title: Effects of N-butylscopolammonium bromide on lung function in horses with recurrent airway obstruction.
abstract: BACKGROUND
  Equine recurrent airway obstruction (RAO) is characterized by airway inflammation, bronchoconstriction, and increased mucus production in the airways. Anticholinergic drugs like atropine induce bronchodilatation and rapid improvement in lung function. N-butylscopolammonium bromide (NBB) is an anticholinergic drug used to relieve spasmodic colic in horses, but its effect on airway smooth muscle is unknown.
  
  
  OBJECTIVE
  To evaluate the effect of NBB on clinical signs and lung function of RAO-affected horses.
  
  
  METHODS
  Nine horses diagnosed with RAO.
  
  
  METHODS
  Double-blind, placebo-controlled, randomized crossover trial. Horses were challenged with moldy hay until a maximum change in transpulmonary pressure (∆P(L) (max) ) > 15 cm H(2) O was achieved. NBB (0.3 mg/kg) or placebo (0.9% saline) was administered IV. Clinical scores and lung function were recorded at baseline and then periodically after treatment administration. Horses were allowed a 6-week washout before administration of opposite treatments.
  
  
  RESULTS
  Clinical score at 10 and 30 minutes (8.7 ± 2.8 and 8.7 ± 3.2, respectively) after NBB administration was significantly lower than baseline (10.8 ± 2.4). NBB administration resulted in a significant decrease in ∆P(L) (max) (baseline: 35.1 ± 6.9 cm H(2) O) starting 2 minutes after administration (16.3 ± 6.6 cmH(2) O) with a maximum decline observed at 10 minutes (13.5 ± 7.1 cm H(2) O). ∆P(L) (max) values between 60 and 120 minutes after NBB administration were not different from placebo.
  
  
  CONCLUSIONS
  N-butylscopolammonium bromide is a potent bronchodilator, reaching maximum effect 10 minutes after intravenous administration. This effect dissipates within 1 hour of drug administration.
authors.affiliation: Department of Veterinary Clinical Sciences, Purdue University College of Veterinary Medicine, West Lafayette, IN 47907, USA. couetill@purdue.edu
authors.forename: L
authors.initials: L
authors.lastname: Couetil
authors.forename: J
authors.initials: J
authors.lastname: Hammer
authors.forename: M
authors.initials: M
authors.lastname: Miskovic Feutz
authors.forename: N
authors.initials: N
authors.lastname: Nogradi
authors.forename: C
authors.initials: C
authors.lastname: Perez-Moreno
authors.forename: K
authors.initials: K
authors.lastname: Ivester
mesh_terms: D000818:Animals; D002086:Butylscopolammonium Bromide / Q000627:therapeutic use*; D018592:Cross-Over Studies; D004311:Double-Blind Method; D006734:Horse Diseases / Q000188:drug therapy*; D006736:Horses; D008173:Lung Diseases, Obstructive / Q000188:drug therapy / Q000662:veterinary*; D010276:Parasympatholytics / Q000627:therapeutic use*
chemical_list: D010276:Parasympatholytics; D002086:Butylscopolammonium Bromide