[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/) › Moxifloxacin

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

# Moxifloxacin

A respiratory fluoroquinolone with anaerobic activity, cleared mostly by the liver. A WHO medicine for drug-resistant tuberculosis.

Updated 2026-11-01

- Class: [Fluoroquinolones](https://durgical.com/en/pharmacology/classes/fluoroquinolones/)
- Enzyme: Bacterial DNA gyrase and topoisomerase IV
- ATC code: J01MA14
- WHO Model List of Essential Medicines

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

ⓘ The figure shows moxifloxacin bound to DNA cut by Staphylococcus aureus DNA gyrase.

**Target in 3D:** Bacterial DNA gyrase and topoisomerase IV. PDB structure 5CDQ (RCSB PDB, public domain). [View the structure at RCSB PDB](https://www.rcsb.org/structure/5CDQ) · Drag to rotate · pinch to zoom

## Mechanism of action

Moxifloxacin traps DNA gyrase and topoisomerase IV on cleaved DNA, turning them into lethal double-strand breaks. Its 8-methoxy group strengthens activity against gram-positive bacteria and anaerobes, but it is weak against Pseudomonas.

- Absorbed by mouth or given IV
- Binds gyrase and topoisomerase IV on cut DNA
- The DNA cannot be resealed
- Double-strand breaks kill the bacterium

## Pharmacokinetics

**Absorption**
Oral bioavailability about 90%.

**Metabolism**
Liver, by glucuronide and sulfate conjugation; cytochrome P450 is not involved.

**Elimination**
Urine and faeces; no dose change in kidney failure.

**Half-life**
About 12 hours.

## Indications

- Community-acquired pneumonia and acute bacterial sinusitis [Community-acquired pneumonia →](https://durgical.com/en/conditions/community-acquired-pneumonia/)
- Drug-resistant tuberculosis (WHO antituberculosis list) [Tuberculosis →](https://durgical.com/en/conditions/tuberculosis/)
- Complicated intra-abdominal and skin infections; plague

## Adverse effects

### Common

- Nausea, diarrhoea and dizziness
- Headache
- Photosensitivity

### Serious (rare, important)

- Tendinitis and tendon rupture, peripheral neuropathy and CNS effects (boxed warning); worse myasthenia gravis
- QT prolongation and torsades de pointes
- Dysglycaemia, aortic aneurysm and dissection, hepatotoxicity, C. difficile colitis

## Contraindications

- Allergy to moxifloxacin or other quinolones

## Key interactions

**Antacids, iron, zinc, sucralfate**
Reduce absorption; doses are spaced.

**Antiarrhythmics and other QT-prolonging drugs**
Additive QT risk; avoided.

**Warfarin**
Stronger anticoagulant effect.

## What is monitored

- ECG and potassium/magnesium if there is QT risk
- Blood glucose in diabetes
- Tendon and nerve symptoms

## Administration and safety

- The IV form is infused slowly, not as a bolus
- Oral doses are spaced from minerals

## Nursing care

- Ask about heart rhythm problems and QT drugs
- Teach to report palpitations, fainting, tendon pain or tingling
- Check glucose in diabetes

## Pregnancy and breastfeeding

No malformations in animal studies at clinical exposures; usually avoided when safer drugs exist.

## Memory aid

«Moxi skips the kidney, hits the lung and the TB»: liver-cleared, respiratory and antituberculous.

## Test yourself

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

## Does moxifloxacin need a dose change in kidney failure?

No; it is not mainly cleared by the kidney.

## Which important gram-negative does moxifloxacin cover poorly?

Pseudomonas aeruginosa.

## Which mycobacterial use does moxifloxacin have?

Treatment of drug-resistant tuberculosis.

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

## Related drugs

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

## Related conditions

- [Community-acquired pneumonia](https://durgical.com/en/conditions/community-acquired-pneumonia/)
- [Tuberculosis](https://durgical.com/en/conditions/tuberculosis/)

[← 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 - MOXIFLOXACIN HYDROCHLORIDE tablet, film coated](https://dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=54377276-96bf-4140-9e90-55623ab6b013) (DailyMed (U.S. National Library of Medicine), 2026); [Moxifloxacin: MedlinePlus Drug Information](https://medlineplus.gov/druginfo/meds/a600002.html) (MedlinePlus (U.S. National Library of Medicine), 2026); [eEML - Electronic Essential Medicines List](https://list.essentialmeds.org/?query=moxifloxacin) (World Health Organization, 2025); [2.95A structure of Moxifloxacin with S.aureus DNA gyrase and DNA](https://www.rcsb.org/structure/5CDQ) (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.

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