What is norfloxacin? What is norfloxacin used for?

Norfloxacin is a fluoroquinolone antibiotic. Other fluoroquinolones include ciprofloxacin (Cipro), levofloxacin (Levaquin), and ofloxacin (Floxin). Norfloxacin works by blocking DNA gyrase enzyme, which is responsible for production and repair of bacterial DNA. Blocking of DNA gyrase leads to bacteria death and prevents worsening of infection. Norfloxacin treats infections caused by gram-positive and gram-negative bacteria like Enterococcus faecalis, Staphylococcus aureus, Staphylococcus epidermidis, Staphylococcus saprophyticus, Streptococcus agalactiae, Citrobacter freundii, Enterobacter aerogenes, Enterobacter cloacae, Escherichia coli, Klebsiella pneumonia, Neisseria gonorrhoeae, Proteus mirabilis, Proteus vulgaris, Pseudomonas aeruginosa, and Serratia marcescens. FDA approved the brand name norfloxacin (Noroxin) in October 1986.

What brand names are available for norfloxacin?


Is norfloxacin available as a generic drug?

Not in US, in Canada

Do I need a prescription for norfloxacin?


What are the side effects of norfloxacin?

Side effects of norfloxacin are nausea, stomach cramps, dizziness, headache, abdominal pain, diarrhea, abnormal heart beats, and photosensitivity (sun sensitivity).

Norfloxacin as well as other antibiotics in the fluoroquinolone class of antibiotics, has been associated with tendinitis and even rupture of tendons, particularly the Achilles tendon. Many antibiotics, including norfloxacin, can alter the normal bacteria in the colon and encourage overgrowth of a bacterium responsible for the development of inflammation of the colon, (C. difficile caused pseudomembranous colitis). Patients who develop signs of pseudomembranous colitis after starting norfloxacin (diarrhea, fever, abdominal pain, and possibly shock) should contact their doctor immediately.

Fluoroquinolones have neuromuscular blocking activity and can worsen muscles weakness in individuals with myasthenia gravis. They also worsen low blood glucose levels when combined with sulfonylureas (for example, glyburide [Micronase, Diabeta, Glynase, Prestab]).


Bowel regularity means a bowel movement every day. See Answer

What is the dosage for norfloxacin?

  • Uncomplicated urinary tract infectionTake 1 tablet (400 mg) by mouth every 12 hours for 3 days
  • Complicated urinary tract infection Take 1 tablet (400 mg) by mouth every 12 hours for 10 to 21 days.
  • For infections caused by E. coli, K. pneumoniae, or P. mirabilis only. Take 1 tablet (400 mg) by mouth every 12 hours for 7 to 10 days, for infections caused by any other bacteria.
  • ProstatitisTake 1 tablet (400 mg) by mouth every 12 hours for 28 to 42 days.
  • Gonorrhea Take 2 tablets (800 mg) by mouth as one single dose.

Safe and effective use of norfloxacin is not established in patients under the age of 18 years.

Note that some organisms are resistant to norfloxacin; organisms should be tested for susceptibility to this drug.

Which drugs or supplements interact with norfloxacin?

: Norfloxacin should be used with caution with medications like caffeine, clozapine (Clozaril), ropinorole (Requip), cyclosporine (Neoral, Sandimmune, Gengraf), theophylline (Theo-24), and tizanidine (Zanaflex) because norfloxacin can slow down breakdown of these medications in and increase their levels in the body.

Norfloxacin should be separated from aluminum and magnesium containing antacids, sucralfate (Carafate), and multivitamins because they can lower absorption of norfloxacin and reduce its effectiveness. They should be administered 2 hours before norfloxacin.

Norfloxacin should be used with caution with warfarin (Coumadin) because norfloxacin can increase the risks of bleeding and bruising.

Norfloxacin should be used with caution with medications used for treating abnormal heart beats because it can affect heart rhythm.

Is norfloxacin safe to take if I'm pregnant or breastfeeding?

It is not known whether norfloxacin enters breast milk; therefore, it is best to be cautious before using it in nursing mothers.

What else should I know about norfloxacin?

What preparations of norfloxacin are available?

Tablets: 400 mg

How should I keep norfloxacin stored?

Store norfloxacin tablets between temperatures of 15 C - 30 C (59 F - 86 F), in a tightly closed container.


Bacterial Infections 101: Types, Symptoms, and Treatments See Slideshow


Norfloxacin (Noroxin) is an antibiotic prescribed to treat a variety of infections such as UTIs, gonorrhea, E. coli, and others. Side effects, drug interactions, dosage, storage, and pregnancy information should be reviewed prior to taking this medication.

Treatment & Diagnosis

Medications & Supplements

Subscribe to MedicineNet's General Health Newsletter

By clicking Submit, I agree to the MedicineNet's Terms & Conditions & Privacy Policy and understand that I may opt out of MedicineNet's subscriptions at any time.

Health Solutions From Our Sponsors

FDA Logo

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

FDA Prescribing Information.