title: N-butylscopolammonium bromide causes fewer side effects than atropine when assessing bronchoconstriction reversibility in horses with heaves.
abstract: BACKGROUND
  Bronchospasm results in airway obstruction in horses with heaves. Atropine is the most potent bronchodilator drug currently available for horses, but is associated with side effects that limit its use. Like atropine, N-butylscopolammonium bromide (NBB) is an anticholinergic agent with bronchodilatory properties.
  
  
  OBJECTIVE
  To compare the bronchodilating effects and side effects of atropine and NBB in horses with heaves.
  
  
  METHODS
  Cross-over experiment using horses with heaves.
  
  
  METHODS
  Eight horses with heaves were administered atropine and NBB, using a cross-over design. Heart rate, pupillary dilatation, transrectal palpation, lung mechanics (maximal changes in transpulmonary pressure, pulmonary resistance and elastance) and arterial blood gases were assessed before and 10 and 30 min after drug administration.
  
  
  RESULTS
  One horse treated with atropine developed colic. Significant pupillary dilatation was observed only with atropine. Tachycardia developed in all horses, but was more marked with atropine. Lung function improved with both drugs, but elastance values had returned to baseline at 30 min with NBB. There was no improvement in arterial hypoxaemia with either drug.
  
  
  CONCLUSIONS
  The study indicated that the bronchodilatory properties of NBB were not statistically different from those of atropine, but were of shorter duration. N-butylscopolammonium bromide was associated with fewer systemic side effects, and therefore NBB should be preferred over atropine when assessing the reversibility of airway obstruction in horses.
authors.affiliation: Université de Montréal, Saint-Hyacinthe, Quebec, Canada.
authors.forename: M
authors.initials: M
authors.lastname: de Lagarde
authors.forename: N
authors.initials: N
authors.lastname: Rodrigues
authors.forename: M
authors.initials: M
authors.lastname: Chevigny
authors.forename: G
authors.initials: G
authors.lastname: Beauchamp
authors.forename: B
authors.initials: B
authors.lastname: Albrecht
authors.forename: J P
authors.initials: JP
authors.lastname: Lavoie
mesh_terms: D000818:Animals; D001285:Atropine / Q000009:adverse effects* / Q000627:therapeutic use; D016084:Bronchoconstriction / Q000187:drug effects*; D002086:Butylscopolammonium Bromide / Q000009:adverse effects* / Q000627:therapeutic use; D018592:Cross-Over Studies; D005260:Female; D006734:Horse Diseases / Q000188:drug therapy*; D006736:Horses; D008173:Lung Diseases, Obstructive / Q000188:drug therapy / Q000662:veterinary*; D008297:Male; D010276:Parasympatholytics / Q000009:adverse effects* / Q000627:therapeutic use
chemical_list: D010276:Parasympatholytics; D002086:Butylscopolammonium Bromide; D001285:Atropine
keywords: N-butylscopolammonium bromide; atropine; bronchodilator; horse; recurrent airway obstruction