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 ...

and 10 mg of dextromethorphan HBr, a cough suppressant The Daytime caplets also contain guaifenesin 200 mg, an expectorant to help loosen phlegm (mucus) to make coughs more productive. The ...