Effect of a single graded dose of terbutaline tablets in patients with chronic bronchitis and bronchoconstriction. A double-blind, placebo, cross-over study.

Terbutaline, a selective beta2-adrenergic receptor stimulator was given to 10 patients with chronic bronchitis. The effects of the drug were tested by measurements of forced expiratory volume in 1 sec (FEV1), peak expiratory flow rate (PEFR), heart rate, blood pressure and blood gas analysis. The measurements were performed before and 1, 2, 4, 5, and 6 h after oral administration of placebo, 2.5 mg, or 5.0 mg terbutaline. Terbutaline caused a significant dose-related increase in FEV1 and PEFR as compared with placebo. The maximal effects were found at the 4-h measurement and were still present at the measurements performed at 6 h. Heart rate, blood pressure and arterial oxygen tension (PaO2) were not significantly affected. Four patients experienced side effects as tremor and/or heart palpitations. It is concluded that orally administered terbutaline may be an important therapeutical agent in the treatment of chronic bronchitis.