Itraconazole

Introduction

Written by Patricia Weiser, PharmD
Medically reviewed by Rosanna Sutherby, PharmD
Updated on July 28, 2023

Itraconazole (i tra KOE na zole) is a generic medication prescribed for certain fungal infections in adults. Itraconazole belongs to a group of drugs called azole antifungals.

The Food and Drug Administration (FDA) has approved itraconazole to treat certain types of fungal infections in adults. Examples of these infections include:

• candidiasis (also known as a yeast infection or thrush) in the mouth, throat, or esophagus
• fungal nail infection
• aspergillosis, which is a fungal infection that usually affects the respiratory system

These approved uses differ based on the form of itraconazole your doctor prescribes.

Boxed warnings

Itraconazole has boxed warnings about the risks of congestive heart failure and serious effects on the heart. It also has a boxed warning about the risk of certain drug interactions. Boxed warnings are the most serious warnings from the FDA.

For details, see the “Interactions and warnings for itraconazole” section.

Side effects of itraconazole

Itraconazole may cause mild or serious side effects. More common mild side effects of itraconazole and its serious side effects are listed below. This article doesn’t include all possible side effects of the drug. Side effects can vary based on your age, overall health, and any other medications you take.

To learn more about itraconazole’s side effects, ask your doctor or pharmacist. You can also refer to the prescribing information for itraconazole listed in the “Resources” section.

Mild side effects

More common mild side effects reported with itraconazole are listed below.

This article doesn’t include all possible mild side effects of the drug. To learn more about itraconazole’s side effects based on the form, refer to the prescribing information for itraconazole listed in the “Resources” section.

With many drugs, mild side effects may go away within a few days or a couple of weeks. But if the side effects are bothersome, tell your doctor or pharmacist. They may be able to suggest ways to manage them.

Mild side effects of itraconazole oral capsule and oral solution may include:

• headache
• nausea and vomiting
• skin rash
• diarrhea
• mild allergic reaction*

* For details about this side effect, see the “Interactions and warnings for itraconazole” section.

Serious side effects

Serious side effects of itraconazole are listed below.

This article doesn’t include all possible serious side effects of the drug. To learn more about itraconazole’s side effects, refer to the prescribing information for itraconazole listed in the “Resources” section.

With many drugs, serious side effects are possible but not common. If you have serious side effects from this drug, call your doctor right away. If you’re having severe symptoms or a medical emergency, call 911 or a local emergency number.

In general, itraconazole’s serious side effects include:

• liver problems, including liver failure
• swelling due to fluid retention
• hearing loss or ringing in the ears
• boxed warnings: risks of congestive heart failure, serious effects on the heart, and certain drug interactions*
• severe allergic reaction*

* For details about this side effect, see the “Interactions and warnings for itraconazole” section.

Common questions about itraconazole

Below you’ll find answers to a few commonly asked questions about itraconazole.

Are there certain foods to avoid while taking itraconazole?

Not necessarily. No specific foods are reported* to interact with itraconazole, so it’s unlikely you’ll need to avoid certain foods while taking the drug.

Whether you’ll need to take itraconazole with or without food depends on the form of the drug. For itraconazole oral solution, the drugmaker recommends taking your dose on an empty stomach, without any food. For itraconazole oral capsule, you should take each dose with a full meal.

If you have questions about how to take itraconazole, talk with your doctor or pharmacist. For details about what the drug interacts with, see the “Interactions and warnings for itraconazole” section.

* For details about itraconazole’s studies, see its prescribing information in the “Resources” section below.

How does itraconazole work? And how long does it take to start working?

Itraconazole is an antifungal drug prescribed to treat certain fungal infections. Itraconazole works by stopping fungal cells from making a type of fat. Fungal cells need this fat to grow and make more cells. Without it, cells die, and the infection goes away.

