What is nitrofurantoin?

Nitrofurantoin is a prescription drug that comes as an oral capsule and an oral suspension. Nitrofurantoin oral capsule is available as the brand-name drugs Macrobid and Macrodantin. It’s also available as a generic drug. Generic drugs usually cost less than the brand-name version. In some cases, they may not be available in all strengths or forms as the brand-name drug.