Levofloxacin

How it works

It inhibits bacterial DNA gyrase (topoisomerase II) and topoisomerase IV, blocking DNA replication and transcription and leading to bacterial cell death.

Prescribing in practice

• MHRA advice restricts fluoroquinolones to situations where other antibacterials are unsuitable because of rare but serious and potentially irreversible musculoskeletal and nervous-system effects, including tendon rupture and peripheral neuropathy.
• It prolongs the QT interval and should be used with caution alongside other QT-prolonging drugs and in those with predisposing electrolyte disturbance or cardiac risk.
• Absorption is markedly reduced by polyvalent cations, so it should be separated in time from antacids, iron, calcium and other multivalent-cation preparations.

Monitoring

Monitor for tendon pain, new neuropathic symptoms and signs of central nervous system effects, with attention to QT risk in susceptible patients.

Counselling the patient

• Stop the medicine and seek advice if you get tendon pain or swelling, or new numbness, tingling or weakness.
• Avoid taking it at the same time as indigestion remedies, or iron or calcium supplements.
• Report any mood changes, confusion or unusual heartbeat sensations.

Evidence & guidelines

MHRA Drug Safety Updates have reinforced restrictions on fluoroquinolone use owing to the risk of disabling and potentially long-lasting adverse effects.