Anti-inflammatory and Lung Function Effects of Montelukast in Asthmatic Volunteers Exposed to Sulfur Dioxide

摘要

Background: Sulfur dioxide (SO2) gas may induce acute asthmatic responses when inhaled bynindividuals in the setting of community or occupational air pollution during exercise. Somenasthma medications mitigate the SO2 response, which is not fully understood but appears toninvolve multiple mechanisms.nObjective: We tested the hypothesis that pretreatment with the cysteinyl-leukotriene inhibitornmontelukast sodium protects against the inflammatory and bronchoconstrictive effects of SO2 innthe airways of asthmatic subjects.nMethods: Asthmatic volunteers (enrolled, 12 subjects; completed study, 11 subjects) were exposednto 0.75 ppm SO2 for 10-min periods during exercise (mean ventilation, 35 L/min) and werenexposed similarly to filtered air (control condition) after double-blinded pretreatments withnmontelukast (10 mg/d for 3 days) and placebo.nResults: After montelukast pretreatment, specific airways resistance, FEV1, symptoms, andneosinophil counts in induced sputum showed statistically and clinically significant improvementsnin preexposure measurements and/or decreased responses to SO2 exposure or exercise. The meannFEV1 immediately after exposure was 95% of baseline FEV1 with montelukast pretreatment vsn82% with placebo.nConclusion: Montelukast significantly protects against airways eosinophilic inflammation andnbronchoconstriction from SO2 exposure during exercise. This implies a role for leukotrienes innSO2-induced lung effects. (CHEST 2001; 119:402–408)