Short description Nizoral (Ketoconazole) is an imidazole antifungal agent used to treat infections. It is like an antibiotic but is used to treat fungal infections. Nizoral is used to treat yeast infections of the mouth, throat, and esophagus fungal infections throughout the whole body and serious fungal infections of the skin and nails. Nizoral may also be used for purposes other than those listed in this medication guide.