nitrofurantoin, Macrodantin, Furadantin, Macrobid

Pharmacy Author:
Medical and Pharmacy Editor:
Medical and Pharmacy Editor:

GENERIC NAME: nitrofurantoin

BRAND NAMES: Macrodantin, Furadantin, Macrobid

DRUG CLASS AND MECHANISM: Nitrofurantoin is an antibiotic that is used for treating urinary tract infections caused by several types of bacteria. It is effective against E. Coli, Enterobacter cystitis, Enterococcus, Klebsiella, and Staphylococcus aureus. Nitrofurantoin interferes with the production of bacterial proteins, DNA, and cell walls. Bacteria cannot survive without a cell wall or multiply without DNA.

Three forms of nitrofurnatoin are available:

  • Furadantin, a microcrystalline form,
  • Macrodantin, a macrocrystalline, and
  • Macrobid, a sustained release form of macrocrystalline used twice daily.

The macrocrystalline form is more slowly absorbed than the microcrystalline form and is useful for patients who cannot tolerate the microcrystalline form. The FDA approved nitrofurantoin in 1953.

PRESCRIPTION: Yes

GENERIC AVAILABLE: Yes

PREPARATIONS: Capsules: 25, 50, 75, and 100 mg. Oral suspension: 25 mg/5 ml.

STORAGE: All formulations should be kept at room temperature, 15 C TO 30 C (59 F to 86 F).

PRESCRIBED FOR: Nitrofurantoin is used to treat or prevent urinary tract infections.

DOSING: The recommended adult dose for treating urinary tract infections is 50-100 mg 4 times daily (Macrodantin, Furadantin) or 100 mg every 12 hours (Macrobid) for 7 days or for 3 days after obtaining sterile urine.

Medically Reviewed by a Doctor on 10/22/2014



Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

Pill Finder Tool

Need help identifying pills and medications?
Use the pill identifier tool on RxList.


Back to Medications Index