Abstract
Background: Ketotifen, an anti-allergic drug with a histamine H1-receptor antagonistic component, has demonstrated sedative effects upon oral administration. The objective of our study was to investigate whether the topical use of ketotifen via the ocular and/or nasal route produced any sedative effects.
Methods: Twelve healthy young male volunteers received each of the following treatments on four different occasions in a randomized, double-blind, Latin-square, placebo-controlled design: (A) ketotifen eye drops (1 mg) + ketotifen nasal drops (1 mg); (B) ketotifen eye drops+ placebo nasal drops; (C) placebo eye drops+ ketotifen nasal drops ; and (D) placebo eye drops + placebo nasal drops. Before and 1 and 2 hours after each treatment the random number addition test (RNAT), digit symbol substitution test (DSST), critical fusion frequency threshold (CFFT) and the visual analog scale (VAS) for subjective feeling of sedation were measured.
Results: Neither RNAT nor DSST showed significant changes after ocular and/or nasal administration of ketotifen. The co-administration of ketotifen via the ocular and nasal routes significantly reduced CFFT (p<0.05). VAS showed no significant changes in the subjective feeling of sedation.
Conclusion: Topical combined use of ketotifen via the ocular and nasal routes led to an impaired response on CFFT.
