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Drug Profile

The information on this site is intended to supplement and enhance, not replace, the advice of a physician who is familiar with your medical history. Decisions about your health should always be made ONLY after detailed conversation with your doctor.

Limited Use [what does this mean?]
Generic drug name: ciprofloxacin (sip roe FLOX a sin)
Brand name(s): CIPRO, CIPRO XR
GENERIC: not available FAMILY: Fluoroquinolones
Find the drug label by searching at DailyMed.

Limited Use [what does this mean?]
Generic drug name: levofloxacin (lee voe FLOX a sin)
Brand name(s): LEVAQUIN
GENERIC: not available FAMILY: Fluoroquinolones
Find the drug label by searching at DailyMed.

Limited Use [what does this mean?]
Generic drug name: ofloxacin (oh FLOKS a sin)
Brand name(s): FLOXIN
GENERIC: not available FAMILY: Fluoroquinolones
Find the drug label by searching at DailyMed.

Pregnancy and Breast-feeding Warnings [top]

Pregnancy Warning

Fluoroquinolones caused fetal harm in animal studies, including decreased body weights and malformed bones as well as an increased risk of death. Because of the potential for serious adverse effects to the fetus, these drugs should not be used by pregnant women.

Breast-feeding Warning

Fluoroquinolones are excreted in human milk. Because of the potential for serious adverse effects in nursing infants, you should not take these drugs while nursing.

Safety Warnings For This Drug [top]

FDA-Required Black-Box Warnings


  • Fluoroquinolones have been associated with disabling and potentially irreversible serious adverse reactions that have occurred together, including:
    • Tendinitis and tendon rupture
    • Peripheral neuropathy (nerve damage)
    • Central nervous system effects

Discontinue fluoroquinolones immediately and avoid the use of fluoroquinolones in patients who experience any of these serious adverse reactions.

  • Fluoroquinolones may exacerbate muscle weakness in patients with myasthenia gravis. Avoid fluoroquinolones in patients with known history of myasthenia gravis.
  • Because fluoroquinolones have been associated with serious adverse reactions, reserve them for use in patients who have no alternative treatment options for the following indications:
    • Acute exacerbation of chronic bronchitis
    • Acute uncomplicated bladder infections
    • Acute bacterial sinusitis

Antibiotic-Associated Diarrhea

Antibiotic-associated diarrhea (AAD) is quite common and its incidence varies from 5% to 20% of patients depending on which antibiotic they are taking, although practically all antibiotics have been associated with AAD. Fortunately, most cases are mild and self-limited, ending with the cessation of use of the offending antibiotic. The antibiotics most commonly associated with this mild form of AAD include ampicillin, amoxicillin, cephalosporins and clindamycin.[1] There have been studies in children or adults in which the use of prophylactic yogurt in people using antibiotics has significantly reduced the occurrence or severity of AAD.[2],[3] However, 10% to 20% of all patients who get AAD (0.5% to 4% of patients using antibiotics) will get the more severe form of AAD known as pseudomembranous colitis (see below). If you are taking any antibiotic and develop diarrhea after starting to use the drug, call your physician to discuss whether another antibiotic should be used and to discuss the need for rehydration due to the fluid loss from the diarrhea.

Pseudomembranous colitis has been reported with nearly all antibacterial agents and may range in severity from mild to life-threatening. Therefore, it is important to consider this diagnosis in patients who present with diarrhea subsequent to the administration of antibacterial agents.

Because antibiotic therapy has been associated with severe colitis, which may end fatally, it should be reserved for serious infections where less toxic antimicrobial agents are inappropriate, as described in the INDICATIONS AND USAGE section. It should not be used in patients with nonbacterial infections such as most upper respiratory tract infections. Treatment with antibacterial agents alters the normal flora of the colon and may permit over-growth of clostridia. Studies indicate that a toxin produced by Clostridium difficile is one primary cause of "antibiotic-associated colitis."

