If you have a certain kind of cancer, your doctor might suggest Tibsovo as a treatment option for you.

Tibsovo is a prescription drug that’s used to treat certain kinds of the following cancers in some adults:

Tibsovo is usually prescribed to treat these conditions until the cancer spreads or worsens, or side effects become bothersome.

Tibsovo comes as a tablet that you swallow. Its active ingredient is ivosidenib. An active ingredient is what makes a drug work.

For more information about Tibsovo, including details about its uses, see this in-depth article on the drug.

Like other drugs, Tibsovo can cause mild to serious side effects. Keep reading to learn more.

Some people may experience mild to serious side effects during Tibsovo treatment.

Listed below are just a few of the more common side effects reported in studies of Tibsovo. These side effects can vary depending on what condition the drug is being taken to treat.

More common side effects in people taking Tibsovo for acute myeloid leukemia (AML) include:

* To learn more about this side effect, see the “Side effects explained” section below.

More common side effects in people taking Tibsovo for bile duct cancer include:

Like most medications, taking Tibsovo can cause mild side effects.

Examples of mild side effects that have been reported with Tibsovo include:

In most cases, these side effects should be temporary. And some may be easily managed, too. But if you have any symptoms that are ongoing or bother you, talk with your doctor or pharmacist. Do not stop taking Tibsovo unless your doctor recommends it.

Tibsovo may cause mild side effects other than the ones listed above. See the Tibsovo prescribing information for details.

Note: After the Food and Drug Administration (FDA) approves a drug, it tracks side effects of the medication. If you’d like to notify the FDA about a side effect you’ve had with Tibsovo, visit MedWatch.

Serious side effects may happen as a result of taking Tibsovo. While serious side effects are rare, some may happen more often than others.

Serious side effects that have been reported with Tibsovo include:

* Tibsovo has a boxed warning for this side effect. This is the most serious warning from the Food and Drug Administration (FDA). To learn more, see the “Side effects explained” section below.
† To learn more about this side effect, see the “Side effects explained” section below.

If you develop serious side effects while taking Tibsovo, 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.

Learn more about some of the side effects Tibsovo may cause.

Differentiation syndrome

Tibsovo has a boxed warning for a risk of differentiation syndrome. A boxed warning is the most serious warning from the Food and Drug Administration (FDA). It alerts doctors and patients about drug effects that may be dangerous.

Differentiation syndrome is a serious condition that affects your blood cells. Without treatment, it can cause organ failure or even death in rare cases.

In studies of Tibsovo, this syndrome was a commonly reported side effect in people taking the drug to treat acute myeloid leukemia (AML). You can develop it right after your first dose or any time within the first 3 months of starting treatment.

Possible symptoms that may be caused by differentiation syndrome include:

What might help

If you notice symptoms of differentiation syndrome while taking Tibsovo, seek emergency medical care immediately. You’ll likely need treatment and monitoring in a hospital. Treatment may include receiving a corticosteroid such as dexamethasone.

After receiving treatment for differentiation syndrome, your doctor will determine whether it’s safe for you to continue taking Tibsovo.

Guillain-Barré syndrome

In rare cases, Tibsovo can cause Guillain-Barré syndrome. This is a condition that affects your nervous system.

Symptoms of Guillain-Barré syndrome can include:

What might help

If you notice symptoms of Guillain-Barré syndrome while taking Tibsovo, contact your doctor right away. If your doctor confirms that you have this syndrome, they’ll have you permanently stop Tibsovo treatment. They’ll likely suggest treatments for Guillain-Barré syndrome and alternatives to Tibsovo for your cancer.

High level of leukocytes

Taking Tibsovo may cause a high level of leukocytes, a kind of white blood cell. This is known as leukocytosis.

Leukocytosis often doesn’t cause symptoms. But if your level of leukocytes becomes high enough, your blood can become thick. This may affect blood flow, which can cause serious issues in rare cases, such as:

  • bleeding from your mouth, stomach, or intestines
  • trouble breathing
  • stroke
  • vision problems

What might help

Before and during treatment with Tibsovo, your doctor will order blood tests to check your leukocyte level. If your leukocyte level becomes too high, your doctor may prescribe you a drug called hydroxyurea. (Doxia, Hydrea). It can help lower your white blood cell count.

If hydroxyurea doesn’t work to manage your leukocytosis, your doctor may have you temporarily stop taking Tibsovo. Then they’ll likely have you resume treatment when your leukocytes return to a usual level.

Long QT syndrome

Tibsovo may cause an abnormal heart rhythm called long QT syndrome. This is a change to certain electrical activity in your heart.

Although this side effect was somewhat common in studies of Tibsovo, it didn’t always cause symptoms or complications. But in rare cases, it can cause more serious heart rhythm problems.

Your risk of abnormal heart rhythm, including long QT syndrome, with Tibsovo may be higher if you:

  • take other medications that can cause long QT syndrome
  • were born with long QT syndrome
  • have frequent problems with your blood electrolyte levels
  • have heart failure

Your doctor may notice QT prolongation using a test called an electrocardiogram (EKG). In rare cases, long QT syndrome can cause symptoms, including:

What might help

During Tibsovo treatment, your doctor will likely check your blood electrolyte levels and order an EKG from time to time. They will use these tests to watch for signs of an abnormal heart rhythm, including long QT syndrome.

If you notice symptoms of long QT syndrome while taking Tibsovo, call your doctor right away. If your doctor suspects you have long QT syndrome, they may suggest:

  • trying a lower Tibsovo dose
  • temporarily or permanently stopping treatment with Tibsovo

Allergic reaction

Like most drugs, Tibsovo can cause an allergic reaction in some people. But these reactions weren’t common in studies.

