The Longterm Treatment of an Asthmatic Patient Using Phentolamine

¹ National Jewish Hospital and Research Center, Denver

A 45-year-old woman who incapacitated by severe exercise-induced asthma is presented. Phentolamine, a drug with adrenergic blocking properties significantly reduced after-exercise bronchospasm, which had been uncontrolled by treatment with xanthines, antihistamines, ephedrine, steroids, isoproterenol and cromolyn sodium. Using a double-blind protocol, blocking of exerciseinduced bronchospasm was demonstrated by both acute inhalation of phentolamine, 5 mg, and longterm oral administration of phentolamine, 300 mg/day. Two right heart catheterizations, one performed after placebo for six days, the other after orally administered phentolamine for over a month, showed little difference in her cardiovascular response to exercise, thus suggesting a direct effect of phentolamine on bronchial smooth muscle.