COMPARISON OF EBASTINE TO CETIRIZINE IN SEASONAL ALLERGIC RHINITIS INADULTS

Background: Second-generation histamine H-1-receptor antagonists are a ccepted first-tine systemic therapy for seasonal allergic rhinitis. Eb astine is a new histamine H-1-receptor blocker that may differ in effi cacy from currently used second-gener ation agents. Objective: To comp are the efficacy of daily treatment with ebastine, 10 mg, ebastine, 20 mg, or cetirizine, 10 mg, for relieving symptoms of seasonal allergic rhinitis in adults. Methods: In this multicenter, double-blind study, outpatients were randomized to one of three parallel treatment groups : ebastine, 10 mg, ebastine, 20 mg, or cetirizine, 10 mg once daily in the morning for a 2-week period. Patients were evaluated clinically a ccording to symptoms, discomfort, and a global assessment at baseline and on days 8 and 15 of treatment. The total symptom score, defined as the sum of the total morning score on the day of evaluation and the t otal evening score on the preceding day, was the primary efficacy para meter. Results: Ebastine, 20 mg (n = 111), ebastine, 10 mg (116), and cetirizine, 10 mg (116), were all effective for improving nasal and oc ular symptoms. There was, however, a general trend towards more rapid relief of symptoms with ebastine, 20 mg, and this reached statistical significance in some efficacy parameters after the first week of treat ment. In a subpopulation of 158 patients who presented with more sever e symptoms, statistically significantly greater improvement was seen w ith ebastine, 20 mg, compared with ebastine, 10 mg, as indicated by th e mean change from baseline in the total symptom score averaged over t he treatment period(-13.7 +/- 4.7 vs -11.8 + 3.8; P = .027) and in the morning symptom score (-6.7 +/- 2.7 vs -5.7 +/- 2.2; P = .042). All t hree treatments were well tolerated. Dry mouth, headache, and somnolen ce were the most common adverse events. Conclusion: Ebastine (10 mg), cetirizine (10 mg), and ebastine (20 mg) administered orally once dail y for 2 weeks all appear to be effective for relieving the symptoms of seasonal allergic rhinitis. Ebastine, 20 mg, may have advantages over ebastine, 10 mg, and cetirizine, 10 mg, in terms of a reduced time to achieve maximal efficacy and a superior level of efficacy in patients with more severe symptoms.