Hyoscine and Buscopan: Different Drugs with Related Properties
No, hyoscine (scopolamine) and Buscopan (hyoscine butylbromide/butylscopolamine) are not the same medication, though they are chemically related compounds with similar anticholinergic effects.
Key Differences
- Chemical Structure: Hyoscine (scopolamine) is the parent compound, while Buscopan (hyoscine butylbromide) is a quaternary ammonium derivative of scopolamine 1
- Blood-Brain Barrier Penetration:
- Bioavailability:
Clinical Applications
Hyoscine (Scopolamine)
- Used for motion sickness prevention
- Premedication before anesthesia
- Available in transdermal patches (TTS-patch) for sustained release 2
- Has central nervous system effects including sedation, amnesia, and antiemetic properties
Buscopan (Hyoscine Butylbromide)
- Specifically used for abdominal cramping and pain associated with gastrointestinal spasms 1
- Acts locally in the gastrointestinal tract due to high affinity for muscarinic receptors in GI smooth muscle 3
- Different potency in various GI segments (higher sensitivity in ileum, jejunum, and colon) 3
- Used during some endoscopic procedures to reduce GI spasms 4
Mechanism of Action
Both drugs work as anticholinergic agents that competitively inhibit muscarinic receptors, but:
- Buscopan primarily exerts local effects on GI smooth muscle with minimal systemic absorption
- Hyoscine has both peripheral and central anticholinergic effects
Side Effect Profiles
Hyoscine (Scopolamine)
- Can cause hallucinations, drowsiness, vertigo, and dry mouth
- Has central nervous system effects including sedation and amnesia 2
Buscopan (Hyoscine Butylbromide)
- Generally well-tolerated due to minimal systemic absorption
- Side effects include dry mouth, dizziness, blurred vision, and tachycardia 1
- Contraindicated in patients with tachycardia, angina, cardiac failure, and prostatic hypertrophy with urinary retention 4
Clinical Considerations
- For GI spasms and abdominal pain, Buscopan is preferred due to its targeted action and minimal central effects 1
- For motion sickness or when central anticholinergic effects are desired, hyoscine (scopolamine) is more appropriate 2
- The American Gastroenterological Association suggests using antispasmodics like Buscopan for IBS symptoms 5
- In palliative care, hyoscine butylbromide (Buscopan) is used for managing diarrhea and malignant bowel obstruction 5
Caution
- Both drugs should be used with caution in patients with cardiac conditions
- Buscopan is specifically contraindicated in patients with tachycardia, angina, and cardiac failure 4
- There have been reports of scopolamine formation when Buscopan is burned in cigarettes, which can lead to hallucinogenic effects 6
In summary, while both medications share a similar base structure and anticholinergic properties, they have different pharmacokinetic profiles and clinical applications due to their distinct chemical modifications.