What is the dosage and administration of Inj Buscopan (hyoscine butylbromide) for acute abdominal cramps and spasms?

Dosage and Administration of Injectable Buscopan (Hyoscine Butylbromide) for Acute Abdominal Cramps and Spasms

The recommended dosage of injectable hyoscine butylbromide (Buscopan) for acute abdominal cramps and spasms is 20-40 mg administered intravenously or intramuscularly, with onset of action within 10 minutes. 1, 2

Dosage Guidelines

• For adults with acute abdominal spasms, the standard dose is 20 mg administered intravenously (IV) or intramuscularly (IM) 2
• For severe cases, the dose may be increased to 40 mg, particularly for biliary or renal colic 2
• The IV route is preferred for rapid relief of acute pain, with noticeable effects within 10 minutes 2
• The IM route may be more effective than oral forms due to poor oral bioavailability (less than 1%) 1, 3
• Doses may be repeated if necessary, typically every 6-8 hours as needed for continued symptoms 2

Clinical Efficacy

• For renal colic, approximately 90% of patients show good to moderate analgesic response within 30 minutes of administration 2
• For biliary colic, pain reduction of 42-78% is observed within 30 minutes after a single IV injection of 20 mg 2
• For severe or refractory abdominal pain, intramuscular hyoscine butylbromide has demonstrated efficacy 4
• The American Gastroenterological Association suggests using antispasmodics like hyoscine butylbromide for abdominal pain associated with gastrointestinal cramping 4, 1

Mechanism of Action

• Hyoscine butylbromide is an anticholinergic agent with high affinity for muscarinic receptors on smooth muscle cells of the gastrointestinal tract 3
• It exerts a smooth muscle relaxing/spasmolytic effect by blocking muscarinic receptors 3
• It also binds to nicotinic receptors, inducing a ganglion-blocking effect that contributes to its spasmolytic activity 3, 5
• As a quaternary ammonium compound, it does not cross the blood-brain barrier, resulting in fewer central nervous system effects compared to other anticholinergics 3, 2

Precautions and Contraindications

• Use with caution in patients with cardiac comorbidities 6
• According to product monograph, Buscopan is contraindicated in patients with:
  • Tachycardia 6
  • Angina 6
  • Cardiac failure 6
  • Prostatic hypertrophy with urinary retention 6
• Patients requiring the medication despite these contraindications should be carefully monitored in an environment with resuscitation equipment and trained staff 6

Common Side Effects

• Typical anticholinergic effects may occur, including:
  • Dry mouth 4
  • Dizziness 4
  • Blurred vision 4
• These side effects are generally mild and self-limiting 2
• The low systemic availability after oral administration (bioavailability <1%) contributes to its favorable safety profile 3

Clinical Applications Beyond Abdominal Cramps

• Used in the treatment of abdominal cramping in irritable bowel syndrome (IBS) 1
• May be used to manage diarrhea associated with coeliac plexus block 1
• Can be used during diagnostic imaging procedures to reduce motion artifacts and improve visualization 2
• Has applications in palliative care for relieving pain and reducing GI secretions in terminal cancer patients with inoperable bowel obstruction 2

Hyoscine butylbromide remains a valuable treatment option for patients with symptoms of abdominal pain or discomfort associated with cramping, with a rapid onset of action when administered parenterally and a favorable safety profile due to its limited systemic absorption and inability to cross the blood-brain barrier 3, 2.