus, urticaria, or other skin rashes; sweating; wheal and flare over the vein with IV injection.

EENT

Visual disturbances.

GI

Abdominal pain; biliary tract spasm; constipation; dry mouth; nausea; vomiting.

Genitourinary

Urinary retention.

Hypersensitivity

Anaphylaxis; histamine release leading to hypotension and/or tachycardia, flushing, sweating, and pruritus; hypersensitivity reactions; shock.

Local

Local tissue irritation and induration following subcutaneous injection, particularly when repeated; pain at injection site; phlebitis (following IV injection).

Miscellaneous

Antidiuretic effect.

Precautions

Pregnancy

Category C (oral). Do not use prior to labor because of the risk of adverse effects in the fetus. When used as an obstetrical analgesic, meperidine can produce depression of respiration and psychophysiological functions in the newborn. Resuscitation may be required.

Lactation

Excreted in breast milk. The American Academy of Pediatrics classifies meperidine as compatible with breast-feeding.

Children

Meperidine administered via a PCA pump is not recommended in patients younger than 19.

Elderly

Use with caution; elderly patients may be more susceptible to the effects of meperidine.

Renal Function

Use with caution.

Hepatic Function

Use with caution.

Special Risk Patients

Use with caution in debilitated patients and patients with hypothyroidism or myxedema; acute alcoholism; CNS depression or coma; delirium tremens; decreased respiratory reserve (eg, acute asthma attack, COPD, cor pulmonale, hypoxia, hypercapnia, respiratory depression, severe pulmonary impairment); head injury, other intracranial lesions, or increased intracranial pressure; atrial flutter; supraventricular tachycardia; sickle cell anemia; pheochromocytoma; adrenocortical insufficiency (eg, Addison disease); toxic psychosis; kyphoscoliosis associated with respiratory depression; and prostatic hypertrophy or urethral stricture. Initial dose may need to be reduced.

Hazardous Tasks

May impair physical and/or mental abilities required to perform potentially dangerous tasks.

Acute abdominal conditions

May obscure the diagnosis or clinical course in patients with acute abdominal conditions.

Convulsions

May aggravate preexisting convulsions in patients with convulsive disorders. High doses, prolonged infusions, or repeated doses may produce convulsions in patients without a history of convulsion disorders.

Drug dependence

Tolerance and psychological and physical dependence may occur with long-term use. Use with caution in patients with alcoholism and other drug dependencies.

Hypotension

Severe hypotension or orthostatic hypotension may occur.

Overdosage

Symptoms

Apnea, bradycardia, cardiopulmonary arrest, circulatory collapse, cold and clammy skin, death, extreme somnolence progressing to stupor or coma, hypotension, hypothermia, miosis, respiratory and CNS depression, seizures, skeletal muscle flaccidity.

Patient Information

• Instruct patients that if dose is missed, it should be taken as soon as possible unless close to time of next dose. Do not double up doses.
• If medication is given long term, explain that dosage will be tapered gradually before stopping to prevent withdrawal symptoms.
• Instruct patients to avoid sudden position changes to avoid orthostatic hypotension.
• Tell patients to avoid the intake of alcoholic beverages or other CNS depressants (eg, sleeping pills, antihistamines).
• Advise patients that the drug may cause drowsiness and impair mental and/or physical abilities and to use caution while driving or performing other potentially hazardous tasks.

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