Fluconazole (Diflucan) is used to prevent and treat a variety of fungal and yeast infections. It belongs to a class of drugs called azole antifungals. It's used to treat infections caused by different kinds of fungus. It can also be used to stop you getting a candida infection. It works by killing the fungus (or yeast) that's causing the infection. infections, including vaginal candidiasis, oropharyngeal candidiasis (thrush, oral thrush), esophageal candidiasis (candida esophagitis), other candida infections (including urinary tract infections, peritonitis [inflammation of the lining of the stomach], and ...