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Related to Utinor: Noroxin


Noroxin, Utinor (UK)

Pharmacologic class: Fluoroquinolone

Therapeutic class: Anti-infective

Pregnancy risk category C

FDA Box Warning

Fluoroquinolones for systemic use are associated with an increased risk of tendinitis and tendon rupture in all ages. This risk is further increased in patients usually over age 60, with concomitant use of corticosteroids, and in kidney, heart, and lung transplant recipients.

Drug may exacerbate muscle weakness in patients with myasthenia gravis. Avoid use in patients with known history of myasthenia gravis.


Inhibits bacterial DNA synthesis by blocking DNA gyrase in susceptible gram-negative and gram-positive aerobic and anaerobic bacteria


Tablets: 400 mg

Indications and dosages

Urinary tract infections (UTIs) caused by Escherichia coli, Klebsiella pneumoniae, or Proteus mirabilis

Adults: 400 mg P.O. q 12 hours for 3 days

UTIs caused by all organisms except E. coli, K. pneumoniae, and P. mirabilis

Adults: 400 mg P.O. q 12 hours for 7 to 10 days. For complicated UTIs, may give for up to 21 days.


Adults: 800 mg P.O. as a single dose

Prostatitis caused by E. coli

Adults: 400 mg P.O. q 12 hours for 28 days

Dosage adjustment

• Renal impairment


• Hypersensitivity to drug

• History of tendinitis or tendon rupture with fluoroquinolone use


Use cautiously in:

• CNS diseases or disorders, renal impairment, cirrhosis, bradycardia, acute myocardial ischemia

• known history of myasthenia gravis (avoid use)

• elderly patients

• pregnant or breastfeeding patients (safety not established except in postex-posure inhalation or cutaneous anthrax).

• children younger than age 18.


• Give with glass of water 1 hour before or 2 hours after a meal.

• Don't give antacids within 2 hours of norfloxacin.

Adverse reactions

CNS: dizziness, light-headedness, drowsiness, headache, asthenia, insomnia, agitation, confusion, acute psychoses, hallucinations, tremors, increased intracranial pressure, seizures

CV: vasodilation, QT prolongation, arrhythmias

GI: nausea, diarrhea, abdominal pain, pancreatitis, pseudomembranous colitis

GU: interstitial cystitis, vaginitis

Hematologic: leukopenia

Hepatic: hepatitis

Metabolic: hyperglycemia, hypoglycemia

Musculoskeletal: tendinitis, tendon rupture

Skin: rash, hyperhidrosis, photosensi-tivity, phototoxicity, Stevens-Johnson syndrome

Other: altered taste, myasthenia gravis exacerbation, hypersensitivity reactions including anaphylaxis


Drug-drug. Antacids, bismuth, iron salts, subsalicylate, sucralfate, zinc salts: decreased norfloxacin absorption

Antineoplastics: decreased norfloxacin blood level

Cimetidine: interference with norfloxacin elimination

Corticosteroids: increased risk of tendon rupture

Nitrofurantoin: antagonism of norfloxacin's antibacterial effects in GU tract

Other fluoroquinolones: increased risk of nephrotoxicity

Probenecid: decreased renal elimination of norfloxacin

Theophylline: increased theophylline blood level, greater risk of toxicity

Warfarin: increased anticoagulant effect

Drug-diagnostic tests. Alanine amino-transferase, alkaline phosphatase, aspartate aminotransferase, bilirubin, eosino-phils, lactate dehydrogenase, platelets: increased levels

Hemoglobin, hematocrit: decreased values

Drug-food. Caffeine: decreased hepatic metabolism of caffeine

Milk or yogurt (consumed alone): impaired drug absorption

Tube feedings: impaired drug absorption

Drug-herbs. Dong quai, St. John's wort: phototoxicity

Fennel: decreased drug absorption

Drug-behaviors. Sun exposure: phototoxicity

Patient monitoring

• Monitor vital signs and cardiovascular status.

• Check fluid intake and output. Keep patient well-hydrated.

Watch for signs and symptoms of tendinitis or tendon rupture.

• Assess patient's response to therapy. Obtain specimens for repeat culture and sensitivity tests if he relapses or doesn't improve.

• Monitor renal function.

Patient teaching

• Tell patient to take on empty stomach with full glass of water, 1 hour before or 2 hours after a meal.

• If patient needs antacid for GI upset, instruct him not to take it within 2 hours of norfloxacin.

Advise patient to stop taking drug and promptly report rash; severe GI problems; tendon pain, swelling, or inflammation; or weakness.

• Caution patient to avoid driving and other hazardous activities until he knows how drug affects concentration and alertness.

• Teach patient ways to counteract photosensitivity, such as by wearing sunglasses and avoiding excessive exposure to bright light.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, foods, herbs, and behaviors mentioned above.

McGraw-Hill Nurse's Drug Handbook, 7th Ed. Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved


A brand name for NORFLOZACIN.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
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