Heterogeneity in the response of asthmatic patients to pre-exercise treatment with cromolyn sodium.
The protective effect of pre-exercise treatment with cromolyn sodium (CS) on exercise-induced asthma (EIA) was investigated. Ten children and young adults each exercised for 6 min by cycling on a cycle ergometer while breathing cold dry air. Each subject performed 2 tests in which ventilation, heart rate, and gas exchange were closely matched; 15 min prior to each test, the patient inhaled either placebo or CS powder in a double-blind, randomized fashion. All subjects were found to be protected by CS, as manifested by a postexercise fall in FEV1 of 14 +/- 4% SE compared with the control postexercise fall of 39 +/- 5%. All 10 subjects had participated in a previous study (7), and we found that the 3 subjects who were not rendered refractory to EIA by a prior warm humid exercise test were only minimally protected by CS, whereas the 7 other patients who were rendered refractory to EIA, even by warm humid exercise, were greatly protected by CS. This finding suggests that there exists a consistent heterogeneity in the response of asthmatic patients to exercise, possibly related to the individual site of receptors or of airway hyperreactivity.
D000293:Adolescent; D001249:Asthma / Q000188:drug therapy*; D001250:Asthma, Exercise-Induced / Q000175:diagnosis / Q000188:drug therapy*; D002648:Child; D004205:Cromolyn Sodium / Q000627:therapeutic use*; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D008297:Male; D005082:Physical Exertion
D004205:Cromolyn Sodium