[Durgical](https://durgical.com/en/) › [DurgiPedia](https://durgical.com/en/durgipedia/) › [Pharmacology](https://durgical.com/en/pharmacology/) › [Fluoroquinolones](https://durgical.com/en/pharmacology/classes/fluoroquinolones/) › Ofloxacin

[Pharmacology](https://durgical.com/en/pharmacology/) · [Fluoroquinolones](https://durgical.com/en/pharmacology/classes/fluoroquinolones/)

# Ofloxacin

A fluoroquinolone mostly used today as eye and ear drops. Its active half, levofloxacin, replaced it for systemic use.

Updated 2026-11-01

- Class: [Fluoroquinolones](https://durgical.com/en/pharmacology/classes/fluoroquinolones/)
- Enzyme: Bacterial DNA gyrase and topoisomerase IV
- ATC code: J01MA01
- WHO Model List of Essential Medicines

✂**Bacterial DNA gyrase and topoisomerase IV**Ofloxacin

ⓘ The figure shows levofloxacin, the active S-isomer of ofloxacin, bound to DNA cut by topoisomerase IV of Streptococcus pneumoniae.

**Target in 3D:** Bacterial DNA gyrase and topoisomerase IV. PDB structure 3RAE (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/3RAE) · Drag to rotate · pinch to zoom

## Mechanism of action

Ofloxacin is a racemic mixture whose S-isomer (levofloxacin) carries most of the activity. It traps DNA gyrase and topoisomerase IV on cut DNA, causing lethal double-strand breaks. Applied to the eye or ear it reaches high local levels with little systemic exposure.

- Applied to the eye or ear (or taken by mouth)
- Binds gyrase or topoisomerase IV on cut DNA
- The DNA cannot be resealed
- Double-strand breaks kill the bacterium

## Pharmacokinetics

**Absorption**
Eye and ear drops act locally; oral forms are well absorbed where available.

## Indications

- Bacterial conjunctivitis (eye drops) [Conjunctivitis →](https://durgical.com/en/conditions/conjunctivitis/)
- External ear infection (ear drops; WHO list as an equivalent of ciprofloxacin) [Otitis externa →](https://durgical.com/en/conditions/otitis-externa/)
- Bacterial corneal ulcers (eye drops)

## Adverse effects

### Common

- Brief burning or discomfort in the eye
- Bitter taste after ear or eye drops
- Itching or redness

### Serious (rare, important)

- Serious allergic reactions
- With oral use, the class warnings: tendon rupture, neuropathy, CNS effects, QT prolongation

## Contraindications

- Allergy to ofloxacin, other quinolones or the product's components

## Key interactions

**Antacids and minerals (oral form)**
Reduce absorption.

**Other eye products**
Applied a few minutes apart.

## What is monitored

- Response of the eye or ear infection
- Signs of allergy

## Administration and safety

- Eye drops are not for injection
- The dropper tip does not touch the eye or ear, to avoid contamination
- Eye and ear products are not interchangeable unless labelled for both

## Nursing care

- Teach correct instillation and hand washing
- Teach to report swelling, rash or worsening pain
- Advise against contact lenses during an eye infection

## Pregnancy and breastfeeding

Little reaches the blood after drops; systemic quinolones are usually avoided in pregnancy when alternatives exist.

## Memory aid

«Ofloxacin went local»: its left-hand half (levo) took over the body, it kept the eyes and ears.

## Test yourself

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

## What is the relation between ofloxacin and levofloxacin?

Levofloxacin is the active S-isomer of the racemic ofloxacin.

## For which ear infection is ofloxacin used?

External otitis (ear drops).

## What is the most frequent effect of ofloxacin eye drops?

Transient burning or discomfort in the eye.

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

## Related drugs

- [Levofloxacin](https://durgical.com/en/pharmacology/levofloxacin/)
- [Ciprofloxacin](https://durgical.com/en/pharmacology/ciprofloxacin/)

## Related conditions

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

[← Back to the class: Fluoroquinolones](https://durgical.com/en/pharmacology/classes/fluoroquinolones/)

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 - OFLOXACIN- ofloxacin ophthalmic solution](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=0f4ae336-0ad6-4382-b63e-827684c036d9) (DailyMed (U.S. National Library of Medicine), 2026); [Ofloxacin: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a691005.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [eEML - Electronic Essential Medicines List](https://list.essentialmeds.org/?query=ofloxacin) (World Health Organization, 2025).

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Representative model, for educational purposes only.

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Source: https://durgical.com/en/pharmacology/ofloxacin/
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