Zeidler MR, Kleerup EC, Goldin JG, et al. Eur Respir J. 2006;27:307–315
PURPOSE OF THE STUDY. To assess the effects of montelukast on regional air-trapping, airway hyperresponsiveness, and small-airway physiology using quantitative image analysis with high-resolution computed tomography (HRCT).
STUDY POPULATION. Sixteen patients (7 women, 9 men) aged 18 to 65 with no use of inhaled corticosteroids for the past 2 months, a forced expiratory volume in 1 second (FEV1) of >60% predicted, a provocation dose that causes a 20% decrease in FEV1, and a clinical diagnosis of asthma.
METHODS. The study was designed as a randomized, double-blind, placebo-controlled crossover trial. Subjects received either montelukast 10 mg or a placebo given once daily in the evening for 4 weeks. The subjects then crossed over to the alternate treatment for 4 more weeks. Regional air-trapping was assessed by HRCT at residual volume before and after methacholine challenge and was performed at baseline and after each of the drug phases was complete. Other indices of hyperresponsiveness and physiology were measured as well.
RESULTS. Significantly less regional air-trapping was seen on the premethacholine images of patients treated with montelukast. However, no effect on increases in regional air-trapping was seen on the postmethacholine images in these same patients. There were no differences seen in global indices of small-airways physiology between montelukast and placebo. Montelukast resulted in improved quality-of-life scores.
CONCLUSIONS. Montelukast improved small-airways disease in asthmatic subjects, but this improvement can only be detected by HRCT, not by physiologic studies.
REVIEWER COMMENTS. Although montelukast improved distal airway function, it is noted that at baseline, the patients in the montelukast group showed a greater degree of air-trapping, and this difference cannot be excluded as having an effect on the findings. One question that this study raised is why montelukast's beneficial effects are only measurable with HRCT and not by physiologic means. The authors alluded to the poor sensitivity of physiologic indices and their large degree of intrasubject test variability. They also refer to the inhomogeneous pattern of small-airway involvement and the greater reliability of computer-derived quantitative image analysis versus qualitative radiographic techniques. Sample size was also limited in this study, which involved only mildly asthmatic subjects, indicating that further and expanded studies need to be performed. Montelukast's inability to reduce hyperresponsiveness to methacholine should also be investigated further.
- Copyright © 2007 by the American Academy of Pediatrics