Dextromethorphan and Promethazine Syrup

Generic name: promethazine hydrochloride and dextromethorphan hydrobromide
Dosage form: syrup
Drug class:Upper respiratory combinations

Medically reviewed by Drugs.com. Last updated on Nov 1, 2021.

Dextromethorphan and Promethazine Syrup Description

Each 5 mL (one teaspoonful), for oral administration contains: dextromethorphan hydrobromide 15 mg; promethazine hydrochloride 6.25 mg. Alcohol 8%(v/v).

Inactive Ingredients: anhydrous citric acid, ascorbic acid, edetate disodium, FD&C yellow No. 6, methylparaben, natural and artificial lemon mint flavor, propylene glycol, propylparaben, purified water, sodium benzoate, sodium citrate anhydrous, saccharin sodium, and sucrose.

Dextromethorphan hydrobromide is a salt of the methyl ether of the dextrorotatory isomer of levorphanol, a narcotic analgesic. It is chemically designated as 3-methoxy-17-methyl-9α, 13α, 14α-morphinan hydrobromide monohydrate. Dextromethorphan hydrobromide occurs as white crystals sparingly soluble in water and freely soluble in alcohol. It has a molecular weight of 370.32, a molecular formula of C18H25NO•HBr•H2O, and the following structural formula:

Promethazine is a racemic compound. Promethazine hydrochloride, a phenothiazine derivative, is chemically designated as 10H-Phenothiazine-10-ethanamine, N,N, α-trimethyl-, monohydrochloride.

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 soluble in water and freely soluble in alcohol. It has a molecular weight of 320.88, a molecular formula of C17H20N2S•HCl, and the following structural formula: