Medical Dictionary Search Engines

Please be patient! It may take up to ONE minute to load all the Engines.
Problems? Please contact our support.


Search For


Specialty Search




WebMD DrugDigest MedicineNet RxList
Other drug names: A-Am An-Az B C-Ch Ci-Cz D-Dh Di-Dz E F G H I-J K-L M-Mh Mi-Mz N-Nh Ni-Nz O P-Pl Pm-Pz Q-R S-Sn So-Sz T-To Tp-Tz U-V W-Z 0-9   

Levofloxacin (Systemic)

Brand Names

In the U.S.-

  • Levaquin

In Canada-

  • Levaquin


  • Antibacterial, systemic


Levofloxacin (lee-voe-FLOX-a-sin) belongs to the class of medicines known as antibiotics. It is used to treat bacterial infections in many different parts of the body.

Levofloxacin works by killing bacteria or preventing their growth. However, this medicine will not work for colds, flu, or other virus infections.

This medicine is available only with your doctor's prescription, in the following dosage forms:

  • Tablets (U.S. and Canada)
  • Injection (U.S. and Canada)

Before Using This Medicine

In deciding to use a medicine, the risks of taking the medicine must be weighed against the good it will do. This is a decision you and your doctor will make. For levofloxacin, the following should be considered:

Allergies- Tell your doctor if you have ever had any unusual or allergic reaction to levofloxacin, other fluoroquinolones, or chemically related quinolone derivatives (e.g., nalidixic acid). Also tell your health care professional if you are allergic to any other substances, such as foods, preservatives, or dyes.

Pregnancy- Studies have not been done in humans. However, this medicine has been shown to cause problems with bone development in young animals. Discuss with your doctor whether or not this medicine should be taken during pregnancy.

Breast-feeding- It is not known whether levofloxacin passes into human breast milk. However, this medicine has been shown to cause bone development problems in young animals. Discuss with your doctor whether to breast-feed during treatment with this medicine.

Children- Caution is recommended in using levofloxacin in children up to 18 years of age because this medicine has been shown to cause bone development problems in young animals. However, your doctor may choose to use this medicine if other medicines cannot be used.

Older adults- There is no specific information comparing use of levofloxacin in the elderly with use in other age groups. However, it has been used in older people and has not been found to cause different side effects or other problems than it does in younger adults.

Other medicines- Although certain medicines should not be used together at all, in other cases two different medicines may be used together even if an interaction might occur. In these cases, your doctor may want to change the dose, or other precautions may be necessary. When you are taking levofloxacin, it is especially important that your health care professional know if you are taking any of the following:

  • Antiarrhythmic agents (medicine for abnormal heart rhythm)-Levofloxacin may cause changes in heart rhythm when taken with these drugs
  • Antidiabetic agents (medicine for sugar diabetes)-Levofloxacin may change the effects of these drugs, which could cause problems in controlling blood sugar
  • Antacids, aluminum-, calcium-, or magnesium-containing or
  • Iron supplements or
  • Sucralfate (e.g., Carafate) or
  • Zinc-Antacids, iron, sucralfate, or zinc may interfere with absorption of levofloxacin into the body
  • Inflammation or pain medicine, except narcotics-Possible increased risk of convulsions (seizures)

Other medical problems- The presence of other medical problems may affect the use of levofloxacin. Make sure you tell your doctor if you have any other medical problems, especially:
  • Brain or spinal cord disease, including hardening of the arteries in the brain, or epilepsy or other seizures-Levofloxacin may increase the chance of convulsions (seizures) occurring
  • Diabetes mellitus (sugar diabetes)-Levofloxacin may cause changes in blood sugar, which could lead to problems in controlling blood sugar
  • Kidney disease-Effects may be increased because of slower removal of levofloxacin from the body

Proper Use of This Medicine

Levofloxacin may be taken with meals or on an empty stomach.

This medicine is best taken with a full glass (8 ounces) of water. Several additional glasses of water should be taken every day, unless you are otherwise directed by your doctor. Drinking extra water will help to prevent some unwanted effects of levofloxacin.

This medicine works best when there is a constant amount in the blood or urine. To help keep the amount constant, do not miss any doses. Also, it is best to take the doses at evenly spaced times, day and night. For example, if you are to take one dose a day, try to take it at the same time each day.


The dose of levofloxacin will be different for different patients. Follow your doctor's orders or the directions on the label . The following information includes only the average doses of levofloxacin. If your dose is different, do not change it unless your doctor tells you to do so.

The number of tablets that you take depends on the strength of the medicine. Also, the number of doses you take each day, the time allowed between doses, and the length of time you take the medicine depend on the medical problem for which you are taking levofloxacin

  • For oral dosage form (tablets):
    • For treatment of infection:
      • Adults-250 to 750 milligrams (mg) once a day.
      • Children younger than 18 years of age-Use and dose must be determined by your doctor
  • For parenteral dosage form (injection):
    • For treatment of infection:
      • Adults-250 to 750 mg once a day.
      • Children younger than 18 years of age-Use and dose must be determined by your doctor.

Missed dose-

If you miss a dose of this medicine, take it as soon as you remember. However, if you don't remember until the next day, skip the missed dose and go back to your regular dosing schedule. Do not double doses.


