Cromolyn sodium, five to six years later.

Ninety-five children with difficult to treat asthma were given cromolyn in double-blind, crossover studies. Of these, 70 were studied for the next five to six years by open trial cromolyn prophylaxis to determine decreasing dependency on bronchodilators or corticosteroids. Evaluated at two-month intervals, 28 children required prednisone and bronchodilators, 37 required round-the-clock bronchodilators only and five required neither. Peak expiratory flow rates were below 80% of predicted normal in eight patients, the remaining 62 showed reversibility of airways obstruction. Exercise-induced asthma was reported by 44 during the first two years but persistent improvement in exercise tolerance occurred in 24 patients. IgE specific RAST indicated a continuing extrinsic element in the etiology of 38 of 45 patients tested. Cromolyn was an effective prophylaxis for children with chronic asthma; however, it was difficult to evaluate in 17 steroid-dependent subjects. Attempts to reduce the need for and especially to discontinue steroids were not as successful as other reports indicate.