Generic Norfloxacin

Common use
Norfloxacin is a fluoroquinolone antibiotic used to treat bacterial infections of the urinary tract, prostate, and gastrointestinal tract. It works by inhibiting bacterial DNA gyrase, an enzyme essential for DNA replication, thereby stopping bacterial growth. It is particularly effective against gram-negative bacteria and is often prescribed for uncomplicated UTIs, prostatitis, and infectious diarrhea. It is not effective against viral infections like colds or flu.

Dosage and direction
The typical adult dose is 400 mg twice daily, usually taken on an empty stomach, one hour before or two hours after meals. Tablets should be swallowed whole with a full glass of water. Maintain adequate fluid intake during treatment. Always complete the full course as prescribed, even if symptoms improve early.

Precautions
Before using norfloxacin, inform your doctor if you have a history of tendon disorders, seizures, kidney disease, or heart rhythm problems. Avoid prolonged sun exposure as the drug may increase photosensitivity. Norfloxacin can affect coordination and reaction time—caution is advised when driving or operating machinery. It is not recommended for children or pregnant women unless absolutely necessary.

Contraindications
Norfloxacin is contraindicated in individuals with known hypersensitivity to fluoroquinolones or any component of the drug. It should not be used by pregnant or breastfeeding women unless benefits outweigh risks. Avoid using in patients with a history of tendon rupture associated with fluoroquinolone use. Not suitable for patients with glucose-6-phosphate dehydrogenase (G6PD) deficiency.

Possible side effect
Common side effects include nausea, headache, dizziness, and abdominal cramps. Less commonly, it may cause tendon inflammation or rupture, especially in elderly patients. Rare but serious side effects include QT prolongation, allergic reactions, and central nervous system effects like seizures or confusion. Discontinue use and seek medical help if severe symptoms occur.

Drug interaction
Norfloxacin may interact with antacids, multivitamins, or supplements containing magnesium, aluminum, calcium, or iron—these should be taken at least 2 hours before or 2 hours after norfloxacin. It may also interact with warfarin, increasing bleeding risk, and with certain antiarrhythmic drugs. Inform your healthcare provider about all medications you're taking.

Missed dose
If a dose is missed, take it as soon as you remember. If it’s almost time for the next dose, skip the missed one. Do not double up to make up for a missed dose. Stick to the regular dosing schedule to ensure effectiveness.

Overdose
Symptoms of overdose may include nausea, vomiting, dizziness, and seizures. Seek immediate medical attention if overdose is suspected. Treatment involves supportive care and monitoring of vital functions. There is no specific antidote.

Storage
Store norfloxacin at room temperature, away from light, heat, and moisture. Keep it in its original packaging. Do not use past the expiration date. Keep out of reach of children.

Disclaimer

We provide only general information about medications which does not cover all directions, possible drug integrations, or precautions. Information at the site cannot be used for self-treatment and self-diagnosis. Any specific instructions for a particular patient should be agreed with your health care adviser or doctor in charge of the case. We disclaim reliability of this information and mistakes it could contain. We are not responsible for any direct, indirect, special or other indirect damage as a result of any use of the information on this site and also for consequences of self-treatment.

Clinical Verification

Last Clinically Updated: August 15, 2026

Written By

Dr. Elena Vance, PharmD

Clinical Specialist in Neuropharmacology

Fact Checked By

Marcus Thorne, MS

Biomedical Data & FDA Label Verification

Medically Reviewed By

Dr. Arthur Campbell, MD

Board-Certified Psychiatrist (ABPN)