Background: Montelukast is a widely used controller agent in childhood asthma. It is modestly effective in reducing symptoms, decreasing the need for rescue albuterol, and improving forced expiratory volume in 1 second (FEV1).
Objective: To determine whether montelukast therapy improves peripheral airway obstruction as measured by lung volumes, air trapping, airway resistance (Raw), and specific conductance (Sgaw).
Methods: Twenty-one children aged 9 to 18 years with mild-to-moderate asthma were randomized into a double-blind, placebo-controlled study to receive montelukast (5 or 10 mg) or matching placebo daily for 8 weeks. Symptoms and albuterol use were recorded twice daily, and exhaled nitric oxide measurement, forced oscillometry, spirometry, and body box plethysmography (before and after beta-agonist use) were performed at randomization and at 2, 4, 6, and 8 weeks. Circulating eosinophil counts and serum eosinophil cationic protein (ECP) levels were obtained at randomization and at 8 weeks.
Results: Montelukast-treated patients had lower residual volume (P = .05), residual volume-total lung capacity ratio (P = .04), Raw (P = .02), Sgaw (P = .03), and serum ECP levels (P = .02) at 8 weeks compared with those treated with placebo. There was a trend toward reduced daytime and nighttime albuterol use, although the difference did not reach statistical significance. There were no significant differences in FEV1, FEV1-forced vital capacity ratio, exhaled nitric oxide levels, or daytime and nighttime symptom scores between the 2 groups.
Conclusions: Montelukast therapy was associated with less air trapping, hyperinflation, and Raw and better Sgaw compared with placebo. Lower serum ECP levels, a surrogate measure of airway inflammation, were associated with improvements in lung function.