Norfloxacin (By mouth)


Norfloxacin (nor-FLOX-a-sin)

Treats certain infections that are caused by bacteria. This medicine is a fluoroquinolone antibiotic.

Brand Name(s)


There may be other brand names for this medicine.

When This Medicine Should Not Be Used

You should not use this medicine if you have had an allergic reaction to norfloxacin or to any other fluoroquinolone antibiotic (such as ciprofloxacin, gatifloxacin, levofloxacin, ofloxacin, Cipro®, Floxin®, Levaquin®, or Tequin?). You should not use this medicine if you have ever had a swollen or ruptured tendon after using a fluoroquinolone antibiotic. This medicine should not be used in patients who have a condition called myasthenia gravis. This medicine should not be given to anyone younger than 18 years of age.

How to Use This Medicine


  • Your doctor will tell you how much of this medicine to use and how often. Do not use more medicine or use it more often than your doctor tells you to.
  • Take this medicine at least 1 hour before or 2 hours after you eat a meal or use dairy products such as milk, cheese, cream, or yogurt. Take the medicine only with water. Do not take it with milk or with any juice that has calcium added to it.
  • Drink extra fluids so you will pass more urine while you are using this medicine. This will keep your kidneys working well and help prevent kidney problems.
  • Keep using this medicine for the full treatment time, even if you feel better after the first few doses. Your infection may not clear up if you stop using the medicine too soon.
  • This medicine should come with a Medication Guide. Read and follow these instructions carefully. Ask your doctor or pharmacist if you have any questions. Ask your pharmacist for the Medication Guide if you do not have one.

If a dose is missed:

  • If you miss a dose or forget to use your medicine, use it as soon as you can. If it is almost time for your next dose, wait until then to use the medicine and skip the missed dose. Do not use extra medicine to make up for a missed dose.

How to Store and Dispose of This Medicine

  • Store the medicine in a closed container at room temperature, away from heat, moisture, and direct light.
  • Ask your pharmacist, doctor, or health caregiver about the best way to dispose of any outdated medicine or medicine no longer needed.
  • Keep all medicine away from children and never share your medicine with anyone.

Drugs and Foods to Avoid

Ask your doctor or pharmacist before using any other medicine, including over-the-counter medicines, vitamins, and herbal products.

  • Make sure your doctor knows if you are using a steroid medicine (such as dexamethasone, prednisolone, prednisone, Decadron®, or Medrol®). Using a steroid together with this medicine may increase your chance of having tendon problems.
  • Make sure your doctor knows if you are also using a heart rhythm medicine such as amiodarone (Cordarone®), disopyramide (Norpace®), dofetilide (Tikosyn®), quinidine (Cardioquin®), procainamide (Pronestyl®), or sotalol (Betapace®). Tell your doctor if you are also using cisapride (Propulsid®), clozapine (Clozaril®), cyclosporine (Gengraf®, Neoral®, Sandimune®), erythromycin (Ery-tab®), nitrofurantoin (Macrodantin®), probenecid (Benemid®), ropinirole (Requip®), tacrine (Cognex®), theophylline (Theo-Dur®), tizanidine (Zanaflex®), a blood thinner (such as warfarin, Coumadin®), or a diabetes medicine (such as glyburide, Diabeta®, Glucovance®, Glynase®, or Micronase®). Make sure that your doctor knows if you are also using a pain or arthritis medicine (such as ibuprofen, naproxen, Advil®, Aleve®, Celebrex®, or Motrin®), medicine for depression (such as amitriptyline, fluoxetine, nortriptyline, Elavil®, Pamelor®, Prozac®, Sarafem®, or Vivactil®), or medicine to treat mental illness (such as haloperidol, mesoridazine, pimozide, prochlorperazine, quetiapine, thioridazine, ziprasidone, Compazine®, Geodon®, Haldol®, Mellaril®, Orap®, Serentil®, or Seroquel®).
  • Some medicines, antacids, and mineral supplements can change with the way norfloxacin works in your body. These medicines include Maalox® or Mylanta®, sucralfate (Carafate®), and multivitamins with calcium, iron, or zinc. Didanosine (Videx®, Videx® EC) powder or chewable buffered tablets may also affect how norfloxacin works. If you use any of these medicines, take them at least 2 hours before or 2 hours after you take norfloxacin.
  • Avoid caffeine (coffee, soda, chocolate) while you are using this medicine. Norfloxacin may cause caffeine to stay in your body longer than usual.

