dextromethorphan + promethazine

Dextromethorphan + promethazine is an oral combination drug comprising a **cough suppressant** (dextromethorphan) and a **first-generation antihistamine** (promethazine) used primarily for the **temporary relief of cough and upper respiratory symptoms** associated with allergies or the common cold[1][2][3][5][6][7][11]. - **Promethazine** acts as an H1 histamine receptor antagonist, providing antihistaminic, sedative, and antiemetic effects[3][6][8][9]. - **Dextromethorphan** is an antitussive agent that elevates the cough threshold by acting on the central nervous system[3][6][7]. The combination reduces symptoms such as cough, runny nose, sneezing, and red, itchy eyes[1][2][3][6][7][10]. The oral solution is contraindicated in children under 2 years due to severe respiratory risks[2][10][11]. Promethazine is structurally a phenothiazine derivative with antihistaminic, anticholinergic, and mild dopamine antagonist action[6][8]. Dextromethorphan is structurally related to morphinan derivatives but devoid of opioid and analgesic properties[7]. The combination is commonly available as an oral solution dosed every 4–6 hours as needed[1][2][3][11].

Brand names

Phen Tuss DMPromethazine DM

Other names

promethazine/dextromethorphanpromethazine HCl/dextromethorphan HBr