Moxifloxacin

Fluoroquinolone·Infectious Diseases - Other Antibiotics

Severe Community Acquired Pneumonia (CAP), complicated intra-abdominal infections, pelvic inflammatory disease

Authority requiredPBSFLUOROQUINOLONEAvelox400 mg tablet+2

Max Dose

400 mg/day

Half-life

12 h

Tendon Rupture

CRITICAL

UTI Treatment

USELESS

Rapid Summary

Overview

The 'Respiratory Fluoroquinolone'. Uniquely potent against Streptococcus pneumoniae and deep anaerobes. Completely bypasses the kidneys, making it useless for UTIs but incredibly safe in renal failure.

Maximum Dose

Max 400 mg/day.

Clinical Focus

Black Box warnings for Achilles tendon rupture and aortic dissection. Do not use for mild infections.

Bottom Line

Moxifloxacin is a respiratory fluoroquinolone covering atypicals and anaerobes without renal dose adjustment, but has the highest QTc prolongation risk of all fluoroquinolones and carries tendon rupture risk.

Formulation & Access

Brand Names

Avelox

Oral Routes

Tablets (400 mg).

Parenteral

Pre-mixed infusion bags for IV use.

Prescribing & PBS

Authority Required (PBS).

Indications & Use

Primary

PBSTGA

Severe Community Acquired Pneumonia (CAP), complicated intra-abdominal infections, pelvic inflammatory disease.

Clinical Place

A powerful monotherapy option for severe pneumonia in penicillin-allergic patients, as it covers typicals, atypicals, and anaerobes in a single pill.

Quick reference

Class & Role

Fluoroquinolone — The 'Respiratory Fluoroquinolone'.

Route / Formulation

Tablets (400 mg). (Avelox)

Usual Dose & Max

PO or IV 400 mg OD. Max 400 mg/day.

Key Indication Doses

Severe CAP / Intra-abdominal Sepsis: PO or IV 400 mg OD. Renal Impairment: No dose adjustment required in severe CKD or dialysis (100% hepatic/biliary clearance).

Best Uses

Avoid / Cautions

Baseline QTc > 500 ms, history of tendon disorders, aortic aneurysm.

Key Risks

Musculoskeletal: Achilles tendon rupture (can occur suddenly and bilaterally). Cardiovascular: Aortic aneurysm dissection/rupture. HIGH — QTc prolongation (highest risk of all fluoroquinolones). Neurological: Peripheral neuropathy, seizures, insomnia/psychosis.

Key Interactions

Iron, Calcium, Antacids. Multi-valent cations bind the drug in the gut, dropping absorption to zero. Separate by 4 hours. Amiodarone, Sotalol, SSRIs (Synergistic fatal QTc prolongation).

Monitoring

Warn patient to stop the drug instantly if they feel heel pain or sudden tearing chest/back pain. Baseline ECG is mandatory in the elderly.

Clinical Pearl

Because Moxifloxacin is metabolised entirely by the liver, NO active drug reaches the urine. If you prescribe Moxifloxacin for a urinary tract infection, the patient will die of urosepsis while taking a potent antibiotic. You MUST use Ciprofloxacin or Norfloxacin for UTIs.

Access

Authority requiredAvelox400 mg tablet

Brand: Avelox
PBS status: Authority required
Formulation: Tablets (400 mg)