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Pharmacologic class: 5-nitrofuran derivative
Therapeutic class: Anti-infective, urinary tract anti-infective
Pregnancy risk category B
Inhibits bacterial enzymes required for normal cell activity at low concentrations; inhibits normal cell-wall synthesis at high concentrations
Capsules: 25 mg, 50 mg, 100 mg (macrocrystals)
Capsules (extended-release): 100 mg (macrocrystals)
Oral suspension: 25 mg/5 ml
Tablets: 50 mg, 100 mg (macrocrystals)
Indications and dosages
➣ Active urinary tract infections (UTIs)
Adults: 50 to 100 mg P.O. q.i.d. or 100 mg q 12 hours (extended-release), continued for 1 week, or for 3 days after urine becomes sterile
Children older than 1 month: 5 to 7 mg/kg/day P.O. in four divided doses, continued for 1 week, or for 3 days after urine becomes sterile
➣ Chronic suppression of UTIs
Adults: 50 to 100 mg P.O. at bedtime
Children: 1 mg/kg/day P.O. in one or two divided doses
• Hypersensitivity to drug or parabens (oral suspension)
• Oliguria, anuria, or significant renal impairment
• Pregnancy near term (38 to 42 weeks' gestation), imminent labor onset, labor and delivery
• Infants younger than 1 month
Use cautiously in:
• diabetes mellitus, renal impairment
• blacks and patients of Mediterranean or near-Eastern descent (because of possible G6PD deficiency)
• elderly or debilitated patients
• pregnant (to week 32) or breastfeeding patients.
• As appropriate, obtain specimens for repeat urine culture and sensitivity tests before therapy.
• To avoid GI upset and increase drug bioavailability, give with food or milk.
CNS: dizziness, drowsiness, headache, asthenia, peripheral neuropathy, vertigo
CV: chest pain
GI: nausea, vomiting, diarrhea, abdominal pain, anorexia, parotitis, pancreatitis
Hematologic: eosinophilia, agranulocytosis, thrombocytopenia, leukopenia, granulocytopenia, G6PD deficiency anemia, hemolytic anemia, megaloblastic anemia
Hepatic: hepatitis, hepatic necrosis
Musculoskeletal: arthralgia, myalgia
Respiratory: asthma attacks, pulmonary hypersensitivity reactions including diffuse interstitial pneumonias (with prolonged therapy)
Skin: rash, exfoliative dermatitis, alopecia, pruritus, urticaria, angioedema, photosensitivity, Stevens-Johnson syndrome
Other: drug fever, chills, superinfection (limited to urinary tract), hypersensitivity reactions including anaphylaxis, lupus-like syndrome
Drug-drug. Anticholinergics: increased nitrofurantoin absorption and bioavailability
Drugs that can cause pulmonary toxicity: increased risk of pneumonitis
Hepatotoxic drugs: increased risk of hepatotoxicity
Magnesium salts: decreased nitrofurantoin absorption
Neurotoxic drugs: increased risk of neu-rotoxicity
Uricosurics (such as probenecid): decreased renal clearance and increased blood level of nitrofurantoin
Drug-diagnostic tests. Alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, bilirubin, blood urea nitrogen, creatinine: increased levels Granulocytes, platelets, hemoglobin: decreased levels
Urine glucose tests using Benedict's reagent or Fehling's solution: false-positive results
Drug-food. Any food: increased drug bioavailability
• Monitor patient's response to therapy. Assess urine culture and sensitivity tests.
Watch for and immediately report peripheral neuropathy.
Assess respiratory status. Watch for signs and symptoms of serious pulmonary hypersensitivity reaction.
Monitor CBC and liver function tests closely. Stay alert for evidence of hematologic and hepatic disorders.
• Evaluate patient for rash.
• Instruct patient to take with food or milk at regular intervals around the clock.
• Advise patient to complete entire course of therapy.
• Tell patient not to take magnesium-containing drugs (such as antacids) during therapy.
• Caution patient not to drive or perform other hazardous activities until he knows how drug affects vision, concentration, and alertness.
