МЕПЕРИДИН ГИДРОХЛОРИД

Химические свойства

White or almost white, crystalline powder.

Использование

Analgesic; sedative; anesthetic. Controlled substance (opiate).

Определение

An addictive drug, use by prescription only.

Клиническое использование

Meperidine is a μ agonist with approximately one-tenth the potency of morphine after intramuscular dose. Meperidine produces the analgesia, respiratory depression, and euphoria caused by other μ opioid agonists, but it causes less constipation and does not inhibit cough. When given orally, meperidine has 40 to 60% bioavailability because of significant first-pass metabolism. Because of the limited bioavailability, it is one-third as potent after an oral dose compared to a parenteral dose.
Meperidine has received extensive use in obstetrics because of its rapid onset and short duration of action. When it is given intravenously in small (25-mg) doses during delivery, the respiratory depression in the newborn child is minimized. Meperidine is used as an analgesic in a variety of nonobstetric anesthetic procedures. Meperidine is extensively metabolized in the liver, with only 5% of the drug being excreted unchanged. Prolonged dosage of meperidine may cause an accumulation of the metabolite normeperidine. Normeperidine has only weak analgesic activity, but it causes CNS excitation and can initiate grand mal seizures. It is recommended that meperidine be discontinued in any patient who exhibits signs of CNS excitation.
Meperidine has a strong adverse reaction when given to patients receiving a monoamine oxidase inhibitor. This drug interaction has been seen recently in patients with Parkinson's disease taking the monoamine oxidase–selective inhibitor selegiline (Eldepryl).
The elimination half-life of meperidine is 3 to 4 hours, and it can double in patients with liver disease. Acidification of the urine will cause enhanced clearance of meperidine, but there is a lesser effect on the clearance of the toxic metabolite normeperidine.

Профиль безопасности

Poison by ingestion, subcutaneous, intravenous, and intraperitoneal routes. Moderately toxic by parenteral route. Experimental teratogenic effects. Mutation data reported. An analgesic. When heated to decomposition it emits very toxic fumes of HCl and NOx.