Antibiotic — Fluoroquinolone Pregnancy: Contraindicated in pregnancy and in breast-feeding women. There are limited data in pregnant women; although animal studies do not indicate direct or indirect reproductive toxicity, in the absence of human data and because experimental data suggest a risk of fluoroquinolone damage to the weight-bearing cartilage of the growing organism, levofloxacin tablets must not be used in pregnant or breast-feeding women. There is insufficient information on excretion in human milk, but other fluoroquinolones are excreted in breast milk. Levofloxacin caused no impairment of fertility or reproductive performance in rats.

Levofloxacin

Brand names: Tavanic

Levofloxacin is a fluoroquinolone antibiotic reserved for serious or resistant infections such as pneumonia, complicated urinary tract and intra-abdominal infections where other antibiotics are unsuitable.

Auto-extracted from the source labelling — not yet independently clinician-verified. These values were distilled from the UK SPC (or the US label where noted) but have not had a clinician sign-off. Confirm against the current SmPC before prescribing.

Adult dose

Dose: 250 mg or 500 mg per dose, given once or twice daily depending on indication and severity (patients with normal renal function, creatinine clearance above 50 ml/min). Community-acquired pneumonia: 500 mg once or twice daily for 7 to 14 days. Complicated skin and soft tissue infections: 500 mg once or twice daily for 7 to 14 days. Acute bacterial sinusitis: 500 mg once daily for 10 to 14 days. Acute bacterial exacerbation of chronic bronchitis: 500 mg once daily for 7 to 10 days. Pyelonephritis: 500 mg once daily for 7 to 10 days. Complicated urinary tract infection: 500 mg once daily for 7 to 14 days. Uncomplicated cystitis: 250 mg once daily for 3 days. Chronic bacterial prostatitis: 500 mg once daily for 28 days. Inhalation anthrax: 500 mg once daily for 8 weeks.

Route: Oral — swallow tablets without crushing, with sufficient liquid; may be taken with or between meals

Frequency: Once or twice daily, according to the indication and severity above

Max: No absolute daily maximum is stated in the SPC; the highest regimen in the dose table is 500 mg twice daily (community-acquired pneumonia and complicated skin and soft tissue infections).

The dosage depends on the type and severity of the infection and the sensitivity of the presumed causative pathogen. SWITCH FROM INTRAVENOUS: levofloxacin tablets may be used to complete a course of therapy in patients who have improved on initial intravenous levofloxacin; given the bioequivalence of the parenteral and oral forms, the SAME dosage can be used. (The intravenous SPC itself was not fetched in this bundle.) ADMINISTRATION SPACING: take at least two hours before or after iron salts, zinc salts, magnesium- or aluminium-containing antacids, didanosine (only formulations with aluminium or magnesium containing buffering agents) and sucralfate, since absorption is reduced. HEPATIC IMPAIRMENT: no dosage adjustment is required, since levofloxacin is not metabolised to any relevant extent by the liver and is mainly excreted by the kidneys. ELDERLY: no dosage adjustment other than that imposed by renal function; note the section 4.4 warning on QT interval prolongation. PAEDIATRIC: levofloxacin is CONTRAINDICATED in children and growing adolescents under 18 years of age. MHRA/EU SAFETY RESTRICTION IN THE SPC: avoid in patients who have experienced serious adverse reactions to any quinolone or fluoroquinolone; initiate only where there is no alternative treatment option and after careful benefit/risk assessment. Very rare cases of prolonged (months to years), disabling and potentially irreversible serious adverse reactions affecting multiple body systems (musculoskeletal, nervous, psychiatric, senses) have been reported irrespective of age or pre-existing risk factors; discontinue immediately at the first sign of any serious adverse reaction. Tendinitis and tendon rupture (especially Achilles, sometimes bilateral) may occur as early as within 48 hours of starting and up to several months after stopping — risk is increased in older patients and in renal impairment. RESISTANCE: methicillin-resistant S. aureus is very likely to be co-resistant, so levofloxacin is not recommended for known or suspected MRSA infection unless susceptibility is confirmed and the usual MRSA agents are inappropriate; take account of local E. coli fluoroquinolone resistance in urinary infections; use in sinusitis and acute exacerbation of chronic bronchitis only when adequately diagnosed. For inhalation anthrax, refer to national and/or international consensus documents. NOTE ON COMPLETENESS: the fetched SPC section 4.5 was not retrieved separately — the interaction entries below come from SPC section 4.2 and from the US prescribing information section 7, and must be checked against the full SPC section 4.5.

