Exhaled nitric oxide before and after montelukast sodium therapy in school-age children with chronic asthma: A preliminary study

Exhaled nitric oxide (ENO) is a surrogate marker of airway inflammation in asthma. In 12 children aged 6-11 years with mild to moderate persistent ast hma, ENO concentrations were measured before and after 4 weeks of treatment with montelukast sodium, a leukotriene receptor antagonist, and 2 weeks af ter withdrawal of therapy. Baseline ENO levels (mean and 95% confidence interval) were significantly e levated in patients with asthma compared to age-matched nonasthmatic contro l subjects, with levels of 83 (42-123) vs. 13 (11-15) ppb (P < 0.001). Afte r treatment with montelukast sodium, there was a significant (P < 0.01) red uction in ENO to 58 (27-89) ppb which again rose to 69 (38-99) ppb 2 weeks after treatment was withdrawn. During treatment, the fail in ENO was accomp anied by nonsignificant improvements in prebronchodilator forced expiratory volume in 1 s (FEV1) from 81-85% predicted or reductions in use of albuter ol from a mean of 2.5 to 1.6 puffs/day. Individual ENO measurements and cha nge in ENO concentrations with treatment did not correlate with either pulm onary function changes or use of bronchodilator. These data show that ENO is elevated in children with relatively mild asthm a treated with bronchodilator alone, and that treatment with montelukast so dium for 4 weeks results in a significant reduction in ENO concentrations, even in the absence of significant changes in pulmonary function. These fin dings suggest an anti-inflammatory role for leukotriene D-4 receptor antago nism in the treatment of children with mild to moderate asthma. (C) 1999 Wi ley-Liss, Inc.