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Nitrofurantoin Dosage

Medically reviewed by Drugs.com. Last updated on Jul 2, 2019.

Applies to the following strengths: macrocrystals 50 mg; macrocrystals 100 mg; macrocrystals 25 mg; macrocrystals-monohydrate 100 mg; 25 mg/5 mL; macrocrystals

Usual Adult Dose for:

Usual Pediatric Dose for:

Additional dosage information:

Usual Adult Dose for Cystitis

Regular release: 50 to 100 mg orally 4 times a day for 1 week or for at least 3 days after urine sterility is obtained
Dual release: 100 mg orally twice a day for 7 days

Comment:
-This drug should be given with food to improve drug absorption and, in some patients, tolerance.

Use: Cystitis

Usual Adult Dose for Cystitis Prophylaxis

Regular release: 50 to 100 mg orally once a day at bedtime

Comments:
-This drug should be given with food to improve drug absorption and, in some patients, tolerance.
-Patients receiving long-term therapy should be monitored periodically for changes in renal function.

Use: Cystitis prophylaxis

Usual Pediatric Dose for Cystitis

Regular release:
1 month or older: 5 to 7 mg/kg/day (up to 400 mg/day) orally in 4 divided doses for 1 week or for at least 3 days after urine sterility is obtained

Dual release:
Greater than 12 years: 100 mg orally twice a day for 7 days for 1 week or for at least 3 days after urine sterility is obtained

Comment:
-This drug should be given with food to improve drug absorption and, in some patients, tolerance.

Use: Cystitis

Usual Pediatric Dose for Cystitis Prophylaxis

Regular release:
1 month or older: Doses as low as 1 mg/kg/day (up to 100 mg/day) orally in 1 to 2 divided doses may be adequate

Comments:
-This drug should be given with food to improve drug absorption and, in some patients, tolerance.
-Patients receiving long-term therapy should be monitored periodically for changes in renal function.

Use: Cystitis prophylaxis

Renal Dose Adjustments

-CrCl 60 mL/min or more: No adjustment recommended
-Anuria, oliguria, or significant renal insufficiency (CrCl less than 60 mL/min or significantly elevated creatinine): Contraindicated

Liver Dose Adjustments

This drug undergoes hepatic elimination; a dosage reduction may be necessary for patients with hepatic dysfunction.

Precautions

Safety and efficacy have not been established in patients younger than 1 month.

Consult WARNINGS section for additional precautions.

Dialysis

This drug can be hemodialyzed.

Other Comments

Administration advice:
-This drug should be given with food to improve drug absorption and, in some patients, tolerance.

Monitoring parameters:
-Renal, liver, and pulmonary function (especially if on long term therapy)

General:
-The lowest effective dose should be used for prophylactic or for long-term suppressive therapy.

Patient advice:
-This drug may cause dizziness and drowsiness; avoid driving or operating machinery if you feel drowsy or dizzy.
-Take this drug with food or milk, avoid missing doses, and complete the entire course of therapy.
-Do not use antacid preparations containing magnesium trisilicate while taking this drug.
-This drug may cause a brownish discoloration of the urine.
-Sometimes after starting treatment with antibiotics, patients can develop watery and bloody stools (with or without stomach cramps and fever) even as late as 2 or more months after having taken the last dose of the antibiotic; if this occurs, contact your physician as soon as possible.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

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