Hyoscine-n-butyl Bromide

What it is and how it works

Hyoscine butylbromide is a quaternary antimuscarinic that blocks muscarinic receptors in smooth muscle of the gastrointestinal, biliary and genitourinary tracts, relieving spasm. As a quaternary compound it is poorly absorbed orally and does not readily cross the blood–brain barrier.

Indications

Gastrointestinal and genitourinary smooth muscle spasm, including abdominal colic, biliary and renal colic and irritable bowel syndrome; as an aid in diagnostic radiology and endoscopy to reduce spasm.

Dosage and administration (summary)

Oral: 10–20 mg up to 4 times daily. Rectal: 10 mg up to 3–4 times daily. Injection: 20 mg by slow intravenous or intramuscular injection, repeated after 30 minutes if needed (maximum 100 mg daily).

Contraindications

Myasthenia gravis, megacolon, mechanical gastrointestinal obstruction or paralytic ileus, untreated angle-closure glaucoma, tachyarrhythmia and urinary retention due to prostatic enlargement.

Warnings and precautions

Injection can cause serious adverse effects, including tachycardia, hypotension and anaphylaxis, and fatal outcomes have occurred in patients with underlying cardiac disease; use with caution and monitor such patients. Antimuscarinic effects (dry mouth, blurred vision, urinary retention) may occur. Unexplained persistent abdominal pain should be investigated.

Pregnancy

Avoid in pregnancy unless clearly necessary.

Storage and supply

Store below 25–30 °C, protected from light.

Source: reference summary prepared from the EU SmPC/EPAR, BNF and WHO Model Formulary. The approved product information in Iran governs.