Clinical trial of 3 days of treatment with oral pseudoephedrine for the common cold in the southern hemisphere.

Background: Single-dose studies indicate that pseudoephedrine (PSE) provides moderate relief for congestion in coryza, but there is a lack of repeated-dose studies.

Methods: Two hundred sixteen subjects participated in this double-blind, randomized placebo-controlled trial over 3 days. Measurements included posterior rhinomanometry, acoustic rhinometry, and subjective measures of congestion using a categorical scale and visual analog scale (VAS). Treatment was with one 60-mg PSE tablet four times daily or matching placebo.

Results: After the first dose, PSE relative to placebo consistently showed small improvements for all objective assessments of nasal congestion. The prespecified primary efficacy outcome (day 1 nasal airway resistance area under the curve) was not significantly different between groups. PSE produced a 5.5% (p = 0.031) increase in total nasal volume for 0.5-3 hours after dosing. A pooled analysis of days 1 and 3 data showed a VAS score decrease of 7.0% (p = 0.072) for the 0.5- to 3-hour period on PSE.

Conclusion: PSE showed small but nonsignificant improvements in objective assessments of nasal congestion relative to placebo after a single dose.