Itraconazole starts working right away to kill certain types of fungi. But it can take time for the infection to clear. How long this takes depends on the specific type and severity of fungal infection. To treat thrush (a type of fungal infection in the mouth), you may need to take itraconazole for 1–4 weeks. To treat a fungal nail infection, you may need to take the medication for several months.

If you’d like to know more about itraconazole treatment, talk with your doctor or pharmacist.

Is itraconazole similar to fluconazole?

Yes, itraconazole is similar to fluconazole (Diflucan). Both drugs belong to the same group of drugs: azole antifungals. They work in a similar way and are prescribed to treat many of the same types of fungal infections.

In some cases, itraconazole may be prescribed after fluconazole hasn’t worked to treat the infection. This may occur if the fungus causing the infection has become resistant to fluconazole. For more information about this, talk with your doctor or pharmacist.

Uses of itraconazole

The Food and Drug Administration (FDA) approves prescription drugs such as itraconazole for certain conditions. Approved uses for itraconazole are described below. These uses differ based on the form of itraconazole prescribed.

Use for certain fungal infections

Doctors may prescribe itraconazole oral solution to treat oral candidiasis in adults. The drug is usually prescribed as a short-term treatment.

Candidiasis is a common type of fungal infection that’s also known as a yeast infection. With oral candidiasis, the infection develops in the mouth, where it’s commonly called thrush. The infection can also involve the throat or esophagus. Symptoms may include sore throat, difficulty swallowing, and white spots on your tongue or the back of your throat.

Doctors may prescribe itraconazole oral capsule for treating certain other fungal infections in adults. It may be prescribed as a short-term or long-term treatment. Examples of these infections include:

• fungal infection of the fingernails or toenails
• aspergillosis, a fungal infection that usually affects the respiratory system

Interactions and warnings for itraconazole

Below, you’ll find information about itraconazole’s possible interactions and warnings.

Interactions of itraconazole

Certain things may affect how a drug works. These include getting vaccines, consuming alcohol or certain foods, or taking the drug with other medications.* This effect is called a drug interaction.

Before you take itraconazole, ask your doctor to check for possible interactions. Be sure to tell them about any of the following you take or use:

• prescription or over-the-counter drugs
• vitamins, herbs, or supplements

To learn about drug-condition interactions, see the “Warnings for itraconazole” section below.

* Itraconazole has a boxed warning about the risk of certain drug interactions. For details, see the “Boxed warning” section just below.

Warnings for itraconazole

Some people should not take itraconazole, and others should take it cautiously.

Boxed warnings

Itraconazole has boxed warnings about the risk of congestive heart failure (CHF) and serious effects on the heart. It also has a boxed warning about the risk of certain drug interactions. Boxed warnings are the most serious warnings from the Food and Drug Administration (FDA).

To learn more about these warnings, read below. You can also talk with your doctor or pharmacist.

Risk of congestive heart failure. Taking itraconazole may increase the risk of congestive heart failure (CHF). With CHF, your heart isn’t able to pump blood as well as it usually does. This side effect was rarely reported in studies* of itraconazole.

Doctors may not prescribe itraconazole for adults with certain conditions due to a higher risk of CHF. These conditions include heart disease, chronic obstructive pulmonary disease (COPD), and kidney problems.

Symptoms of CHF may include:

• fatigue (low energy)
• swelling of your lower legs and feet due to fluid buildup
• sudden weight gain
• difficulty breathing, especially when you walk or exercise

If you experience these symptoms during itraconazole treatment, tell your doctor. They’ll likely recommend that you stop taking the drug. They may also prescribe other treatments.

Risk of serious effects on the heart. With heart effects from itraconazole, a person’s heart contractions may weaken, and their heart rate may decrease. This side effect was rarely reported in studies* of itraconazole.

Symptoms may include:

• dizziness
• weakness
• headache
• constipation
• dry mouth
• sweating
• nervousness

If you have concerns about possible heart effects with itraconazole, tell your doctor. They’ll likely recommend a different treatment option if you already have problems with your heart or blood flow.

