The effect of cromolyn sodium on exercise-induced bronchospasm using a free running system.

This study was designed to assess the effectiveness of comolyn sodium in modifying exercise-induced bronchospasm (EIB). Twenty children and adolescents with EIB were given either cromolyn or placebo in a prerandomized double-blind fashion. They then performed a free running maneuver. Pulmonary function tests were obtained before and after this exercise. Patients returned one week later to repeat the same precedure. This time subjects took placebo if they had previously taken cromolyn and vice versa. Significant beneficial effects of cromolyn were noted in forced vital capacity and forced expiratory volume in one second measurements but not in forced expiratory fhis suggests that larger airway disease is preferentially helped by cromolyn when subjects are stressed maximally as with a free running system. Subjects who received placebo on study day 1 and cromolyn on study day 2 showed the most striking benefit from cromolyn. This may be related to the better baseline status of subjects on day 2 as well as to familiarity with the procedure and medication.