Butylscopolamine Bromide (N-Butylscopolammonium Bromide)
Butylscopolamine bromide is a short-acting quaternary antimuscarinic used in horses.
Group
Antimuscarinic antispasmodic
Mechanism of Action
Blocks muscarinic receptors, relaxing smooth muscle and reducing gastrointestinal secretion and motility.
Dose Rates
Horses
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Spasmodic colic | 0.3 mg/kg | IV | Once | Administer slowly; also used to reduce spasm during rectal examination. |
| Bronchoconstriction | 0.3 mg/kg | IV | Once | |
| Esophageal obstruction adjunct | Reference only | IV | Butylscopolamine bromide 0.3 mg/kg IV once with oxytocin 0.11–0.22 IU/kg IV once. Avoid oxytocin in pregnant mares and substantially reduce or avoid its use in other mares. |
Cattle
| Use / stage | Dose | Route | Schedule | Instructions |
|---|---|---|---|---|
| Calf scour antispasmodic adjunct | 0.4 mg/kg | IM | Once | Calves only; the specific 20 mg/mL hyoscine butylbromide product supports IM use. Provide oral rehydration and other indicated therapy; this is symptomatic treatment, not a replacement for fluid correction. |
Indications
- Spasmodic and flatulent colic
- Intestinal impaction-associated spasm
- Facilitation of rectal examination
- Short-term bronchoconstriction relief
Contraindications
- Use cautiously where further reduction in gastrointestinal motility is undesirable.
- Paralytic ileus or impaction with ileus; equine glaucoma.
- The cited equine product lacks established safety in nursing foals or pregnant/lactating mares.
- For the cited horses-and-calves product, do not use in foals younger than six weeks; pregnancy use is not recommended.
Interactions
- Opposes cholinergic or prokinetic therapy, including metoclopramide.
- Atropine and other anticholinergics can add to tachycardia and intestinal hypomotility.
Adverse effects
- Transient tachycardia
- Dry mucous membranes and reduced secretion
- Mydriasis
- Reduced gut motility
Preparations
| Preparation | Form | Strength | Route |
|---|---|---|---|
| Butylscopolamine Bromide (N-Butylscopolammonium Bromide) 20 mg/mL injection | Injection | 20 mg / mL | IV |
| Buscopan 20 mg/mL injection for horses and calves Hyoscine butylbromide salt basis. Horses: IV only; calves: IM only. Species-specific permitted routes must be respected; a route list alone does not make equine IM dosing appropriate. | Injection | 20 mg / mL | IV, IM |
Monitoring and Administration
Monitor heart rate, gut sounds and fecal output. Give slowly intravenously; onset is usually within 2 minutes and effects last less than 2 hours.
Transient drug-induced tachycardia makes heart rate unreliable as a pain indicator for approximately 30 minutes after administration. Persistent colic despite treatment warrants reassessment for a surgical lesion.
Buscopan Compositum is not plain Buscopan: the described combination contains metamizole 500 mg/mL and hyoscine butylbromide 4 mg/mL. Its dose cannot be inferred from the single-active 20 mg/mL injection.