What is fluconazole?

Fluconazole is a prescription azole antifungal medication that may be used to treat serious fungal or yeast infections including those that affect the vagina, mouth or throat, lungs, bladder, or blood. It is available as an oral tablet, suspension, or injectable form.

• Examples of conditions treated by fluconazole include vaginal candidiasis, oropharyngeal candidiasis, esophageal candidiasis, and cryptococcal meningitis.

Fluconazole may also be used to prevent fungal infections in people with a weak immune system caused by cancer or cancer treatment including radiation therapy, bone marrow transplant, conditions such as AIDS, or children on life support (extracorporeal membrane oxygenation [ECMO]).

Fluconazole works by targeting a key enzyme (lanosterol 14-alpha-demethylase) responsible for building a crucial cell wall component (ergosterol) in fungi. By blocking this enzyme, Fluconazole prevents the fungus from forming a normal cell wall, leading to the buildup of abnormal sterols. These abnormal sterols weaken the fungal cell wall, hindering its growth. Fluconazole's mechanism of action means it has a much greater effect on this enzyme in fungi compared to the same enzyme in human cells. This selectivity helps minimize side effects.

What is fluconazole used for?

Fluconazole may be used to treat:

• Vaginal candidiasis (vaginal yeast infections due to Candida)
• Oropharyngeal and esophageal candidiasis
• Candida urinary tract infections and peritonitis
• Systemic Candida infections including candidemia, disseminated candidiasis, and pneumonia
• Cryptococcal meningitis.

Fluconazole may be used to prevent:

• Candidiasis in patients undergoing bone marrow transplantation who receive cytotoxic chemotherapy and/or radiation therapy
• Fungal infections in people with a weak immune system caused by cancer or cancer treatment including radiation therapy, conditions such as AIDS, or children on life support (extracorporeal membrane oxygenation [ECMO]).

It is recommended swabs or specimens for fungal culture and other laboratory tests be conducted before starting treatment with fluconazole; however, therapy may be started before the results of the cultures and other laboratory studies are known so long as anti-infective therapy is adjusted accordingly.

Fluconazole side effects

The most common side effects of fluconazole are:

• headache
• diarrhea
• nausea or upset stomach
• dizziness
• stomach pain
• changes in the way food tastes.

Serious side effects and warnings

Fluconazole can cause serious side effects including the following.

Allergic reactions to fluconazole. These are rare, but they can be serious and may include anaphylaxis. If you cannot reach your doctor, go to the nearest hospital emergency room. Signs of an allergic reaction can include shortness of breath; coughing; wheezing; fever; chills; throbbing of the heart or ears; swelling of the eyelids, face, mouth, neck, or any other part of the body; or skin rash, hives, blisters or skin peeling. 

Liver injury. Fluconazole has been associated with rare cases of serious liver toxicity, including death primarily in patients with serious underlying medical conditions including pre-existing liver disease. In some cases, there was no obvious relationship to the total daily dose, duration of therapy, sex, or patient age. Fluconazole liver toxicity has usually, but not always, been reversible once treatment has stopped. Tell your healthcare provider if you experience signs of liver problems which may include loss of appetite, stomach pain (upper right side), tiredness, itching, dark urine, clay-colored stools, or jaundice (yellowing of the skin or eyes).

Skin conditions, including exfoliative skin disorders that have resulted in death in patients with serious underlying diseases, have been reported. Patients with deep-seated fungal infections who develop rashes during treatment with fluconazole should be monitored closely by a healthcare provider. Tell your doctor right away if you get a skin rash or lesions while taking fluconazole.

Cases of reversible adrenal insufficiency have been reported with fluconazole. Tell your doctor if you experience chronic, or long-lasting fatigue, muscle weakness, loss of appetite, weight loss, or abdominal pain.

Fluconazole may harm an unborn baby.

This is not a complete list of side effects and others may occur.

What should I avoid while using fluconazole?

Avoid driving or hazardous activity until you know how fluconazole will affect you. Your reactions could be impaired.

Do not use fluconazole for a condition for which it was not prescribed.

Do not give fluconazole to other people, even if they have the same symptoms you have. It may harm them.

Many medications interact with fluconazole. Ask your doctor if your medication interacts.

Disclaimer: Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.