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Related to norfloxacin: ofloxacin, ciprofloxacin


a broad-spectrum quinolone antibacterial agent effective against penicillin-resistant gram-negative and gram-positive bacteria.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.


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


An oral antibiotic, C20H24N5O4, of the fluoroquinolone class.
The American Heritage® Medical Dictionary Copyright © 2007, 2004 by Houghton Mifflin Company. Published by Houghton Mifflin Company. All rights reserved.


Antibiotics A broad-spectrum–gram-negative bacilli, staphylococci–fluoroquinolone with limited activity against streptococci and anaerobes. See Fluoroquinolone.
McGraw-Hill Concise Dictionary of Modern Medicine. © 2002 by The McGraw-Hill Companies, Inc.


A quinolone antibacterial drug used to treat urinary tract infections. A brand name is Utinor.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005


1. Pertaining to the ability to destroy or inhibit other living organisms.
2. A substance derived from a mould or bacterium, or produced synthetically, that destroys (bactericidal) or inhibits the growth (bacteriostatic) of other microorganisms and is thus used to treat infections. Some substances have a narrow spectrum of activity whereas others act against a wide range of both gram-positive and gram-negative organisms (broad-spectrum antibiotics). Antibiotics can be classified into several groups according to their mode of action on or within bacteria: (1) Drugs inhibiting bacterial cell wall synthesis, such as bacitracin, vancomycin and the β-lactams based agents (e.g. penicillin, cephalosporins (e.g. ceftazidime, ceftriaxone, cefuroxime). (2) Drugs affecting the bacterial cytoplasmic membrane, such as polymyxin B sulfate and gramicidin. (3) Drugs inhibiting bacterial protein synthesis, such as aminoglycosides (e.g. amikacin sulfate, framycetin sulfate, gentamicin, neomycin sulfate and tobramycin), tetracyclines, macrolides (e.g. erythromycin and azithromycin) and chloramphenicol. (4) Drugs inhibiting the intermediate metabolism of bacteria, such as sulfonamides (e.g. sulfacetamide sodium) and trimethoprim. (5) Drugs inhibiting bacterial DNA synthesis, such as nalixidic acid and fluoroquinolones (e.g. ciprofloxacin, levofloxacin, moxifloxacin, norfloxacin and ofloxacin). (6) Other antibiotics such as fusidic acid, the diamidines, such as propamidine isethionate and dibrompropamidine. Syn. antibacterial. See antiinflammatory drug; fusidic acid.
Millodot: Dictionary of Optometry and Visual Science, 7th edition. © 2009 Butterworth-Heinemann
References in periodicals archive ?
multocida isolates against ten commercially available antibiotics (gentamicin erythromycin amoxicillin ampicillin chloramphenicol ciprofloxacin norfloxacin enrofloxacin sulfadiazine and amikacin) was determined by disc diffusion assay (Bauer et al.1966).
In our study, we have used ten different antibiotics, where the efficacy of penicillin, oxacillin, ampicillin, erythromycin and norfloxacin will largely be determined by [C.sub.mix]/MIC and [AUC.sub.0-24]/MIC.
Sucralfate reduces the gastrointestinal absorption of norfloxacin. Antimicrob Agents Chemother 1989; 33:99--102.
Keywords: Citronellol; Geraniol; Norfloxacin; Pelargonium essential oil; Synergism; Triacetin
pneumoniae obtained from the community-acquired cases were more susceptible to Norfloxacin (75%) than the hospital-acquired cases (13%) (Bar Diagram 3).
Stock solutions of 400 [micro]g/ml galangin and 1000 [micro]g/ml norfloxacin were prepared in 0.1% (v/v) ammonia solution and 6.93 mM sodium hydroxide, respectively.
Ampicillin, amoxicillin, ciprofloxacin, norfloxacin, cephalexin were some of the antimicrobials that bade heavy resistance from organisms that belonged to Enterobacteriaceae family.
The recruited subjects were divided into eight groups of fluoroquinolones: - Ofloxacin, Ciprofloxacin, Norfloxacin, Levofloxacin, Lomefloxacin, Moxifloxacin, Gemifloxacin and Sparfloxacin.
Coli were resistant to ampicillin, cephalexin, cefixime, cepodoxime and cefdinir, 8% isolates were sensitive to amoxicillin, 36% to co-amoxiclav, 13.3% to piperacillin-tazobactum, 4% to cefuroxime, 21.7% to cefotaxime, 18% to ceftriaxone, 40% to ceftazidime, 42.3% to gentamicin, 33.3% to tobramycin, 85.7% to amikacin, 54.1% to netilmycin, 12.1% to norfloxacin, 11.4% to ciprofloxacin, 13.7% to ofloxacin, 33.3% to levofloxacin, 91.6% to gatifloxacin, 85.7% to nitrofurantoin, 25% to cotrimoxazole, 95.2% to fosfomycin, 100% to imipenem and meropenem, colistin and polimyxin.
dysenteriae 1 showed resistance to chloramphenicol (80%), ampicillin (100%), tetracycline (100%), co-trimoxazole (100%), nalidixic acid (100%), norfloxacin (100%), and ciprofloxacin (100%).
Norfloxacin is fluoroquinolone anti-infective antibacterial drug firstly used in the treatment of urinary tract infections, prostatitis, gonorrhea, and genital tract infections.