Antitussive Effect of a Naturally Flavored Syrup Containing Diphenhydramine, Compared With Dextromethorphan and Placebo

Antitussive Effect of a Naturally Flavored, Multi-Component Syrup Containing Diphenhydramine, Compared With Dextromethorphan and Placebo

The purpose of this study is to evaluate the antitussive (cough-suppressing) effects of two liquid medications: a combination of diphenhydramine and phenylephrine in a naturally cocoa flavoring, and, dextromethorphan syrup, compared with placebo.

Inclusion Criteria:

• healthy adult nonsmokers
• onset of acute, viral upper respiratory tract infection (common cold) within 72 hours of enrollment

Exclusion Criteria:

• smokers
• history of asthma or other respiratory disorders