Fluconazole (Diflucan) is a generic prescription medication used to treat certain fungal infections in some adults and children ages 6 months and older. Specifically, fluconazole is used to treat the following infections:

In certain situations, fluconazole is also used to help prevent yeast infections in people who have had bone marrow transplants. This is because their immune system may be weakened, which can make them more likely to develop an infection.

Fluconazole comes as an oral tablet. Fluconazole also comes in other forms, including an injectable and an oral suspension. However, this article does not cover them.

Fluconazole is typically a short-term treatment option for people with fungal infections. However, if you’re taking fluconazole to help prevent a yeast infection, your doctor may recommend taking the drug long term.

As with other drugs, fluconazole can cause side effects. Read on to learn about potential common, mild, and serious side effects (also called adverse effects). For a general overview of fluconazole, including details about its uses, refer to this article. Your doctor can also tell you more about fluconazole.

Fluconazole can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

These are just a few of the more common side effects reported by people who took fluconazole in clinical trials:

* For more information about this side effect, see “Fluconazole: Side effect specifics” below.

Mild side effects can occur with fluconazole. This list doesn’t include all possible mild side effects of the drug. For more information, you can refer to fluconazole’s prescribing information.

Mild side effects that have been reported with fluconazole include:

These side effects may be temporary, lasting a few days to weeks. However, if the side effects last longer than that, bother you, or become severe, be sure to talk with your doctor or pharmacist.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you develop a side effect while taking fluconazole and want to tell the FDA about it, visit MedWatch.

* For more information about this side effect, see “Fluconazole: Side effect specifics” below.

Fluconazole may cause serious side effects. Though serious side effects weren’t common, they can occur. The list below may not include all possible serious side effects of the drug. For more information, you can refer to fluconazole’s prescribing information.

If you develop serious side effects while taking fluconazole, call your doctor right away. If the side effects seem life threatening or you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Serious side effects that have been reported and their symptoms include:

* For more information about this side effect, see the “Fluconazole: Side effect specifics” section below.

It’s possible that the tablet strength of fluconazole that you take may affect the side effects that you experience. People taking a higher strength of fluconazole may be at an increased risk of side effects. This is because when you take a higher dose of medication, your body is exposed to more of the drug. And being exposed to more of the drug increases your risk of side effects occurring.

If you have questions about side effects that you may experience from fluconazole, talk with your doctor before starting treatment.

Fluconazole may cause several side effects. Here are some frequently asked questions about the drug’s side effects and their answers.

Could I have long-term side effects from taking fluconazole?

Although rare, it’s possible to develop long-term side effects from taking fluconazole. Long-term side effects that have been reported with fluconazole include:

  • liver problems
  • heart rhythm problems

If you’re concerned about developing long-term side effects from taking fluconazole, talk with your doctor or pharmacist. In many cases, this drug is used for only a short time, so you may be at a lower risk of side effects in this case. Your doctor can help determine the best treatment plan for you.

What are the most common side effects of taking one dose of fluconazole 150 mg?

Doctors commonly prescribe a fluconazole 150-milligram (mg) tablet as a single dose to treat a vaginal yeast infection. In clinical trials for this dose and use, the most commonly reported side effects were headache, nausea, and abdominal pain. If they occur, these side effects are typically mild to moderate in severity. Other side effects are possible, though they aren’t common.

If you are taking one dose of fluconazole and have questions about side effects, talk with your doctor or pharmacist.

Learn more about some of the side effects that fluconazole may cause. To find out how often side effects occurred in clinical trials, see the prescribing information for fluconazole.

Skin rash

It’s possible to develop a skin rash during your treatment with fluconazole. Although a skin rash was not one of the most common side effects reported in clinical trials, it may occur. Skin rashes may occur more often in older adults (adults ages 65 years and older) compared with younger people.

In some cases, a skin rash can be serious or even life threatening. Symptoms of a serious skin rash can include:

  • fever
  • peeling of the skin
  • soreness of the mouth or throat
  • fatigue
  • blistering of the skin

What you can do

In some cases, a skin rash can also be a symptom of an allergic reaction. So your doctor may want to make sure that you’re not having an allergic reaction or a serious skin reaction to the drug.

If you develop a skin rash during your treatment with fluconazole, talk with your doctor. They can determine how serious your rash may be and the best way to treat it.

Sometimes, they may recommend that you stop taking fluconazole and try a different medication for your condition. Other times, they may monitor your skin rash to be sure that it doesn’t worsen.

Nausea

You may experience nausea during your treatment with fluconazole. Nausea was one of the most common side effects reported in clinical trials of fluconazole.

What you can do

If you experience nausea from taking fluconazole, talk with your doctor or pharmacist. In rare cases, nausea can also be related to other side effects of fluconazole, such as liver or kidney problems.

Your doctor can help determine what may be causing your nausea and the best ways to treat it. In some cases, taking a medication with food may decrease nausea that you experience. Your doctor or pharmacist may also be able to recommend other ways to decrease your nausea.

Feeling dizzy

You may develop dizziness during your treatment with fluconazole. Though dizziness wasn’t a common side effect reported in clinical trials of fluconazole, it can occur.

What you can do

Due to the risk of dizziness, your doctor may recommend that you avoid driving or operating heavy machinery until you know how fluconazole may affect you.

