Dose-dependent effects of inhaled mometasone furoate on airway function and inflammation after allergen inhalation challenge

Comparisons of the potency of different inhaled corticosteroids, delivery d evices, and treatment regimens in the management of asthma can only be made when outcome measurements display a dose-dependent effect. These outcomes have been difficult to identify. In this study, we compared in a randomized , double-blind, crossover design, the effects of 6 d treatment with placebo and three doses (50, 100, and 400 mug, twice daily) of mometasone furoate delivered by dry powder inhaler (MF-DPI) on responses after allergen Inhala tion challenge. Twelve mild asthmatic subjects with dual responses after al lergen inhalation were studied. Outcome measurements included early and lat e asthmatic responses, the change in methacholine airway responsiveness 24 h after challenge, and sputum eosinophilia measured 7 and 24 h after challe nge. All three doses of MF-DPI demonstrated similar attenuation of early re sponses and allergen-induced airway hyperresponsiveness relative to placebo (p < 0.05). The late maximal %fall in FEV1 after placebo treatment was 23. 5% and was significantly reduced in a dose-dependent manner to 12.3%, 11.0% , and 5.9% for the 50-, 100-, and 400-mug twice-daily treatments (p = 0.007 ). The allergen-induced increase in sputum eosinophilia (x 10(4) cells/ml) 24 h after challenge during placebo treatment was 60.2 and was significantl y reduced to 24.0, 15.3, and 6.2 for the 50-, 100-, and 400-mug twice-daily treatments. MF-DPI is effective at attenuating allergen-induced early and late responses, airway hyperresponsiveness, and sputum eosinophilia, and do se-response effects exist for the attenuation of the late response.