Effects of montelukast (MK-0476), a potent cysteinyl leukotriene receptor antagonist, on bronchodilation in asthmatic subjects treated with and without inhaled corticosteroids

Background - Cysteinyl leukotriene release in association with airway inflammation is a feature of clinical asthma. The acute effects of montelukast (MK-0476), a potent, orally administered, specific cysteinyl leukotriene receptor antagonist, on airways obstruction was assessed in patients with mild to moderately severe asthma. Methods - Twenty two asthmatic subjects were randomised to receive montelukast, 100 mg or 250 mg, or placebo in a double blind, three period, crossover trial. Ten of the patients were using concomitant inhaled corticosteroids. Results - Montelukast increased the forced expiratory volume in one second (FEV(1)) from predose baseline values compared with placebo, the percentage point differences between montelukast and placebo being 8.6% (95% CI 3.6 to 13.6) and 8.5% (95% CI 3.5 to 13.5) for the 100 mg and 250 mg doses, respectively. Conclusion - Single oral doses of montelukast 100 mg and 250 mg produced significant increases in FEV(1) irrespective of the concurrent use of inhaled corticosteroids in asthmatic subjects with airflow limitation.