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 H-1-receptor antagonist cetirizine (10 mg q.d.) and terfenadine (60 mg b.i.d. and 120 mg q.d.) versus the older H-1-receptor antagonist triprolidine (5 mg b.i.d.) and placebo. Medication was administered 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. Thereafter they performed three computerized memory tasks. On the 4th treatment day, sleep latency was measured before and after the driving test. On both days, triprolidine significantly impaired performance in the driving and psychometric tests. Triprolidine also significantly reduced sleep latency in comparison to placebo on the 4th treatment day. Terfenadine 60 mg b.i.d. impaired psychometric performance after subchronic treatment. It was concluded that cetirizine, like terfenadine, belongs to the newer class of antihistamines and can be safely used by patients who continue their daily activities.