Norfloxacin information from DrugsUpdate
P - Caution when used during pregnancy
L - Contraindicated in lactation
FI - Food*
Norfloxacin is a synthetic chemotherapeutic agent occasionally used to treat common as well as complicated urinary tract infections. It is sold under various brand names with the most common being Noroxin. In form of ophthalmic solutions it is known as Chibroxin. Norfloxacin is a second generation synthetic fluoroquinolone (quinolone) developed by Kyorin Seiyaku K.K. (Kyorin).
Pharmacodynamics
Pharmacokinetics
Norfloxacin inhibits the action of DNA gyrase in DNA replication, transcription, repair, recombination and transposition.
Absorption
30-40% absorbed from the GI tract (oral); peak plasma concentrations after 1-2 hours. May be delayed by the presence of food.
Distribution
Genitourinary tract, placenta, bile (high concentrations). Protein-binding: 14%.
Metabolism
Hepatic; converted to several metabolites with antibacterial activity.
Excretion
Via urine by glomerular filtration and tubular secretion within 24 hours (30% as unchanged); via faeces (30%); 4 hours (elimination half-life); may be prolonged in renal impairment.
Norfloxacin Indications / Norfloxacin Uses
Information Not Available
Norfloxacin Adverse Reactions / Norfloxacin Side Effects
Nausea, vomiting, heartburn, constipation, diarrhoea, abdominal cramping, anorexia; headache, dizziness; depression, insomnia; phototoxicity; rash, fever, arthralgia; elevated liver enzymes, urea and creatinine. Eosinophilia, neutropenia, thrombocytopenia and anaemia; hyperhidris; tendon rupture; QT prolongation.
Potentially Fatal: Anaphylaxis, acute renal failure, seizures.
Precautions
Information Not Available
Special Precautions
Renal impairment; history of CNS disorders; myasthaenia gravis. Pregnancy. QT prolongation; discontinue if signs of neuropathy occur.
Other Drug Interactions
Antacids reduce absorption from GI tract. Probenecid reduces urinary excretion of norfloxacin. Norfloxacin may increase concentration of clozapine, ropinirole, tacrine, tizanidine. Severe hypoglycaemia has occured rarely with glyburide. Increased risk of CNS stimulation and seizures with NSAIDs.
Potentially Fatal: Raises theophylline and ciclosporin levels. Effects of warfarin potentiated. Risk of QT prolongation and torsades de pointes with class I and III antiarrythmics, cisapride, erythromycin, antipsychotics, TCAs.
Other Interactions
Food Interaction
Absorption reduced, especially when taken with dairy products e.g. milk or yogurt.
Dosage
Oral
Uncomplicated gonorrhoea
Adult: 800 mg as a single daily dose.
CrCl (ml/min) Dosage Recommendation
≤30 400 mg single dose
Oral
Chronic bacterial prostatitis
Adult: 400 mg bid for 28 days.
CrCl (ml/min) Dosage Recommendation
≤30 400 mg once daily
Oral
Complicated urinary tract infections
Adult: 400 mg bid for 10-21 days.
CrCl (ml/min) Dosage Recommendation
≤30 400 mg once daily
Oral
Chronic relapsing urinary tract infections
Adult: 400 mg bid for up to 12 weeks, may be reduced to 400 mg once daily if adequate suppression within first 4 weeks.
CrCl (ml/min) Dosage Recommendation
≤30 400 mg once daily
Oral
Gastroenteritis
Adult: 400 mg bid for 3-5 days
CrCl (ml/min) Dosage Recommendation
≤30 400 mg once daily
Oral
Uncomplicated urinary tract infections
Adult: Infections caused by susceptible Escherichia coli, Klebsiella pneumoniae, roteus mirabilis species: 400 mg bid for 3 days. Infections caused by other susceptible bacteria: 400 mg bid for 7-10 days.
CrCl (ml/min) Dosage Recommendation
≤30 400 mg once daily
Ophthalmic
Conjunctivitis
Adult: As 0.3% solution: Usual dose, 1 or 2 drops in the eye 4 times daily for up to 7 days. Dosage may be increased to 1 or 2 drops every 2 hours for the 1st day in more severe infections.
Child: ≥1 year, as 0.3% solution: Usual dose, 1 or 2 drops in the eye 4 times daily for up to 7 days. Dosage may be increased to 1 or 2 drops every 2 hr for the 1st day in more severe infections.
Food(before/after)
Should be taken on an empty stomach. (Take on an empty stomach 1 hr before or 2 hr after meals. Do not take w/dairy products.)
List of Contraindications
Norfloxacin and Pregnancy
Caution when used during pregnancy
Caution esp in 1st trimester.
Category C: Either studies in animals have revealed adverse effects on the foetus (teratogenic or embryocidal or other) and there are no controlled studies in women or studies in women and animals are not available. Drugs should be given only if the potential benefit justifies the potential risk to the foetus.
Norfloxacin and Lactation
Contraindicated in lactation
Norfloxacin and Children
There have been numerous side effects that have been recorded in reference to the unapproved use of norfloxacin in the pediatric population.
Norfloxacin and Geriatic
Information Not Available
Norfloxacin and Other Contraindications
Hypersensitivity to quinolones; children <18 years. Lactation.
Storage
Ophthalmic
Store at 15-30°C.
Oral
Store at 15-30°C.
Lab interference
Ophthalmic
Store at 15-30°C.
Oral
Store at 15-30°C.
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