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Related to Macrobid: ciprofloxacin, nitrofurantoin


Apo-Nitrofurantoin, Furadantin, Novo-Furantoin

nitrofurantoin macrocrystals

Macrobid, Macrodantin

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.

Adverse reactions

CNS: dizziness, drowsiness, headache, asthenia, peripheral neuropathy, vertigo

CV: chest pain

EENT: nystagmus

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

Patient monitoring

• 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.

Patient teaching

• 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.

McGraw-Hill Nurse's Drug Handbook, 7th Ed. Copyright © 2013 by The McGraw-Hill Companies, Inc. All rights reserved


(nye-troe-fyoor-an-toyn) ,


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Therapeutic: anti infectives
Pregnancy Category: B


Prevention and treatment of urinary tract infections caused by susceptible organisms; not effective in systemic bacterial infections.


Interferes with bacterial enzymes.

Therapeutic effects

Bactericidal or bacteriostatic action against susceptible organisms.
Many gram-negative and some gram-positive organisms, specifically:
  • Citrobacter,
  • Corynebacterium,
  • Enterobacter,
  • Escherichia coli,
  • Klebsiella,
  • Neisseria,
  • Salmonella,
  • Shigella,
  • Staphylococcus aureus,
  • Staphylococcus epidermidis,
  • Enterococcus.


Absorption: Readily absorbed after oral administration. Absorption is slower but more complete with macrocrystals (Macrodantin).
Distribution: Crosses placenta; enters breast milk.
Protein Binding: 40%.
Metabolism and Excretion: Partially metabolized by the liver; 30–50% excreted unchanged by the kidneys.
Half-life: 20 min (↑ in renal impairment).

Time/action profile (urine levels)

POunknown30 min6–12 hr


Contraindicated in: Hypersensitivity;Hypersensitivity to parabens (suspension);Oliguria, anuria, or significant renal impairment (CCr <60 mL/min);History of cholestatic jaundice or hepatic impairment with previous use of nitrofurantoin;Pregnancy near term and infants <1 mo (↑ risk of hemolytic anemia).
Use Cautiously in: genetic implication Glucose–6–phosphate dehydrogenase (G6PD) deficiency (↑ risk of hemolytic anemia, especially in Blacks and Mediterranean and Near-Eastern ethnic groups);Patients with diabetes or debilitated patients (neuropathy may be more common); Obstetric / Safety not established but has been used safely in pregnant women. Lactation: May cause hemolysis in infants with G6PD deficiency who are breast fed; Geriatric: Appears on Beers list; ↑ risk for renal, hepatic, and pulmonary reactions.

Adverse Reactions/Side Effects

Central nervous system

  • dizziness
  • drowsiness
  • headache

Ear, Eye, Nose, Throat

  • nystagmus


  • 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
  • diarrhea


  • rust/brown discoloration of urine


  • photosensitivity


  • blood dyscrasias
  • hemolytic anemia


  • peripheral neuropathy


  • hypersensitivity reactions (most frequent)


Drug-Drug interaction

Probenecid 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.


Oral (Adults) Treatment of active infection—50–100 mg q 6–8 hr or 100 mg q 12 hr as extended-release product. Chronic suppression—50–100 mg single evening dose.
Oral (Children >1 mo) Treatment of active infection—5–7 mg/kg/day divided q 6 hr; maximum dose: 400 mg/day. Chronic suppression—1–2 mg/kg/day as a single dose at bedtime; maximum dose: 100 mg/day (unlabeled).

Availability (generic available)

Oral suspension: 25 mg/5 mL Cost: Generic — $608.68 / 230 mL
Capsules: 25 mg, 50 mg, 100 mg Cost: Generic — 50 mg $199.00 / 100, 100 mg $338.00 / 100
Extended-release capsules: 100 mg Cost: Generic — $320.92 / 100

Nursing implications

Nursing assessment

  • 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 Diagnoses

Risk 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.

Patient/Family Teaching

  • 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.

Evaluation/Desired Outcomes

  • 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.
Drug Guide, © 2015 Farlex and Partners


A brand name for NITROFURANTOIN.
Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005
References in periodicals archive ?
A total of 202 women were randomized to receive Macrobid (nitrofurantoin) 100 mg / day, and 212 received placebo.
The study was funded by grants from the National Institutes of Health and Procter & Gamble, which manufactures Macrobid.
from selling a generic version of its urinary tract infection remedy Macrobid during a time when Mylan had expected to enjoy sole rights to the generic version of the drug.
It was stated that nitrofurantoin (Macrobid) is "generally safe, even during pregnancy." The product labeling, however, states that the drug should be avoided at term (38-42 weeks' gestation), during labor and delivery or when the onset of labor is imminent because of the risk of hemolytic anemia in newborns exposed in utero.
In March Mylan filed suit against Procter & Gamble Pharmaceuticals (P&G) and Watson Pharmaceuticals Inc., alleging that the distribution of the former's Macrobid product as a generic during Mylan's 180-day exclusivity period violates federal law.
and Watson alleging that the distribution of the former's Macrobid as a generic during Mylan's 180-day exclusivity period violates the law.
It offers money-back guarantees to patients who are not satisfied with the results of Macrodantin or Macrobid, drugs for urinary tract infections.