Meperidine and Promethazine Capsules

Generic name: meperidine hydrochloride and promethazine hydrochloride
Dosage form: capsule
Drug class:Narcotic analgesic combinations

Medically reviewed by Drugs.com. Last updated on Nov 22, 2021.

Disclaimer: This drug has not been found by FDA to be safe and effective, and this labeling has not been approved by FDA. For further information about unapproved drugs, click here.

Meperidine and Promethazine Capsules Description

Meperidine HCl and Promethazine HCl capsules each contain 50 mg meperidine hydrochloride and 25 mg promethazine hydrochloride for oral administration. Meperidine hydrochloride is a white crystalline substance with a melting point of 186°C to 189°C. It is readily soluble in water and has a neutral reaction and a slightly bitter taste. Chemically, Meperidine hydrochloride is 4-Piperidinecarboxylic acid, 1-methyl-4-phenyl-, ethyl ester, hydrochloride and has the following structure:

Promethazine hydrochloride occurs as a white to faint yellow, practically odorless, crystalline powder which slowly oxidizes and turns blue on prolonged exposure to air. It is freely soluble in water and soluble in alcohol.

Chemically, Promethazine hydrochloride is (10H-phenothiazine-10-ethanamine, N,N,α-trimethyl-, monohydrochloride, (±)-) is a racemic compound and has the following structural formula:

Inactive Ingredients:

Black ink, FD&C Blue #1, FD&C Red #3, FD&C Yellow #6, gelatin, lactose, magnesium stearate, talc and titanium dioxide.

Meperidine and Promethazine Capsules - Clinical Pharmacology

Meperidine hydrochloride is a narcotic analgesic 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.

There is some evidence which suggests that me...