The effect of montelukast on exhaled nitric oxide and lung function in asthmatic children 2 to 5 years old

Objective: The study was undertaken to investigate the influence of once-daily treatment with montelukast (Singulair; MSD; Glattbrugg, Switzerland) on levels of exhaled nitric oxide (eNO) and lung function in preschool children with asthma. Methods: A total of 30 children (19 girls), 2 to 5 years of age, in whom asthma had been newly diagnosed, who had a positive first-degree family history of asthma and a positive allergy test result, were allocated to undergo a 1-week run-in period of montelukast treatment. eNO and airway resistance were measured in all patients before (visit 1) and after the run-in period (visit 2), and after treatment with montelukast (4 mg once daily) for 4 weeks (visit 3). Results: There were no significant differences in all parameters before and after the run-in period. However, the mean (SD) levels of eNO and the mean (SD) levels of airway resistance after treatment at visit 3 were 11.6 parts per billion (ppb) [9.5 ppb] and 1.15 kPa/L/s (0.26 kPa/L/s), respectively, and were significantly lower compared to values of 33.1 ppb (12.0 ppb) and 1.28 kPa/L/s (0.23 kPa/L/s), respectively, before treatment (p < 0.001) and at visit 2 (p = 0.01). There was no significant change in mean bronchodilator responsiveness between visit 3 (13.2%; SD, 6.8%) and visit 1/visit 2 (13.3%; SD, 7.0%; p = 0.47). Conclusion: We have shown that montelukast has a positive effect on lung function and airway inflammation as measured by nitric oxide level in preschool children with allergic asthma.