After the diagnosis of pseudomembranous colitis has been established, therapeutic measures should be initiated. Mild cases of pseudomembranous colitis usually respond to drug discontinuation alone. In moderate to severe cases, consideration should be given to management with fluids and electrolytes, protein supplementation, and treatment with an antibacterial drug that is clinically effective against C. difficile colitis.

Diarrhea, colitis, and pseudomembranous colitis have been observed to begin up to several weeks following cessation of therapy.


Extreme caution should be used when fluoroquinolones such as ciprofloxacin are to be prescribed in conjunction with aminophylline or theophylline, particularly in elderly patients. Aminophylline or theophylline doses should be adjusted, perhaps reduced by 30 to 50% at the start of fluoroquinolone therapy. The reduction in dose must be guided by the clinical conditions of the patient, the use of other medications, and the baseline level of the aminophylline or theophylline in the blood. In addition, blood aminophylline or theophylline levels should be obtained following the initiation of a fluoroquinolone no later than two days into therapy.

Facts About This Drug [top]

The fluoroquinolone family of antibiotics is used to treat bacterial infections in many different parts of the body. The drugs work by killing bacteria or preventing its growth. Fluoroquinolones will not work for colds, flu or other viral infections.[4] Antibiotics should be used only if there is a real suspicion of a bacterial infection against which the antibiotic is effective.[5]

The Journal of the American Medical Association reports widespread misuse of the fluoroquinolone...

The fluoroquinolone family of antibiotics is used to treat bacterial infections in many different parts of the body. The drugs work by killing bacteria or preventing its growth. Fluoroquinolones will not work for colds, flu or other viral infections.[4] Antibiotics should be used only if there is a real suspicion of a bacterial infection against which the antibiotic is effective.[5]

The Journal of the American Medical Association reports widespread misuse of the fluoroquinolone ciprofloxacin (CIPRO, CIPRO XR). Ciprofloxacin is inappropriate for common sinus and ear infections and community-acquired pneumonias. For most pneumonias and streptococcal infections, penicillin or a cephalosporin remain the drugs of choice.[6]

Adverse effects

Antibiotic-associated diarrhea (AAD) is a common adverse effect of antibiotic treatment. A report appearing in the Oct. 25, 2005, Canadian Medical Association Journal estimates that as many as 2,000 patients may have died in Quebec hospitals since 2003 from AAD.[7] Many different types of antibiotics can cause AAD, but reports have recently implicated the use of fluoroquinolone antibiotics as an important risk factor in the development of a potentially life-threatening form of AAD called pseudomembranous colitis, which is caused by a type of bacteria called Clostridium difficile.

Peripheral neuropathy and tendon ruptures have been reported in patients receiving fluoroquinolones. The Food and Drug Administration (FDA) now requires that the product labeling for all fluoroquinolone antibiotics must warn about the possibility of peripheral neuropathy (nerve damage) and tendon rupture. See the "Peripheral Neuropathy" boxed warning above for more information.

Severe allergic reactions, including life-threatening anaphylactic shock and a serious skin reaction called Stevens-Johnson syndrome (also known as toxic epidermal necrolysis), have been reported with the use of ciprofloxacin in postmarketing adverse event reports.

Some fluoroquinolones, including levofloxacin and ofloxacin, have been associated with a risk of QT prolongation, a change in the electrical activity of the heart that can lead to a fatal heart rhythm disturbance called torsades de pointes, resulting in sudden death. In fact, rare cases of torsades de pointes have been sporadically reported during postmarketing surveillance in patients receiving fluoroquinolones, including levofloxacin and ofloxacin. Levofloxacin and ofloxacin should be avoided in patients with known QT prolongation, patients with hypokalemia (low blood potassium level) and patients receiving class IA (quinidine, procainamide) or class III (amiodarone, sotalol) antiarrhythmic agents.

Elderly patients may be more susceptible to fluoroquinolone-associated effects on the QT interval.

