Controlled Study of a New Inhalant in Asthma and Bronchitis

Abstract

Lung-function tests in 35 asthmatics and 25 bronchitics were used in a double-blind controlled trial to compare the effect and duration of a new sym-pathomimetic aerosol[long dash]isoetharine (Bronchilator) with those of iso-prenaline. The differences between improvements in lung-function tests following both active drugs and the placebo were highly significant. The means of maximum improvements in lung-function tests were much more pronounced in asthmatics than in bronchitics, and were greater after Bronchilator than after isoprenaline. Maximum improvement in FEV1. occurred 30 to 45 minutes after Bronchilator and the effect was still significant at 105 minutes. For isoprenaline, maximum improvement occurred at 15 minutes and the effect was still significant at 90 minutes. The improvement shown in lung-function tests after Bronchilator was greater than that following isoprenaline for at least 2 hours. The observed difference in improvements between the 2 drugs was real and not due to random fluctuation or variation between patients. A mean increase in pulse rate for 15 minutes followed isoprenaline. This was not demonstrated after Bronchilator. Reductions in blood-pressure occurred after both active drugs, and were consistently greater after isoprenaline for at least 90 minutes.