To store this medicine:

  • Keep out of the reach of children.
  • Store away from heat and direct light.
  • Do not store in the bathroom, near the kitchen sink, or in other damp places. Heat or moisture may cause the medicine to break down.
  • Do not keep outdated medicine or medicine no longer needed. Ask your health care professional how you should dispose of any medicine you do not use. Be sure that any discarded medicine is out of the reach of children.

Precautions While Using This Medicine

If your symptoms do not improve within a few days, or if they become worse, check with your doctor.

For patients with an abnormally slow heartbeat: Levofloxacin may increase your risk of experiencing a fast, slow or irregular heartbeat

If you are taking aluminum-, calcium-, or magnesium-containing antacids, iron supplements, sucralfate, or zinc, do not take them at the same time that you take this medicine . It is best to take these medicines at least 2 hours before or 2 hours after taking levofloxacin. These medicines may keep levofloxacin from working properly.

Some people who take levofloxacin may become more sensitive to sunlight than they are normally. Exposure to sunlight, even for brief periods of time, may cause severe sunburn or skin rash, redness, itching, or discoloration . When you begin taking this medicine:

  • Stay out of direct sunlight, especially between the hours of 10:00 a.m. and 3:00 p.m., if possible.
  • Wear protective clothing, including a hat and sunglasses.
  • Apply a sun block product that has a skin protection factor (SPF) of at least 15. Some patients may require a product with a higher SPF number, especially if they have a fair complexion. If you have any questions about this, check with your health care professional.
  • Do not use a sun lamp or tanning bed or booth.
If you have a severe reaction from the sun, check with your doctor.

If you get a skin rash or other signs of an allergic reaction, stop taking levofloxacin and check with your doctor .

Levofloxacin may cause some people to become dizzy, lightheaded, drowsy, or less alert than they are normally. Make sure you know how you react to this medicine before you drive, use machines, or do anything else that could be dangerous if you are dizzy or are not alert . If these reactions are especially bothersome, check with your doctor.

Levofloxacin may cause pain, inflammation, or rupture of a tendon. If you experience these symptoms in your hands, shoulders, or calves, stop taking levofloxacin and check with your doctor right away . Refrain from exercise until your doctor says otherwise.

For diabetic patients taking insulin or diabetes medicine by mouth: Levofloxacin may cause hypoglycemia (low blood sugar) in some patients. Symptoms of low blood sugar must be treated before they lead to unconsciousness (passing out) . Different people may feel different symptoms of low blood sugar. If you experience symptoms of low blood sugar, stop taking levofloxacin and check with your doctor right away:

  • Symptoms of low blood sugar can include: Anxious feeling, behavior change similar to being drunk, blurred vision, cold sweats, confusion, cool pale skin, difficulty in concentrating, drowsiness, excessive hunger, headache, nausea, nervousness, rapid heartbeat, shakiness, unusual tiredness or weakness.

For patients with low potassium levels: Levofloxacin may increase your risk of experiencing a fast, slow or irregular heartbeat

Side Effects of This Medicine

Side Effects of This Medicine

Along with its needed effects, a medicine may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur:

  • Rare
    • Skin rash, itching, or redness 

Also, check with your doctor as soon as possible if any of the following side effects occur:

  • Rare
    • Abdominal or stomach cramps or pain (severe);  abdominal tenderness;  agitation;  blisters;  confusion;  diarrhea (watery and severe) which may also be bloody;  fever ;  hallucinations (seeing, hearing, or feeling things that are not there);  pain, inflammation, or swelling in calves of legs, shoulders, or hands;  psychosis ;  sensation of skin burning;  redness and swelling of skin;  trembling 

Other side effects may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. However, check with your doctor if any of the following side effects continue or are bothersome:

  • Less common
    • Abdominal or stomach pain or discomfort;  change in sense of taste;  constipation;  diarrhea;  dizziness;  drowsiness;  headache;  lightheadedness ;  nausea;  nervousness;  trouble in sleeping;  vaginal itching and discharge;  vomiting 

After you stop using this medicine, your body may need time to adjust. The length of time this takes depends on the amount of medicine you were using and how long you used it. During this period of time check with your doctor or nurse immediately if you notice any of the following side effects:

  • Abdominal or stomach cramps and pain (severe);  abdominal tenderness;  diarrhea (watery and severe) which may also be bloody;  fever 

Other side effects not listed above may also occur in some patients. If you notice any other effects, check with your doctor.

  • Incidence not determined--Observed during clinical practice; estimates of frequency cannot be determined
    • Difficult breathing ;  sharp drop in blood pressure;  hives;  abnormal brain wave patterns;  blurred vision;  coma;  confusion;  black, tarry stools;  sore throat;  swollen glands;  unusual bleeding or bruising;  blistering, peeling, loosening of skin;  itching;  joint or muscle pain;  bleeding gums;  dark urine;  fatigue;  general body swelling;  failure of the heart, lungs, kidneys and/or liver;  increased bleeding time;  diarrhea;  red skin;  fast, irregular heartbeat 

©2009 [Privacy Policy] [Disclaimer]
Last updated: Tue, 06 Jan 2009 00:20:03 GMT