The September/October issue of the Journal of Allergy and Clinical Immunology in Practice contained a randomised, controlled trial published by Meltzer et al. The FDA had previously noted that sufficiently powered, multicentre, dose-ranging studies were needed to evaluate the efficacy and safety of phenylephrine hydrochloride used orally as a nasal decongestant.

This study investigated the efficacy of 10, 20, 30 or 40mg phenylephrine versus placebo. The primary endpoint was the average change from baseline over seven days of a participant-rated congestion score recorded 12 hourly.

No dose between 10 and 40mg was significantly more effective than placebo in the amelioration of congestion associated with seasonal allergic rhinitis. The authors recommended that the FDA monograph on OTC cough, cold, allergy, bronchodilator and asthma medications should be revised in line with their findings.