Fluconazole is an antifungal medicine used to treat infections caused by fungus, which can invade any part of the body including the mouth, throat, esophagus, lungs, bladder, genital area, and the blood. It belongs to a class of drugs called azole antifungals and works by stopping the growth of certain types of fungus. Fluconazole is also used to prevent fungal infection in people who have a weak immune system due to cancer treatment, bone marrow transplant, or diseases such as AIDS. Additionally, it is used to treat a certain type of meningitis in people with HIV or AIDS. Common side effects include nausea, stomach pain, diarrhea, headache, and changes in taste perception.