Clinical study of broncholytic effect and side-effects of isoetharine ('Numotac')

In thirty-nine adult asthmatics a clinical trial was carried out with 10 mg slow-release tablets of isoetharine ('Numotac', 3M Riker) at two dose levels: 10 mg and 20 mg four times a day. The trial was double-blind with crossover after six weeks. Twenty-three patients reported a positive effect on their respiratory symptoms when isoetharine had replaced their previous treatment; negative effect was reported by one patient while twelve patients were undecided. Tremor was a common side-effect but except in three cases it was slight. There was no difference in side-effects between the high and the low doses if the initial dose was low. However, there were significantly more side-effects when the trial was started with the high dose.