Pirbuterol versus orciprenaline aerosols in the treatment of bronchial asthma.

In a multiple-dose, double-blind parallel group study two groups of 19 male outpatients each with chronic pulmonary obstructive disease received either pirbuterol aerosol (0.4 mg) or orciprenaline aerosol (1.3 mg) 3--4 times daily for 12 weeks (after about 1 week of placebo administration). Bronchodilator efficacy persisted throughout the treatment period. However, the initial (week 0) response to pirbuterol, but not orciprenaline, tended to be greater than responses on subsequent test days. Side effects, changes in blood pressure or pulse rate, and clinical chemical abnormalities were of minor clinical importance, but post-inhalation dysrhythmias were seen in four patients receiving orciprenaline. In both treatment groups, some patients showed prolongation in bleeding and/or clotting times.