Treatment of bronchial asthma with terfenadine; a randomized controlled trial

1. Terfenadine, a histamine H1-receptor antagonist, was studied in 52 patients with stable mild perennial asthma with an allergic basis. 2. After a placebo run-in period, patients were randomly allocated to either terfenadine 120 mg twice daily or placebo. After 2 weeks they were crossed over to the other treatment. Forty-six patients completed the study. 3. Terfenadine was significantly more effective than placebo as measured by peak expiratory flows and by symptom scores. 4. These results suggest that histamine may play a more significant role in asthmatic bronchoconstriction than is currently recognised.