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Gastrointestinal · Drug monograph

Hyoscine Butylbromide (N-Butylscopolammonium): veterinary dose and monograph

Hyoscine Butylbromide (N-Butylscopolammonium) is a veterinary gastrointestinal drug. Quaternary antimuscarinic spasmolytic for spasmodic/gas colic, simple impactions and oesophageal choke in horses, and as a short-acting bronchodilator. Indications include spasmodic / flatulent colic and simple impactions (horses); oesophageal obstruction (choke) — with oxytocin in geldings/stallions; bronchospasm relief (diagnostic/short-term). This monograph lists 2 reference doses for horses, each with route, frequency and source.

At a glance

Drug class
Gastrointestinal
Also known as
Buscopan, Butylscopolamine, Hyoscine butylbromide, N-butylscopolammonium bromide
Species with doses
Horses
General dose range
0.3 mg/kg IV single dose — check the species tables for the indication
Routes
IV
Last reviewed
1 October 2026

Indications

  • Spasmodic / flatulent colic and simple impactions (horses)
  • Oesophageal obstruction (choke) — with oxytocin in geldings/stallions
  • Bronchospasm relief (diagnostic/short-term)

Hyoscine Butylbromide (N-Butylscopolammonium) dose by species

Doses are per administration unless stated. mg/kg doses scale with body weight; per-animal, per-quarter and infusion-rate doses are shown as the reference writes them.

Horses

Hyoscine Butylbromide (N-Butylscopolammonium) doses for horses
IndicationDoseRouteFrequencyDuration
Spasmodic colic / bronchoconstriction0.3 mg/kgIVsingle dose (slow IV)—
Oesophageal obstruction (choke)0.3 mg/kgIVonce, with oxytocin—
  • Spasmodic colic / bronchoconstriction: Papich 5e and Plumb’s p.881 (label): 0.3 mg/kg (1.5 mL per 100 kg of 20 mg/mL) slowly IV once; onset within 2 min, duration <2 h.
  • Oesophageal obstruction (choke): Plumb’s p.881 (Beard 2008): 0.3 mg/kg IV once with oxytocin 0.11–0.22 U/kg IV; avoid or greatly reduce oxytocin in mares and do not use in pregnant mares.

Contraindications

Ileus or suspected strangulating lesion where masking signs is dangerous; tachyarrhythmias; glaucoma. Combination products with metamizole (dipyrone) are dosed differently — check the label.

Adverse effects

  • Transient tachycardia (~30 min)
  • Reduced GI sounds
  • Mydriasis, dry mucous membranes

Formulations and products

  • Injection 20 mg/mL

Before you use this dose

Reference doses for veterinary professionals. Confirm the dose against the product label, the patient’s condition, current guidance and local regulations before use; the attending veterinarian remains responsible for every clinical decision.

Frequently asked questions

What is the dose of Hyoscine Butylbromide (N-Butylscopolammonium) for horses?

Reference doses for Hyoscine Butylbromide (N-Butylscopolammonium) in horses: 0.3 mg/kg IV single dose (slow IV) (Spasmodic colic / bronchoconstriction); 0.3 mg/kg IV once, with oxytocin (Oesophageal obstruction (choke)). Confirm against the label and the patient before use.

When should Hyoscine Butylbromide (N-Butylscopolammonium) not be used?

Ileus or suspected strangulating lesion where masking signs is dangerous; tachyarrhythmias; glaucoma. Combination products with metamizole (dipyrone) are dosed differently — check the label.

What are the side effects of Hyoscine Butylbromide (N-Butylscopolammonium) in animals?

Transient tachycardia (~30 min); Reduced GI sounds; Mydriasis, dry mucous membranes.

Sources

  • Plumb's Veterinary Drug Handbook
  • Papich 5e — N-Butylscopolammonium Bromide
  • Papich, Papich Handbook of Veterinary Drugs, 5th edition

Last reviewed · VetMasterJi