Protection against exercise‐induced bronchoconstriction by montelukast in aspirin‐sensitive and aspirin‐tolerant patients with asthma

<jats:title>Summary</jats:title><jats:p><jats:bold>Background</jats:bold> Montelukast, a cysteinyl‐leukotriene receptor antagonist, was reported to have a protective effect against exercise‐induced bronchoconstriction (EIB). Aspirin‐induced asthma (AIA) is characterized by overproduction of cysteinyl‐leukotrienes.</jats:p><jats:p><jats:bold>Objective</jats:bold> The aim of the study was to compare the response to exercise and the effect of montelukast on EIB in AIA as compared to aspirin‐tolerant asthma (ATA).</jats:p><jats:p><jats:bold>Methods</jats:bold> A placebo‐controlled, double blind, cross‐over randomized study was performed in 19 AIA and 21 ATA patients with stable asthma. A single dose of montelukast (10 mg) or placebo (PL), was given orally one hour prior to exercise challenge. FEV<jats:sub>1</jats:sub> was measured before and 5, 10, 15 min after exercise and then at 15‐minute intervals for 4 h. Urinary LTE<jats:sub>4</jats:sub> excretion and blood eosinophil count were measured at baseline, 2 h and 4 h following exercise challenge.</jats:p><jats:p><jats:bold>Results</jats:bold> Positive bronchial response to exercise was observed in 47.5% of all patients studied. Exercise led to almost identical maximal fall in FEV<jats:sub>1</jats:sub> in AIA and ATA patients (23.5% ± 6.8% vs. 21.8% ± 12.0%, respectively; <jats:italic>P</jats:italic> = 0.7). Montelukast, as compared to PL, significantly attenuated EIB in 63.2% of 19 patients with positive exercise test preceded by PL. The mean of maximum fall in FEV<jats:sub>1</jats:sub> from the pre‐exercise value was 10.2% ± 13.8 after montelukast as compared to 22.5% ± 10.2 after placebo (<jats:italic>P</jats:italic> < 0.001). No significant differences between protective effect of montelukast was observed in AIA as compared to ATA patients (<jats:italic>P</jats:italic> = 0.63, <jats:sc>anova</jats:sc>). Urinary LTE<jats:sub>4</jats:sub> excretion showed no change following exercise, irrespective of the result of the test in all subjects.</jats:p><jats:p><jats:bold>Conclusion</jats:bold> Patients with AIA and ATA react similarly to exercise challenge and obtain similar protection against EIB by montelukast.</jats:p>