Fluconazole interactions: A guide to safe usage and precautions

Common medications that interact with fluconazole

Before you start treatment with fluconazole tablets, tell your doctor and pharmacist about all the prescription, over-the-counter (OTC), and other medications you take. By sharing this information with them, you may help prevent possible interactions.

Here’s a table of drugs that can interact with fluconazole:

Note: This table does not include all drugs that may interact with fluconazole. For questions about interactions between fluconazole and drugs not listed here, talk with your doctor or pharmacist.

Here’s a closer look at certain common fluconazole drug interactions:

Certain antidepressants

Antidepressants are often prescribed to treat depression. Doctors may also prescribe them for obsessive-compulsive disorder, anxiety, and nerve pain.

Interaction result: Taking fluconazole with certain antidepressants can increase the risk of side effects of these drugs, including serious heart rhythm problems.

Interaction explained: Both fluconazole and certain antidepressants can cause QT prolongation as a side effect. This is when your heart muscle takes longer than usual to contract and relax. Taking these medications together can further increase your risk of heart rhythm problems. Symptoms of QT prolongation may include dizziness, heart palpitations, and fainting.

In addition, some antidepressants are broken down by an enzyme called CYP3A4. Fluconazole can slow down this enzyme, leading to a higher level of antidepressants in your body. This may increase the risk of side effects from the antidepressant medication.

Examples of antidepressant drugs: Here are some antidepressants that may interact with fluconazole:

• amitriptyline
• nortriptyline
• citalopram (Celexa)
• fluoxetine (Prozac)

Steps you or your doctor may take: Tell your doctor about all the medications you take before starting fluconazole treatment. If you take certain antidepressants, your doctor will likely want to monitor you more closely for side effects. In some cases, they may recommend reducing the antidepressant dose.

Certain diabetes drugs

Diabetes drugs are prescribed to lower blood sugar in people with type 2 diabetes.

Interaction result: Taking fluconazole with certain diabetes drugs can increase the risk of your blood sugar getting too low (hypoglycemia).

Interaction explained: Fluconazole may prevent the body from breaking down some diabetes drugs as it should. This may lead to a higher level of these drugs in your system. A high level of these drugs in your body can increase your risk of dangerously low blood sugar.

Examples of diabetes drugs: Here are some diabetes drugs that may interact with fluconazole:

• glipizide (Glucotrol)
• glyburide (Diabeta)
• glimepiride (Amaryl)

Steps you or your doctor may take: Your doctor may recommend checking your blood sugars more often than usual. Depending on your blood sugars, your doctor may adjust the dose of your diabetes medications.

If you have questions about taking these drugs together, talk with your doctor or pharmacist.

Warfarin

Warfarin is an anticoagulant (commonly called a blood thinner) that is prescribed to treat and help prevent blood clots.

Interaction result: Taking fluconazole with warfarin can increase the risk of bleeding episodes.

Interaction explained: Fluconazole may prevent the body from breaking down warfarin as it should. This can lead to higher warfarin levels in your system, potentially making your blood too thin. You may have an increased risk of bleeding if your blood is too thin. Symptoms may include bruising, nosebleeds, and blood in your urine or stool.

Steps you or your doctor may take: Your doctor will likely want to check your international normalized ratio (INR) more often than usual during treatment with fluconazole. The INR test measures how quickly your blood clots and shows your doctor how well warfarin is working for you. Depending on your test results, your doctor may need to adjust your warfarin dose.

Talk with your doctor or pharmacist if you’d like more information about taking fluconazole with warfarin.

Can you drink alcohol while taking fluconazole?

There are no known interactions between fluconazole and alcohol. But both can be hard on your liver. If you have questions about drinking alcohol while taking fluconazole, talk with your doctor or pharmacist.

Other possible fluconazole interactions

Fluconazole may interact with certain supplements, foods, vaccines, or lab tests.

Fluconazole interactions with supplements

It’s possible for drugs to interact with supplements such as vitamins and herbs.

Vitamins

Fluconazole has been reported to interact with vitamin A in a case report. A person who received all-trans-retinoic acid, a form of vitamin A used to treat acute promyelocytic leukemia (APL), and fluconazole developed intracranial hypertension (high pressure in the brain). The condition resolved after discontinuing fluconazole treatment.

Your doctor can give you more information about this interaction. They can also advise whether the combination of vitamin A and fluconazole is safe for you to take.

Other vitamin interactions may be recognized in the future. Because of this, you should talk with your doctor or pharmacist before taking any vitamin product with fluconazole.

Herbs

There are no specific reports of herbs interacting with fluconazole. However, that doesn’t mean herbal interactions won’t occur or be recognized in the future. Because of this, it’s important to check with your doctor or pharmacist before taking any of these products during fluconazole treatment.

Fluconazole interactions with food

Fluconazole may interact with caffeine. Fluconazole can slow the clearance of caffeine from the body. This may increase the risk of caffeine side effects, such as feeling jittery or having a fast heartbeat. Examples of foods and beverages that contain caffeine include:

• coffee
• tea
• chocolate
• energy drinks

Because of this interaction, your doctor may recommend limiting your caffeine intake while you’re taking fluconazole.

