BECLOMETHASONE GIVEN AFTER THE EARLY ASTHMATIC RESPONSE INHIBITS THE LATE RESPONSE AND THE INCREASED METHACHOLINE RESPONSIVENESS AND CROMOLYN DOES NOT

Purpose of the Study. To investigate whether beclomethasone or cromolyn provides any protection from the late asthmatic response if given after the allergen exposure. Methods. Ten patients with mild, stable, atopic asthma with late asthmatic responses entered a double blind, double dummy trial comparing a single dose of inhaled beclomethasone (500 µg), cromolyn (20 mg), and placebo administered 2 hours after allergen challenge on the severity of the late asthmatic response and the change in the log of PC20 methacholine. Findings. The late asthmatic response after beclomethasone of 7.3% ± 6.1% decrease in FEV1 was significantly less than that experienced after cromolyn (20.4% ± 15.2%) or placebo (26.4% ± 8.2%); cromolyn was not different than placebo. There was a trend for the change in log PC20 methacholine to be less following beclomethasone administration than that seen with placebo or cromolyn. Reviewer's Comments. It is well known that a single dose of cromolyn given before allergen exposure inhibits both the early and late phase response, whereas beclomethasone given prior to exposure will only prevent the late phase response. However, many individuals don't plan ahead well enough and need to know what medication should be taken if they have forgotten to take any pretreatment. This study indicates that, if bedomethasone, albeit in a dose equal to 12 puffs of the U.S. concentration, is taken even as late as 2 hours after the exposure, it can significantly inhibit the development of the late phase response. Cromolyn given at that time provides only minimal benefit.