Evaluation of the efficacy and safety of loratadine in perennial allergic rhinitis.

Loratadine, a new nonsedating antihistamine, was evaluated for efficacy and safety in 228 patients with perennial allergic rhinitis. Taken at a dose of 10 mg once daily, loratadine was significantly more effective than placebo and comparable to terfenadine, 60 mg taken twice daily, in reducing combined symptom scores in this patient population. Efficacy was maintained throughout the 28-day course of treatment. The overall incidence of side effects with loratadine was low (14%) with few occurrences of sedation (3%) and dry mouth (4%).