title: Montelukast improves regional air-trapping due to small airways obstruction in asthma.
abstract: Quantitative image analysis of high-resolution computed tomography (HRCT) performed at residual volume, before and after methacholine, is a sensitive method of detecting small airways involvement in asthma and response to therapy targeted to the small airways. Since an oral anti-leukotriene reaches the small airways via the circulation, the present authors hypothesised that treatment with montelukast would lead to improved small airway patency. A double-blind crossover study compared the effect of montelukast versus placebo for 4 weeks in 16 mild-to-moderate steroid-naïve asthmatics. Small airways function was evaluated by HRCT at residual volume before and after methacholine to assess regional air-trapping and airways hyperresponsiveness, as well as by physiological studies of small airways. Montelukast treatment resulted in significantly less regional air-trapping on HRCT on the pre-methacholine images when compared with placebo, as well as improvement in total quality of life scores and symptom sub-scores. However, montelukast treatment had no effect on increases in regional air-trapping on HRCT in response to methacholine. No differences were noted in global measures of small airways physiology between placebo and montelukast. In conclusion, distal airways disease improves in asthmatic subjects treated with montelukast. This improvement can be detected with high-resolution computed tomography, but not with conventional physiological studies.
authors.affiliation: Division of Pulmonary, Critical Care Medicine and Hospitalists, David Geffen School of Medicine at the University of California, Los Angeles, CA 90095-1690, USA. mzeidler@mednet.ucla.edu
authors.forename: M R
authors.initials: MR
authors.lastname: Zeidler
authors.forename: E C
authors.initials: EC
authors.lastname: Kleerup
authors.forename: J G
authors.initials: JG
authors.lastname: Goldin
authors.forename: H J
authors.initials: HJ
authors.lastname: Kim
authors.forename: D A
authors.initials: DA
authors.lastname: Truong
authors.forename: M D
authors.initials: MD
authors.lastname: Simmons
authors.forename: J W
authors.initials: JW
authors.lastname: Sayre
authors.forename: W
authors.initials: W
authors.lastname: Liu
authors.forename: R
authors.initials: R
authors.lastname: Elashoff
authors.forename: D P
authors.initials: DP
authors.lastname: Tashkin
mesh_terms: D000085:Acetates / Q000627:therapeutic use*; D000293:Adolescent; D000328:Adult; D000368:Aged; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use*; D001249:Asthma / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology*; D018592:Cross-Over Studies; D003521:Cyclopropanes; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D016014:Linear Models; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged; D011804:Quinolines / Q000627:therapeutic use*; D012129:Respiratory Function Tests; D018709:Statistics, Nonparametric; D013440:Sulfides; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
chemical_list: D000085:Acetates; D018927:Anti-Asthmatic Agents; D003521:Cyclopropanes; D011804:Quinolines; D013440:Sulfides; D016210:Methacholine Chloride; C093875:montelukast