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Nitrofurantoin

Brand names: Macrobid, Macrodantin

Nitrofurantoin is an antibiotic that treats and prevents bladder infections. It concentrates in the urine.

Brand namesMacrobid, Macrodantin
Type of medicineUrinary antibiotic
Prescription?Prescription
ImportantThis page is general information, not a prescription. Don't start, stop, or change a medicine without talking to your provider or pharmacist.

Overview

It works for bladder infections but not for kidney infections.

What it's used for

  • Bladder infections (UTIs)
  • Preventing frequent UTIs

How to take it

  • Take it with food or milk.
  • Finish the full course.
  • Your urine may turn dark yellow or brown. That's harmless.

Your dose depends on your health and other medicines. Always follow your prescription label, and ask your pharmacist if anything is unclear.

Side effects

Common side effects

  • Nausea
  • Headache
  • Gas
Call 911Sudden fever, chills, cough, chest pain, or shortness of breath
Call your provider todayNumbness, tingling, or burning in hands or feet
Call your provider todayYellow skin or eyes
Call your provider todayFever, back pain, or vomiting (possible kidney infection)
Call your provider todaySevere watery or bloody diarrhea, even weeks after finishing (possible C. diff infection)

Warnings

  • Not used with significant kidney disease.
  • Long-term use can rarely cause lung or liver problems.

Other medicines, foods, and alcohol

  • Magnesium antacids lower absorption.

Tell your provider and pharmacist about every medicine, vitamin, and supplement you take.

Pregnancy and breastfeeding

Sometimes used in pregnancy, but avoided near delivery. Talk with your provider.

Missed doses, overdose, and storage

If you miss a dose

Take it as soon as you remember. If it's almost time for the next dose, skip the missed one. Don't double up, and still finish the full course.

If someone takes too much

Call Poison Control at 1-800-222-1222 or get help online at poison.org. Call 911 if the person collapses, has a seizure, has trouble breathing, or can't be woken.

Storing it

Store at room temperature, away from heat and moisture (not in the bathroom), and out of reach of children and pets.

Conditions it's used for

Sources

Last updated 2026-11-13.