Once daily loratadine versus astemizole once daily.

This study was designed to compare the efficacy and safety of loratadine and astemizole for the treatment of seasonal allergic rhinitis. A total of 167 adult patients with seasonal allergic rhinitis was enrolled in a randomized double-blind, parallel group study. Patients were treated once daily for 2 months during a spring allergy season. Both treatment groups showed significant reduction of symptoms (P < .01) from baseline. The physicians' and patients' evaluations of response to treatment were generally higher for loratadine than astemizole but only reached statistical significance (P < .05) at the 1-week evaluation. Astemizole-treated patients showed statistically significantly more weight gain than did loratadine-treated patients. Loratadine and astemizole were comparable in reducing the signs and symptoms of seasonal allergic rhinitis. Both treatments were well tolerated, although less weight gain was observed in patients treated with loratadine.