Noroxin

No·rox·in (n-rksn)

A trademark for the drug norfloxacin.

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Noroxin,

trademark for an oral antibacterial drug (norfloxacin).

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norfloxacin

Chibroxin, Noroxin, Utinor (UK)

Pharmacologic class: Fluoroquinolone

Therapeutic class: Anti-infective

Pregnancy risk category C

Action

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

Availability

Ophthalmic solution: 0.3% in 5-ml bottle

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.

➣ Gonorrhea

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

➣ Conjunctivitis caused by susceptible organisms

Adults and children ages 1 and older: One or two drops of ophthalmic solution instilled into affected eye(s) q.i.d. for up to 7 days. Depending on infection severity, first-day dosage may be one or two drops q 2 hours while awake.

Dosage adjustment

• Renal impairment

Contraindications

• Hypersensitivity to drug
• History of tendinitis or tendon rupture with fluoroquinolone use

Precautions

Use cautiously in:
• CNS diseases or disorders, renal impairment, cirrhosis, bradycardia, acute myocardial ischemia
• elderly patients
• pregnant or breastfeeding patients (safety not established except in postexposure inhalation or cutaneous anthrax).
• children younger than age 18 (except with ophthalmic solution).

Administration

• Give with glass of water 1 hour before or 2 hours after a meal.
• Don't give antacids within 2 hours of norfloxacin.

Route	Onset	Peak	Duration
P.O.	Rapid	2-3 hr	12 hr
Ophthalmic	Unknown	Unknown	Unknown

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

EENT: eye burning and discomfort, conjunctival hyperemia, corneal deposits, photophobia (all with ophthalmic use)

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, photosensitivity, phototoxicity, Stevens-Johnson syndrome

Other: altered taste, hypersensitivity reactions including anaphylaxis

Interactions

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 aminotransferase, alkaline phosphatase, aspartate aminotransferase, bilirubin, eosinophils, 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.
• 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 promptly report rash, severe GI problems, 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.
• Teach patient how to use eye drops. Caution him not to touch dropper tip to any surface (including eye).
• 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.