Fluconazole: uses, interactions and precautions

Fluconazole is an antifungal medicine in the azole family. According to MedlinePlus, it stops the growth of fungi that cause some infections. It requires a prescription and comes as tablets, an oral liquid and an injection used in the hospital.

Many people search for it as "the fungus pill." That phrase lumps together very different infections (vaginal, mouth, skin and nails), and fluconazole is not the answer for all of them. Below we explain when it is used and when another option is better.

According to MedlinePlus and the FDA label published on DailyMed, fluconazole is used to treat infections caused by fungi, including:

If you have itching, burning and a thick white discharge, it may be a vaginal yeast infection. According to the CDC, a single oral dose of fluconazole is one option, and vaginal creams and suppositories (such as clotrimazole or miconazole) are the other. Neither is "better" for everyone: it depends on your case, your other medicines and whether you could be pregnant.

If symptoms are severe, if you have had three or more infections in a year, if you have diabetes or weakened defenses, or if previous treatment did not work, the doctor may consider a complicated or recurrent infection. For recurrent infections, the CDC describes maintenance treatment with weekly fluconazole for 6 months, decided with your doctor.

Before treating yourself, keep in mind that not every discharge is yeast. Bacterial vaginosis, sexually transmitted infections and other causes give similar symptoms and do not improve with an antifungal. See vaginal discharge to learn how to tell them apart.

Fungal infections of the skin (ringworm), feet (athlete's foot) and groin are usually treated first with antifungal creams or lotions applied to the skin. See fungal skin infections and athlete's foot.

Using oral fluconazole for skin or nail fungus is not one of the indications on its FDA label; when it is used, it is an individual medical decision (off-label use). Nail fungus also takes a long time to improve: a healthy nail grows slowly and treatment can last months. If your skin infection is widespread, does not improve with cream, keeps coming back, or you have diabetes, the doctor evaluates you and explains your options.

Fluconazole interacts with many medicines because it changes how the liver processes others. Before taking it, tell the doctor and the pharmacist everything you take, including supplements. According to the FDA label and MedlinePlus, these are the most important precautions:

According to MedlinePlus, the most common effects are headache, dizziness, nausea, stomach pain, diarrhea, heartburn and changes in taste. They are usually mild.

Rare but serious: liver damage (yellow skin or eyes, dark urine, pain in the upper right abdomen), severe skin reactions (a spreading rash, blisters or peeling skin), irregular heartbeat and allergic reactions (swelling of the face or throat). If you have these, stop the medicine and get urgent care.

Pregnancy. For vaginal yeast infections, the CDC recommends only 7-day vaginal treatments during pregnancy, not the pill. The FDA label and MedlinePlus warn of a risk to the baby, especially with high, repeated doses in the first trimester. If you could be pregnant, take a test and tell the doctor before taking fluconazole.

Breastfeeding. If you are breastfeeding, tell the doctor: she reviews the benefits and risks with you before deciding.

Children. Fluconazole is also used in children for some fungal infections, but the decision and dose depend on age and weight. In video visits, patients under 21 are seen with a parent or guardian on camera.

If you take fluconazole and have any of these signs, stop taking it and call 911 or go to the emergency room. See when to go to the ER.