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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.


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.


/nor·flox·a·cin/ (nor-flok´sah-sin) a broad-spectrum antibacterial effective against a wide range of aerobic gram-negative and gram-positive organisms.


An oral antibiotic, C20H24N5O4, of the fluoroquinolone class.


an oral antibacterial drug.
indications It is prescribed for the treatment of bacterial urinary tract infections, sexually transmitted gonorrhea, and proctitis.
contraindications Hypersensitivity to quinolones or pregnancy or lactation prohibits its use. It should be used with caution in patients younger than 18 years because of arthropathy. Concomitant use of nitrofurantoin drugs is not recommended, and concomitant use of corticosteroids can increase the risk of arthropathy in the elderly.
adverse effects Typical side effects include nausea, dizziness, and headache. Severe hypersensitivity reactions, tendon rupture, and numerous other effects have been reported with relatively low incidence.


Antibiotics A broad-spectrum–gram-negative bacilli, staphylococci–fluoroquinolone with limited activity against streptococci and anaerobes. See Fluoroquinolone.


A quinolone antibacterial drug used to treat urinary tract infections. A brand name is Utinor.


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.


a fluoroquinolone antibiotic, used particularly in urinary tract infection.
References in periodicals archive ?
The uropathogens were more resistant to Nalidixic acid, Norfloxacin and fluoroquinolones and many are found to be multi-drug resistant isolates.
less than or 6-15 >15 equal to]5 Ampicillin 57 8 28 Trimothprim/ sulfamethoxazole 94 16 50 Nalidixic acid 98 17 46 Norfloxacin 64 11 30 Cefotaxime 5 0 5 Cefixime 9 0 8 [less than or 6-15 >15 equal to]5 Ampicillin 50 8 23 Trimothprim/ sulfamethoxazole 93 0 41 Nalidixic acid 88 18 40 Norfloxacin 16 4 10 Cefotaxime 10 3 3 Cefixime 8 2 3 Note: Table made from bar graph.
8] CFU/ml) into each tube containing 5 ml fresh broth with norfloxacin at 1/2 MIC concentration alone as well as in combination with CD.
All the three most frequently isolated organisms showed resistant to commonly used antibiotics like Ampicillin, Norfloxacin and Nalidixic acid.
Besides the enhancement of the light mediated toxic activity of the extracts, these activities were lower than that observed by the norfloxacin and 8-MOP (Table II).
9 (n = 3) percent isolates showed resistance to amoxicillin, oxytetracycline, norfloxacin, enrofloxacin and ciprofloxacin, respectively.
The antibiotics used were penicillin, ampicillin, oxacillin, erythromycin, polymyxin B sulphate, tetracycline, chloramphenicol, vancomycin, rifampin and norfloxacin.
They also assess technologies for human infant health, including molecular imaging, metabolic profiling, and screening of newborns for metabolic disorders, while papers on the health challenges of human infants include considerations of obesity, intestinal immune health, gut decontamination through norfloxacin and insulin, individual epigenetic variation, the relationship of early infant feeding and heredity and the development of allergies and sensitivity, and personalized care of pediatric cancer patients.
with Streptomycin (10 [micro]g), Erythromycin (15 [micro]g), Tetracycline (30 [micro]g), Penicillin (10 [micro]g), Norfloxacin (10 [micro]g), Riphampicin (5 [micro]g), Neomycin (30 [micro]g), Cephalexin (30 [micro]g), Ampicillin (10 [micro]g), Kanamycin (20 [micro]g), Gentamicin (10 [micro]g) were used.
Medications on the list include the fluoroquinolones ciprofloxacin (Cipro), levofloxacin (Levaquin), moxifloxacin (Aveiox), norfloxacin (Noroxin), and ofloxacin (Floxin).
The antimicrobial susceptibility tests included the following drugs: amikacin (an aminoglycoside), cephalexin, cefuroxime and cephotaxime (1st, 2nd and 3rd generation cephalosporins, respectively), norfloxacin, ciprofloxacin and nalidixic acid (fluoroquinolines), nitrofurantoin, ampicillin, and trimethoprim-sulfamethoxazole (TMP/SMX).