Asthma: comparative bronchodilator effects of ipratropium bromide and isoproterenol.

The effect of ipratropium bromide administered at two dosage levels, 40 and 80 mug, isoproterenol, 150 mug, and placebo using a metered dose inhaler was evaluated in ten adult patients with asthma in a double-blind, crossover study. The new atropine-like drug proved to be as effective a bronchodilator as isoproterenol in this study, although it had a later peak effect. Ipratropium bromide had a longer course of action than isoproterenol (4 hours compared to 1-2 hours) and was free of significant side effects. The larger dose of the new drug produced a slightly greater and longer-acting effect than the smaller dose. Ipratropium bromide seems to have had bronchodilator effects on both large and small airways.