Warnings While Using This Medicine

  • Make sure your doctor knows if you are pregnant or breastfeeding, or if you have kidney disease, liver disease, diabetes, nerve problems, or G6PD deficiency. Your doctor should also know if you have a history of seizures, epilepsy, head injury, or stroke. Tell your doctor if you have a history of heart disease, heart rhythm problems (such as QT prolongation), or hypokalemia (low blood potassium).
  • This medicine may cause serious allergic reactions including anaphylaxis, which can be life-threatening and require immediate medical attention. Call your doctor right away if you have itching; hives; hoarseness; shortness of breath; trouble with breathing; trouble with swallowing; or any swelling of your hands, face, or mouth after you receive this medicine.
  • Your tendons may be more easily injured while you are using this medicine. Stop using this medicine and call your doctor if you have pain or swelling in your knee, ankle, shoulder, elbow, hand, or wrist. You may also need to avoid exercise or certain physical activities. Children and elderly patients (over 60 years of age) are more likely to have tendon problems. This risk of tendon problems may also increase if you have rheumatoid arthritis, if you are taking steroid medicines (corticosteroids), or if you have received an organ (such as heart, kidney, or lung) transplant.
  • Serious skin reactions can occur with this medicine. Check with your doctor right away if you have blistering, peeling, or loosening of the skin; red skin lesions; severe acne or skin rash; sores or ulcers on the skin; or fever or chills while you are using this medicine.
  • Liver problems can occur while using this medicine. Stop using this medicine and check with your doctor right away if you have dark urine, clay-colored stools, abdominal or stomach pain, or yellow eyes or skin.
  • This medicine may make your skin more sensitive to sunlight. Use a sunscreen when you are outdoors. Avoid sunlamps and tanning beds.
  • If you have severe diarrhea, ask your doctor before taking any medicine to stop the diarrhea. It may occur 2 months or more after you stop using this medicine.
  • Tell your doctor right away if you start having numbness, tingling, or burning pain in your hands, arms, legs, or feet. These may be symptoms of a condition called peripheral neuropathy.
  • This medicine may make you dizzy or drowsy. Avoid driving, using machines, or doing anything else that could be dangerous if you are not alert.
  • Your doctor will need to check your blood or urine at regular visits while you are using this medicine. Be sure to keep all appointments.
  • If your symptoms do not improve or if they get worse, call your doctor.
  • Use this medicine only to treat the infection your doctor has prescribed it for. Do not use this medicine for any infection that has not been checked by a doctor.

Possible Side Effects While Using This Medicine

Call your doctor right away if you notice any of these side effects:

  • Allergic reaction: Itching or hives, swelling in your face or hands, swelling or tingling in your mouth or throat, chest tightness, trouble breathing
  • Blistering, peeling, or red skin rash.
  • Change in how much or how often you urinate.
  • Chest pain.
  • Diarrhea that may contain blood.
  • Fast, pounding or uneven heartbeat.
  • Fever, chills, cough, sore throat, and body aches.
  • Numbness, tingling, weakness, or burning pain in your hands, arms, legs, or feet.
  • Pain or swelling in your knee, ankle, shoulder, elbow, hand, or wrist.
  • Seizures or tremors.
  • Unusual bleeding, bruising, or weakness.
  • Yellowing of your skin or the whites of your eyes.

If you notice these less serious side effects, talk with your doctor:

  • Anxiety, confusion, nervousness, or restlessness.
  • Mild skin rash or itching.
  • Headache or dizziness.
  • Heartburn, gas, nausea, vomiting, stomach pain, constipation, or loss of appetite.
  • Sores or white patches in your mouth or throat.
  • Trouble with sleeping.
  • Vaginal itching or discharge.

If you notice other side effects that you think are caused by this medicine, tell your doctor

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088

Version Info

  • Last Reviewed on 06/12/2013

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This page was last updated: September 18, 2013

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