Oral Montelukast compared with inhaled salmeterol to prevent exercise-induced bronchoconstriction - A randomized, double-blind trial

Background: Montelukast, an oral, once-daily leukotriene receptor antagonist, provides protection against exercise-induced bronchoconstriction. Objective: To evaluate the effect of 8 weeks of therapy with salmeterol aerosol or montelukast on exercise-induced bronchoconstriction in adults with asthma. Design: 8-week multicenter, randomized, double-blind study. Setting: 17 asthma treatment centers in the United States. Patients: 191 adults with asthma who had documented exercise-induced bronchoconstriction. Intervention: qualified patients were randomly assigned to double-blind treatment with montelukast (10 mg once in the evening) or salmeterol (50 mu g [2 puffs] twice daily). Measurements: Changes in pre-exercise and postexercise challenge values; percentage inhibition in the maximal percentage decrease in FEV,; the area above the FEV1-time curve; and time to recovery of FEV, at days 1 to 3, week 4, and week 8 of treatment. Results: By day 3, similar and statistically significant reductions in maximal percentage decrease in FEV, were seen with both therapies. Sustained improvement occurred in the montelukast group at weeks 4 and 8; at these time points, the bronchoprotective effect of salmeterol decreased significantly. At week 8, the percentage inhibition in the maximal percentage decrease in FEV, was 57.2% in the montelukast group and 33.0% in the salmeterol group (P = 0,002), By week 8, 67% of patients receiving montelukast and 46% of patients receiving salmeterol had a maximal percentage decrease in FEV, of less than 20%, Conclusions: The bronchoprotective effect of montelukast was maintained throughout 8 weeks of study. In contrast, significant loss of bronchoprotection at weeks 4 and was seen with salmeterol. Long-term administration of montelukast provided consistent inhibition of exercise- induced bronchoconstriction at the end of the 8-week dosing interval without tolerance.