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Levofloxacin: 7 things you should know

Medically reviewed by Carmen Pope, BPharm. Last updated on March 31, 2023.

1. How it works

  • Levofloxacin is an antibiotic that may be used to treat certain bacterial infections.
  • Levofloxacin works by converting two bacterial enzymes, topoisomerase IV and DNA gyrase, into toxic enzymes that inhibit the manufacture and repair of DNA and other DNA processes, killing the bacteria.
  • Levofloxacin belongs to a group of medicines called fluoroquinolone antibiotics.

2. Upsides

  • Levofloxacin may be used to treat infections of the skin, sinuses, kidneys, bladder, and prostate caused by susceptible bacteria. However, it is usually only used in the treatment of urinary tract infections, chronic bronchitis, and sinusitis when other alternative treatment options have failed or cannot be used.
  • Levofloxacin may also be used to treat certain types of lung infections.
  • May be given as a preventive measure when people have been exposed to anthrax.
  • Effective against susceptible strains of several gram-positive and gram-negative bacteria, for example: Staphylococcus aureus (methicillin-susceptible strains only), S. epidermidis (methicillin-susceptible isolates), S. pneumoniae (including multi-drug resistant isolates), S. pyogenes, Escherichia coli, Haemophilus influenzae, and Pseudomonas aeruginosa. Also effective against Chlamydophila pneumoniae and Mycoplasma pneumoniae.
  • Available as oral tablets, oral solution, eye drops, and in an injectable form.
  • Generic levofloxacin is available.

3. Downsides

If you are between the ages of 18 and 60, take no other medication or have no other medical conditions, side effects you are more likely to experience include:

  • Headache, insomnia, nausea, diarrhea, constipation, and abdominal pain.
  • Tendonitis and tendon rupture, peripheral neuropathy (nerve pain in fingers and toes), and central nervous system effects (side effects that affect the brain including psychosis, convulsions, or hallucinations) have been associated with levofloxacin and other fluoroquinolones. These side effects may be irreversible and can all occur together in some patients. May occur at any time after starting levofloxacin and in any patient. If any of these very severe side effects happen, levofloxacin should be discontinued immediately and all fluoroquinolones avoided in the future. The risk of tendonitis and tendon rupture is increased in people over the age of 60, in those taking corticosteroids, or with a history of organ transplant. Previous tendon disorders or strenuous activity may also increase risk.
  • May disturb blood glucose levels in people with diabetes; careful monitoring of blood glucose is required.
  • May cause photosensitivity reactions and severe sunburn on exposed areas of skin.
  • May exacerbate muscle weakness in people with myasthenia gravis.
  • Should only be used by adults (at least 18 years old).
  • Not suitable for people with myasthenia gravis, certain heart rhythm disturbances, or pediatric patients (unless being given to prevent inhalation anthrax or plague). Dosage may need the reducing in people with poor kidney function. May cause liver damage or heart rhythm disturbances.
  • May interact with some medications including NSAIDs (increasing the risk of CNS stimulation and seizures), antacids, or preparations containing iron or zinc. Administer at least two hours before or two hours after these preparations.
  • Some fluoroquinolones, including levofloxacin, may cause false-positive urine screening results for opiates. Other more specific testing methods may be needed.

Note: In general, seniors or children, people with certain medical conditions (such as liver or kidney problems, heart disease, diabetes, seizures) or people who take other medications are more at risk of developing a wider range of side effects. View complete list of side effects

4. Bottom Line

Levofloxacin treats a wide range of bacterial infections; however, it can cause some very severe and potentially irreversible side effects such as tendonitis or tendon rupture, and should only be used to treat infections that have not responded to alternative treatment options.

5. Tips

  • Oral levofloxacin tablets can be administered without regard to food. Take oral levofloxacin solution one hour before or two hours after food.
  • Take levofloxacin at least two hours before or two hours after antacids or preparations containing iron or zinc.
  • Should be taken exactly as directed and for the duration indicated to reduce the risk of resistant bacteria developing, unless side effects force early discontinuation.
  • Ensure you keep hydrated while taking levofloxacin to prevent crystal formation in your urine.
  • Discontinue levofloxacin immediately if you experience tendon pain, swelling, inflammation, or rupture, and contact your healthcare provider.
  • Discontinue levofloxacin immediately and contact your healthcare provider if you experience pain, tingling, or numbness in your fingers and toes; severe diarrhea; or any central nervous system effects (such as paranoia, depression, hallucinations), a severe rash, jaundice (skin yellowing), a change in your heartbeat, or any sign of an allergic reaction.
  • Do not drive or operate machinery if levofloxacin makes you feel dizzy or tired. Avoid alcohol.
  • Avoid excessive sun or UV light exposure, and wear sunblock when outdoors. Report any apparent sunburn to your doctor immediately.

6. Response and effectiveness

  • Peak levels are reached within one to two hours but it may take up to three days before symptoms of the infection begin to resolve.
  • Levofloxacin is the L-isomer of ofloxacin, which is also a quinolone antibiotic. However, the majority of the antibacterial activity of ofloxacin resides in the L-isomer, which is levofloxacin.

7. Interactions

Medicines that interact with levofloxacin may either decrease its effect, affect how long it works, increase side effects, or have less of an effect when taken with levofloxacin. An interaction between two medications does not always mean that you must stop taking one of the medications; however, sometimes it does. Speak to your doctor about how drug interactions should be managed.

Common medications that may interact with levofloxacin include:

  • antacids containing magnesium or aluminum
  • blood-glucose-lowering agents, such as insulin or glimepiride
  • corticosteroids, such as prednisone. May enhance the risk of tendonitis or tendon rupture
  • bowel cleansing agents such as sodium picosulfate
  • lactobacillus
  • NSAIDs such as ibuprofen, diclofenac, or naproxen
  • photosensitizing agents, such as aminolevulinic acid
  • probenecid
  • QTc-prolonging agents, such as amiodarone, domperidone, methadone, ondansetron, or haloperidol
  • sucralfate
  • supplements containing calcium, iron, or zinc
  • warfarin
  • vaccinations, such as BCG, cholera, or typhoid.

Note that this list is not all-inclusive and includes only common medications that may interact with levofloxacin. You should refer to the prescribing information for levofloxacin for a complete list of interactions.


Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use levofloxacin only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Copyright 1996-2023 Revision date: March 31, 2023.