Ketoconazole may also be used for purposes other than those listed in this medication guide, Nizoral (Ketoconazole) is an antifungal medication. You may not be able to take ketoconazole, or you may require a dosage adjustment, special monitoring, or special directions for use during your treatment Ketoconazole 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