Exercise-induced asthma

Though exercise-induced asthma (EIA) has been recognized for centuries, its characteristics, standardized testing, and pharmacologic management have been clarified only in the last two decades. Controversy continues concerning etiology; whether or not cold air, hypertonic and hypotonic bronchial challenges involve the same mechanism(s); and the incidence and clinical significance of late phase reactions. Aerosolized adrenergic agents such as albuterol or terbutaline, when administered prior to exercise, are usually effective in preventing EIA. Theophylline varies in effectiveness from subject-to-subject as does cromolyn sodium. Other agents such as H-1 antihistamines, ipratropium bromide, calcium channel blockers and adrenocorticosteroids are less effective when used alone, but may be useful when used in association with the more potent drugs.