Symptoms can be mild to serious and can include:

  • skin rash
  • itchiness
  • flushing (temporary warmth, redness, or deepening of skin color)
  • swelling under your skin, usually in your eyelids, lips, hands, or feet
  • swelling of your mouth, tongue, or throat, which can make it hard to breathe

What might help

If you have mild symptoms of an allergic reaction, such as a mild rash, call your doctor right away. To manage symptoms, they may suggest an over-the-counter antihistamine you take by mouth, such as Benadryl (diphenhydramine). Or they may recommend a product you apply to your skin, such as hydrocortisone cream.

If your doctor confirms you had a mild allergic reaction to Tibsovo, they’ll decide if you should continue taking it.

If you have symptoms of a severe allergic reaction, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms could be life threatening and require immediate medical care.

If your doctor confirms you had a serious allergic reaction to Tibsovo, they may have you switch to a different treatment.

Keeping track of side effects

During Tibsovo treatment, consider keeping notes on any side effects you’re having. You can then share this information with your doctor. This is especially helpful when you first start taking new drugs or using a combination of treatments.

Your side effect notes can include things such as:

  • what dose of drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what symptoms you were having
  • how it affected your daily activities
  • what other medications you were taking
  • any other information you feel is important

Keeping notes and sharing them with your doctor will help them learn more about how Tibsovo affects you. They can then use this information to adjust your treatment plan if needed.

Before taking Tibsovo, there are certain warnings and precautions to consider. These may affect whether Tibsovo is a good treatment option for your cancer.

Boxed warning: Risk of differentiation syndrome

Tibsovo has a boxed warning for the risk of differentiation syndrome. A boxed warning is the most serious warning from the Food and Drug Administration (FDA).

In studies of Tibsovo, this syndrome was a commonly reported side effect in people taking the drug to treat acute myeloid leukemia (AML). This syndrome is a serious condition that affects your blood cells. Without treatment, it can cause organ failure or even death in rare cases.

To learn more, see the “Side effects explained” section above.

Other warnings

Tibsovo may not be right for you if you have certain medical conditions or other factors that affect your health. Talk with your doctor about your health history before starting Tibsovo. The list below includes factors to consider.

Electrolyte problems. Treatment with Tibsovo can cause a heart rhythm condition called long QT syndrome. If you have electrolyte problems, such as low potassium or low sodium levels, you may have a higher risk of this Tibsovo side effect. Tell your doctor about any electrolyte problems you have. This will help them determine whether Tibsovo is safe for you to take.

Heart problems, including long QT syndrome. Treatment with Tibsovo can cause a heart rhythm condition called long QT syndrome. If you have existing heart problems, you may have a higher risk of this Tibsovo side effect. And if you already have long QT syndrome, taking Tibsovo could worsen your condition. Before you start taking Tibsovo, tell your doctor about any heart problems you have. They can let you know if Tibsovo is a good treatment option for you.

Liver problems. People with mild or moderate liver problems can usually take Tibsovo safely. But it’s not known if it’s safe for people with severe liver problems to take Tibsovo. If you have liver problems, talk with your doctor before beginning treatment with Tibsovo. They can determine the severity of your liver problems and then advise whether it’s safe for you to take Tibsovo.

Nervous system problems. In rare cases, taking Tibsovo can cause nervous system side effects. These can include new nervous system problems, such as Guillain-Barré syndrome. But if you already have a nervous system problem, taking Tibsovo could worsen your condition. Tell your doctor if you have this kind of condition. They can let you know whether Tibsovo is safe for you to take.

Allergic reaction. If you’ve had an allergic reaction to Tibsovo or any of its ingredients, your doctor will likely not prescribe Tibsovo. Ask them what other medications are better options for you.

Alcohol and Tibsovo

There isn’t a known interaction between Tibsovo and alcohol.

But alcohol can raise your risk of or worsen certain side effects from Tibsovo, including diarrhea, nausea, and low energy.

Talk with your doctor about how much alcohol is safe for you to consume while you’re taking Tibsovo.

Pregnancy and breastfeeding while taking Tibsovo

It’s not known if it’s safe to take Tibsovo while pregnant. But it’s thought that doing so could cause harm.

Before you begin taking Tibsovo, it’s important to talk with your doctor if you’re pregnant or planning to become pregnant. They can discuss the risks and benefits of taking Tibsovo or other alternative treatments for your condition during this time.

Tibsovo is not safe to take while breastfeeding. You should avoid breastfeeding during Tibsovo treatment and for at least 1 month following your last dose of the drug. Talk with your doctor about safe ways to feed your child.

Like most medications, taking Tibsovo can cause side effects. If you’re considering treatment with Tibsovo, talk with your doctor about possible side effects. Ask questions that help you feel more comfortable with your treatment options. Here are some examples to get you started:

  • If I have side effects while taking Tibsovo, will taking a lower dose help?
  • How do Tibsovo’s side effects compare with other medications for treating my condition?
  • Does Tibsovo cause any long-term side effects?

Q:

Can other medications I take increase my risk of side effects with Tibsovo?

Anonymous

A:

It’s possible. Certain medications can interact with Tibsovo, which may raise your risk of side effects. These medications include:

The list above does not contain all drugs that may increase your risk of side effects if taken with Tibsovo. Before you begin taking Tibsovo, be sure to tell your doctor and pharmacist about any medications you take. They can check for any interactions with Tibsovo.

The Healthline Pharmacist TeamAnswers represent the opinions of our medical experts. All content is strictly informational and should not be considered medical advice.

Disclaimer: Healthline 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.