Effect of Montelukast on Exhaled Leukotrienes and Quality of Life in Asthmatic Patients

Study objectives In some patients with asthma treated with inhaled corticosteroids, suppression of inflammation is incomplete. This may be because the effect of corticosteroids on cysteinyl-leukotriene (cys-LT) biosynthesis is limited. Montelukast is a cys-LT antagonist that significantly improves asthma control in corticosteroid-treated asthmatic patients. However, not all patients treated with cys-LT antagonists show a clinical improvement. Design We have studied the effect of treatment for 4 weeks with montelukast (10 mg/d) on exhaled cys-LTs and leukotriene B 4 (LTB 4 ), exhaled nitric oxide, asthma quality of life (AQL), and respiratory function in patients with stable asthma. Setting Asthma clinics in general practice. Patients We studied 50 patients (30 men; mean ± SEM age, 53 ± 2 years) who were treated with inhaled corticosteroids. Measurements and results We detected cys-LTs in exhaled breath condensate in 25 of 50 patients; however, in the normal nonasthmatic subjects, cys-LTs were below the limit of detection. After treatment with montelukast, there was a fall in cys-LT concentrations from 14.6 ± 3.3 to 8.5 ± 2.6 pg/mL after 2 weeks (p > 0.05) and to 3.9 ± 1.3 pg/mL after 4 weeks (p 4 levels were also elevated. After treatment with montelukast, LTB 4 levels fell from 33.0 ± 3.9 to 20.4 ± 2.5 pg/mL after 2 weeks of treatment (p 4 were associated with significant improvements in AQL scores. Conclusions It appears that in some patients with stable asthma treated with inhaled corticosteroids, the suppression of inflammation is incomplete. Adding a leukotriene receptor antagonist can provide a complementary effect of controlling inflammation, with a significant improvement in quality of life.