To learn more about possible interactions between certain foods and fluconazole, talk with your doctor.

Fluconazole interactions with vaccines

There aren’t any known interactions between fluconazole and vaccines. You can talk with your doctor or pharmacist to see whether you’re due for any vaccines.

Fluconazole interactions with lab tests

Fluconazole isn’t known to interact with any lab tests. If you have concerns about this medication interacting with lab tests, talk with your doctor for more information.

FLUCONAZOLE INTERACTION WITH CANNABIS OR CBD

Cannabis (often called marijuana) and cannabis products, such as dronabinol (Marinol), have been specifically reported to interact with Diflucan (a brand-name version of fluconazole). Fluconazole may prevent the body from breaking down dronabinol as it should. This can lead to a higher level of dronabinol in your body. A higher level of dronabinol in your system may increase your risk of side effects, such as dizziness and confusion.

Before you start treatment with fluconazole, tell your doctor and pharmacist if you use cannabis. By sharing this information with them, you may help prevent possible interactions.

Note: Cannabis is illegal at a federal level but is legal in many U.S. states to varying degrees.

Contraindications: When to avoid fluconazole

In some cases, factors or conditions could prevent your doctor from prescribing fluconazole due to the risk of harm. These are known as contraindications, and include:

Certain medications that can cause heart rhythm problems

Doctors typically will not prescribe fluconazole in combination with certain drugs that:

• are broken down by an enzyme in the liver called CYP3A4 and
• increase your risk of a heart rhythm condition called QT prolongation

Fluconazole slows the activity of CYP3A4. If you take a drug that gets broken down by CYP3A4, the drug will break down more slowly if you also take fluconazole. It will also take your body longer to clear the drug from your system. This can cause a higher level of the drug in your system. Having higher levels may increase the risk of the drug’s side effects, including QT prolongation.

People with QT prolongation usually do not experience any symptoms. If symptoms are present, they may include dizziness, heart palpitations, seizures, or sudden fainting. However, QT prolongation can also lead to a life threatening heart rhythm problem called torsades de pointes.

Below are a few examples of drugs that can interact with fluconazole:

• quinidine
• pimozide
• erythromycin

Before starting fluconazole, it’s important to tell your doctor about all of the medications you take. Because of these risks, your doctor will likely not prescribe fluconazole if you’re taking one of these drugs. For more information about this risk, talk with your doctor.

A previous allergic reaction to fluconazole or any of its ingredients

If you have had an allergic reaction to fluconazole or any of its ingredients, your doctor will likely not prescribe fluconazole. Taking the drug could cause another allergic reaction. You can ask them about other treatments that may be better choices for you.

Note:Before starting fluconazole treatment, tell your doctor if any of these contraindications apply to you. They can determine whether to prescribe fluconazole.

Fluconazole and health-related interactions

Certain medical conditions and other factors may increase the risk of interactions with fluconazole. Before you take this drug, be sure to talk with your doctor about your health history. Fluconazole may not be the right treatment option if you have certain medical conditions or other factors affecting your health, including:

• liver problems
• abnormal heart rhythm
• kidney problems, such as chronic kidney disease
• low blood potassium level
• pregnancy and breastfeeding

For more information about possible contraindications for taking fluconazole, talk with your doctor.

Frequently asked questions

Stay safe: Preventing fluconazole interactions

You can take certain steps to help prevent interactions with fluconazole. Your doctor and pharmacist are key resources, so reach out to them before starting treatment. For example, you should plan to do the following:

• Let them know if you drink alcohol or use cannabis.
• Tell them about any other medications you take, as well as any supplements, herbs, and vitamins.
• Create a medication list, which your doctor and pharmacist can help you fill out.

It’s also important to read the fluconazole label and other paperwork that may come with the drug. The label may have colored stickers that mention an interaction. And the paperwork, sometimes called the medication guide or patient package insert, may contain details about interactions.

If fluconazole doesn’t come with paperwork, you can ask your pharmacist to print a copy. If you need help reading or understanding this information, ask your doctor or pharmacist.

You can also help prevent interactions with fluconazole by taking it exactly as your doctor prescribes.

Summary: Fluconazole interactions and safety at a glance

Fluconazole is a common medication used to treat fungal infections (such as yeast infections). While it is very effective, it can change how other drugs work in your body. This is called a drug interaction.

Key safety facts:

• Mixing with other medications: Some drugs for diabetes, high cholesterol, depression, and heart rhythm problems can cause side effects if taken with fluconazole. Always show your doctor a full list of your current medications before starting fluconazole.
• Alcohol: There is no known interaction between fluconazole and alcohol, but both can be hard on your liver. It is usually best to avoid drinking until you finish your fluconazole treatment.
• Caffeine: Fluconazole can slow your body’s caffeine metabolism. You might feel extra “jittery” or have a racing heart after drinking coffee or soda.
• When to call a doctor: If you feel dizzy, have a fast heartbeat, or get a rash when taking fluconazole, contact a healthcare professional immediately.

The Bottom Line: To stay safe, tell your doctor about every pill, vitamin, or herbal supplement you take before starting fluconazole, and take it exactly as prescribed.