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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
• 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.
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
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
• 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.
• 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.
ClassificationTherapeutic: anti infectives
See for ophthalmic use
- Urinary tract and gynecologic infections including cystitis, gonorrhea, and prostatitis.
- Staphylococcus aureus,
- Staphylococcus epidermidis,
- Streptococcus agalactiae,
- Enterococcus faecalis.
- Escherichia coli,
- Klebsiella pneumoniae,
- Enterobacter aerogenes,
- Proteus mirabilis,
- Proteus vulgaris.
Time/action profile (blood levels)
|PO||rapid||2–3 hr||12 hr|
Adverse Reactions/Side Effects
Central nervous system
- elevated intracranial pressure (including pseudotumor cerebri) (life-threatening)
- seizures (life-threatening)
- headache (most frequent)
- torsade de pointes (life-threatening)
- QT interval prolongation
- hepatotoxicity (life-threatening)
- pseudomembranous colitis (life-threatening)
- diarrhea (most frequent)
- nausea (most frequent)
- abdominal pain
- drug rash with eosinophilia and systemic symptoms syndrome (life-threatening)
- stevens-johnson syndrome (life-threatening)
- muscle spasm
- tendon rupture
- peripheral neuropathy
- hypersensitivity reactions including anaphylaxis (life-threatening)
Drug-Drug interactionConcurrent use ofamiodarone, disopyramide, procainamide, quinidine, dofetilide, or sotalol ↑ risk of torsade de pointes in susceptible individuals.↑ serumtheophylline levels and may lead to toxicity.Administration withantacids, iron salts, bismuth subsalicylate,sucralfate, and zinc salts ↓ absorption.May ↑ effects of warfarin.Serum levels may be ↓ by antineoplastic agents.Cimetidine may interfere with elimination.Probenecid ↓ renal elimination.May ↑ risk of nephrotoxicity from cyclosporine.Concurrent corticosteroid therapy may ↑ risk of tendon rupture.May ↑ effects of some oral antidiabetic agents.Absorption is ↓ by concurrent enteral feeding (because of metal cations).Absorption ↓ by food and/or dairy products (take 1 hr before or 2 hr after).
Renal ImpairmentOral (Adults) CCr ≤30 mL/min—400 mg once daily.
- Assess for infection (vital signs; appearance of wound, sputum, urine, and stool; WBC; urinalysis; frequency and urgency of urination; cloudy or foul-smelling urine) at beginning of and during therapy.
- Obtain specimens for culture and sensitivity prior to initiating therapy. First dose may be given before receiving results.
- Observe patient for signs and symptoms of anaphylaxis (rash, pruritus, laryngeal edema, wheezing). Discontinue drug and notify health care professional immediately if these problems occur. Keep epinephrine, an antihistamine, and resuscitation equipment close by in case of an anaphylactic reaction.
- Monitor bowel function. Diarrhea, abdominal cramping, fever, and bloody stools should be reported to health care professional promptly as a sign of pseudomembranous colitis. May begin up to several weeks following cessation of therapy.
- Assess for rash periodically during therapy. May cause Stevens-Johnson syndrome. Discontinue therapy if severe or if accompanied with fever, general malaise, fatigue, muscle or joint aches, blisters, oral lesions, conjunctivitis, hepatitis and/or eosinophilia.
- Assess for signs and symptoms of peripheral neuropathy (pain, burning, tingling, numbness, and/or weakness or other alterations of sensation including light touch, pain, temperature, position sense, and vibratory sensation) periodically during therapy. Symptoms may be irreversible; discontinue norfloxacin if symptoms occur.
- Lab Test Considerations: May cause ↑ serum AST, ALT, LDH, bilirubin, and alkaline phosphatase.
- May also cause ↑ or ↓ serum glucose.
- Monitor prothrombin time closely in patients receiving norfloxacin and warfarin; may enhance the anticoagulant effects of warfarin.
Potential Nursing DiagnosesRisk for infection (Indications)
- Do not confuse Noroxin with Neurontin (gabapentin).
- Oral: Administer on an empty stomach 1 hr before or 2 hr after meals, with a full glass of water. Products or foods containing calcium, magnesium, aluminum, iron, or zinc should not be ingested for 2 hr before and 2 hr after administration.
- Instruct patient to take medication as directed at evenly spaced times and to finish drug completely, even if feeling better. Take missed doses as soon as possible, unless almost time for next dose. Do not double doses. Advise patient that sharing of this medication may be dangerous.
- Advise patients to notify health care professional immediately if they are taking theophylline.
- Encourage patient to maintain a fluid intake of at least 1500–2000 mL/day to prevent crystalluria.
- Advise patient that antacids or medications containing calcium, magnesium, aluminum, iron, or zinc will decrease absorption and should not be taken within 2 hr before or 2 hr after taking this medication.
- May cause dizziness and drowsiness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
- Advise patient to notify health care professional of any personal or family history of QTc prolongation or proarrhythmic conditions such as recent hypokalemia, significant bradycardia, or recent myocardial ischemia or if fainting spells or palpitations occur. Patients with this history should not receive norfloxacin.
- Advise patient to stop taking norfloxacin and notify health care professional immediately if signs and symptoms of peripheral neuropathy occur.
- Caution patient to use sunscreen and protective clothing to prevent phototoxicity reactions during and for 5 days after therapy. Notify health care professional if a sunburn-like reaction or skin eruption occurs.
- Advise patient that frequent mouth rinses, good oral hygiene, and sugarless gum or candy may minimize dry mouth.
- Instruct patients being treated for gonorrhea that partners also must be treated.
- Advise patient to report signs of superinfection (furry overgrowth on the tongue, vaginal itching or discharge, loose or foul-smelling stools).
- Advise patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult with health care professional before taking other medications.
- Instruct patient to notify health care professional if fever and diarrhea develop, especially if stool contains blood, pus, or mucus. Advise patient not to treat diarrhea without consulting health care professional.
- Instruct patient to notify health care professional immediately if rash, jaundice, signs of hypersensitivity, or tendon (shoulder, hand, Achilles, and other) pain, swelling, or inflammation occur. If tendon symptoms occur, avoid exercise and use of the affected area. Increased risk in >65 yrs old, kidney, heart and lung transplant recipients, and patients taking corticosteroids concurrently. Therapy should be discontinued.
- Resolution of the signs and symptoms of bacterial infection. Time for complete resolution depends on organism and site of infection.