Norfloxacin: Uses, History, Precautions, Side Effects, Administration and Interactions

It is a first generation fluoroquinolone that is generally used for urinary tract infections and prostatitis.

Norfloxacin has been associated with rare cases of acute hepatocellular injury.


Norfloxacin is a first-generation fluoroquinolone that has been available for the treatment of bacterial infections for many years, but now has limited indications and is not commonly used.

Like other fluoroquinolones, norfloxacin is active against a wide range of gram-positive and gram-negative aerobic organisms and is believed to act by inhibiting the toposiomerases (girasases) of type II DNA that are necessary for the synthesis of bacterial mRNAs (transcription) and replication of the DNA


It was first approved for use in the United States in 1986. The current indications are for urinary tract infections, sexually transmitted diseases and prostatitis due to sensitive organisms.

Norfloxacin has also been used in an unauthorized manner as prophylaxis against spontaneous bacterial peritonitis in patients with cirrhosis and ascites .

It is available as 400 mg tablets under the trade name Noroxin. Typical doses are 400 mg every 12 hours for 3 to 10 days, but chronic therapy has been used for antibacterial prophylaxis.


  • Do not use it if you are allergic to norfloxacin or other ingredients in the tablet, or similar quinolone antibiotics.
  • Do not use in children before puberty.
  • Be careful in patients with a history of seizures (such as epilepsy), myasthenia gravis, defects in glucose-6-phosphate dehydrogenase activity or kidney problems.
  • Norfloxacin is not recommended in pregnancy.

Side effects

Side effects are rare. Only about 3% of patients reported side effects in studies of more than 2000 patients. The following are some possible side effects:

  • Upset stomach, heartburn, abdominal pain, diarrhea.
  • Headache, dizziness, confusion, convulsions (rare).
  • Acne.
  • Greater sensitivity to the sun
  • Allergy.
  • Liver problems
  • Tendonitis or rupture of the tendon (more likely if steroids are also taken).
  • Vaginal candidiasis (thrush).


Multivitamins, iron, zinc, antacids, and sucralfate should not be taken 2 hours before or 2 hours after using norfloxacin. Also with:


Follow the instructions on the medication label or as directed by your doctor.

Take it preferably on an empty stomach (at least one hour before or two hours after eating).

Finish the norfloxacin treatment prescribed by your doctor to make sure it works. Do not stop in the middle of treatment, even if you feel better, unless your doctor tells you to stop.

Do not share the medication with anyone else.

If you are taking norfloxacin for a urinary tract infection , you can also take sachets to alkalize the urine, this makes it less painful to urinate.


Norfloxacin, like other fluoroquinolones, is associated with a low rate (1% to 3%) of elevations of serum enzymes during treatment. These anomalies are usually mild, asymptomatic and transient, and are resolved even with the continuation of therapy.

Norfloxacin has also been linked to rare but occasionally serious and even fatal cases of acute liver damage. Although the number of cases has been scarce, the clinical pattern has been consistent with a short latency period of 1 day to 3 weeks and an abrupt onset of hepatocellular injury.

The pattern of elevations of serum enzymes may be hepatocellular or cholestatic, cases with shorter onset times tend to be more hepatocellular with markedly elevated levels of ALT, and occasionally with a rapid worsening of prothrombin time and signs of liver failure.

The onset of the disease may occur a few days after the medication is stopped. Many (but not all) cases have had allergic manifestations with fever, rash, and eosinophilia. Autoantibodies are usually not present.

Cholestatic and mixed lesion patterns have also been described, particularly with delayed recognition of liver injury. These characteristics are typical of all the hepatotoxicity associated with fluoroquinolones and it is believed that the lesion is of a specific class.

Mechanism of injury

The cause of the liver injury is unknown, but it seems to be hypersensitive.

Result and management

The severity of the liver injury caused by norfloxacin ranges from elevations of mild and transient serum enzymes to self-limited but severe hepatitis, acute liver failure and death. A full recovery is expected after stopping the medication and recovery is usually rapid (2 to 8 weeks).

The cross-reactivity of liver injury between different fluoroquinolones has not been well documented, but is suspected based on the similarity of the clinical patterns of injury and latency. Therefore, patients should be advised to avoid increased exposure to fluoroquinolones.