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Overview: Fluconazole is used to treat certain fungal infections. It stops the fungus from growing. Common side effects include diarrhea, stomach pain, and headache. Serious side effects are rare, but can include skin reactions and liver damage. Contact your healthcare provider right away if you develop a rash. Fluconazole comes as a tablet, oral liquid, and injection.

Uses

What is fluconazole used for?

Fluconazole is commonly used to treat certain fungal infections, such as candidiasis (including vaginal yeast infections or oral thrush) or a more serious infection called cryptococcal meningitis. Fluconazole may also be used to prevent certain fungal infections in people who have weakened immune systems.

Fluconazole may not be appropriate for some of the infections listed above, depending on which germs are causing the infection. Yeast and fungi in some locations may have developed resistance to fluconazole, which will make it not work as well.

Fluconazole may also be used for other conditions as determined by your healthcare provider.

How does fluconazole work (mechanism of action)?

Fluconazole is an antifungal medicine that stops the growth of the fungus causing infection.

How is fluconazole supplied (dosage forms)?

Brand and other names

  • Diflucan

Dosage forms and strengths

  • 10 mg/mL, 40 mg/mL oral suspension
  • 50 mg, 100 mg, 150 mg, 200 mg oral tablets

Fluconazole is also available in injectable forms.

How should I store fluconazole?

Oral Tablet. Store fluconazole tablets below 86 F (30 C).

Oral Liquid. Store fluconazole oral liquid between 41 F and 86 F (5 C to 30 C). Throw away any unused liquid two weeks after opening. Do not freeze.

Injectable Liquid. Fluconazole injection is usually given by a healthcare provider in a hospital or clinic. You will not store it at home.

Side Effects

What are the most common side effects of fluconazole?

The most common side effects of fluconazole are listed below. Tell your healthcare provider if you have any of these side effects that bother you.

  • Nausea, vomiting, or diarrhea
  • Stomach pain or upset stomach
  • Rash
  • Headache
  • Dizziness
  • Change in the way food tastes

There may be other side effects of fluconazole that are not listed here. Contact your healthcare provider if you think you are having a side effect of a medicine. In the U.S., you can report side effects to the FDA at www.fda.gov/medwatch or by calling 800-FDA-1088. In Canada, you can report side effects to Health Canada at www.health.gc.ca/medeffect or by calling 866-234-2345.

What are the serious side effects of fluconazole?

While less common, the most serious side effects of fluconazole are described below, along with what to do if they happen.

Severe Allergic Reactions. Fluconazole may cause allergic reactions, which can be serious. Stop taking fluconazole and get help right away if you have any of the following symptoms of a serious allergic reaction.

  • Breathing problems or wheezing
  • Racing heart
  • Fever or general ill feeling
  • Swollen lymph nodes
  • Swelling of the face, lips, mouth, tongue, or throat
  • Trouble swallowing or throat tightness
  • Itching, skin rash, or pale red bumps on the skin called hives
  • Nausea or vomiting
  • Dizziness, feeling lightheaded or fainting
  • Stomach cramps
  • Joint pain

Liver Damage. Liver damage, also called hepatotoxicity, can happen when taking fluconazole. This can be serious or life-threatening. Call your healthcare provider right away if you have any of the following symptoms of liver damage.

  • Nausea or vomiting
  • Stomach or belly pain
  • Fever
  • Weakness or unusual tiredness
  • Itching
  • Loss of appetite
  • Light-colored poop
  • Dark-colored urine (pee)
  • Your skin or the whites of your eyes turning yellowish in color (also called jaundice)

Severe Skin Reactions. Fluconazole can cause severe skin reactions, called Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN), that can lead to death if not treated. If you develop a rash, stop fluconazole and call your healthcare provider right away. Get emergency help right away if you have any of the following symptoms of SJS or TEN.

  • Painful red or purple skin that looks burned and peels off
  • Flat red rash or blisters on your skin, mouth, nose, and genitals
  • Red, painful, watery eyes

Heart Rhythm Changes. Fluconazole may cause a rare, dangerous heart rhythm problem called QT prolongation and torsade de pointes. Some people have a higher risk of this, including people who are older, have other people in their family who have had these conditions, have low potassium or magnesium levels, or take some medicines for other heart rhythm problems. Tell your healthcare provider right away if you faint or have changes in your heart rate or rhythm, such as a fast or skipping heartbeat.

Reduced Adrenal Function. Fluconazole can cause your body’s adrenal glands to stop making as much cortisol (the stress hormone). This is known as adrenal insufficiency. Adrenal insufficiency can get worse if your body is under stress because of fever, surgery, or trauma. Tell your healthcare provider if you have any of the following symptoms of adrenal insufficiency.

  • Nausea and vomiting
  • Weakness, tiredness, or lack of energy
  • Low blood pressure

Warnings & Precautions

Who should not use fluconazole?

Allergies to Ingredients. People who are allergic to any of the following should not take fluconazole.

  • Diflucan
  • Fluconazole
  • Any of the ingredients in the specific product dispensed

Your pharmacist can tell you all of the ingredients in the specific fluconazole products they stock.

Drug Interactions. Fluconazole should not be taken while you are using certain other medicines. Before taking fluconazole, tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. See the Interactions section for more details.

