Levofloxacin

How it works

It inhibits bacterial DNA gyrase and topoisomerase IV, blocking DNA replication, and has broad-spectrum activity including respiratory pathogens such as pneumococci and Gram-negative organisms.

Prescribing in practice

• MHRA advice restricts systemic fluoroquinolones to situations where other antibiotics are inappropriate, owing to rare but serious and potentially disabling tendon, musculoskeletal, neurological and psychiatric reactions.
• It can prolong the QT interval, so caution is needed with other QT-prolonging drugs and in patients with electrolyte disturbance or cardiac risk factors.
• Tendon rupture (notably Achilles) can occur and the risk is higher with concurrent corticosteroids and in older patients.

Monitoring

Monitor for tendon, joint, neurological or psychiatric symptoms and, where relevant, QT interval and electrolytes during treatment.

Counselling the patient

• Stop the medicine and seek urgent advice if you develop tendon pain or swelling, new numbness or tingling, or marked mood changes.
• Avoid taking it at the same time as antacids, iron or calcium, which reduce its absorption.
• Protect your skin from strong sunlight while taking it.

Evidence & guidelines

MHRA safety reviews advise reserving systemic fluoroquinolones such as levofloxacin for use only when other antibiotics cannot be used, because of the risk of long-lasting adverse effects.