Double-blind trials of inhaled beclomethasone diproprionate and fluocortin butyl ester in allergen-induced immediate and late asthmatic reactions.

The blocking effects of inhaled beclomethasone dipropionate (BDP) and fluocortin butyl ester (FCB) on the immediate and late asthmatic reactions induced by inhaled allergen were studied in two trials. In the first, a double-blind cross-over trial compared BDP (800 micrograms daily as powder) with FCB 8 mg daily (1:20 by wt.-Formulation 1). The second trial was identical in design and compared FCB 8 mg daily (1:20) with FCB 8 mg daily as Formulation 2 (1:40). Known BDP, 400 micrograms daily by pressurized aerosol was studied at the end of the second trial. Allergen provocation was performed before and after 7 days treatment with each drug, with a 2-week interval between each drug. Overall, a blocking index for the immediate reaction of greater than 50% was obtained in ten of twenty patients (50%) using BDP, and five of twenty-one (25%) using FCB (P less than 0.01). The late reaction was blocked in nine of eleven (82%) instances on BDP, and four of fourteen (33%) on FCB. Contrary to earlier reports, inhaled corticosteroid agents used for several days prior to bronchial challenge, were found to block both the immediate as well as the late reaction in many individuals.