Comparison of cromoglycate (cromolyn) and theophylline in controlling symptoms of chronic asthma. A collaborative study.

28 children with chronic asthma (15 in Denver and 13 in London) completed a 12 wk double-blind trial of treatment with sodium cromoglycate (cromolyn sodium), theophylline, and a combination of both. The three regimens were administered, each for 4 wk, in random sequence as part of a collaborative investigation of the relative efficacy of the two antiasthmatic agents. Cromoglycate was administered by inhalation in standard doses of 20 mg q.i.d. Theophylline dosage was individualized with the assistance of serum-theophylline measurements and averaged 6 mg/kg/dose q.i.d. (range 3-8--8-5 mg/kg/dose). Peak expiratory-flow rates measured twice daily on all patients averaged 75% of that predicted during cromoglycate administration, 79% during theophylline, and 81% during the combined-drug regimen (P less than 0.05). Patients had an average of 59% of days free of symptoms while on cromoglycate and 71% of days symptom-free when on both the theophylline and the combination regimens (P less than 0.025). None of the 13 patients whose asthmatic symptoms were previously controlled with cromoglycate was unable to complete the 4 wk trial with theophylline alone; 1 patient whose symptoms had been previously controlled with theophylline twice developed severe asthmatic symptoms while receiving cromoglycate, and he had to be withdrawn from that study period. No significant differences in adverse effects of the medication were observed during the 12 wk trial.