Norfloxacin: How does it work? Precautions, Presentation and Side Effects

It is an antibiotic that belongs to the class of medicines called quinolones.

How does this medication work? What will he do for me?

It is used to treat infections caused by certain types of bacteria. It is most often used to treat urinary tract infections (bladder). Norfloxacin works by killing some types of bacteria that can cause these infections.

This medication may be available under multiple brands and in different forms. Any specific brand of this medication may not be available on all documents or approved for all conditions listed here.


Also, some forms of this medication can not be used for all conditions treated here.

Your doctor may have suggested this medication for conditions other than those listed in these medication information articles. If you have not discussed this with your doctor or are unsure why you are taking this medication, talk to your doctor.

Do not stop taking this medication without consulting your doctor.

Do not give this medicine to anyone else, even if they have the same symptoms you have. It can be harmful to people to take this medicine if their doctor has not prescribed it.


What form (s) does this medication have?

Each white, oval, biconvex, film-coated tablet, marked and engraved “APO 400” on one side and smooth on the other, contains 400 mg of Norfloxacin.

Non-medicinal ingredients:

  • Crospovidone
  • Magnesium stearate
  • Colloidal silicon dioxide
  • Hydroxypropyl cellulose
  • Hydroxypropyl methylcellulose
  • Polyethylene glycol
  • Titanium dioxide

How should I use this medication?

The usual recommended dose for adults is 400 mg twice a day, taken with a glass of water at least one hour before or 2 hours after a meal or milk. It would help if you drank plenty of fluids (water or juice) every day unless your doctor tells you otherwise.

Norfloxacin should not be taken within 2 hours of taking iron, zinc supplements, or multivitamins. The dose of Norfloxacin may vary depending on the circumstances and the condition being treated.

Many things can affect the dose of medication a person needs, such as body weight, other medical conditions, and other drugs.

If your doctor has recommended a different dose than the previous one, do not change how you take the medication without consulting your doctor.

To consider:

  • You must take this medication exactly as prescribed by your doctor.
  • Finish all this medication, even if you have started to feel better.
  • If you miss a dose, take it as soon as possible and continue your usual schedule.
  • If it is almost time for your next dose, skip the missed dose and continue with your regular dosing schedule.
  • Do not take a double amount to make up for the one you forgot.
  • If you are not sure what to do after skipping a dose, contact your doctor or pharmacist.
  • Store this medication at room temperature, protect it from light and moisture and keep it out of the reach of children.
  • Do not dispose of medications in wastewater (for example, in the sink or the toilet) or household waste.
  • Ask your pharmacist how to get rid of drugs that are no longer needed or are no longer valid.

Who should NOT take this medicine?

Do not take Norfloxacin if you are allergic to it, other Quinolones (for example, Ciprofloxacin, Nalidixic Acid), or any other medicine component.

What side effects are possible with Norfloxacin?

Many medications can cause side effects. A side effect is an unwanted response to a medication when taken in regular doses. Side effects can be mild or severe, temporary or permanent.

The side effects listed below are not experienced by everyone who takes this medication. If you are concerned about side effects, discuss the risks and benefits of this medication with your doctor.

At least 1% of people taking this medication have reported the following side effects. Many of these side effects can be controlled, and some may go away on their own over time.

Contact your doctor if you experience these side effects that are severe or bothersome. Your pharmacist can advise you on the management of side effects:

  • Diarrhea (mild)
  • Dizziness or lightheadedness
  • Headache
  • Acidity
  • Increased sensitivity of the skin to the sun
  • Loss of appetite
  • Nausea
  • Problems sleeping
  • Vomiting

Although most of the side effects listed below do not happen very often, they could cause severe problems if you do not see your doctor or seek medical attention.

Check with your doctor as soon as possible if you experience any of the following side effects:

  • Blisters of the skin.
  • Increase muscle weakness
  • Pain in the joints or muscles.
  • Mood changes such as anxiety or depression
  • Pain, swelling, or rupture of a tendon.
  • Skin burning sensation.
  • Itchy skin, rash, redness, or swelling.
  • Symptoms of high blood sugar levels (for example, frequent urination, increased thirst, excessive food intake, unexplained weight loss, poor wound healing, infections, and the odor of fruity breath).
  • Symptoms of low blood sugar (cold sweat, pale and cold skin, headache, fast heartbeat, weakness) and vision changes.

Stop taking the medication and seek immediate medical attention if any of the following symptoms occur:

  • Diarrhea (watery, severe, or bloody)
  • Signs of a severe allergic reaction (swelling of the face or throat, hives, or difficulty breathing).
  • Signs of a severe skin reaction (e.g., blistering, peeling, rash covering a large area of ​​the body, a rapidly spreading rash or rash combined with fever or discomfort).

Some people may experience side effects other than those listed.

Check with your doctor if you notice any symptoms that bother you while taking this medicine.

Other precautions or warnings for Norfloxacin

Before you start using a medication, tell your doctor about any medical conditions or allergies you have. You can have any medication you are taking, whether pregnant or breastfeeding, and any other important information about your health.

These factors can affect the way you should use this medicine.

