Dose-response comparison of broxaterol and salbutamol pressurized aerosols

The bronchodilating activity and tolerability of broxaterol and salbutamol administered by pressurized metered dose inhalers have been compared in 9 adult patients with bronchial asthma and clinically stable and reversible bronchospasm. Placebo was used as a control. On 3 different days broxaterol and salbutamol in cumulative doses of 100, 200 and 400 micrograms and placebo were administered every 30 min according to a double-blind, Latin-square design. After each dose of broxaterol and salbutamol the increases in FVC and FEV1 were always significantly larger than after placebo. Broxaterol at the doses tested induced a bronchodilator response which depended on the dose according to a relation not significantly different from a straight line, and with a potency at least comparable to that of salbutamol. The tolerability of the two drugs was good: only in 1 patient were slight tremors observed after the highest dose of each drug. The bronchodilating activity and the tolerability of broxaterol were not significantly different from those of salbutamol at the same doses.