Risk of certain drug interactions. Itraconazole should not be taken with certain drugs. Also, some drug combinations should be taken with caution, especially by people with certain conditions.

When taken together with certain other drugs, itraconazole may increase the level of the other drug in your body. This can raise the risk or severity of the other drug’s side effects. For more details about the types of drugs that can interact with itraconazole, see the prescribing information in the “Resources” section.

Talk with your doctor or pharmacist for more information about drug interactions that may affect you. In some cases, they may adjust your dosages or recommend changes to your treatment plan.

* For details about itraconazole’s studies, see its prescribing information in the “Resources” section below.

Other warnings

Itraconazole could cause harm to people with certain health conditions. This effect is called a drug-condition interaction. Other factors can also affect whether itraconazole is a safe option for you. These warnings may differ based on the form of itraconazole you take.

Ask your doctor about specific warnings for itraconazole, and be sure to tell your doctor about your:

• current health, including any allergies to medications
• past health conditions or surgeries

Allergic reaction

Itraconazole can cause an allergic reaction in some people. Severe allergic reactions are rare but possible.

If you’ve had an allergic reaction to itraconazole or any of its ingredients, your doctor will likely not prescribe itraconazole. They can tell you about medications that are safer options for you.

A mild allergic reaction may cause the following symptoms:

• skin rash
• itchiness
• flushing (temporary warmth, redness, or deepening of skin color)

A severe allergic reaction may cause the following symptoms:

• swelling under your skin, usually in your hands, feet, eyelids, or lips
• swelling of your mouth, throat, or tongue, which can cause breathing problems

If you have an allergic reaction to itraconazole, call your doctor right away. If you have severe symptoms, call 911 or a local emergency number.

Overdose of itraconazole

If you take itraconazole by mouth, you should not swallow more itraconazole than your doctor prescribes. For some drugs, doing so may lead to harmful effects or overdose. To learn about the drug’s side effects, see “Side effects of itraconazole” section.

If you think you’ve taken too much itraconazole, call your doctor or pharmacist right away. Or you could call 800-222-1222 to speak with someone at America’s Poison Centers. You can also use its online resource. If you have concerning symptoms, call 911 or a local emergency number immediately. You can also go to the closest emergency room.

Pregnancy or breastfeeding and itraconazole

Information about itraconazole and pregnancy and breastfeeding is described below.

Itraconazole and pregnancy

Itraconazole should not be taken during pregnancy. If you’re planning a pregnancy or can become pregnant, talk with your doctor before taking this medication. Your doctor may suggest birth control options to use during treatment with itraconazole.

Itraconazole and breastfeeding

It’s not known whether itraconazole should be taken while breastfeeding. If you’re currently breastfeeding or planning to do so, talk with your doctor before taking this medication.

What to ask your doctor

Let your doctor know if you have questions about itraconazole or would like more details about it.

Here’s a list of some possible questions you may want to ask your doctor:

• How long will I need to take itraconazole?
• Will you need to adjust my dosage of itraconazole if I’m taking other medications with it?
• Is itraconazole effective for the type of infection I have?
• Will itraconazole help to ease symptoms of the fungal infection, such as itching?

Resources

• Itraconazole. (2022). https://www.ncbi.nlm.nih.gov/books/NBK500573/
• Itraconazole capsules. (2022). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/59c18e0d-a7ed-48ad-a419-bc47a5d5aafd/spl-doc
• Itraconazole oral solution. (2023). https://nctr-crs.fda.gov/fdalabel/services/spl/set-ids/43ded1aa-f825-40fe-aa9a-addd36a07f06/spl-doc
• Food and Drug Administration. (2023). Orange Book: Approved drug products with therapeutic equivalence evaluations. https://www.accessdata.fda.gov/scripts/cder/ob/index.cfm

Disclaimer: Optum Perks 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.