Known brand names include Diflucan.
An antifungal tablet or liquid for yeast infections of the vagina, mouth, throat, and esophagus, and for cryptococcal meningitis, a fungal infection around the brain and spinal cord. It interacts with many other drugs and can rarely cause liver injury or a dangerous heart rhythm.
Fluconazole blocks a fungal enzyme that turns lanosterol into ergosterol, a normal sterol in the fungal cell. As ergosterol runs short, unusual sterols pile up inside the fungus. This slows or stops the fungus from growing rather than killing it outright. The matching enzyme in human cells is far less sensitive to the drug.
Nearly all of a dose is absorbed by mouth, the blood level peaks within 1 to 2 hours, and the drug reaches body fluids and tissues such as spinal fluid, saliva, and the vagina. Half of it leaves the body in about 30 hours, so it is taken once a day, and a double first dose brings levels up faster. The kidneys clear most of it unchanged, so weak kidneys let it build up. It also slows enzymes that break down many other medicines, which explains its many drug interactions, and it can lengthen the heart's QT interval and trigger a dangerous rhythm.
Fluconazole treats yeast infections caused by Candida, including vaginal yeast infections and yeast infections of the mouth, throat, and esophagus, the tube that carries food to the stomach. It also treats cryptococcal meningitis, a fungal infection of the membranes that cover the brain and spinal cord. In people getting chemotherapy or radiation before a bone marrow transplant, it lowers the chance of a yeast infection. Its job is to clear the fungus and, for some infections, keep it from coming back.
It comes as a tablet or a liquid taken by mouth, with or without food, and a vaginal yeast infection is treated with a single dose. Other infections need daily doses for weeks, and people with AIDS may keep taking it to stop cryptococcal meningitis or thrush in the mouth from returning. Children 6 months and older can take it for yeast infections of the mouth and esophagus. It must not be combined with certain drugs that affect heart rhythm, such as erythromycin, pimozide, and quinidine.
Headache, nausea, stomach pain, diarrhea, and a changed sense of taste are the most common complaints. The label treats rare but serious liver damage, sometimes fatal, as a key risk, along with severe allergic reactions and peeling skin rashes. It also warns about a lengthened QT interval and a dangerous heart rhythm called torsade de pointes, especially alongside other drugs that affect heart rhythm, and about harm to an unborn baby with high doses early in pregnancy. Dizziness, seizures, low potassium, and reversible adrenal gland problems can also occur.