Dose adjustments

Renal

Required when creatinine clearance is 50 ml/min or less. For a 250 mg/24 h regimen: first dose 250 mg, then creatinine clearance 50-20 ml/min give 125 mg/24 h; 19-10 ml/min give 125 mg/48 h; under 10 ml/min (including haemodialysis and CAPD) give 125 mg/48 h. For a 500 mg/24 h regimen: first dose 500 mg, then 50-20 ml/min give 250 mg/24 h; 19-10 ml/min give 125 mg/24 h; under 10 ml/min (including haemodialysis and CAPD) give 125 mg/24 h. For a 500 mg/12 h regimen: first dose 500 mg, then 50-20 ml/min give 250 mg/12 h; 19-10 ml/min give 125 mg/12 h; under 10 ml/min (including haemodialysis and CAPD) give 125 mg/24 h. No additional doses are required after haemodialysis or continuous ambulatory peritoneal dialysis (CAPD).

Dose auto-extracted from UK Summary of Product Characteristics (SPC) via the eMC; US FDA prescribing information (openFDA / DailyMed) — cross-check; US labelling may differ from UK — not yet clinician-verified. Always confirm against the product SmPC and your local formulary before prescribing.

Contraindications

Hypersensitivity to levofloxacin, to other quinolones, or to any of the excipients
Patients with epilepsy
Patients with a history of tendon disorders related to fluoroquinolone administration
Children or growing adolescents (under 18 years of age)
Pregnancy
Breast-feeding women

Side effects

Gastrointestinal: diarrhoea, nausea (common); vomiting, abdominal pain, dyspepsia, flatulence and constipation (uncommon); haemorrhagic diarrhoea which very rarely may indicate enterocolitis including pseudomembranous colitis
Nervous system and psychiatric: headache and dizziness (uncommon); insomnia (common); somnolence, tremor, dysgeusia, anxiety, confusional state and nervousness; rarely convulsion, peripheral sensory neuropathy, psychotic reactions and psychotic disorders with self-endangering behaviour including suicidal ideation or attempt
Tendinitis and tendon rupture (especially Achilles, sometimes bilateral), which may occur within 48 hours of starting and up to several months after stopping
Cardiac: tachycardia and palpitation (uncommon); rarely ventricular tachycardia which may result in cardiac arrest, ventricular arrhythmia and torsade de pointes and QT prolongation (predominantly in patients with risk factors for QT prolongation)
Hepatobiliary and haematological: increased hepatic enzymes (ALT/AST, alkaline phosphatase, GGT) (common); jaundice and severe liver injury including fatal acute liver failure (very rare); leukopenia and eosinophilia (common), thrombocytopenia and neutropenia (uncommon), and rarely bone marrow failure including aplastic anaemia, pancytopenia, agranulocytosis and haemolytic anaemia. Hypersensitivity including angioedema and anaphylactic shock also occur

Interactions

Iron salts, zinc salts, magnesium- or aluminium-containing antacids, didanosine (aluminium/magnesium-buffered formulations) and sucralfate — reduce gastrointestinal absorption of levofloxacin; separate administration by at least two hours (SPC section 4.2; US label section 7.1, which also lists multivitamin preparations containing zinc)
Warfarin — anticoagulant effect may be enhanced; monitor prothrombin time and INR and watch for bleeding (US label section 7.2)
Antidiabetic agents — carefully monitor blood glucose; hypoglycaemia (including hypoglycaemic coma) and hyperglycaemia are reported adverse reactions, particularly in diabetic patients (US label section 7.3; SPC section 4.8)
NOTE: the UK SPC section 4.5 was NOT retrieved in this bundle — this list is not exhaustive and must be checked against the full SPC

Clinical monograph

How it works

It inhibits bacterial DNA gyrase (topoisomerase II) and topoisomerase IV, blocking DNA replication and transcription, producing a bactericidal effect.

Prescribing in practice

MHRA warns of disabling and potentially long-lasting or irreversible musculoskeletal and nervous system effects, including tendon rupture and aortic aneurysm or dissection, so reserve fluoroquinolones and stop at the first sign of tendon pain.
It can prolong the QT interval, so use caution with other QT-prolonging drugs and in electrolyte disturbance.
Absorption is reduced by calcium, iron, zinc and antacids, and it lowers the seizure threshold.

Monitoring

There is no routine laboratory monitoring, but observe for tendon, neurological and cardiac adverse effects and stop promptly if they occur.

Counselling the patient

Stop and seek advice if you develop tendon pain or swelling, new numbness or tingling, or significant mood changes.
Separate from indigestion remedies and iron or calcium supplements, and avoid excessive sun exposure.
Report palpitations or fainting.

Evidence & guidelines

MHRA fluoroquinolone safety reviews restrict levofloxacin to situations where other antibiotics cannot be used, reflected in NICE antimicrobial prescribing guidance.

Reference: MHRA Drug Safety Update 2019 (Fluoroquinolone Antibiotics); NICE NG138 (Pneumonia); Drug verified in RxNorm (NLM); confirm dosing against the manufacturer SPC (eMC). Verify against your local formulary and current prescribing references before prescribing. The structured dose values shown have been reviewed by a clinician. Monograph status: clinician-reviewed (2026-07-04).

Curated clinical cross-links plus same-class fallbacks.

Calculators

Drugs

Levofloxacin · Antibiotic — Fluoroquinolone

Pathways