[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Antiglaucoma agents](https://durgical.com/en/pharmacology/classes/antiglaucoma-agents/) › Brimonidine

# Brimonidine

## Antiglaucoma agents?

Antiglaucoma agents

An alpha-2 agonist eye drop that lowers eye pressure two ways. It must never be used in babies under 2: it can stop their breathing.

Updated Nov 1, 2026

## Quick facts

**Group**
[Antiglaucoma agents](https://durgical.com/en/pharmacology/classes/antiglaucoma-agents/)

**Target**
α2A adrenergic receptor

**Used for**
Open-angle glaucoma · Ocular hypertension

**Key effects**
Dry mouth · Red · Fatigue

**Monitor**
Intraocular pressure · Pulse and blood pressure

**ATC**
S01EA05

No doses: the clinician sets them by the current guideline.

On this page

- The basics Mechanism of action
- Indications
- Adverse effects
- Pharmacokinetics
- Memory aid

- Safety Contraindications
- Key interactions
- What is monitored
- Administration and safety
- Pregnancy and breastfeeding
- Nursing care

- Study Test yourself

- Connections Connections

## Mechanism of action

◎**α2A adrenergic receptor**Brimonidine

ⓘ The figure shows brimonidine bound to the human α2A adrenergic receptor in its complex with the Go protein (cryo-EM).

**Target in 3D:** α2A adrenergic receptor. PDB structure 7EJ8 (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/7EJ8) · Drag to rotate · pinch to zoom

Brimonidine is a relatively selective α2 adrenergic agonist. It lowers intraocular pressure by reducing the production of aqueous humour and by increasing its uveoscleral outflow. The drug reaches the blood, where its central α2 effects explain the drowsiness, low blood pressure and, in infants, the depression of breathing.

- Brimonidine activates α2 receptors in the eye
- Less aqueous humour is made
- More fluid leaves by the uveoscleral route
- Absorbed drug acts on the brain: drowsiness

## Indications

- Open-angle glaucoma [Open-angle glaucoma →](https://durgical.com/en/conditions/open-angle-glaucoma/)
- Ocular hypertension

## Adverse effects

### Common

- Dry mouth
- Red, burning or itchy eye; blurred vision
- Allergic conjunctivitis with follicles
- Fatigue, drowsiness and headache

### Serious (rare, important)

- In infants: apnoea, bradycardia, hypotension, hypothermia, lethargy and coma
- Severe drowsiness in young children
- Bradycardia or hypotension in adults (rare)
- Iritis

## Contraindications

- Neonates and infants under 2 years
- Hypersensitivity to any component
- Caution: depression, cerebral or coronary insufficiency, Raynaud phenomenon, orthostatic hypotension, thromboangiitis obliterans

## Key interactions

**Alcohol, opioids, sedatives, anaesthetics**
Additive drowsiness and CNS depression

**Antihypertensives and cardiac glycosides**
Blood pressure may fall further

**MAO inhibitors**
May reduce brimonidine metabolism and increase hypotension (theoretical)

## What is monitored

- Intraocular pressure
- Pulse and blood pressure in heart disease
- Drowsiness, especially in children

## Administration and safety

- Never given to babies under 2 years.
- Other eye drops are spaced at least 5 minutes apart.
- Soft contact lenses go back in no sooner than 15 minutes after the drop (benzalkonium chloride).
- Gentle pressure on the tear duct after the drop reduces systemic absorption.

## Pregnancy and breastfeeding

Animal studies showed no birth defects and human data are lacking; it is used only if the benefit justifies the risk. Breastfeeding is avoided while using it.

## Nursing care

- Confirm the patient's age; in a child, report any drowsiness, slow breathing or floppiness at once.
- Warn that it can cause drowsiness: avoid driving until the effect is known, and alcohol adds to it.
- Ask about depression, Raynaud phenomenon, dizziness on standing and heart or brain circulation problems.
- Teach the patient to report rash, trouble breathing, flashes of light or blind spots.

## Pharmacokinetics

**Absorption**
Reaches the blood after eye drops, with peak levels within 1–4 hours

**Metabolism**
Extensively metabolised in the liver

**Elimination**
Mainly in the urine

**Half-life**
About 3 hours in the blood

**Onset and duration**
Greatest pressure-lowering effect about 2 hours after the drop

## Memory aid

BRIMonidine works at both ends of the cup: less fluid in, more fluid out. And the «BRIM» of the cot: never for babies under 2.

## Test yourself

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

## What are brimonidine's two effects on aqueous humour?

Less production and more uveoscleral outflow.

## In which age group is brimonidine contraindicated, and why?

Under 2 years: infants have had apnoea, bradycardia, hypotension, hypothermia and coma.

## What common systemic effect of brimonidine should a patient know about before driving?

Drowsiness and fatigue.

[Add to my cards (3)](https://durgical.app/estudiar/?add=/en/pharmacology/brimonidine/)

[More Pharmacology questions →](https://durgical.com/en/practice/?f=pharmacology)

## Connections

## Related drugs 3

- [Timolol](https://durgical.com/en/pharmacology/timolol/)
- [Latanoprost](https://durgical.com/en/pharmacology/latanoprost/)
- [Dorzolamide](https://durgical.com/en/pharmacology/dorzolamide/)

## Related conditions 1

- [Open-angle glaucoma](https://durgical.com/en/conditions/open-angle-glaucoma/)

[← Back to the class: Antiglaucoma agents](https://durgical.com/en/pharmacology/classes/antiglaucoma-agents/)

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 - BRIMONIDINE TARTRATE- brimonidine tartrate solution/ drops](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=75c5f708-1afb-4505-94a6-a2c0afb0aedc) (DailyMed (U.S. National Library of Medicine), 2025); [Brimonidine Ophthalmic: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a601232.html) (MedlinePlus (U.S. National Library of Medicine), 2023); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=S01EA05) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); [RCSB PDB - 7EJ8: Structure of the alpha2A-adrenergic receptor GoA signaling complex bound to brimonidine](https://www.rcsb.org/structure/7EJ8) (RCSB Protein Data Bank, 2026).

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Representative model, for educational purposes only.

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