A parallel-group comparison of astemizole and loratadine for the treatment of perennial allergic rhinitis.

The efficacy and safety of the two antihistamines, astemizole and loratadine, were compared in a double-blind study of 84 patients with perennial allergic rhinitis. Patients were randomized to receive orally either astemizole 10 mg once daily (n = 40) or loratadine 10 mg once daily (n = 44) for 1 week. No other antirhinitis medication was allowed during the study. By day 7 the mean daily symptom scores, recorded on diary cards, were lower in patients receiving astemizole than in those receiving loratadine for runny nose, itchy nose and sneezing, although not for blocked nose, and treatment differences only reached statistical significance for runny nose. After 7 days, 53.75% of patients on astemizole and 38.6% on loratadine were free of symptoms, and 87% of patients on astemizole described the treatment as good or excellent compared with 62% on loratadine. The present results suggest that astemizole may be more effective than loratadine in controlling symptoms of perennial allergic rhinitis.