Buscopan (hyoscine butylbromide)

Generic Name

Hyoscine butylbromide

Brand Names

Buscopan

Buscopan Plus (combined with paracetamol)

Buscopan Cramps

Buscapina (Latin America)

Scopolamine butylbromide (alternative naming)

Available as tablets, oral drops, suppositories, and ampoules for injection

Drug Class

Antispasmodic agent

Peripheral anticholinergic

Quaternary ammonium derivative of scopolamine

Belongs to belladonna alkaloid derivatives

Classified as a muscarinic receptor antagonist

Mechanism of Action

Hyoscine butylbromide acts as a competitive antagonist at muscarinic acetylcholine receptors located in the smooth muscle of the gastrointestinal, biliary, urinary, and female reproductive tracts

It does not significantly cross the blood–brain barrier due to its quaternary ammonium structure, which limits central nervous system effects

The anticholinergic action reduces smooth muscle tone, motility, and peristalsis, thereby relieving cramps and spasms

This leads to rapid reduction in colicky or spastic pain, particularly in abdominal or pelvic regions

Indications

Approved Indications

Irritable Bowel Syndrome (IBS) and functional bowel disorders

Spasm of the gastrointestinal tract

Spasm of the genitourinary tract

Renal colic and biliary colic (as adjunctive treatment)

Dysmenorrhea (painful menstrual cramps)

Diagnostic and therapeutic procedures requiring smooth muscle relaxation (e.g. endoscopy)

Spasms of the lower urinary tract

Adjuvant in radiological procedures to reduce intestinal peristalsis

Off-Label Uses

Labor augmentation in obstetrics (controversial, limited evidence)

Intraoperative use during cesarean section to reduce uterine spasm (as adjunct)

Gastrointestinal cramping related to infectious gastroenteritis

Ureteric stone expulsion therapy (in combination with NSAIDs)

Dosage and Administration

Oral (tablets)

Adults and children >12 years: 10–20 mg 3 to 5 times daily

Maximum daily dose: 100 mg

Administer 30–60 minutes before meals or when symptoms arise

Injectable (IM, IV, SC)

Usual dose: 20 mg up to 4 times per day

In acute colic: 20–40 mg IV injection slowly over 1–3 minutes

In endoscopy or radiology: single IV or IM dose of 20 mg

Can be repeated after 30 minutes if necessary

Onset of action after injection: within 5–15 minutes

Rectal (suppositories)

Adults: 10–20 mg up to 4 times per day

Used when oral route is not feasible

Children

6–12 years: 10 mg orally 3 times daily

<6 years: not recommended orally due to lack of safety data

Use under physician supervision for parenteral formulations

Pregnancy and Obstetrics Use

Occasionally used during labor to shorten first stage duration (off-label)

Dose: 20 mg IV single dose

Use only under obstetric supervision

Not routinely recommended due to lack of robust evidence

Pharmacokinetics

Absorption: Low oral bioavailability (due to poor absorption and first-pass metabolism)

Peak plasma concentration: ~1–2 hours (oral), 15–30 minutes (parenteral)

Half-life: 5 hours (oral), 4 hours (IV)

Does not cross the blood–brain barrier significantly

Excretion: Primarily renal as metabolites and parent compound

Not metabolized by cytochrome P450 enzymes significantly

Contraindications

Known hypersensitivity to hyoscine butylbromide or any excipients

Myasthenia gravis

Megacolon (especially toxic megacolon)

Narrow-angle glaucoma

Prostatic hypertrophy with urinary retention

Mechanical stenosis in the GI tract (e.g. pyloric stenosis)

Paralytic ileus

Tachyarrhythmia

Children <6 years (oral formulations) without physician advice

Warnings and Precautions

May cause anticholinergic effects—use cautiously in elderly or patients with cardiac disease

Caution in patients with suspected intestinal obstruction

Avoid long-term or unsupervised use in chronic abdominal symptoms

May mask symptoms of serious abdominal pathology (e.g. appendicitis)

Rare risk of severe allergic reactions including anaphylaxis

Contains lactose in tablet form—avoid in lactose intolerance

IM injection may cause local irritation

IV administration requires slow injection to avoid hypotension

Adverse Effects

Common

Dry mouth

Constipation

Blurred vision

Tachycardia

Urinary retention

Nausea

Dizziness

Redness at injection site

Uncommon

Skin rash

Hypotension

Hot flushes

Gastrointestinal discomfort

Rare but Serious

Anaphylaxis

Bronchospasm

Angioedema

Collapse or circulatory shock (mainly with IV form)

Severe hypotension (especially if rapid IV push)

Pregnancy and Lactation

Pregnancy Category B (UK BNF/EMC)

Generally considered low risk in pregnancy

Not teratogenic in animal studies

Occasional use in early labor for pain relief or cervical dilation

Avoid prolonged use unless under medical supervision

Lactation

Unknown if excreted in breast milk

Low systemic absorption makes significant transfer unlikely

Use with caution in breastfeeding mothers

Drug Interactions

Anticholinergic drugs (e.g. atropine, diphenhydramine, tricyclic antidepressants)

Additive effects—dry mouth, constipation, blurred vision, urinary retention increased

Metoclopramide and domperidone

Pharmacodynamic antagonism—Buscopan reduces their prokinetic effects

Beta-blockers or calcium channel blockers

May potentiate bradycardia when combined with IV Buscopan

Opioids

May enhance the risk of constipation and paralytic ileus when combined with anticholinergics

Antiglaucoma medications

May antagonize effects in narrow-angle glaucoma

Monitoring Parameters

Relief of colicky pain

Heart rate (especially after IV dosing)

Signs of anticholinergic toxicity (dryness, confusion, urinary retention)

In elderly: monitor for cognitive effects or constipation

Blood pressure if administered IV in acute settings

Counseling Points

Take tablets with a full glass of water before meals if needed

Do not crush or chew the tablets

Do not exceed recommended dose without consulting a healthcare provider

May cause drowsiness or blurred vision—caution when driving

Increase fluid and fiber intake if constipation occurs

Seek medical attention if abdominal pain persists or worsens despite treatment

Store away from heat and moisture

Inform healthcare provider about any eye pain or difficulty urinating

Comparative Notes

Hyoscine Butylbromide vs Atropine

Hyoscine is peripherally acting with less CNS penetration

Atropine crosses the blood–brain barrier—more CNS side effects

Buscopan preferred for abdominal cramping due to lower systemic activity

Hyoscine Butylbromide vs Dicycloverine (Dicyclomine)

Both antispasmodics

Dicycloverine may cause more CNS side effects (drowsiness, dizziness)

Buscopan better tolerated in elderly

Hyoscine Butylbromide vs Mebeverine

Mebeverine has direct smooth muscle relaxant activity without anticholinergic effects

Mebeverine preferred in patients who are sensitive to anticholinergics

Buscopan faster acting in acute spasm

Legal and Regulatory Status

Over-the-counter in many countries for short-term use

Prescription-only for injectable and high-dose formulations

Included in many national formularies and widely used in primary and palliative care

Approved by MHRA (UK), EMA, and other global regulatory agencies