Tell patient to immediately report fever, chills, cough, chest pain, difficulty breathing, rash, bleeding or easy bruising, dark urine, yellowing of skin or eyes, numbness or tingling of fingers or toes, or intolerable GI distress.
• Advise female patient to avoid taking drug during pregnancy, especially near term.
• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs, tests, and foods mentioned above.
ClassificationTherapeutic: anti infectives
- Escherichia coli,
- Staphylococcus aureus,
- Staphylococcus epidermidis,
Time/action profile (urine levels)
|PO||unknown||30 min||6–12 hr|
Adverse Reactions/Side Effects
Central nervous system
Ear, Eye, Nose, Throat
- pneumonitis (life-threatening)
- pulmonary fibrosis (life-threatening)
- chest pain
- hepatotoxicity (life-threatening)
- pseudomembranous colitis (life-threatening)
- anorexia (most frequent)
- nausea (most frequent)
- vomiting (most frequent)
- abdominal pain
- rust/brown discoloration of urine
- blood dyscrasias
- hemolytic anemia
- peripheral neuropathy
- hypersensitivity reactions (most frequent)
Drug-Drug interactionProbenecid prevents high urinary concentrations; may ↓ effectiveness.Antacids may ↓ absorption.↑ risk of neurotoxicity with neurotoxic drugs.↑ risk of hepatotoxicity with hepatotoxic drugs.↑ risk of pneumonitis with drugs having pulmonary toxicity.
Availability (generic available)
- Assess for signs and symptoms of urinary tract infection (frequency, urgency, pain, and burning on urination; fever; cloudy or foul-smelling urine) before and periodically during therapy.
- Obtain specimens for culture and sensitivity before and during drug administration.
- Monitor intake and output ratios. Report significant discrepancies in totals.
- 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 signs and symptoms of pulmonary reactions periodically during therapy. Acute reactions (fever, chills, cough, chest pain, dyspnea, pulmonary infiltration with consolidation or pleural effusion on x-ray, eosinophilia) usually occur within first week of treatment and resolve when therapy is discontinued. Chronic reactions (malaise, dyspnea on exertion, cough, altered pulmonary function) may indicate pneumonitis or pulmonary fibrosis and are more common in patients taking nitrofurantoin for 6 mo or longer.
- Lab Test Considerations: Monitor CBC routinely with patients on prolonged therapy.
- Monitor liver function tests periodically during therapy. May cause ↑ serum glucose, bilirubin, alkaline phosphatase, BUN, and creatinine. If hepatotoxicity occurs, discontinue therapy.
- Monitor renal function periodically during therapy.
Potential Nursing DiagnosesRisk for infection (Indications)
- Oral: Administer with food or milk to minimize GI irritation, to delay and increase absorption, to increase peak concentration, and to prolong duration of therapeutic concentration in the urine.
- Do not crush tablets or open capsules.
- Administer liquid preparations with calibrated measuring device. Shake well before administration. Oral suspension may be mixed with water, milk, fruit juices, or infant formula. Rinse mouth with water after administration of oral suspension to avoid staining teeth.
- Instruct patient to take medication around the clock, as directed. Take missed doses as soon as remembered and space next dose 2–4 hr apart. Do not skip or double up on missed doses.
- May cause dizziness or drowsiness. Caution patient to avoid driving or other activities requiring alertness until response to medication is known.
- Inform patient that medication may cause a rust-yellow to brown discoloration of urine, which is not significant.
- Advise patient to notify health care professional if fever, chills, cough, chest pain, dyspnea, skin rash, numbness or tingling of the fingers or toes, or intolerable GI upset occurs. Signs of superinfection (milky, foul-smelling urine; perineal irritation; dysuria) should also be reported.
- 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 consult health care professional if no improvement is seen within a few days after initiation of therapy.
- Resolution of the signs and symptoms of infection. Therapy should be continued for a minimum of 7 days and for at least 3 days after the urine has become sterile.
- Decrease in the frequency of infections in chronic suppressive therapy.