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

Background: Single doses of inhaled beclomethasone or inhaled cromolyn, given before allergen inhalation, inhibit allergen-induced late asthmatic responses (LARs) and increased airway responsiveness (DELTA log methacholine PC20). We hypothesized that when given 2 hours after allergen, beclomethasone might work better than cromolyn. Methods: In 10 patients with mild, stable, atopic asthma with LARs or DELTA log PC20 or both, we performed a double-blind, double-dummy, random-order trial comparing a single dose of inhaled beclomethasone (500 mug), cromolyn (20 mg), and placebo, administered 2 hours after allergen challenge on LAR and DELTA log PC20. Results: The treatment effect on LAR was significant (p < 0.001). The LAR after beclomethasone (7.3% +/- 6.1%) was significantly less than after cromolyn (20.4% +/- 15.2%) or placebo (26.4% +/- 8.2%); cromolyn was not different from placebo. There was a borderline treatment effect on DELTA log PC20 (p = 0.056) with beclomethasone (0.12 +/- 0.31) less than placebo (0.37 +/- 0.39) but not less than cromolyn (0.34 +/- 0.18). Conclusion: Beclomethasone (500 mug) administered 2 hours after allergen challenge markedly inhibited the LAR and had a small effect on allergen-induced airway responsiveness. Cromolyn (20 mg) was not effective on maximal LAR; a small effect on the early part of the LAR was suggested.