A double-blind, placebo-controlled crossover trial consisting of two four-week treatment periods was carried out with cromolyn sodium in 54 children. Patients selected were severe, chronic asthmatics with reversible airway obstruction and positive skin tests.
Symptoms of wheezing, breathlessness, tightness, and coughing were significantly less in most of the patients during the active-drug period as compared with the placebo period. Of the pulmonary function tests, only the increase in forced expiratory volume—one second (FEV1), measured biweekly, reached statistical significance in favor of cromolyn. Of the children, 20% became essentially asymptomatic while on the drug and 65% more were improved to some degree.