In 2007, Health Canada, an agency similar to the FDA, reported that between 1997 and 2006 the agency received multiple reports of irregularities in blood sugar, including diabetes, hyperglycemia (high blood sugar levels) and hypoglycemia (low blood sugar levels), in people using various drugs in the fluoroquinolone class. The agency also received multiple reports of disorders of the liver and bile duct, including liver failure, hepatitis, hepatorenal syndrome (loss of kidney function in a person with a liver disorder), elevated liver enzymes, jaundice and cholestatic jaundice (a kind of hepatitis in which the bile backs up instead of draining from the liver, and the patient becomes jaundiced).[8]

Retinal detachment

A study in the Journal of the American Medical Association found that patients taking oral fluoroquinolones appear to have an increased risk of developing retinal detachment, a medical emergency that can result in permanent vision loss unless promptly treated by an ophthalmologist. The authors of this study estimated that as many as 1,400 cases of retinal detachment each year in the U.S. may be caused by the use of these drugs.[9]

Effects on blood sugar levels

In 2013, a study conducted in diabetic patients found an increased risk of abnormal blood sugar levels in diabetic patients using oral fluoroquinolones.[10]

Aortic aneurysm or dissection

An article published in JAMA Internal Medicine in 2015 warned that oral fluoroquinolone use was associated with an increased risk of aortic aneurysm or dissection. An aneurysm (bulge) or dissection (tear) in the wall of the aorta (blood vessel) can grow and burst, causing bleeding and even death.[11]

In March 2018, the BMJ published a study on the increased risk of aortic aneurysm or aortic dissection with fluoroquinolone use.[12]


As of Jan. 15, 2004, Health Canada received 57 reports of suspected interactions associated with fluoroquinolones and the oral anticoagulant warfarin (COUMADIN, JANTOVEN). If you take warfarin and are prescribed a fluoroquinolone antibiotic, ask your doctor what tests should be performed to monitor your blood coagulation levels.[13]

In October 2014, JAMA Internal Medicine published a study warning that older patients taking one of two commonly used oral sulfonylurea diabetes drugs — glipizide (GLUCOTROL, GLUCOTROL XL) or glyburide (DIABETA, GLUCOVANCE, GLYNASE) — in combination with either ciprofloxacin or levofloxacin had an increased risk of developing dangerously low blood sugar levels.[14]

Studies say...

Fluoroquinolone antibiotics are subject to rampant, out-of-control misprescribing and overprescribing. In a study on the use of these drugs in the emergency rooms of two academic medical centers, 100 consecutive patients who were prescribed a fluoroquinolone were studied to find out if the use was appropriate according to the guidelines used at those institutions. Of the 100 patients, 81 were given the antibiotic for an inappropriate use, including 43 (53% of the 81 patients) for whom another antibiotic should have been the first-line treatment and 27 (33% of the 81 patients) in whom there was no evidence of a bacterial infection. Of the 19 patients for whom the prescribing of this class of antibiotics was appropriate, only one patient was prescribed the right dose for the correct length of time.[15]

The New England Journal of Medicine published a study indicating that levofloxacin (LEVAQUIN) may increase the risk of cardiovascular death, particularly sudden death from heart rhythm disturbances. Based on this research and previous studies, levofloxacin is thought to cause a heart rhythm disturbance known as torsades de pointes, which can lead to sudden cardiac death.

Regulatory actions surrounding fluoroquinolones

2006: Public Citizen filed a petition with the FDA on Aug. 29, 2006, urging that the agency immediately warn consumers about the risks of tendinitis and tendon rupture associated with the use of fluoroquinolone antibiotics. Public Citizen called on the FDA to add a black-box warning, the strongest type of warning the FDA can request, to the product labels of all fluoroquinolone antibiotics, alerting health care professionals about these risks.

