Generic Medicine Info
Indications and Dosage
Chronic bacterial prostatitis
Adult: 400 mg bid for 28 days. Max: 800 mg daily.

Acute uncomplicated urinary tract infections, Complicated urinary tract infections
Adult: For patients with no alternative treatment options: Usual dose: 200-400 mg bid for 3-10 days. Max: 800 mg daily.

Uncomplicated gonorrhoea
Adult: 800 mg as a single dose.
Renal Impairment
Acute uncomplicated urinary tract infections; Complicated urinary tract infections; Chronic bacterial prostatitis:
CrCl (mL/min) Dosage
≤30 400 mg once daily.
Should be taken on an empty stomach. Take 1 hr before or 2 hr after meals, w/ a glass of water. Ensure adequate hydration. Do not take w/ dairy products.
Hypersensitivity to norfloxacin or other quinolones. History of tendon disorders, tendinitis or tendon rupture. Pre-pubertal children. Pregnancy.
Special Precautions
Patient with pre-existing or history of aortic aneurysm, and its risk factors (e.g. hypertension, peripheral atherosclerotic vascular diseases, Takayasu arteritis, giant cell arteritis, Behcet's disease, genetic disorders that involve blood vessel changes such as Marfan syndrome or Ehlers-Danlos syndrome); cardiac disease (e.g. heart failure, MI, bradycardia), congenital long QT syndrome, uncorrected electrolyte imbalance (e.g. hypokalaemia, hypomagnesaemia), history of QT prolongation; known history of myasthenia gravis, G6PD deficiency, known or suspected CNS disorder, risk factors predisposing to seizures or lowers seizure threshold, rheumatoid arthritis. Solid organ transplant recipients. Not effective and may mask symptoms of syphilis. Renal impairment. Elderly. Lactation.
Adverse Reactions
Significant: Tendinitis or tendon rupture (particularly Achilles tendon), CNS effects (e.g. seizures, increased intracranial pressure including pseudotumour cerebri, toxic psychosis), peripheral neuropathy, aortic aneurysm ruptures or dissection (particularly in the elderly), QT interval prolongation; cholestatic hepatitis, hyperglycaemia, moderate to severe phototoxicity; bacterial or fungal superinfection, including Clostridium difficile-associated diarrhoea and pseudomembranous colitis (prolonged use). Rarey, haemolytic reactions (in G6PD deficient patients).
Cardiac disorders: Tachycardia, ventricular arrhythmia, torsades de pointes.
Ear and labyrinth disorders: Rarely, tinnitus.
Eye disorders: Rarely, visual disturbances.
Gastrointestinal disorders: Nausea, vomiting, abdominal pain, dyspepsia, diarrhoea.
Investigations: Increased AST, ALT, and blood alkaline phosphatase; prolonged prothrombin time, decreased haematocrit.
Musculoskeletal and connective tissue disorders: Rhabdomyolysis.
Nervous system disorders: Headache, dizziness, drowsiness.
Psychiatric disorders: Rarely, insomnia, confusion, hallucination, nervousness, disorientation, depression, anxiety, mood changes.
Renal and urinary disorders: Crystalluria (high doses).
Skin and subcutaneous tissue disorders: Rash, pruritus, petechiae. Rarely, Stevens-Johnson syndrome, exfoliative dermatitis, toxic epidermal necrolysis.
Potentially Fatal: Severe hypoglycaemia, severe exacerbation of myasthenia gravis; severe hypersensitivity reactions, including anaphylaxis.
Patient Counseling Information
This drug may cause dizziness, if affected, do not drive or operate machinery. Avoid or limit exposure to excessive sunlight. Ensure adequate hydration.
Monitoring Parameters
Perform culture and susceptibility tests; consult local institutional recommendations before treatment initiation due to antibiotic resistance risks. Screen patients for syphilis at the time of gonorrhoeal diagnosis and 3 months later. Periodically monitor CBC, hepatic and renal function during prolonged therapy.
Drug Interactions
Increased risk of QT prolongation with agents known to prolong the QT interval (e.g. class IA and III antiarrhythmic drugs, macrolides, antipsychotics, TCAs). May increase the plasma levels of theophylline and ciclosporin. Rarely, may cause severe hypoglycaemia when given with glibenclamide. Antacids, sucralfate, multivitamins or drugs containing Fe or Zn may decrease the absorption of norfloxacin. May increase the risk of CNS stimulation and convulsive seizures with NSAIDs. May enhance the effects of anticoagulants (e.g. warfarin). May inhibit the metabolism of caffeine. Diminished urinary excretion with probenecid. Increased risk of tendinitis and tendon rupture with corticosteroids.
Food Interaction
Food and dairy products may reduce the absorption and average peak serum concentrations of norfloxacin.
Mechanism of Action: Norfloxacin is a fluoroquinolone derivative with a broad spectrum of bactericidal activity. It exerts its antibacterial activity by inhibiting deoxyribonucleic acid (DNA) gyrase, a bacterial enzyme necessary for DNA replication, transcription, repair, recombination and transposition.
Absorption: Rapidly but incompletely absorbed from the gastrointestinal tract (approx 30-40%). Food and dairy products decrease the absorption. Time to peak plasma concentration: Approx 1-2 hours.
Distribution: Penetrates well into tissues of the genitourinary tract; detected in bile, prostatic fluid and amniotic fluid. Crosses the placenta. Plasma protein binding: 10-15%.
Metabolism: Metabolised in the liver into several metabolites.
Excretion: Mainly via urine (26-32% as unchanged drug, 5-8% as metabolites); faeces (30%). Elimination half-life: 3-4 hours.
Chemical Structure

Chemical Structure Image

Source: National Center for Biotechnology Information. PubChem Compound Summary for CID 4539, Norfloxacin. Accessed July 29, 2022.

Store between 15-30°C. Protect from light.
MIMS Class
ATC Classification
J01MA06 - norfloxacin ; Belongs to the class of fluoroquinolones. Used in the systemic treatment of infections.
Anon. Norfloxacin. Lexicomp Online. Hudson, Ohio. Wolters Kluwer Clinical Drug Information, Inc. Accessed 05/07/2022.

Buckingham R (ed). Norfloxacin. Martindale: The Complete Drug Reference [online]. London. Pharmaceutical Press. Accessed 05/07/2022.

Janacin (Medispec [M] Sdn Bhd). MIMS Malaysia. Accessed 05/07/2022.

Janacin Tablet (Medispec [M] Sdn Bhd). National Pharmaceutical Regulatory Agency - Ministry of Health Malaysia. Accessed 05/07/2022.

Norfloxacin. Gold Standard Drug Database in ClinicalKey [online]. Elsevier Inc. Accessed 29/07/2022.

Teva Pharma (New Zealand) Limited. Arrow - Norfloxacin data sheet 9 November 2020. Medsafe. Accessed 05/07/2022.

Disclaimer: This information is independently developed by MIMS based on Norfloxacin from various references and is provided for your reference only. Therapeutic uses, prescribing information and product availability may vary between countries. Please refer to MIMS Product Monographs for specific and locally approved prescribing information. Although great effort has been made to ensure content accuracy, MIMS shall not be held responsible or liable for any claims or damages arising from the use or misuse of the information contained herein, its contents or omissions, or otherwise. Copyright © 2024 MIMS. All rights reserved. Powered by
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