Usage
Hyoscine butylbromide is an antispasmodic medication primarily prescribed for gastrointestinal and genitourinary spasms. It is also used to alleviate symptoms of irritable bowel syndrome (IBS). This medication belongs to the anticholinergic drug class. It works by blocking the action of acetylcholine, a neurotransmitter that stimulates muscle contractions, at muscarinic receptors in the smooth muscle of the gastrointestinal and genitourinary tracts. This inhibitory action leads to muscle relaxation and reduced spasms.
Alternate Names
Hyoscine butylbromide is also known as butylscopolamine. Brand names include Buscopan®, Scopinal®, and others (regional variations may exist).
How It Works
Pharmacodynamics: Hyoscine butylbromide exerts its antispasmodic effects by competitively antagonizing the action of acetylcholine at muscarinic receptors, specifically M1, M2, and M3 subtypes. This action results in a decrease in smooth muscle tone and motility within the gastrointestinal and genitourinary tracts, providing relief from spasms and pain.
Pharmacokinetics:
- Absorption: Hyoscine butylbromide undergoes limited systemic absorption following oral administration. Peak plasma concentrations are reached approximately two hours after oral ingestion.
- Metabolism: Information regarding the metabolism of hyoscine butylbromide is limited. It is a quaternary ammonium compound, which restricts its ability to cross the blood-brain barrier, thereby minimizing central nervous system effects.
- Elimination: Hyoscine butylbromide is primarily excreted unchanged in the feces and urine.
Dosage
Standard Dosage
Adults:
- Oral: 10-20 mg, three to four times daily. For IBS, the initial dose may be 10 mg three times a day, potentially increased to 20 mg four times daily if necessary.
- Intravenous (IV), Intramuscular (IM), or Subcutaneous (SC) injection: 20-40 mg via slow injection, repeatable every 30 minutes if needed. The maximum daily dose is 100 mg.
Children:
- Oral (6-12 years): 10 mg three times daily. Oral administration is not generally recommended for children under 6.
- IV, IM, or SC injection: 0.3-0.6 mg/kg bodyweight, administered as a slow injection several times a day, with a maximum daily dose of 1.2 mg/kg.
Special Cases:
- Elderly Patients: Initiate with lower doses due to increased sensitivity to anticholinergic side effects like constipation and urinary retention.
- Patients with Renal Impairment: Dose adjustment is necessary based on renal function.
- Patients with Hepatic Dysfunction: Exercise caution as data on dose adjustment is limited.
- Patients with Comorbid Conditions: Use with caution in patients with cardiovascular disease, glaucoma, or other conditions sensitive to anticholinergic effects.
Clinical Use Cases
- Intubation, Surgical Procedures, Mechanical Ventilation, ICU Use: As an adjunct to manage spasms or secretions.
- Emergency Situations: Can be used to alleviate acute spasms, but its role in specific emergencies is limited. Dosage should be adjusted based on clinical response and patient’s condition.
Side Effects
Common Side Effects
Dry mouth, blurred vision, dizziness, constipation, and reduced sweating.
Rare but Serious Side Effects
Allergic reactions (rash, itching, difficulty breathing), anaphylactic shock, tachycardia, urinary retention, painful red eye with vision loss.
Long-Term Effects
Chronic complications from prolonged use are rare, but long-term use should be avoided without investigating the underlying cause of abdominal pain.
Contraindications
Myasthenia gravis, mechanical stenosis of the gastrointestinal tract, paralytic or obstructive ileus, megacolon, untreated narrow-angle glaucoma, prostatic hypertrophy with urinary retention, tachycardia.
Drug Interactions
Antidepressants (tricyclic and tetracyclic), antihistamines, antipsychotics, quinidine, amantadine, disopyramide, other anticholinergics (tiotropium, ipratropium), metoclopramide, antacids, adsorbent antidiarrheal medications, hormonal contraceptives, cyclosporine, rifampin, warfarin, zidovudine.
Pregnancy and Breastfeeding
Hyoscine butylbromide is generally considered safe to use during pregnancy and breastfeeding based on limited human data. Consult a doctor before use.
Drug Profile Summary
- Mechanism of Action: Muscarinic receptor antagonist, relaxing smooth muscle in the gastrointestinal and genitourinary tracts.
- Side Effects: Dry mouth, blurred vision, dizziness, constipation, reduced sweating (common); allergic reactions, anaphylaxis, tachycardia, urinary retention (serious).
- Contraindications: Myasthenia gravis, glaucoma, gastrointestinal obstruction, urinary retention, tachycardia.
- Drug Interactions: Numerous interactions; consult drug interaction resources for specifics.
- Pregnancy & Breastfeeding: Generally considered safe, but consult a doctor before use.
- Dosage: See detailed section above.
- Monitoring Parameters: Heart rate, blood pressure, visual acuity, bowel movements, urinary output.
Popular Combinations
Hyoscine butylbromide is sometimes combined with paracetamol (acetaminophen) for enhanced pain relief.
Precautions
Pre-existing conditions should be assessed (cardiac, glaucoma, gastrointestinal, etc.). Caution in elderly patients due to anticholinergic sensitivity. Avoid alcohol. Monitor patients for vision changes and advise against driving or operating machinery until vision normalizes.
FAQs (Frequently Asked Questions)
Q1: What is the recommended dosage for Hyoscine butylbromide?
A: See the detailed dosage section above.
Q2: How does Hyoscine butylbromide differ from Hyoscine hydrobromide?
A: Hyoscine butylbromide is primarily used for gastrointestinal and genitourinary spasms. Hyoscine hydrobromide is primarily used for motion sickness. Butylbromide has limited central nervous system effects due to restricted blood-brain barrier penetration.
Q3: What are the most common side effects of Hyoscine butylbromide?
A: Dry mouth, blurred vision, dizziness, constipation, and decreased sweating.
Q4: Can Hyoscine butylbromide be used during pregnancy?
A: Generally considered safe but consult a doctor before use.
Q5: What are the contraindications to using Hyoscine butylbromide?
A: Myasthenia gravis, glaucoma, gastrointestinal obstruction, urinary retention, tachycardia.
Q6: Does Hyoscine butylbromide interact with other medications?
A: Yes, it can interact with numerous medications. Consult drug interaction resources for details.
Q7: Can Hyoscine butylbromide be used in children?
A: Yes, but dosing differs from adults. Oral administration is not generally recommended for children under 6 years old.
Q8: How should Hyoscine butylbromide be administered?
A: Orally as tablets or liquid, or parenterally as a slow IV, IM, or SC injection.
Q9: What should I monitor in a patient taking Hyoscine butylbromide?
A: Monitor heart rate, blood pressure, vision, bowel movements, and urinary output, especially in elderly patients.
