A trial of an alpha-adrenoreceptor blocking drug (indoramin) in exercise-induced bronchoconstriction.

In 10 patients with exercise-induced asthma oral indoramin, an alpha adrenoreceptor blocking drug, was ineffective in preventing the post-exercise fall in peak expiratory flow rate (PEFR). The values of PEFR at rest increased after administration of indoramin, providing indirect evidence for the existence of alpha receptors in the bronchial smooth muscle of asthmatic subjects.