[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Ophthalmic antiallergics](https://durgical.com/en/pharmacology/classes/ophthalmic-antiallergics/) › Olopatadine

# Olopatadine

## Ophthalmic antiallergics?

Ophthalmic antiallergics

An antihistamine eye drop that also steadies mast cells. It relieves the itch of allergic conjunctivitis caused by pollen, dust or animals.

Updated Nov 1, 2026

## Quick facts

**Group**
[Ophthalmic antiallergics](https://durgical.com/en/pharmacology/classes/ophthalmic-antiallergics/)

**Target**
Histamine H1 receptor (plus mast cell stabilisation)

**Used for**
Itching of allergic conjunctivitis

**Key effects**
Burning · Blurred vision

**Monitor**
Relief of itching · Eye pain

**ATC**
S01GX09

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

◎**Histamine H1 receptor (plus mast cell stabilisation)**Olopatadine

ⓘ The figure shows desloratadine, another H1 antihistamine, in the human H1 receptor; olopatadine blocks the same receptor.

**Target in 3D:** Histamine H1 receptor (plus mast cell stabilisation). PDB structure 8X64 (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/8X64) · Drag to rotate · pinch to zoom

Olopatadine blocks histamine H1 receptors in the conjunctiva, so histamine released by mast cells no longer causes itching and redness. It also reduces the release of mediators from conjunctival mast cells, which helps prevent the next wave of symptoms.

- Allergen triggers conjunctival mast cells
- Olopatadine blocks H1 receptors and steadies mast cells
- Less itching and redness

## Indications

- Itching of allergic conjunctivitis (pollen, grass, ragweed, animal hair and dander) [Conjunctivitis →](https://durgical.com/en/conditions/conjunctivitis/)

## Adverse effects

### Common

- Burning, stinging or redness
- Blurred vision
- Dry eye or abnormal sensation in the eye

### Serious (rare, important)

- Eye pain or vision change (may not be allergy)
- Itching that worsens or lasts beyond a few days

## Contraindications

- Hypersensitivity to olopatadine or any component
- Not for contact-lens irritation

## Key interactions

**Other eye drops**
Spaced at least 5 minutes apart

## What is monitored

- Relief of itching
- Eye pain, worsening redness or vision change

## Administration and safety

- Contact lenses come out before the drop and go back in at least 10 minutes later; no lenses while the eye is red.
- The bottle tip should not touch any surface.
- A solution that changes colour or turns cloudy is not used.
- Also exists as a nasal spray; eye and nose products are different.

## Pregnancy and breastfeeding

Human data are limited; with little systemic absorption, it is used only if the benefit justifies the risk.

## Nursing care

- Confirm the symptom is itching with allergen exposure, not pain or loss of vision.
- Teach drop technique and lens removal.
- Teach to stop and seek review for eye pain, vision change or worsening redness.

## Pharmacokinetics

**Absorption**
Acts locally in the eye

## Memory aid

«Olopatadine: Off the itch, On the mast cell»: H1 block plus mast cell brake.

## Test yourself

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

## What are olopatadine's two actions?

H1 receptor blockade and mast cell stabilisation.

## What should a contact-lens wearer do?

Remove them before the drop, wait before reinserting, and not wear them while the eye is red.

## Which symptoms suggest something other than allergy?

Eye pain, vision change or worsening redness.

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

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

## Connections

## Related drugs 3

- [Ketotifen](https://durgical.com/en/pharmacology/ketotifen/)
- [Cromoglicic acid](https://durgical.com/en/pharmacology/cromoglicic-acid/)
- [Cetirizine](https://durgical.com/en/pharmacology/cetirizine/)

## Related conditions 1

- [Conjunctivitis](https://durgical.com/en/conditions/conjunctivitis/)

[← Back to the class: Ophthalmic antiallergics](https://durgical.com/en/pharmacology/classes/ophthalmic-antiallergics/)

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 - OLOPATADINE HYDROCHLORIDE solution/ drops](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=616da51c-70f4-3f87-320f-4685ad1520fa) (DailyMed (U.S. National Library of Medicine), 2026); [Olopatadine Ophthalmic: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a602025.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [ATCDDD - ATC/DDD Index](https://atcddd.fhi.no/atc_ddd_index/?code=S01GX09) (WHO Collaborating Centre for Drug Statistics Methodology, 2026); [RCSB PDB - 8X64: CryoEM structure of the histamine H1 receptor-BRIL/Anti BRIL Fab complex with desloratadine](https://www.rcsb.org/structure/8X64) (RCSB Protein Data Bank, 2026).

## **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/olopatadine/
License: CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/). Cite as: DurgiPedia (durgical.com), https://durgical.com/en/pharmacology/olopatadine/