What should I know about fluconazole before using it?

Do not take fluconazole unless it has been prescribed to you by a healthcare provider. Take it as prescribed.

Do not share fluconazole with other people, even if they have the same condition as you. It may harm them.

Keep fluconazole out of the reach of children.

Fluconazole may cause dizziness. Do not drive or do other activities that require alertness or coordination until you know how fluconazole affects you.

If you are prescribed liquid fluconazole, use an accurate measuring device to measure your dose. A household spoon is not an accurate measuring device and may cause you to take the wrong dose. Ask your pharmacist to recommend an appropriate measuring device.

What should I tell my healthcare provider before using fluconazole?

Tell your healthcare provider about all of your health conditions and any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using. This will help them determine if fluconazole is right for you.

In particular, make sure that you discuss any of the following.

Current and Past Health Conditions. Tell your healthcare provider if you have any of the following.

  • Kidney or liver problems
  • Heart problems, including arrhythmias
  • Cancer
  • HIV or AIDS
  • Trouble digesting certain sugars (fluconazole oral liquid)
  • Low potassium levels (also called hypokalemia)

Pregnancy. Fluconazole may cause harm to an unborn baby. Tell your healthcare provider if you are or plan to become pregnant. Talk to your healthcare provider about your birth control options.

Breastfeeding. Fluconazole passes into breast milk. Tell your healthcare provider if you are breastfeeding or plan to breastfeed. Your healthcare provider will advise you if you should take fluconazole while breastfeeding.

Interactions

Does fluconazole interact with foods or drinks?

There are no known interactions between fluconazole and foods or drinks.

It is unknown if drinking alcohol will affect fluconazole, but the risk of dizziness may be increased if you drink alcohol while taking itraconazole.

Does fluconazole interact with other medicines (drug interactions)?

Fluconazole interacts with many other medicines. Always tell your healthcare provider about any prescription or over-the-counter (OTC) medicines, vitamins/minerals, herbal products, and other supplements you are using.

In particular, make sure that you discuss if you are using any of the following before taking fluconazole.

  • Erythromycin (Ery-Tab and others), which is a medicine used for bacterial infections
  • Medicines that can cause QT prolongation, which is a potentially dangerous heart rhythm problem, such as pimozide or quinidine
  • Amiodarone (Pacerone and others), which is a medicine used for an irregular heart rhythm
  • A tricyclic antidepressant, such as amitriptyline, nortriptyline, or protriptyline, even if it is not used for depression
  • Lurasidone (Latuda), which is a medicine for certain mental health conditions
  • A medicine for blood pressure, such as losartan, hydrochlorothiazide, amlodipine (Norvasc), verapamil (Verelan, Verelan PM), nifedipine, isradipine, or felodipine
  • A nonsteroidal anti-inflammatory drug (NSAID), such as ibuprofen, naproxen, and others, which is in many prescription and OTC products for pain, swelling, and fever
  • Warfarin, which is a blood thinner
  • Any medicine for treating cancer or cystic fibrosis
  • Cyclosporine (Gengraf, Neoral, Sandimmune, and others), sirolimus, or tacrolimus, which is a medicine that suppresses your immune system
  • An opioid, such as fentanyl or methadone, which is a medicine used for certain types of pain
  • A statin, such as atorvastatin (Lipitor and others), fluvastatin, lovastatin, simvastatin, or rosuvastatin (Crestor), which is a medicine to lower cholesterol
  • A medicine for seizures, such as carbamazepine or phenytoin (Dilantin, Phenytek, and others)
  • Rifabutin (Mycobutin), which is a medicine used to prevent Mycobacterium avium complex infection
  • Rifampin, which is a medicine commonly used to treat an infection called tuberculosis
  • Voriconazole (Vfend), which is a medicine used for fungal infections
  • A medicine for diabetes, such as glipizide or glyburide
  • Theophylline (Theo-24, Elixophyllin), which is a medicine for asthma or certain other breathing problems
  • Lemborexant (Dayvigo), which is a medicine used for trouble sleeping
  • A medicine for HIV or AIDS
  • Tofactinib (Xeljanz), which is a medicine used for certain inflammatory conditions, such as rheumatoid arthritis
  • Abrocitinib (Cibinqo), which is a medicine used to treat atopic dermatitis or eczema
  • Tolvaptan (Samsca, Jynarque), which is used for low sodium levels

Fluconazole may alter the blood levels of many other medicines, and vice versa. Tell your healthcare provider about all medicines that you take or have recently taken.

This may not be a complete list of medicines that can interact with fluconazole. Always check with your healthcare provider.

Does interact with other drugs you are taking?

Enter your medication into the WebMD interaction checker

Overdose/Missed Dose

What should I do if I accidentally use too much fluconazole?

If you or someone else has used too much fluconazole, get medical help right away, call 911, or contact a Poison Control center at 800-222-1222.

What should I do if I miss a dose of fluconazole?

It is important to complete your prescribed course of fluconazole, even if your symptoms get better or go away. This will reduce the risk that future infections are resistant to fluconazole or other similar medicines.

If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and only take the next dose. Do not take double or extra doses.