Background: Treatment with inhaled steroids is an effective method of reducing bronchoconstriction and airway inflammation after allergen challenge. However, the duration of the protective effects of inhaled steroids after discontinuation of therapy has not been established.
Objective: We sought to evaluate the protective effect of 1 week of inhaled steroid therapy against inhaled allergen challenge 12 hours after discontinuation of therapy.
Methods: In this randomized, double-blind, placebo-controlled crossover trial, 26 asthmatic subjects (>18 years old) not using inhaled steroids were administered 200 microg of budesonide twice daily, 200 microg of fluticasone twice daily, or placebo twice daily for 1 week. Twelve hours after discontinuation of therapy, subjects were administered an inhaled allergen challenge. Each treatment period was separated by a 3-week washout period.
Results: When compared with placebo (26% +/- 14%), there was a slight but significant protection against the allergen-induced early response after fluticasone treatment (19% +/- 10%, P = .001) but not after budesonide treatment (23% +/- 13%, P = .08). However, when the area under the curve for the early airway response was examined, there was no difference between the 2 drugs in the amount of protection ( P = .62). Partial protection was demonstrated against the late-response allergen-induced sputum eosinophilia with both treatments ( P = .001). By contrast, no protection was observed against allergen-induced airway hyperresponsiveness for either treatment.
Conclusions: The protective effects of inhaled steroids against allergen-induced early responses, airway eosinophilia, and allergen-induced airway hyperresponsiveness are partially or completely lost as early as 12 hours after discontinuation of therapy.