In addition, it’s possible for dizziness to be related to rare, serious heart rhythm changes, such as long QT syndrome, that can occur in people taking fluconazole.

Talk with your doctor if you experience dizziness. They can determine what may be causing your dizziness and the best way to treat it.

Liver-related side effects

It’s possible to develop liver-related side effects from taking fluconazole. Although they were not common in clinical trials of fluconazole, liver side effects are possible.

You should be aware of the symptoms of liver conditions, so that you can contact a doctor right away if you develop any. Symptoms may include:

What you can do

If you develop symptoms of liver problems during your treatment with fluconazole, tell your doctor right away. They can do blood tests to check your liver health.

If you develop liver-related side effects from taking fluconazole, your doctor may recommend that you stop treatment with fluconazole. In many cases, stopping fluconazole can reverse any liver damage that occurred due to the drug. Your doctor can help determine the best treatment plan for you if you develop liver problems.

Diarrhea

You may experience diarrhea from taking fluconazole. In clinical trials, this side effect was slightly more common in children and older adults (adults ages 65 years and older) taking fluconazole. However, it is possible for anyone taking this drug to experience diarrhea.

What you can do

If you develop diarrhea during your treatment with fluconazole, talk with your doctor or pharmacist. They may be able to recommend ways to decrease the diarrhea that you experience. For example, your doctor or pharmacist may recommend taking an over-the-counter medication to treat your diarrhea.

Allergic reaction

As with most drugs, fluconazole can cause an allergic reaction in some people. It isn’t clear how often allergic reaction occurred in the drug’s clinical trials.

Symptoms can be mild or serious and can include:

  • skin rash
  • itching
  • flushing
  • swelling under your skin, typically in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What you can do

For mild symptoms of an allergic reaction, call your doctor right away. They may recommend ways to ease your symptoms and determine whether you should keep taking fluconazole. However, if your symptoms are serious and you think you’re having a medical emergency, immediately call 911 or your local emergency number.

Be sure to talk with your doctor about your health history before you take fluconazole. This drug may not be the right treatment option for you if you have certain medical conditions or other factors that affect your health. These are known as drug-condition or drug-factor interactions. The conditions and factors to consider include:

Heart problems. Tell your doctor if you have any heart or heart rhythm conditions, such as atrial fibrillation, before starting treatment with fluconazole. This medication can increase your risk of an irregular heart rhythm. If you already have a heart condition, taking fluconazole may make your condition worse. In this case, your doctor can help determine whether it’s safe for you to take fluconazole.

Kidney problems. The kidneys are important for clearing fluconazole out of your body. In people with kidney problems, such as chronic kidney disease, your body may take longer to clear this drug than is typical. This increases the risk of side effects. Be sure to tell your doctor about any kidney problems that you have before starting fluconazole. Depending on your kidney function, they may prescribe you a lower dosage of this medication.

Allergic reaction. If you’ve had an allergic reaction to fluconazole or any of its ingredients, your doctor will likely not prescribe fluconazole. Taking fluconazole could cause you to have another allergic reaction. Ask your doctor what other medications may be better options for you.

Liver problems. If you have liver problems, tell your doctor before taking fluconazole. This medication may increase your risk of liver problems occurring. It’s possible that fluconazole can make liver conditions that you already have even worse. In this case, your doctor can help determine whether fluconazole may be safe for you.

Alcohol with fluconazole

There aren’t any known interactions between fluconazole and alcohol. However, drinking alcohol while taking fluconazole may increase your risk of side effects from the drug. For example, both alcohol and fluconazole can cause dizziness, nausea, vomiting, and liver problems.

Consuming alcohol and taking fluconazole can increase your risk of side effects. If you’d like to drink alcohol while taking fluconazole, talk with your doctor about alcohol interactions to find out whether it may be safe for you.

Pregnancy and breastfeeding while taking fluconazole

Fluconazole is not safe to take during pregnancy. While the manufacturer of fluconazole recommends that caution be used when taking fluconazole while breastfeeding, most doctors agree that fluconazole is safe to take while breastfeeding.

In clinical trials, congenital anomalies (also known as birth defects) were reported in people who took the drug during pregnancy. Due to this risk, doctors may recommend you use birth control if you can become pregnant and you’re taking fluconazole, especially if you’re taking fluconazole for a long period of time.

Because of this risk, it’s only recommended to take fluconazole during pregnancy to treat serious infections. Your doctor can help determine whether another medication may be a safer treatment option for you during pregnancy.

In addition, fluconazole is known to pass into breast milk, so a child who is breastfed will be exposed to the drug. A small clinical trial showed that children who were breastfed didn’t experience any serious side effects when exposed to the drug.

If you’re pregnant or planning to become pregnant, talk with your doctor. You should also talk with them if you’re breastfeeding or considering it. Your doctor can help determine whether another medication may be a safer treatment option for you.

In most cases, side effects of fluconazole are mild. However, it’s possible to experience serious side effects from this drug as well. If you’d like to learn more about fluconazole, talk with your doctor or pharmacist. They can help answer any questions you have about side effects from taking the drug.

Referring to the following articles about fluconazole can provide you with additional information:

  • More information about fluconazole. For details about other aspects of fluconazole, refer to this article.
  • Cost. If you’d like to learn about fluconazole and cost, see this article.

Disclaimer: Medical News Today has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.