Related Experiment Video
Updated: May 4, 2026

Bronchial Thermoplasty: A Novel Therapeutic Approach to Severe Asthma
Published on: November 4, 2010
N-butylscopolammonium bromide causes fewer side effects than atropine when assessing bronchoconstriction
M de Lagarde1, N Rodrigues, M Chevigny
1Université de Montréal, Saint-Hyacinthe, Quebec, Canada.
Reasons For Performing Study:
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.
Objectives:
To compare the bronchodilating effects and side effects of atropine and NBB in horses with heaves.
Study Design:
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.
More Related Videos
Related Concept Videos
Antiasthma Drugs: β2-Adrenoceptor Agonists
One class of bronchodilators includes β2-adrenoceptor agonists. These agents target the β2-adrenoceptors located on bronchial smooth muscle cells. By stimulating these receptors, β2-agonists induce...
Antiasthma Drugs: Muscarinic Receptor Antagonists
Antimuscarinic agents compete with ACh for the same binding site on the muscarinic receptors. By binding to these receptors, they inhibit the downstream effects of ACh and block the parasympathetic...
Cholinergic Antagonists: Therapeutic Uses
Respiratory Tract: Ipratropium, aclidinium, and tiotropium treat asthma, chronic bronchitis, and chronic obstructive pulmonary disease (COPD). They protect against bronchoconstriction caused by irritants like cigarette smoke, sulfur dioxide, and ozone. They also help reduce nasopharyngeal...
Direct-Acting Cholinergic Agonists: Therapeutic Uses
Nondepolarizing (Competitive) Neuromuscular Blockers: Pharmacological Actions
Although all competitive neuromuscular blockers are designed...
Adrenergic Antagonists: Pharmacological Actions of β-Receptor Blockers

