DOUBLE-BLIND COMPARISON OF CETIRIZINE AND PLACEBO IN THE TREATMENT OF SEASONAL RHINITIS

The efficacy and safety of cetirizine were evaluated in 419 patients with seasonal allergic rhinitis. Using a 4-way, double-blind randomization schedule, patients were given a 1-week course of once daily cetirizine (5, 10, or 20 mg) or placebo. Patient and physician efficacy ratings corresponded, indicating superiority of cetirizine to placebo (P < .05) in reducing symptom severity scores for sneezing, rhinorrhea, ocular pruritus, watering of the eyes, and redness of the eyes. All cetirizine doses achieved higher efficacy ratings (72.7%. 79.2%, and 75.7%, respectively) than placebo (52.9%; P < .05) by the physician's global assessment. Cetirizine was well tolerated, with sedation being the most common adverse experience, increasing in frequency at higher doses. A dose-response relationship was evident for selected symptoms, and the once daily 5-mg dose was found to be an effective minimum dose.