Mometasone furoate antagonizes AMP-induced bronchoconstriction in patientswith mild asthma

Background: Mometasone furoate (MF) is a new potent corticosteroid for use in treating asthma. Objective: To test the lower range of the dose-response curve, effects of M F delivered by dry ponder inhaler (DPI) AMP-induced bronchoconstriction wer e compared with those of placebo. Methods: In a placebo-controlled, 3-phase cross-over, single-center, double -blind study, 15 patients with mild asthma were randomized to three 2-week treatment phases (separated by 4-week washout phases) with MF DPI 50 mu g t wice daily, MF DPI 100 mu g twice daily, or placebo. AMP challenge was perf ormed before and at the end of each treatment phase. Results: Thirteen patients completed all 3 phases and were included in the primary efficacy analysis. Treatment with MF DPI 50 mu g twice daily or wit h MF DPI 100 mu g twice daily significantly reduced the bronchoconstrictor response to AMP, displacing the dose-response curve to the right by 2.81 an d 3.11 doubling dilutions, respectively, compared with placebo (P < .0001). The improvement in FEV1 over the 2-week treatment phase was significantly (P less than or equal to .033) greater during treatment with MF DPI 50 mu g or 100 mu g twice daily then with placebo. Peak expiratory flow rate, whee zing scores, difficulty breathing scores. nocturnal awakenings requiring sa lbutamol, and puffs of salbutamol per day also indicated a greater improvem ent in respiratory function and symptoms of asthma with MF DPI 50 or 100 mu g twice daily than with placebo. Both doses of MF DPL were well tolerated. Conclusions: Treatment Kith low doses of MF DPI decreased airway responsive ness to AMP challenge and improved secondary measures of pulmonary function and asthma symptoms.