Oskela
Get started

Drug Reference

levofloxacin

fluoroquinolone antibiotic· Brands: Levaquin, Tavanic, LevofloxIVPO

Mechanism of action
Levofloxacin is a fluoroquinolone antibiotic that inhibits bacterial DNA gyrase and topoisomerase IV, enzymes essential for DNA replication, transcription, repair and recombination. This inhibition leads to rapid bacterial cell death.
Pharmacokinetics
Levofloxacin is well absorbed after oral administration with a bioavailability of about 99%. It is widely distributed, with a volume of distribution of approximately 1.1 L/kg, and is only about 24% to 38% bound to plasma proteins. The terminal half-life is about 5 to 7 hours, allowing once-daily dosing. It is primarily excreted unchanged in the urine, so dose adjustment is needed in renal impairment.
Indications & dosing

Community-acquired pneumonia

Duration 5-14 days; 750 mg for 5 days or 500 mg for 7-14 days.

  • adult · PO: 500–750 mg once daily · Duration 5-14 days; 750 mg for 5 days or 500 mg for 7-14 days.

Acute bacterial sinusitis

Duration 5-14 days; 750 mg for 5 days or 500 mg for 10-14 days.

  • adult · PO: 500–750 mg once daily · Duration 5-14 days; 750 mg for 5 days or 500 mg for 10-14 days.

Acute exacerbation of chronic bronchitis

Duration 7 days.

  • adult · PO: 500 mg once daily · Duration 7 days.

Uncomplicated urinary tract infection

Duration 3 days.

  • adult · PO: 250 mg once daily · Duration 3 days.

Complicated urinary tract infection or acute pyelonephritis

Duration 7-14 days; 750 mg for 5 days is an alternative.

  • adult · PO: 500–750 mg once daily · Duration 7-14 days; 750 mg for 5 days is an alternative.
Contraindications & precautions
  • Hypersensitivity to levofloxacin or other fluoroquinolones · Cross-reaction between quinolones may occur.
  • Pregnancy and breastfeeding · Risk of cartilage toxicity in animal studies; avoid unless benefit outweighs risk.
  • Children and adolescents under 18 years · May cause arthropathy; use only for specific indications such as anthrax or plague.
  • Previous tendon disorders with fluoroquinolone use · Recurrence risk high; avoid if history of tendinopathy or tendon rupture.
  • Myasthenia gravis · Fluoroquinolones can exacerbate neuromuscular weakness; avoid use in patients with myasthenia gravis.
  • Known QT interval prolongation · Risk of ventricular arrhythmias; consider alternatives or monitor ECG.
  • Dose adjust in renal impairment to avoid accumulation.
  • Use caution in patients with hypokalaemia or concurrent QT-prolonging drugs; monitor ECG if risk factors present.
  • Concomitant corticosteroids increase risk of tendon rupture; advise patients to report tendon pain promptly.
  • Separate levofloxacin from antacids, iron, zinc, or calcium by at least 2 hours before or 6 hours after.
  • Advise patients to avoid excessive sun exposure and to report symptoms of peripheral neuropathy such as numbness or tingling.
Adverse effects
  • Nausea
  • Diarrhoea
  • Headache
  • Dizziness
  • Tendonitis and tendon ruptureserious
  • QT interval prolongationserious
  • Seizuresserious
  • Peripheral neuropathyserious
  • Clostridioides difficile-associated diarrhoeaserious
Interactions
  • warfarinmajorIf co-prescription is necessary, monitor INR frequently (e.g., every 2-3 days) during the first week of levofloxacin therapy and for at least one week after stopping. Consider reducing warfarin dose based on INR. Advise patients to report any signs of bleeding.
  • theophyllinemoderateAvoid concomitant use if possible. If co-prescription is necessary, monitor serum theophylline levels closely (e.g., before starting and within 1-2 days after adding levofloxacin) and reduce the theophylline dose as needed. Monitor the patient for clinical signs of theophylline toxicity. Consider an alternative antibiotic with less interaction potential, such as azithromycin; ciprofloxacin is itself a potent CYP1A2 inhibitor and is not an alternative.
Renal & hepatic adjustment
  • eGFR 50+: No dose adjustment required.
  • eGFR 20–49: For a usual 500 mg daily dose, reduce to 250 mg once daily. For a usual 750 mg dose, give 750 mg every 48 hours.
  • eGFR 0–19: For a usual 500 mg daily dose, reduce to 250 mg every 48 hours. For a usual 750 mg dose, give 750 mg every 48 hours. Use with caution; consider alternative if possible.
Monitoring, pregnancy & toxicity
  • Renal function (serum creatinine/eGFR) · Baseline and periodically in patients with renal impairment
  • Blood glucose · In patients with diabetes, monitor more frequently
  • QT interval (ECG) · In patients at risk of QT prolongation (e.g., hypokalaemia, bradycardia, concurrent QT-prolonging drugs)
  • Tendon pain or inflammation · At start of treatment and at each assessment (advise patient to report)
  • Signs of peripheral neuropathy (numbness/tingling) · During treatment (advise patient to report)
  • Signs of C. difficile infection (diarrhoea) · During and after treatment (advise patient to report)
  • Pregnancy: Levofloxacin is not recommended during pregnancy. Use an alternative antibiotic where possible, especially in the first trimester, due to potential risk of cartilage damage in the developing fetus. Consider reserving for severe infections when no other options are available.
  • Toxicity: Tendon rupture, especially Achilles tendon · Discontinue levofloxacin immediately. Immobilise the affected limb and refer for orthopaedic review. Avoid strenuous exercise.
  • Toxicity: QT interval prolongation leading to torsades de pointes · Discontinue levofloxacin. Correct electrolyte imbalances (e.g., hypokalaemia, hypomagnesaemia), monitor ECG, and review other QT-prolonging drugs.
  • Toxicity: Central nervous system effects, including seizures, confusion, and hallucinations · Discontinue levofloxacin. Provide supportive care. For seizures, administer an intravenous benzodiazepine or standard anticonvulsant.
  • Toxicity: Hypoglycaemia (especially in diabetic patients) · Discontinue levofloxacin. Monitor blood glucose frequently. Administer oral or intravenous glucose if indicated.
Clinical notes
Levofloxacin is used for respiratory tract infections, urinary tract infections, skin and soft tissue infections, and some intra-abdominal infections. It should be avoided in patients with a history of tendon disorders, myasthenia gravis, or prolonged QT interval. It may cause photosensitivity and central nervous system effects. It can interact with antacids, iron and zinc supplements, so it should be taken 2 hours before or after these. Reserve for infections where other antibiotics are not suitable.

Log in to read the full levofloxacin monograph

A free account unlocks the complete drug reference, the interaction checker, prescription practice and every other learning tool.

Log inCreate a free account

BNF; local formulary