Hyoscine N-Butylbromide Does Not Cause Ileus
Hyoscine N-butylbromide (hyoscine butylbromide) is contraindicated in patients with existing bowel obstruction or recent bowel anastomosis due to its anticholinergic effects that reduce intestinal motility, but it does not cause ileus in patients with normal bowel function. 1
Mechanism and Contraindications
Hyoscine butylbromide acts as an antimuscarinic agent that blocks muscarinic receptors on gastrointestinal smooth muscle, producing smooth-muscle relaxation and reducing intestinal motility. 2
The drug is specifically contraindicated in patients with recent bowel anastomosis because its anticholinergic mechanism could theoretically impair healing or unmask subclinical obstruction. 1
In patients with existing malignant bowel obstruction, hyoscine butylbromide has been used therapeutically (via subcutaneous infusion at 60-120 mg/day) to reduce gastrointestinal secretions and manage symptoms—it does not worsen the obstruction itself. 3
Clinical Safety Profile
Hyoscine butylbromide has extremely low systemic bioavailability (<1% after oral administration) because it is a quaternary ammonium compound that does not cross the blood-brain barrier and remains localized to the gastrointestinal tract. 2
The most common adverse effects are anticholinergic in nature: dry mouth, visual disturbances (including temporary diplopia), and dizziness—not ileus or bowel obstruction. 1, 4
In endoscopy studies, hyoscine butylbromide is used specifically to induce smooth-muscle relaxation; the Canadian Association of Gastroenterology reviewed its safety profile and did not identify ileus as a recognized complication. 5
Important Clinical Caveat
Do not confuse reduced motility with ileus. Hyoscine butylbromide transiently reduces peristalsis as part of its therapeutic mechanism, but this is reversible and does not constitute pathologic ileus in patients with normal baseline bowel function. 2
The drug should be avoided in patients with prostatic hypertrophy with urinary retention and used cautiously in those with tachycardia, angina, or cardiac failure, but these contraindications relate to other anticholinergic effects, not bowel obstruction. 5