In addition, Public Citizen’s petition asked that a “Dear Doctor" letter be sent to warn physicians about these potentially serious adverse drug reactions. The petition also asked the FDA to require pharmacists to distribute FDA-approved Medication Guides informing consumers about the potential tendon damage that can result from these antibiotics and what steps to take if unexplained tendon pain develops.[16]

2008: The FDA updated the product label on all fluoroquinolones to include a black-box warning with information about the increased risk of developing tendinitis and tendon rupture. The FDA also required manufacturers to develop a Medication Guide for patients.[17]

2011: The FDA added a black-box warning to the fluoroquinolone group of drugs stating that when fluoroquinolones are used in patients with myasthenia gravis (a disease that causes muscle weakness), the drugs may exacerbate muscle weakness.[18]

The 2011 warning also requires that a Medication Guide about this risk be provided to patients taking this drug.

2012: In April, the FDA updated the drug product labeling of Levaquin to include information on its use in pediatric patients six months of age and older. The advisory stated that compared with controls, pediatric patients had an increased incidence of musculoskeletal disorders, including arthralgia, arthritis, tendinopathy and gait abnormality.[19]

Lomefloxacin is no longer marketed in the U.S., either because it was withdrawn for safety reasons or because its manufacturer discontinued its production.[20]

2016: The FDA updated the drug product label for fluoroquinolones to state that these drugs are associated with disabling and potentially permanent adverse effects of the tendons, muscles, joints, nerves and central nervous system.[21] The FDA also required that the new black-box warnings and other sections of the labeling for all oral and intravenous fluoroquinolones advise doctors not to prescribe the antibiotics to patients who have other treatment options for the following three common infections:

  • Acute bacterial exacerbation of chronic bronchitis (a type of chronic obstructive pulmonary disease, or COPD)
  • Acute uncomplicated bladder infection
  • Acute sinusitis

2018: The FDA strengthened the warning on the drug product labels of fluoroquinolones to warn that these drugs can cause low blood sugar (hypoglycemia) and psychiatric adverse effects.[22]

The FDA updated the product labels of fluoroquinolones to warn that fluoroquinolone use has been associated with an increased risk of aortic aneurysm or dissection, which can lead to bleeding and death.[23]

2020: In December, the Medicines and Healthcare products Regulatory Agency (MHRA, a regulatory agency in the U.K. similar to the FDA) issued an advisory that fluoroquinolones are associated with a small risk of a heart valve defect called heart valve regurgitation, which occurs when the heart valves do not close completely, allowing blood to flow in the wrong direction.[24] Such heart valve problems may lead to heart failure.

Before You Use This Drug [top]

Do not use if you have or have had:

  • allergies to fluoroquinolones or quinolone-type drugs
  • photosensitivity
  • inflammation or rupture of tendons

Tell your doctor if you have or have had:

  • epilepsy or seizures
  • kidney and liver problems (ciprofloxacin)
  • liver problems (ofloxacin)
  • kidney problems
  • myasthenia gravis[25]
  • an implanted metal device[26]
  • brain or spinal cord disease
  • slow heart rate (levofloxacin)
  • diabetes (levofloxacin)
  • low potassium blood level (levofloxacin)
  • pregnancy or are breast-feeding

Tell your doctor about any other drugs you take, including aspirin, herbs, vitamins, and other nonprescription products. It is especially important you tell your doctor if you take any heart drug.

When You Use This Drug [top]

  • Do not drive or perform other activities that require alertness because this drug may make you drowsy, dizzy, or lightheaded.
  • If you plan to have any surgery, including dental, tell your doctor that you take this drug.
  • Check with your doctor if there is no improvement of symptoms within a few days.
  • Protect yourself from sunburn. Do not use a sunlamp.
  • Stop taking ciprofloxacin at the first sign or symptom of blistering, itching, rash, or redness of skin or sensation of skin burning or swelling. Check with your doctor.
  • If you get a skin reaction to the sun, avoid further sunlight and artificial light until reaction has stopped or for five days, whichever is longer.
  • Call your doctor and discontinue the drug if you get pain, inflammation, or rupture of a tendon.
  • Caution diabetics: call your doctor and discontinue drug if you have a hypoglycemic episode.
  • For oral forms of this drug: Do not take this drug and antacids or sucralfate (CARAFATE) at the same time. Take six hours before or two hours after ciprofloxacin. Ask your doctor or pharmacist how long you have to wait for the drug that you are taking.

