Do OTC remedies relieve cough in acute URIs?

Dextromethorphan (DM) for adults and honey for children provide some relief. DM may modestly decrease cough in adults compared with placebo. The data supporting zinc for the common cold are mixed. Antihistamines, antihistamine-decongestant combinations, and guaifenesin do not provide greater relief than placebo in adults. In children, antihistamines, decongestants, DM, or combinations of them do not relieve cough better than placebo. Honey may modestly decrease frequency and severity of cough compared with DM or no treatment.