Objective: To study the efficacy of montelukast, a cysteinyl leukotriene receptor antagonist, in the treatment and prevention of exercise-induced bronchoconstriction (EIB) in mild asthmatic patients and patients with exercise-induced asthma (EIA).
Methods: Thirty mild asthmatic patients with positive standardized exercise challenge test were enrolled. The subjects received montelukast 10 mg once daily in the evening. Standard exercise challenge was performed before, three days and twenty-eight days after the administration of the drug. The end points included: (1) Area under the percent fall in forced expiratory volume in one second (FEV1) versus time curve (AUC0 to approximately 60 min); (2) Time of recovery to within 5% of the pre-exercise baseline FEV1 value; and (3) Maximal percent fall in FEV1 from pre-exercise baseline.
Results: Montelukast caused significant reduction in AUC0 to approximately 60 min, which was (39 +/- 21)%.min before treatment as compared to (13 +/- 14)%.min and (12 +/- 14)%.min three days and twenty-eight days respectively after the treatment with montelukast. Time of recovery to within 5% of the pre-exercise baseline FEV1 value were (51 +/- 36) min, (26 +/- 28) min and (25 +/- 33) min respectively. The mean maximal percentage decrease in FEV1 after exercise was 44.4% before treatment, 26.8% and 18.2% following montelukast. FEV1 and peak expiratory flow rate (PEFR) were maintained to nearly normal during all the study. Inhale corticosteroid did not prevent EIB/EIA.
Conclusion: Montelukast attenuates and protects against EIB/EIA.