Background: The protective effect of a new long acting beta 2-agonist, salmeterol, against exercise-induced bronchoconstriction has been documented when given as inhaled aerosol.
Objective: The aim of the present study was to examine the duration of the protective effect of a single dose of salmeterol, 50 micrograms, inhaled as dry powder, against exercise-induced bronchoconstriction.
Methods: Sixteen patients with reproducible exercise-induced bronchoconstriction were challenged on a treadmill on two prestudy visits and six study days. The patients were challenged 4, 8, and 12 hours postdosing. The study was designed as a double blind placebo-controlled randomized crossover trial.
Results: Statistically significant differences in % maximum fall in PEFR were found at four and eight hours postdosing, in favor of salmeterol. At 12 hours postdosing, no clear statistical inference was possible, owing to the presence of a statistical carry-over effect; however, significant differences in area under curve in favor of salmeterol were found at 4, 8, and 12 hours postdosing.
Conclusion: Salmeterol, 50 micrograms, dry powder inhalation had a protective effect against exercise-induced bronchoconstriction up to 12 hours postdosing, as compared with placebo. No adverse effects were identified.