If you have a certain type of cancer, your doctor might suggest Gleevec (imatinib) as a treatment option for you. Along with other questions you may have about the drug, you could be wondering about its side effects.

Gleevec is a prescription medication that’s used to treat certain types of blood cancer, such as leukemia, in adults and some children. It’s also used to treat a type of gastrointestinal cancer and a type of skin cancer in adults. For these purposes, Gleevec can be used alone or with other medications.

Gleevec comes as a tablet that is taken by mouth. If the drug works for you, your doctor will likely recommend that you take it long term.

For more information about Gleevec, including details about its uses, see this in-depth article.

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

Some people may have mild or serious side effects during Gleevec treatment. Examples of Gleevec’s more commonly reported side effects include:

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

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

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

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 that bother you, talk with your doctor or pharmacist. And don’t stop taking Gleevec unless your doctor recommends it.

Gleevec may cause mild side effects other than the ones listed above. See the Gleevec 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 Gleevec, visit MedWatch.

Serious side effects that have been reported with Gleevec include:

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

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction is possible after taking Gleevec. But it’s not clear whether this side effect occurred in studies.

Side effects in children | Side effects in children

Overall, side effects in children taking Gleevec were very similar to those reported by adults taking the drug. But there were a few differences. For example, children didn’t report muscle or bone pain as often as adults. In addition, swelling of the arms or legs wasn’t a side effect reported in children taking the drug.

The most common side effects of Gleevec reported in children were nausea and vomiting. The drug can also cause growth problems in children. While your child takes Gleevec, their doctor may monitor their growth patterns.

If you have concerns about side effects that your child may have from taking Gleevec, talk with their doctor.

Get answers to some frequently asked questions about Gleevec’s side effects.

Will stopping Gleevec treatment cause withdrawal side effects?

It’s possible. A study shows that withdrawal symptoms such as bone pain or itching may occur after stopping Gleevec treatment.

In addition, stopping treatment can make your cancer worse. This, in turn, can worsen symptoms of the cancer that you were taking Gleevec to treat.

If you would like to stop taking Gleevec, talk with your doctor about the best way to do it. They may recommend that you switch to a different medication to treat your cancer. If you want to stop taking Gleevec, be sure to talk with your doctor first.

If you experience symptoms from stopping Gleevec treatment, your doctor may be able to recommend medications to reduce those symptoms. For example, they may suggest that you take an over-the-counter pain reliever, such as Tylenol (acetaminophen).

Does Gleevec cause certain side effects when taken for GISTs?

Yes, Gleevec can cause certain side effects when it’s taken to treat gastrointestinal stromal tumors (GISTs). This type of cancer can affect the intestines or stomach. If you’re taking Gleevec for GISTs, you may have:

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

For more information about the side effects that Gleevec might cause when used to treat GISTs, talk with your doctor or pharmacist.

Is my risk of side effects higher with Gleevec 400-mg tablets, compared with 100-mg tablets?

It’s possible that you may have a higher risk of side effects if you’re taking a higher dosage of Gleevec. But studies of Gleevec haven’t directly compared side effects of the 100-milligram (mg) tablets with those of the 400-mg tablets. Side effects of the medication vary for each person.

If you’re taking 400-mg tablets of Gleevec, and you develop bothersome or serious side effects, talk with your doctor. They may prescribe a lower dosage of Gleevec or recommend a different treatment option for you.

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

Eye-related side effects

You may have eye-related side effects from taking Gleevec. Some, such as swelling of the eyelid or area around the eye, are common. Others, such as eye pain, occur less often.

In addition to those eye-related side effects, people taking Gleevec have reported:

What might help

If you experience eye-related side effects, tell your doctor. Depending on the side effect, your doctor may be able to recommend ways to reduce your symptoms. For example, if you have dry eye, your doctor may suggest eye drops to soothe and moisten your eyes.

Tell your doctor about any eye-related side effects that you’re experiencing. They’ll be able to recommend a treatment option for you.

Hair loss

Gleevec can cause hair loss in people taking it, although this isn’t a common side effect of the drug.

Keep in mind that hair loss during cancer treatment is usually temporary. In general, hair lost while taking Gleevec is expected to grow back after you stop taking the drug.

What might help

During Gleevec treatment, if you have hair loss that’s bothersome, talk with your doctor. They may be able to recommend ways to reduce this side effect, including medications and other treatment options.

If you’re concerned about hair loss during Gleevec treatment, talk with your doctor.

Liver damage

Gleevec can affect the liver and may increase liver enzyme levels. This can indicate liver damage. Although rare, liver damage may occur, and in some cases, it could be severe or even fatal.

If you’re also taking chemotherapy drugs or other medications that may affect your liver, you may have an increased risk of liver damage.

