Clinical perspective - cough: an unmet need.

Cough is among the most common complaints for which individuals worldwide seek medical attention. The vast majority of cases of acute cough (<3 weeks duration) are due to acute viral upper respiratory tract infection (URI) (common cold). Fortunately, acute cough is typically transient and self-limited. However, should severe and/or persistent acute cough require pharmacological treatment, satisfactory therapeutic options are scarce. Narcotic antitussives are limited by unacceptable side effects at therapeutic doses, and most over-the-counter (OTC) remedies are not supported by adequate clinical trials. The goal in chronic cough (>8 weeks duration) is to meticulously evaluate and treat all potential underlying etiologies. Despite thorough investigation, a significant minority of patients will suffer refractory, unexplained cough. For this challenging population, safe, effective, non-narcotic antitussive therapies are desperately needed.