Evaluation of a new bronchodilating compound (broxaterol) administered as a pressurized aerosol.

The bronchodilating activity and the tolerability of a new beta 2-agonist, broxaterol hydrochloride, administered in single doses of 200 and 400 micrograms as pressurized aerosol were studied in 12 adult patients with reversible airway obstruction, taking placebo as a control. A double-blind three-way cross-over design using a series of randomly chosen latin squares was employed. FVC, FEV1, MMEF, heart rate, and blood pressure were measured immediately before and 7.5, 15, 30, 60, 120, 180, and 240 min after each treatment. Our results show that broxaterol is an effective bronchodilating drug with a dose-related activity. The areas under the curves of the changes in FVC, FEV1, and MMEF after the 400 micrograms dose were found to be significantly greater as compared to the 200 micrograms dose. Both broxaterol doses produced significant increases in all the spirometric indices already at the first measurement, i.e., 7.5 min after treatment. Broxaterol 400 micrograms induced significant increases in FVC, FEV1, and MMEF through at least 4 h. The tolerability of the new compound was good.