Imbruvica (ibrutinib) is a brand-name drug that’s prescribed for certain cancers and immune system conditions. As with other drugs, Imbruvica can cause side effects, such as diarrhea.

Imbruvica can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days or weeks. But 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 Imbruvica in clinical trials. These side effects can vary depending on which condition the drug is being used to treat.

More common side effects in people taking Imbruvica for cancer include:

More common side effects in people taking Imbruvica for chronic (long-term) graft-versus-host disease include:

  • diarrhea
  • bruising
  • fatigue (low energy)

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

Mild side effects that have been reported with Imbruvica when taken for cancer include:

Mild side effects that have been reported with Imbruvica when taken for chronic (long-term) graft-versus-host disease include:

  • eye-related side effects*
  • rash or other skin problems*
  • mouth ulcers*
  • muscle spasms (sudden involuntary muscle movement)
  • diarrhea
  • nausea
  • fatigue (low energy)

These side effects may be temporary, lasting a few days or weeks. But 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 Imbruvica and want to tell the FDA about it, visit MedWatch.

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

Imbruvica may cause serious side effects. The list below may not include all possible serious side effects of the drug. For more information, you can refer to Imbruvica’s prescribing information.

If you develop serious side effects while taking Imbruvica, 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:

  • High blood pressure,* which doesn’t usually cause symptoms. But symptoms of very high blood pressure can include:
    • dizziness
    • double vision or blurry vision
    • the feeling of your heart pounding in your neck or ears
    • headache
  • Thrombocytopenia (low level of blood cells called platelets, which help your blood clot). Symptoms can include:
    • bruising more easily than usual
    • unusual bleeding, such as bleeding from your nose or gums
  • Anemia (low level of red blood cells). Symptoms can include:
    • heart rate that’s irregular or faster than usual
    • fatigue
    • headache
    • lightheadedness
  • Serious bleeding. Symptoms can include:
    • bloody urine
    • bloody stool
    • unmanageable bleeding
    • bruising more easily than usual
    • confusion
    • dizziness
    • weakness
  • Neutropenia (low level of white blood cells called neutrophils, which help fight infections). This doesn’t usually cause symptoms, except on blood test results.
  • Tumor lysis syndrome (a condition in which cancer cells are broken down in your body and the cells release their contents into your blood). Symptoms can include:
  • Serious infections, such as pneumonia. Symptoms depend on the infection but can include:
    • chills
    • fever
    • weakness
  • Heart problems, such as an atypical heart rhythm. Symptoms vary but can include:
    • irregular or fast heart rate
    • chest pain
    • a feeling of dizziness, faintness, or lightheadedness
  • Cancers, such as skin cancer. Depending on the type of cancer, symptoms can include:
    • lumps on your skin
    • skin sores that bleed or don’t heal
    • fatigue
    • fever
    • weight loss
  • Allergic reaction.†

* The risk of high blood pressure increases the longer you take Imbruvica.
† An allergic reaction is possible after taking Imbruvica. But this side effect wasn’t reported in clinical studies. For more information, see “Side effect specifics” below.

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

Are there side effects after stopping Imbruvica?

Yes, it’s possible you may have side effects after stopping Imbruvica.

These side effects weren’t reported in initial trials of the drug. However, after the drug was made available to the public, there have been reports of side effects in people who stopped taking Imbruvica. Most of these side effects went away after the drug was started again.

Examples of side effects that may happen after stopping Imbruvica include:

If you have side effects after stopping Imbruvica, be sure to tell your doctor right away. They can suggest ways to relieve these side effects.

Does Imbruvica cause weight gain?

No, Imbruvica isn’t likely to cause weight gain. This side effect wasn’t reported in clinical trials of the drug.

In fact, Imbruvica is more likely to cause weight loss than weight gain. Weight loss was a common side effect in studies of the drug.

Keep in mind that weight loss is a common symptom of cancer, which Imbruvica is used to treat. And as Imbruvica treats your cancer, you may gain back some of the weight you’ve lost. However, the weight gain would likely be a result of your condition improving. Imbruvica itself may not be the cause of the weight gain.

If you have other questions about weight gain while you’re taking Imbruvica, talk with your doctor.

Is hair loss a side effect of Imbruvica?

No, Imbruvica likely doesn’t cause hair loss. This wasn’t a side effect reported in clinical trials of the drug.

However, cancer drugs other than Imbruvica can cause hair loss. For example, hair loss is a common side effect of chemotherapy drugs. Imbruvica isn’t a chemotherapy drug, though.

If you’re concerned about hair loss from Imbruvica or other cancer drugs, talk with your doctor.

Can Imbruvica cause long-term side effects?

It’s possible Imbruvica may cause long-term side effects.

Most of the side effects from Imbruvica are short term. These usually go away either soon after your body gets used to the drug or after you stop taking it.

However, certain side effects from Imbruvica may last longer. For example, it’s possible to develop cancers as a side effect of Imbruvica, such as skin cancer. These cancers may require long-term treatment. You may also have heart problems, such as an atypical heart rhythm, after taking Imbruvica. This can lead to long-term heart damage.

If you’re concerned about long-term side effects with Imbruvica, talk with your doctor. It’s important to follow up on any side effects you might be having during or after Imbruvica treatment.

What are the side effects of Imbruvica 420 mg?

The side effects you have with Imbruvica may vary depending on the dosage you’re prescribed.

This can happen because the dosage of Imbruvica you’ll take depends on whether you’re taking the drug to treat immune system problems or certain cancers. Some side effects of Imbruvica can also vary depending on these conditions.

