Nitrofurantoin is used to treat urinary tract infections. Nitrofurantoin is in a class of medications called antibiotics. It works by killing bacteria that cause infection.
Nitrofurantoin comes as a capsule and a suspension (liquid) to take by mouth. Nitrofurantoin usually is taken with food two or four times a day for at least 7 days. Try to take nitrofurantoin at the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take nitrofurantoin exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.
Summary from MedlinePlus.gov, click for more information.