Does cetirizine belong to the new generation of antihistamines ? : an investigation into its acute and subchronic effects on highway driving, psychometric test performance and daytime sleepiness.

Twenty-seven healthy male volunteers participated in a double-blind, five-way crossover designed comparison of the new, selective H1-receptor antagonist cetirizine (10 mg q.d.) and terfanadine (60 mg b.i.d. and 120 mg. q.d.) versus the older H1-receptor antagonist triprolidine (5 mg b.i.d.) and placebo. Medication was administred during four consecutive days. Subjects were tested on the 1st and 4th treatment day. On each test day subjects drove an instrumented vehicle over a 100 km highway circuit while attempting to maintain a constant speed (90 km/hr) and a steady lateral position within the right traffic lane.