For example, you’ll likely take 420 milligrams (mg) of Imbruvica per day to treat:

For details about specific side effects of Imbruvica based on the conditions the drug treats, see the “Mild side effects of Imbruvica” and “Serious side effects of Imbruvica” sections above.

Learn more about some of the side effects that Imbruvica may cause.

Eye-related side effects

Imbruvica may cause side effects that affect the eyes. Eye-related side effects can happen regardless of which condition you’re taking Imbruvica to treat. However, these side effects were more common in people taking Imbruvica for cancer than for chronic (long-term) graft-versus-host disease.

The eye-related side effects below have been reported with Imbruvica:

What you can do

Tell your doctor right away if you have any eye-related side effects from Imbruvica. They can suggest ways to help you manage or treat these side effects.

Rash or other skin problems

Rash is a common side effect of Imbruvica. Bruising and skin infections were other common skin problems reported in clinical trials of the drug.

Imbruvica may also raise your risk for cancers other than those Imbruvica is used to treat. This can include skin cancer. Symptoms of skin cancer can include:

  • moles that change in size or color
  • areas of skin that are discolored, raised, or rough
  • sores or growths

What you can do

If you have a rash or other skin problems while taking Imbruvica, talk with your doctor. They may prescribe creams or other treatments that can help ease your symptoms. If you have any of the above symptoms, talk with your doctor about screening for skin cancer.

Mouth ulcers

Mouth ulcers can occur with Imbruvica. These are painful sores that can affect your cheeks, gums, lips, throat, or tongue. They may appear as a small cut or as a fluid-filled blister. Other symptoms can include:

  • burning or stinging sensation
  • peeling
  • swelling
  • trouble eating

Mouth ulcers were a common side effect in clinical trials of the drug.

What you can do

Tell your doctor if you develop bothersome or painful mouth ulcers while taking Imbruvica. They can suggest ways to relieve your discomfort.

Allergic reaction

As with most drugs, Imbruvica can cause an allergic reaction in some people. But this side effect wasn’t reported in clinical trials.

Symptoms can be mild or serious and can include:

  • rash
  • itching
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin, typically in your lips, eyelids, feet, or hands
  • 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 Imbruvica. But 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 Imbruvica. This drug may not be the right treatment for you if you have certain medical conditions or other factors that affect your health. The conditions and factors to consider include:

Liver problems. If you have problems with your liver, your body may not fully break down Imbruvica. This can raise the level of Imbruvica in your body, which may increase your risk of side effects. Before you start taking Imbruvica, tell your doctor about any liver problems you have.

Heart problems or risk factors for heart disease. Imbruvica may cause heart problems, such as an atypical heart rhythm. Tell your doctor if you have heart problems or other risk factors for heart disease, such as high cholesterol or diabetes. If you have these conditions, you may have a higher risk of heart problems with Imbruvica. Your doctor will watch you closely for signs of heart problems while you’re taking Imbruvica.

Bleeding problems. Tell your doctor about any bleeding problems you have before starting Imbruvica. This is because the drug may cause serious bleeding. Taking Imbruvica while you already have bleeding problems can increase your risk for this side effect.

Allergic reaction. You should not take Imbruvica if you’ve ever had an allergic reaction to this drug or any of its ingredients. Talk with your doctor about other treatments that might be better for you.

Current infections. Tell your doctor about any infections you have before starting Imbruvica. The drug can increase your risk of certain infections, such as pneumonia and skin infections. If you currently have an infection, your doctor will treat it before you start Imbruvica.

Planned or recent surgeries. Before you start taking Imbruvica, tell your doctor if you plan to have surgery or a dental procedure or if you’ve recently had one. Imbruvica can increase your risk of bleeding. Your doctor may need to stop your Imbruvica treatment to lower your risk of bleeding during surgery. Be sure to talk with your doctor before you stop taking Imbruvica. They’ll advise whether it’s safe for you to stop the drug temporarily.

Alcohol use with Imbruvica

There aren’t any known interactions between alcohol and Imbruvica. You should be able to safely drink alcohol during your Imbruvica treatment.

However, if you drink alcohol, it’s important to talk with your doctor. They can recommend the amount of alcohol that’s safe for you to drink while taking Imbruvica.

Pregnancy and breastfeeding while taking Imbruvica

Imbruvica should not be taken while pregnant or breastfeeding. You should also avoid pregnancy or breastfeeding for at least 1 month after your last dose.

It’s important to use birth control while you’re taking Imbruvica. You should continue using birth control for at least 1 month after your last dose. This helps make sure the drug is completely removed from your body before pregnancy may occur.

Before taking Imbruvica, tell your doctor if you’re pregnant, breastfeeding, or planning to become pregnant or to breastfeed.

As with most medications, Imbruvica may cause mild or serious side effects. Most side effects should go away with time. But be sure to tell your doctor if you have any symptoms of side effects while taking Imbruvica. They can help you manage your side effects and advise if it’s safe for you to keep taking the drug.

If you’d like to learn more about Imbruvica, talk with your doctor or pharmacist. They can help answer any questions you have about side effects from taking the drug.

Besides talking with your doctor, you can do some research on your own. These articles might help:

  • More information on Imbruvica. For details on other aspects of Imbruvica, refer to this article.
  • Drug comparison. To learn how Imbruvica compares with Calquence, read this article.
  • Cost. If you’d like to learn about Imbruvica and cost, see this article.
  • Dosage. For information about the dosage of Imbruvica, view this article.
  • A look at your condition. For details on the conditions that Imbruvica treats, see our cancer hub. This list of articles about leukemia may also be helpful.

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.