Levofloxacin

How it works

It inhibits the bacterial enzymes DNA gyrase and topoisomerase IV, blocking DNA replication, transcription and repair, leading to bacterial cell death.

Prescribing in practice

• MHRA advice restricts fluoroquinolones because of rare but disabling, potentially long-lasting or irreversible musculoskeletal and neurological effects, including tendon rupture, so they should be reserved for situations where other antibacterials cannot be used.
• It prolongs the QT interval and lowers the seizure threshold, warranting caution with other QT-prolonging drugs and in those at risk of convulsions.
• Absorption is reduced by antacids and iron, zinc or calcium products, which must be separated from the dose.

Monitoring

Review for tendon pain, neuropathy, neuropsychiatric symptoms and, where relevant, QT interval, stopping treatment at the first sign of serious adverse effects.

Counselling the patient

• Stop the antibiotic and seek advice if you develop tendon pain or swelling, numbness, or new mood or sleep changes.
• Separate indigestion remedies and iron, zinc or calcium supplements from your dose.
• Avoid excessive sun exposure and report any new joint or muscle problems.

Evidence & guidelines

Use is governed by MHRA and NICE guidance restricting fluoroquinolones to situations where other antibacterials are inappropriate.