Nitrofurantoin is an antibiotic medication commonly used to treat urinary tract infections. There are a few different synonymous terms for this medication, including Macrodantin, Macrobid, Furadantin, and Nifuran. Macrodantin and Macrobid are brand name versions of nitrofurantoin, while Furadantin and Nifuran are generic names for the drug. Regardless of the name under which it is sold, nitrofurantoin works by inhibiting bacterial enzyme activity, ultimately leading to the death of the harmful bacteria causing an infection. While it is generally well-tolerated, some individuals may experience mild side effects such as nausea or diarrhea while taking nitrofurantoin.