Effects of N-Butylscopolammonium Bromide on Lung Function in Horses with Recurrent Airway Obstruction
Article first published online: 27 AUG 2012
Copyright © 2012 by the American College of Veterinary Internal Medicine
Journal of Veterinary Internal Medicine
Volume 26, Issue 6, pages 1433–1438, November/December 2012
How to Cite
Couetil, L., Hammer, J., Miskovic Feutz, M., Nogradi, N., Perez-Moreno, C. and Ivester, K. (2012), Effects of N-Butylscopolammonium Bromide on Lung Function in Horses with Recurrent Airway Obstruction. Journal of Veterinary Internal Medicine, 26: 1433–1438. doi: 10.1111/j.1939-1676.2012.00992.x
- Issue published online: 20 NOV 2012
- Article first published online: 27 AUG 2012
- Manuscript Accepted: 17 JUL 2012
- Manuscript Revised: 17 JUN 2012
- Manuscript Received: 27 APR 2012
- Anticholinergic therapy;
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.
To evaluate the effect of NBB on clinical signs and lung function of RAO-affected horses.
Nine horses diagnosed with RAO.
Double-blind, placebo-controlled, randomized crossover trial. Horses were challenged with moldy hay until a maximum change in transpulmonary pressure (∆PLmax) > 15 cmH2O 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.
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 ∆PLmax (baseline: 35.1 ± 6.9 cmH2O) starting 2 minutes after administration (16.3 ± 6.6 cmH2O) with a maximum decline observed at 10 minutes (13.5 ± 7.1 cmH2O). ∆PLmax values between 60 and 120 minutes after NBB administration were not different from placebo.
Conclusion and Clinical Importance
N-butylscopolammonium bromide is a potent bronchodilator, reaching maximum effect 10 minutes after intravenous administration. This effect dissipates within 1 hour of drug administration.