Background: Dextromethorphan (DM), the d-isomer of the codeine analog levorphanol, is an active ingredient present in a variety of cough and cold remedies. Recently, data generated from a study in ...

Dextromethorphan HBr 10mg, guaifenesin 100mg; per 5mL; syrup; contains sodium 4mg/5mL; sugar- and alcohol-free.

It acts centrally and elevates the threshold for coughing. It is about equal to codeine in depressing the cough reflex. In therapeutic dosage dextromethorphan does not inhibit ciliary activity.

After trying every cough syrup and lozenge in the pharmacy ... like DayQuil, Robitussin DM, and Triaminic DM—but they’re not as effective as prescription meds, says Dr. Han.