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Why is it prescribed?

Levofloxacin is used to treat infections caused by various bacteria. This material will be limited to the treatment of respiratory tract infections (e.g. pneumonia, bronchitis).

Along with its needed effects, levofloxacin may cause some unwanted or undesirable effects. Generally, levofloxacin is well tolerated and many people will not experience unwanted effects. The frequency and severity of these effects is dependant on many factors including dose, duration of therapy and individual susceptibility. Possible unwanted effects include:

  • diarrhea
  • nausea
  • vomiting
  • headache
  • dizziness
  • troubles sleeping
  • stomach discomfort


  • agitation
  • tremors
  • seizures
  • shortness of breath
  • confusion


  • rash
  • pseudomembranous colitis (inflammation of the colon caused by the overgrowth and toxin production of bacteria that are not killed by the antibiotic)


Levofloxacin is an antibiotic medication that kills various bacteria. It works by inhibiting the synthesis of bacterial DNA which results in bacterial cell death. Levofloxacin does not kill all types of bacteria, but only those that have a sensitivity to this antibiotic. Infections caused by bacteria that are not sensitive to levofloxacin will not show improvement after taking this medication.

Use as directed. Many antacids and multivitamins may interfere with the absorption of levofloxacin. You should take levofloxacin either two hours before or two hours after taking these products. Allergic reactions have occurred rarely with levofloxacin use. The reaction can be immediate and severe. Allergic symptoms include wheezing, hives, itching, swelling, joint and muscle pain, difficulty breathing, fever and skin rashes. Nausea and vomiting are not symptoms of an allergic reaction.
Diabetics should monitor their blood sugar regularly while taking levofloxacin. Discontinue the medication and notify your doctor if a hypoglycemic (low blood sugar) reaction occurs.
Taking the antibiotic repeatedly or for prolonged periods may result in bacterial or fungal overgrowth which can lead to a second infection. When this occurs, the levofloxacin may need to be stopped and another antibiotic prescribed to treat the new infection.
Diarrhea may develop while taking levofloxacin. This is sometimes caused by an overgrowth of bacteria in the gut that are not killed by the antibiotic. In severe cases, this may be life threatening and would require treatment with other antibiotics. In mild cases, symptoms disappear shortly after the drug is discontinued.
Levofloxacin may make you more sensitive to sunlight. Wear sunscreens and protective clothing and avoid exposure to the sun for long periods of time.
If you experience joint or muscle pain while taking levofloxacin, notify your doctor, rest and do not exercise. There are some reports of tendon tears (mostly in the ankle) occurring during treatment with drugs similar to levofloxacin
Drug Interactions: It is important to tell your doctor and pharmacist of any prescription or over-the-counter medications you are taking. In some cases, the dose of one or both drugs may need to be altered or another drug may be prescribed. The following drugs or drug classes have been known to interact with levofloxacin:

  • antacids that contain aluminum or magnesium
  • iron or mineral supplements
  • zinc-containing products
  • warfarin (e.g. Coumadin®)
  • hypoglycemic drugs (e.g. glyburide, insulin)
  • sucralfate (e.g. Sulcrate®)
  • theophylline (e.g. Theo-Dur®)

Use is not recommended in the following situations

  • allergy to levofloxacin or any quinolone (e.g. ciprofloxacin, ofloxacin)

Caution is recommended in the following situations:

  • kidney disease
  • tendon problems (e.g. tendinitis) diabetics on blood sugar lowering agents (e.g. glyburide, insulin)
  • nervous system disorders (e.g. epilepsy)
  • liver disease

Use in pregnancy: Human data suggests low risk, however,  consult your doctor or pharmacist if you suspect you are pregnant or if you are planning to become pregnant.
Use while breastfeeding: Levofloxacin does appear in breast milk however, effects on the infant are unknown.  Other medications in this family are considered appropriate to use if breastfeeding, however, consult your doctor or pharmacist before using.