How to Use This Drug [top]

  • If you miss a dose, take it as soon as you remember, but skip it if it is almost time for the next dose. Do not take double doses.
  • Do not share your medication with others.
  • Take the drug at the same time(s) each day.
  • Drink plenty of fluids.
  • Take with a full glass (eight ounces) of water.
  • Take with or without food.
  • Take this drug for the prescribed length of time. If you stop too soon, your symptoms could come back.
  • Store at room temperature with lid on tightly. Do not store in the bathroom. Do not expose to heat, moisture, or strong light. Keep out of reach of children.

Interactions with Other Drugs [top]

The following drugs, biologics (e.g., vaccines, therapeutic antibodies), or foods are listed in Evaluations of Drug Interactions 2003 as causing “highly clinically significant” or “clinically significant” interactions when used together with any of the drugs in this section. In some sections with multiple drugs, the interaction may have been reported for one but not all drugs in this section, but we include the interaction because the drugs in this section are similar to one another. We have also included potentially serious interactions listed in the drug’s FDA-approved professional package insert or in published medical journal articles. There may be other drugs, especially those in the families of drugs listed below, that also will react with this drug to cause severe adverse effects. Make sure to tell your doctor and pharmacist the drugs you are taking and tell them if you are taking any of these interacting drugs:

aluminum hydroxide, AMPHOJEL, caffeine (beverages or drugs), calcium carbonate, CALTRATE, CARAFATE, COUMADIN, cyclosporine, DIABETA, DILANTIN, ELIXOPHYLLIN, FEOSOL, ferrous sulfate and other iron preparations, glyburide, MAALOX, magnesium hydroxide, methotrexate, MEXATE, NEORAL, OS-CAL 500, phenytoin, PHILLIPS’ MILK OF MAGNESIA, PRIFTIN, REQUIP, rifapentine, ropinirole, SANDIMMUNE, SLOW FE, sucralfate, THEO-24, theophylline, warfarin, zinc preparations.

Adverse Effects [top]

Call your doctor immediately if you experience:

  • watery and severe or bloody diarrhea
  • agitation
  • dizziness
  • sensation of skin burning
  • joint pain
  • fast or irregular heartbeat
  • fainting
  • blood in urine
  • dark or amber urine
  • loss of appetite
  • stomach pain
  • yellow eyes or skin
  • difficulty breathing
  • confusion, hallucinations
  • fever
  • skin rash, itching, redness, or peeling
  • seizure
  • swelling of face, neck, calves, or lower legs
  • tremors
  • blurred vision
  • pain in calves radiating to heels
  • heartbeat change

For levofloxacin (in addition to above):

  • sharp drop in blood pressure
  • coma
  • bleeding gums
  • failure of heart, lungs, kidneys, and/or liver

Call your doctor if these symptoms continue:

  • dizziness, lightheadedness
  • drowsiness
  • headache
  • nervousness
  • difficulty sleeping
  • insomnia, restlessness
  • nausea or vomiting
  • mild diarrhea
  • mild pain in abdomen, stomach, or joints
  • vaginal pain or discharge
  • increased sensitivity of skin to sunlight

Call your doctor if these symptoms continue after you stop taking this drug:

  • severe abdominal or stomach cramps
  • abdominal tenderness
  • watery and severe diarrhea
  • pain in calves radiating to heels
  • sensation of skin burning
  • skin rash, itching, redness, or peeling
  • swelling of face, neck, calves, or lower legs

Periodic Tests[top]

Ask your doctor which of these tests should be done periodically while you are taking this drug:

  • bleeding times

last reviewed April 30, 2023