Child assessment of dextromethorphan, diphenhydramine, and placebo for nocturnal cough due to upper respiratory infection.

This study sought to investigate the efficacy of dextromethorphan (DM), diphenhydramine (DPH), and placebo (PL) for symptoms attributed to upper respiratory infections as determined by children, and to evaluate the concordance of perception of nocturnal symptoms between children and parents. A total of 37 children age 6 to 18 years of age were randomized in a double-masked fashion to receive a single bedtime dose of DM, DPH, or PL. Children found no significant difference in the effect of DM, DPH, or PL for any study outcome, and responses by parents and children were significantly correlated.