This medication is a Schedule II drug.
Common Brand Names: Demerol
Therapeutic Class: A synthetic phenylpiperidine-derivative opiate agonist
Common Injectable Dosage Forms:
Injection: 25 mg/mL, 50 mg/mL, 75 mg/mL, and 100 mg/mL in vials, ampules, and syringes. Also available in combination with promethazine in prefilled syringes (Mepergan injection, Wyeth-Ayerst).
Meperidine should be given in the smallest effective dose and as infrequently as possible to minimize the development of tolerance and/or physical dependency. Usual adult dose for analgesia range from 50-150 hours as necessary, or when given by continuous IV infusion, 15-35 mg/hour is initially used, with titration based on patient response and tolerance.
Preoperatively, doses of 50-100 mg are given 30-90 minutes before beginning anesthesia, and then repeated by slow IV injections of a dilute solution (10 mg/mL), or by continuous IV infusion (1 mg/mL) to supplement anesthesia.
For analgesia during labor, 50-100 mg may be given when labor becomes regular, and repeated at 1–3-hour intervals.
Children may receive 1.1-1.8 mg/kg every 3-4 hours for analgesia and 1-2.2 mg/kg as a preoperative dose with individual doses not to exceed 100 mg.
Adjustments may be necessary in patients with hepatic or renal dysfunction.
Administration and Stability:
May be administered by SQ, IM, or slow IV injection. When repeated doses are required, IM is preferred to SQ due to local tissue effects at injection sites. IM administration should be done deeply into a large muscle mass, taking care to avoid nerve trunks. When given by IV injection, dosage should be decreased and given very slowly, preferably in dilute concentrations.
Pharmacology/Pharmacokinetics:
Opiate agonists exert their principal pharmacologic effect on receptors at several sites in the CNS involving several systems of neurotransmitters to produce analgesia. However, their precise mechanism of action has not been fully elucidated. The drugs alter the perception of pain at the spinal cord and higher levels in the CNS, and the patient’s emotional response to pain. Meperidine has a more rapid onset and may have a shorter duration of action than does morphine. Peak analgesia occurs about 40-60 minutes after SQ, and 30-50 minutes after IM administration, with analgesia maintained for 2-4 hours. Elimination of meperidine is biphasic in nature, with terminal half-life being 3-5 hours in normal individuals. Meperidine is metabolized in the liver to several metabolites, with at least one being pharmacologically active, and then excreted in the urine.
Drug and Lab Interactions:
Opiates may potentiate the effects of other CNS DEPRESSANTS including other opiate agonists, general anesthetics, tranquillizers, sedatives, hypnotics, alcohol, and other CNS drugs such as MAO inhibitors and tricyclic antidepressants. Opiate agonists may also decrease the effects of diuretics in patients with congestive heart failure. Meperidine may also aggravate the adverse effects of isoniazid. It may produce death, coma, severe respiratory depression, and cyanosis in patients receiving MAO INHIBITORS including selegiline.
Contraindications/Precautions:
Meperidine is contraindicated in patients currently receiving MAO inhibitors, or within 14 days of cessation of therapy. The drug should be used with caution in patients with atrial flutter and SVT due to increased ventricular response. Injection of IM meperidine into or near nerve trunks may produce sensory-motor paralysis. The drug should also be used with caution in patients with known hypersensitivity to other opiate agonists. Dosage adjustments may be necessary in the presence of hepatic and/or renal dysfunction. Injectable naloxone hydrochloride should be readily available in cases of severe adverse reactions. Pregnancy Category C/D.
Monitoring Parameters:
Serum Cr, BUN
Adverse Effects:
Respiratory and/or circulatory depression are the chief hazards to opiate agonist therapy as respiratory arrest, shock, and cardiac arrest have occurred. Other CNS adverse effects include dizziness, sedation, coma, and dysphoria. Other side effects reported include nausea, vomiting, constipation, and urinary retention. Tolerance, psychological and physical dependence may occur. Meperidine may also cause hyperexcitability, insomnia, and hallucinations.
Common Clinical Applications:
A strong analgesic used in the relief of moderate-to-severe pain. It is also used for preoperative sedation, as a supplement to anesthesia, and for analgesia during labor.