Noroxin


norfloxacin

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.

Action

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

Availability

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

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

• 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.

Administration

• 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

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 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.

norfloxacin

(nor-flox-a-sin) norfloxacin,

Noroxin

(trade name)

Classification

Therapeutic: anti infectives
Pharmacologic: fluoroquinolones
Pregnancy Category: C
See for ophthalmic use

Indications

Treatment of the following bacterial infections:
  • Urinary tract and gynecologic infections including cystitis, gonorrhea, and prostatitis.

Action

Inhibits bacterial DNA synthesis by inhibiting DNA gyrase enzyme.

Therapeutic effects

Death of susceptible bacteria.Active against gram-positive pathogens including:
  • Staphylococcus aureus,
  • Staphylococcus epidermidis,
  • Streptococcus agalactiae,
  • Enterococcus faecalis.
Gram-negative spectrum notable for activity against:
  • Escherichia coli,
  • Klebsiella pneumoniae,
  • Enterobacter aerogenes,
  • Proteus mirabilis,
  • Proteus vulgaris.

Pharmacokinetics

Absorption: Well absorbed (30–40%) following oral administration.Distribution: Widely distributed. High concentrations are achieved in the urine and tissues of the urinary tract. Appears to cross the placenta.Metabolism and Excretion: 10% metabolized by the liver, 30% excreted unchanged by the kidneys, 30% excreted unchanged in feces.Half-life: 6.5 hr.

Time/action profile (blood levels)

ROUTEONSETPEAKDURATION
POrapid2–3 hr12 hr

Contraindications/Precautions

Contraindicated in: Hypersensitivity (cross-sensitivity within class may exist); History of myasthenia gravis (may worsen symptoms including muscle weakness and breathing problems); Pediatric: Children ; Obstetric: Pregnancy.Use Cautiously in: Known or suspected CNS disorder; Renal impairment (dose ↓ recommended if CCr ≤30 mL/min); Cirrhosis; QTc interval prolongation; Uncorrected hypokalemia or hypomagnesemia; Concurrent use of Class IA antiarrhythmics (disopyramide, quinidine, procainamide) or Class III antiarrhythmics (amiodarone, sotalol) (↑risk of QTc interval prolongation and torsade de pointes); Underlying conduction abnormalities (may rarely cause QTc prolongation); Concurrent use of corticosteroids (↑ risk of tendinitis/tendon rupture); Kidney, heart, or lung transplant patients (↑ risk of tendinitis/tendon rupture); Dialysis patients (↑ risk of adverse reactions); Geriatric: ↑ risk of adverse reactions; Lactation: Safety not established.

Adverse Reactions/Side Effects

Central nervous system

  • elevated intracranial pressure (including pseudotumor cerebri) (life-threatening)
  • seizures (life-threatening)
  • headache (most frequent)
  • agitation
  • anxiety
  • confusion
  • depression
  • dizziness
  • drowsiness
  • hallucinations
  • insomnia
  • nightmares
  • paranoia
  • tremor

Cardiovascular

  • torsade de pointes (life-threatening)
  • QT interval prolongation

Gastrointestinal

  • hepatotoxicity (life-threatening)
  • pseudomembranous colitis (life-threatening)
  • diarrhea (most frequent)
  • nausea (most frequent)
  • abdominal pain

Genitourinary

  • vaginitis

Dermatologic

  • drug rash with eosinophilia and systemic symptoms syndrome (life-threatening)
  • stevens-johnson syndrome (life-threatening)
  • photosensitivity
  • rash

Endocrinologic

  • hyperglycemia
  • hypoglycemia

Musculoskeletal

  • muscle spasm
  • tendinitis
  • tendon rupture

Neurologic

  • peripheral neuropathy

Miscellaneous

  • hypersensitivity reactions including anaphylaxis (life-threatening)

Interactions

Drug-Drug interaction

Concurrent 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).

Route/Dosage

Oral (Adults) Urinary tract infections—400 mg q 12 hr (for 3–21 days, depending on severity of infection). Gonorrhea—800 mg single dose. Prostatitis-400 mg q 12 hr (for 28 days).

Renal Impairment

Oral (Adults) CCr ≤30 mL/min—400 mg once daily.

Availability

Tablets: 400 mg

Nursing implications

Nursing assessment

  • 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 Diagnoses

Risk for infection (Indications)

Implementation

  • 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.

Patient/Family Teaching

  • 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.

Evaluation/Desired Outcomes

  • Resolution of the signs and symptoms of bacterial infection. Time for complete resolution depends on organism and site of infection.

Noroxin

(nə-rŏk′sĭn) A trademark for the drug norfloxacin.