It’s important to know the symptoms of liver damage so that you can tell your doctor if you develop any while taking Gleevec. Symptoms to watch for include:

What might help

Before and during Gleevec treatment, your doctor will check your liver enzyme levels with blood tests. This is to monitor you for liver damage.

If you develop liver problems from taking Gleevec, your doctor may decrease your dosage of the drug. Or, they may have you stop treatment until your liver levels return to normal.

If you notice any symptoms of liver damage, tell your doctor right away.

Nausea or vomiting

You may have nausea or vomiting from taking Gleevec. These side effects are common in people who take this drug.

What might help

If you develop nausea or vomiting from taking Gleevec, talk with your doctor. They may be able to recommend other medications that can help prevent these side effects. You might also be able to prevent or reduce these side effects by taking Gleevec with food and a large glass of water.

If you’re experiencing nausea or vomiting from taking this drug, tell your doctor.

Allergic reaction

Like most drugs, Gleevec can cause an allergic reaction in some people. But it’s not clear whether this side effect occurred in studies.

Symptoms may be mild or serious and can include:

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

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

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

Keeping track of side effects

During your Gleevec treatment, consider keeping notes about any side effects you’re having. Then, you can 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 dosage of the drug you were taking when you had the side effect
  • how soon after starting that dosage you experienced it
  • the specific symptoms of the side effect
  • how it affected your daily activities
  • what other medications you were also taking
  • any other information you feel is important

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

Gleevec 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 you take Gleevec. The list below includes factors to consider.

Liver problems. Gleevec may cause liver problems, including liver damage. If you already have a liver problem, taking Gleevec may make it worse. Depending on your liver condition, your doctor may monitor your liver function more frequently. They may also recommend a lower dosage of Gleevec or a different treatment option for you.

Allergic reaction. If you’ve had an allergic reaction to Gleevec or any of its ingredients, you shouldn’t take Gleevec. Ask your doctor what other medications are better options for you.

Heart conditions, such as heart failure. Gleevec may increase your risk of developing heart conditions, including heart failure. Tell your doctor about any heart conditions that you may have. If you already have a heart condition, Gleevec can make it worse. Your doctor may monitor you more often during your treatment, or they may recommend a different treatment option for you.

Thyroid problems. People who’ve had their thyroid removed and are currently taking Synthroid (levothyroxine) may have an increased risk of a low thyroid hormone level. Before starting Gleevec treatment, tell your doctor about any thyroid conditions you have. They will monitor your thyroid levels throughout your treatment.

Kidney problems. Gleevec may cause kidney problems in some people. If you already have kidney problems, taking this medication may make your condition worse. Before you start taking Gleevec, tell your doctor about any kidney conditions you may have. They may monitor your kidney function more frequently or recommend a different treatment option for you.

Hypereosinophilic conditions. If you have certain conditions that increase your level of eosinophils, you may have an increased risk of developing heart problems during Gleevec treatment. (Eosinophils are a type of blood cell.)

Tell your doctor if you have any conditions that increase your eosinophil level, such as a myelodysplastic disease or aggressive systemic mastocytosis. They can advise if it’s safe for you to take Gleevec.

Older adults. Adults ages 65 years and older may have an increased risk of developing side effects when taking Gleevec. An example is swelling. If you’re an older adult, your doctor may monitor you more often for side effects throughout your Gleevec treatment.

Alcohol use and Gleevec

There are no known interactions between alcohol and Gleevec.

But alcohol and Gleevec may cause similar side effects, including nausea and vomiting. So drinking alcohol during Gleevec treatment may increase your risk of these side effects.

Alcohol may affect your liver and can cause liver damage. Gleevec can also cause liver problems or liver damage. As a result, drinking alcohol while taking the drug may increase your risk of developing liver problems.

If you drink alcohol, talk with your doctor about how much is safe to drink while you’re taking Gleevec.

Pregnancy and breastfeeding while taking Gleevec

Gleevec can cause harm to a developing fetus or breastfeeding child. As a result, you should not become pregnant or breastfeed during your Gleevec treatment.

If you can become pregnant, it’s recommended that you use an effective form of birth control during treatment. And you should continue using birth control for at least 14 days after stopping treatment.

You should also avoid breastfeeding during treatment and for at least 30 days after stopping it.

If you’re pregnant or breastfeeding, or planning to become pregnant or breastfeed, talk with your doctor before you start taking Gleevec.

You may have side effects from taking Gleevec. In most cases, they should be mild. But some of the drug’s side effects can be serious. You should be aware of the possible side effects so that you can discuss any with your doctor right away.

Here are some questions about Gleevec’s side effects that you may want to ask your doctor before starting treatment:

  • How should I treat any side effects of Gleevec that I may have?
  • Do I have an increased risk of side effects based on my other medical conditions?
  • Do the other medications that I’m taking with Gleevec increase my risk of side effects?
  • What should I do if I become pregnant while I’m taking Gleevec?

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.