Comparative study of the efficacy and tolerance of terfenadine and clemastine in patients with seasonal allergic rhinitis.

The efficacy and tolerance of alpha-[4-(1,1-dimethylethyl)phenyl]-4-(hydroxyphenylmethyl)-1- piperidinebutanol (terfenadine, RMI 9918, Triludan, Teldane, resp.) and clemastine were investigated in 20 patients in a single blind, randomized clinical study of three months duration. A total of 15 patients was treated with terfenadine (2 X 60 mg/day), and five patients were treated with clemastine (2 X 1 mg/day). Clemastine and terfenadine were applied as a prophylaxis against seasonal allergic rhinitis. No change in body function or in laboratory values (heart rate, respiratory rate, body temperature, and blood pressure) was seen after antihistamine treatment. Two patients taking clemastine reported moderate sedation. No sedative effects were reported in the terfenadine group. Two patients in the clemastine group and one patient in the terfenadine group had an attack of allergic rhinitis during the study. In this study terfenadine showed good efficacy and tolerance similar to that reported by former clinical studies. It should be emphasized that sedation was not observed with terfenadine.