EFFICACY AND DURATION OF SALMETEROL POWDER INHALATION IN PROTECTING AGAINST EXERCISE-INDUCED BRONCHOCONSTRICTION

Background: The protective effect of a new long acting beta(2)-agonist , salmeterol, against exercise-induced bronchoconstriction has been do cumented when given as inhaled aerosol. Objective: The aim of the pres ent study was to examine the duration of the protective effect of a si ngle dose of salmeterol, 50 mu g, inhaled as dry powder, against exerc ise-induced bronchoconstriction. Methods: Sixteen patients with reprod ucible exercise-induced bronchoconstriction were challenged on a tread mill on two prestudy visits and six study days. The patients were chal lenged 4, 8, and 12 hours postdosing. The study was designed as a doub le blind placebo-controlled randomized crossover trial. Results: Stati stically significant differences in % maximum fall in PEFR were found at four and eight hours postdosing, in favor of salmeterol. At 12 hour s postdosing, no clear statistical inference was possible, owing to th e presence of a statistical carry-over effect; however, significant di fferences in area under curve in favor of salmeterol were found at 4, 8, and 12 hours postdosing. Conclusion: Salmeterol, 50 mu g, dry powde r inhalation had a protective effect against exercise-induced bronchoc onstriction up to 12 hours postdosing, as compared with placebo. No ad verse effects were identified.