A controlled study of cromolyn sodium sponsored by the Drug Committee of the American Academy of Allergy

Abstract

Because of several controversial reports concerning the efficacy of cromolyn sodium in the treatment of asthma, the Drug Committee of the American Academy of Allergy instituted a collaborative study in November, 1969. The protocol was designed to select patients according to age, cooperativeness, severity of asthma, and type of asthma—extrinsic, intrinsic, or mixed. The basic design of the study involved a baseline period of one week in which inert filler (lactose) was administered in the Spinhaler apparatus and during which the patient could be familiarized with the complex record keeping. The basal period was followed by two 4 week crossover periods during which cromolyn sodium was alternated with placebo. Symptom scores, drug intake, physician evaluation, patient preference, and simple pulmonary function tests were subjected to statistical analysis. Results gleaned from 252 completed patients indicated a favorable response for the drug as compared to placebo in patient symptom scoring, ephedrine-like drug scores, physician evaluation, and patient preference. A drug carry-over effect extending over a period of 4 weeks created difficulty in assessing results of the placebo period in patients who received active drug during the first 4 week period. Although a favorable drug effect was usually observed when cromolyn sodium was the first drug in the trial sequence, efficacy was more clear-cut during active drug administration in patients who received placebo during the first 4 weeks of the study. The mechanism of this carry-over effect was not apparent. The amelioration index tended to be higher in the pediatric group and in those patients whose asthma was classified as mixed. No change in the objective indices of one-second forced expiratory volume or peak expiratory flow measured once every 2 weeks was obtained. No serious side effects were noted by the participating investigators. These results indicate that cromolyn sodium will be a useful adjunct to the pharmacological treatment of asthma.