Skip to content
ClinCalc Pro
Menu
Calculators Drugs Pathways AI Dx Donate Get the App
Antibiotic — Severe CAP / Legionella

Levofloxacin

Brand names: Tavanic

A fluoroquinolone antibiotic with broad respiratory activity used for community-acquired pneumonia and other respiratory infections, often when first-line agents are unsuitable. Its use is restricted owing to recognised serious adverse effects.

Dosing — being independently re-sourced

ClinCalc Pro is rebuilding its dose data from primary open sources — the manufacturer SmPC (eMC), the WHO Model Formulary and other official references — under clinician review. This drug's structured dose is not yet published here. Confirm all doses against the product SmPC and your local formulary before prescribing.

Clinical monograph

How it works

Levofloxacin inhibits bacterial DNA gyrase and topoisomerase IV, blocking DNA replication and producing a bactericidal effect against many respiratory pathogens.

Prescribing in practice

  • Reserve for situations where other antibiotics are inappropriate — the MHRA warns of rare but disabling and potentially irreversible tendon, musculoskeletal and neuropsychiatric effects, and patients should stop at the first sign of tendon pain.
  • It prolongs the QT interval, so use cautiously with other QT-prolonging drugs and in those with electrolyte disturbance or relevant cardiac risk.
  • It can lower the seizure threshold and interacts with cations and other agents, and tendon risk is higher in older patients and with corticosteroids.

Monitoring

Monitor clinical response and watch for tendon, joint or neurological symptoms, QT-related effects and signs of Clostridioides difficile-associated diarrhoea.

Counselling the patient

  • Stop the antibiotic and seek advice if you develop tendon pain or swelling, new numbness or significant mood changes.
  • Separate it from antacids, iron and dairy, and avoid excess sun exposure.

Evidence & guidelines

Levofloxacin is supported for respiratory infection in NICE and BTS guidance as a reserve agent given MHRA fluoroquinolone safety restrictions.

Reference: NICE NG138; MHRA Drug Safety Update (2019, 2023); BTS CAP Guidelines; PHE Legionella guidance; Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. Monograph status: clinician-reviewed (2026-07-04).

Related

Curated clinical cross-links plus same-class fallbacks.

Calculators
Pathways