title: The effect of ipratropium nasal spray on bronchial methacholine challenge.
abstract: OBJECTIVE
  To determine the effect ipratropium bromide nasal spray has on methacholine challenge testing for airway hyperresponsiveness.
  
  
  METHODS
  Ten subjects with known airway hyperresponsiveness to methacholine who had been clinically stable in the preceding 2 months participated in a randomized, double-blind, placebo-controlled, crossover study. Methacholine challenge testing was conducted on successive days: day 1 after pretreatment with aqueous 0.03% nasal ipratropium, and day 2 with normal saline solution placebo.
  
  
  RESULTS
  The provocative concentration of methacholine causing a 20% fall in FEV1 (PC20) was higher after nasal ipratropium than after saline solution placebo (2.1 mg/mL vs 1.6 mg/mL, p = 0.02). This difference is equal to approximately one-half concentration difference, probably within the limits of reproducibility of the test.
  
  
  CONCLUSIONS
  Pretreatment with nasal ipratropium results in a small increase in PC20. Although this difference achieves statistical significance, it is probably not clinically significant.
authors.affiliation: Division of Respiratory, Critical Care, and Sleep Medicine, University of Saskatchewan, 5th Floor, Ellis Hall, 103 Hospital Dr, Saskatoon, SK, Canada S7N 0W8.
authors.forename: John K
authors.initials: JK
authors.lastname: Reid
authors.forename: Beth E
authors.initials: BE
authors.lastname: Davis
authors.forename: Donald W
authors.initials: DW
authors.lastname: Cockcroft
mesh_terms: D000328:Adult; D001249:Asthma / Q000150:complications / Q000175:diagnosis; D001980:Bronchi / Q000187:drug effects*; D016535:Bronchial Hyperreactivity / Q000175:diagnosis* / Q000209:etiology; D001985:Bronchial Provocation Tests / Q000379:methods*; D016085:Bronchoconstrictor Agents; D001993:Bronchodilator Agents / Q000494:pharmacology*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D005260:Female; D006801:Humans; D009241:Ipratropium / Q000494:pharmacology*; D008297:Male; D016210:Methacholine Chloride; D008875:Middle Aged; D012129:Respiratory Function Tests
chemical_list: D016085:Bronchoconstrictor Agents; D001993:Bronchodilator Agents; D016210:Methacholine Chloride; D009241:Ipratropium