Notice of studies conducted in Canada

Health Canada has issued new restrictions regarding the use of Norfloxacin

Symptoms that the patient should watch:

  • Blood sugar levels: Norfloxacin can cause a loss of control of blood sugar levels, and glucose tolerance may change.
  • People with diabetes may need to control their blood sugar levels more often while using this medication.
  • It is also known that people without diabetes experience high or low blood sugar levels while taking Norfloxacin.
  • If you have diabetes or are at risk of developing diabetes, talk to your doctor about how this medicine may affect your medical condition, how your medical condition may affect the dose and effectiveness of this medicine, and if any special monitoring is needed.
  • Contact your doctor if you experience high blood sugar levels (odor of fruity breath, weight loss, increased thirst, or increased need to urinate) or low blood sugar levels (cold sweat, pale, cold skin, pain head, or weakness).
  • Diarrhea: People who take this medicine may develop diarrhea caused by an infection with C. difficile bacteria. After taking Norfloxacin, get medical attention as soon as possible if you have loose, watery, and bloody stools, with or without fever or stomach cramps.
  • Diarrhea caused by C. difficile infection can cause serious health problems if not treated properly.
  • Kidneys: Norfloxacin is transmitted from the body mainly by the kidney. If you have reduced kidney function, talk to your doctor about how this medication may affect your medical condition, how your medical condition may affect the dosage and effectiveness, and if special monitoring is needed.
  • Neuromuscular disorders: Norfloxacin can cause muscle weakness to increase for people with Myasthenia Grave (an autoimmune disease that causes muscle weakness).

If you have Myasthenia Grave, talk with your doctor about how this medication may affect your medical condition, how your medical condition may affect the dosage and effectiveness of this medication, and if any special monitoring is needed.

  • Attacks: it can be considered that it is not a frequent occurrence since there have been no seizures with this medicine.

If you have a history of epilepsy or medical conditions that increase the risk of seizures, talk with your doctor about how this medication may affect your medical condition, how your medical condition may affect the dosage and effectiveness of this medication, and whether there is any control notable necessary.

  •  If you have seizures while taking this medication, stop taking it and seek medical attention immediately.
  • Sunburn: People who take Norfloxacin are more prone to sunburn. Avoid exposure to excessive sunlight, including sunlamps and tanning beds, and use sunscreen with a minimum SPF of 15.
  • Stop taking the medication if there is solar sensitivity.
  • Tendons: Most people who take Norfloxacin have experienced tendonitis and tendon rupture, especially if they are also taking corticosteroids. If you experience pain or swelling in the joints or tendons, contact your doctor as soon as possible.
  • Pregnancy: This medication should not be used during pregnancy unless the benefits outweigh the risks. If you become pregnant while taking this medication, contact your doctor immediately.
  • Breastfeeding: Norfloxacin can pass into breast milk. If you are a nursing mother and take this medication, it can affect your baby. Consult your doctor if you should continue breastfeeding.
  • Children: The safety and efficacy of this medication have not been established for children under 16 years of age.

What other drugs may interact with this medicine?

There may be an interaction between Norfloxacin and any of the following:

  • Aminophylline, Amiodarone, and Acids containing aluminum, Calcium, or Magnesium (do not take within 2 hours of Norfloxacin).
  • Anti-psychotics (e.g., Chlorpromazine, Clozapine, Haloperidol, Olanzapine, Quetiapine), Risperidone)
  • Caffeine-based supplements and multivitamins containing calcium (do not take Norfloxacin within 2 hours)
  • Steroids with Chloroquine, Colchicine, or Cortico (e.g., Dexamethasone, Hydrocortisone, Prednisone) Cyclosporin
  • Drugs (eg, chlorpropamide, glipizide, glyburide, insulin, metaformin, nateglinide, rosiglitazone) didanosine (do not take within 2 hours of norfloxacin)
  • Iron supplements, such as Ferrous Sulfate or Multivitamins that contain iron (do not take Norfloxacin within 2 hours)
  • Antibiotics (e.g., Clarithromycin, Erythromycin)
  • Methadone
  • Mifepristone
  • Anti-inflammatory drugs with Steroids (e.g., Diclofenac, Ibuprofen, Ketoprofen, Naproxen).
  • Selective Serotonin Reuptake Inhibitors (SSRIs, e.g., Citalopram, Duloxetine, Fluoxetine, Paroxetine, Sertraline).
  • Serotonin antagonists (antiemetic medications, e.g., Granisetron, Ondansetron) Supplements or multivitamins that contain Zinc (do not take within 2 hours of Norfloxacin).

If you are taking any of these medications, talk to your doctor or pharmacist.

Depending on your specific circumstances, your doctor may want you to:

  • Stop taking one of the medications
  • Change one of the medications to another
  • Change the way you take one or both medications, or leave everything.

An interaction between two medications does not always mean you should stop taking one of them.

If you have any of the symptoms described above, do not hesitate or lose time to consult; talk with your doctor about how drug interactions are handled or controlled.

Medications other than those mentioned above may interact with this medication.

Tell your doctor or prescriber about all prescription, over-the-counter (OTC), and herbal medications you are taking.

Also, tell them about any supplements you are taking. Because caffeine, alcohol, and nicotine in cigarettes or illegal drugs can affect the action of many medications, you should inform your doctor if you use them.