title: Effect of montelukast, a once-daily leukotriene receptor antagonist, on peak expiratory flow variability.
abstract: BACKGROUND
  Peak expiratory flow (PEF) is an important measure of airway functin in asthma. PEF variability (PEFvar) assessment is described in asthma treatment guidelines as another means of evaluating patient status and response to therapy.
  
  
  OBJECTIVE
  The goal of this study was to determine the clinical effect of oral montelukast, a leukotriene receptor antagonist, on PEFvar in asthmatic patients and to assess the relationship of PEFvar with other clinical measures.
  
  
  METHODS
  This was a retrospective analysis of data from a multicenter, randomized, double-blind, placebo-controlled, parallel-group study, details of which have been published previously. Eligible patients had chronic stable asthma, had a forced expiratory volume in 1 second (FEV1) that was 50% to 85% of the predicted value, used inhaled beta-agonists, had at least 15% improvement in absolute FEV1 after inhaled beta-agonist administration, and showed a minimal predefined level of daytime asthma symptoms. Treatment consisted of a 2-week, single-blind, placebo run-in period followed by a 12-week, double-blind treatment period (montelukast 10 mg or matching placebo once daily at bedtime).
  
  
  RESULTS
  Six hundred eighty-one patients (age range, 15-79 years) were randomized to treatment at 50 centers. Baseline PEFvar was 11.44% +/- 6.55% and 10.62% +/- 6.48% in the montelukast and placebo groups, respectively. PEFvar decreased 20.1% and 7.5% from baseline in the montelukast and placebo groups, respectively. The between-group difference was significant (P < 0.001). PEFvar had low correlation with other clinical measures.
  
  
  CONCLUSIONS
  Over 12 weeks of treatment, montelukast significantly reduced PEFvar compared with placebo, indicating improved asthma control. The relative reduction in PEFvar was similar in patients with different degrees of variability at baseline. PEFvar did not correlate highly with other outcome variables and may measure different aspects of the disease.
authors.affiliation: Department of Clinical Biostatistics, Merck Research Laboratories, Rahway, New Jersey 07065, USA. zhangj@merck.com
authors.forename: Ji
authors.initials: J
authors.lastname: Zhang
authors.forename: Chang
authors.initials: C
authors.lastname: Yu
authors.forename: Gertrude
authors.initials: G
authors.lastname: Noonan
authors.forename: Theodore F
authors.initials: TF
authors.lastname: Reiss
mesh_terms: D000085:Acetates / Q000627:therapeutic use*; D000293:Adolescent; D000328:Adult; D000368:Aged; D018927:Anti-Asthmatic Agents / Q000627:therapeutic use*; D001249:Asthma / Q000188:drug therapy* / Q000503:physiopathology*; D002908:Chronic Disease; D003521:Cyclopropanes; D005260:Female; D005541:Forced Expiratory Volume / Q000187:drug effects; D006801:Humans; D020024:Leukotriene Antagonists; D008297:Male; D008875:Middle Aged; D015337:Multicenter Studies as Topic; D010366:Peak Expiratory Flow Rate / Q000187:drug effects*; D011804:Quinolines / Q000627:therapeutic use*; D016032:Randomized Controlled Trials as Topic; D012129:Respiratory Function Tests; D012189:Retrospective Studies; D013440:Sulfides
chemical_list: D000085:Acetates; D018927:Anti-Asthmatic Agents; D003521:Cyclopropanes; D020024:Leukotriene Antagonists; D011804:Quinolines; D013440:Sulfides; C093875:montelukast