[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Antimuscarinics (anticholinergics)](https://durgical.com/en/pharmacology/classes/antimuscarinics/) › Hyoscine hydrobromide (scopolamine)

[Pharmacology](https://durgical.com/en/pharmacology/) · [Antimuscarinics (anticholinergics)](https://durgical.com/en/pharmacology/classes/antimuscarinics/)

# Hyoscine hydrobromide (scopolamine)

A belladonna alkaloid that enters the brain; a skin patch prevents motion sickness. In Colombia it is also known for criminal poisoning («burundanga»).

Updated 2026-11-01

- Class: [Antimuscarinics (anticholinergics)](https://durgical.com/en/pharmacology/classes/antimuscarinics/)
- Receptor: Muscarinic acetylcholine receptors (M1 to M5)
- ATC code: A04AD01
- WHO Model List of Essential Medicines

Also called: Scopolamine, L-hyoscine

◎**Muscarinic acetylcholine receptors (M1 to M5)**Hyoscine hydrobromide (scopolamine)

ⓘ No structure of scopolamine bound to its receptor exists. The figure shows N-methylscopolamine, the quaternary form of scopolamine and a close relative, in the acetylcholine (orthosteric) pocket of the human M2 muscarinic receptor; all muscarinic subtypes share this pocket.

**Target in 3D:** Muscarinic acetylcholine receptors (M1 to M5). PDB structure 5ZK8 (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/5ZK8) · Drag to rotate · pinch to zoom

## Mechanism of action

Scopolamine competitively blocks muscarinic receptors in the periphery and, being a tertiary amine, in the brain. Blocking cholinergic signals from the vestibular nuclei to higher centres and to the vomiting centre prevents motion sickness. Compared with atropine it has stronger effects on the eye and glands and depresses the brain (drowsiness, amnesia) rather than stimulating it at usual doses; high doses cause delirium.

- Absorbed through the skin and enters the brain
- Blocks muscarinic signals from the vestibular nuclei
- The vomiting centre is not triggered by motion
- Also dries secretions; high doses cause amnesia and delirium

## Pharmacokinetics

**Absorption**
Well absorbed through the skin behind the ear from a patch; also given by injection

**Distribution**
Crosses the blood-brain barrier and the placenta

**Elimination**
Levels fall steadily after the patch is removed; withdrawal symptoms can start a day or more later

## Indications

- Prevention of nausea and vomiting of motion sickness (patch)
- Prevention of postoperative nausea and vomiting (patch)
- Symptom control in palliative care, patch or injection (WHO Essential Medicines List)

## Adverse effects

### Common

- Dry mouth
- Drowsiness and dizziness
- Blurred vision and dilated pupils, especially if the eye is touched after handling the patch
- Confusion and agitation, more in older adults

### Serious (rare, important)

- Hyperthermia, including deaths, mainly in children and older adults in hot conditions
- Acute angle-closure glaucoma
- Psychosis, hallucinations and delirium
- Eclamptic seizures in severe preeclampsia (after injection)
- Criminal poisoning: in Colombia scopolamine is slipped to victims in drinks, food or other products and impairs memory; a Bogotá health bulletin (2022) reported such poisonings and found no scopolamine medicine with a current INVIMA registration

## Contraindications

- Angle-closure glaucoma
- Hypersensitivity to scopolamine or other belladonna alkaloids

## Key interactions

**Alcohol, sedatives, opioids and anxiolytics**
More drowsiness and disorientation

**Other anticholinergic drugs (antihistamines, meclizine, tricyclics)**
Higher risk of delirium, bowel obstruction and urinary retention

**Oral drugs with a narrow therapeutic range**
Slower stomach emptying can change their absorption

## What is monitored

- Mental status and new psychiatric symptoms
- Temperature in heat, exercise or fever
- Eye pain or vision change
- Bladder and bowel function

## Administration and safety

- The patch goes on clean, dry, hairless skin behind the ear; hands are washed after handling it
- Removed before an MRI scan: the aluminised layer can burn the skin
- Not cut; one patch at a time

## Nursing care

- Teach handwashing after touching the patch to avoid a dilated, blurry eye
- Watch older adults for confusion and falls
- Warn about driving and alcohol
- After several days of use, removal can cause dizziness, nausea, headache and slow pulse

## Pregnancy and breastfeeding

Observational data have not shown a higher risk of major birth defects; it is avoided in severe preeclampsia because of eclamptic seizures.

## Memory aid

SCOPolamine «scopes» the brain: patch behind the ear for the boat, but in the wrong hands it erases memory.

## Test yourself

Think of the answer, then tap the question to see it.

## Where is the scopolamine patch applied?

On clean, dry, hairless skin behind the ear.

## Why must a scopolamine patch be removed before an MRI?

It contains an aluminised layer that can cause skin burns during the scan.

## How does scopolamine differ from hyoscine butylbromide?

Scopolamine is tertiary and enters the brain (motion sickness, sedation, delirium); the butylbromide is quaternary and acts only in the periphery (gut cramps).

## Which antidote reverses severe central scopolamine poisoning?

Physostigmine, with supportive care.

[Add to my cards (4)](https://durgical.app/estudiar/?add=/en/pharmacology/hyoscine-hydrobromide/)

## Related drugs

- [Hyoscine butylbromide](https://durgical.com/en/pharmacology/hyoscine-butylbromide/)
- [Atropine](https://durgical.com/en/pharmacology/atropine/)
- [Physostigmine](https://durgical.com/en/pharmacology/physostigmine/)

[← Back to the class: Antimuscarinics (anticholinergics)](https://durgical.com/en/pharmacology/classes/antimuscarinics/)

Educational content on how drugs work; not a prescribing guide and no substitute for a health professional's advice. No doses are given.

Sources: [DailyMed - SCOPOLAMINE patch, extended release](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=2a6f9aaf-a70a-481f-a82b-1dcaaadc185b) (DailyMed (U.S. National Library of Medicine), 2026); [Scopolamine Transdermal Patch: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a682509.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [Comportamiento de las intoxicaciones con escopolamina durante 2021-2022](https://revistas.saludcapital.gov.co/index.php/BED/article/view/43) (Secretaría Distrital de Salud de Bogotá (Boletín Epidemiológico Distrital), 2022); [eEML - Electronic Essential Medicines List](https://list.essentialmeds.org/) (World Health Organization, 2025).

## **Spotted a mistake?** We are always improving for the community. Tell us what is wrong and our team will review it. Report a mistake

Representative model, for educational purposes only.

---
Source: https://durgical.com/en/pharmacology/hyoscine-hydrobromide/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/hyoscine-hydrobromide/