If you have a certain type of cancer, your doctor might suggest Pomalyst (pomalidomide) as a treatment option. It’s a prescription medication used to treat the following cancers in adults:

Pomalyst comes as a capsule you take by mouth. If you and your doctor agree that Pomalyst is working well for you, you’ll likely take it long term.

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

Like other drugs, Pomalyst can cause mild or serious side effects (also referred to as adverse effects). Keep reading to learn more.

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

Below are a few of the more common side effects reported in studies of people taking Pomalyst. Side effects can vary, depending on the condition that Pomalyst is being used to treat.

Some of the more common side effects in people taking Pomalyst for multiple myeloma include:

Some of the more common side effects in people taking Pomalyst for Kaposi sarcoma include:

  • low level of certain white blood cells called neutrophils
  • mildly high blood sugar levels
  • constipation
  • fatigue (low energy)
  • mild rash*

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

Like most drugs, Pomalyst can cause mild side effects. Some of these are more common than others. Examples of mild side effects that have been reported with Pomalyst 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. But if you have symptoms that are ongoing or bother you, talk with your doctor or pharmacist. And don’t stop taking Pomalyst unless your doctor recommends it. It’s not uncommon for people to need to reduce their Pomalyst dosage due to side effects.

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

Like most drugs, Pomalyst can cause side effects, including some serious ones, in rare cases.

Serious side effects that have been reported with Pomalyst include:

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

* Pomalyst 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 “Pregnancy and breastfeeding while taking Pomalyst” under the “Warnings for Pomalyst” section below.
** Pomalyst has a boxed warning for this side effect. This is the most serious warning from the 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.

Below are answers to some frequently asked questions about Pomalyst’s side effects.

Can Pomalyst cause long-term side effects?

While it’s not common, Pomalyst could cause long-term side effects.

Long-term side effects reported by people taking Pomalyst include:

These side effects could start any time while you’re taking Pomalyst. But they aren’t expected to start after your treatment has ended. Talk with your doctor or pharmacist if you’re interested in learning more about Pomalyst and its long-term side effects.

Will I experience hair loss from Pomalyst?

No, hair loss wasn’t a side effect reported by people taking Pomalyst in studies.

Hair loss can be caused by other drugs used to treat cancer, such as chemotherapy medications. But this side effect hasn’t been reported with Pomalyst.

Is weight gain possible with Pomalyst?

It’s possible, but weight gain while taking Pomalyst alone isn’t expected. This side effect was reported by people taking Pomalyst with the drug dexamethasone in studies. It’s not known how much weight was gained or whether it went away when people stopped the treatment.

Talk with your doctor if you’re concerned or have questions about your weight. They can recommend ways to maintain a weight that’s healthy for you.

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

Blood clots

Pomalyst has a boxed warning for blood clots. 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.

While blood clots with Pomalyst aren’t common, they did develop in studies when the drug was used to treat multiple myeloma. This side effect wasn’t reported in people taking the drug to treat Kaposi sarcoma, but it could still happen.

Symptoms of blood clots can include:

Certain risk factors can increase your chances of having blood clots while taking Pomalyst, including:

What might help

Before you start taking Pomalyst, tell your doctor if you have any of the risk factors for blood clots mentioned above. Your doctor can discuss with you the risks and benefits of taking Pomalyst.

Contact your doctor right away if you notice symptoms of blood clots while taking Pomalyst. Blood clots can be life threatening and may require treatment in a hospital.

Rash

It’s possible to have a skin rash while taking Pomalyst. Both mild and serious rashes were reported as side effects in Pomalyst’s studies. For more information about serious rashes and Pomalyst, see “Severe skin reactions” and “Allergic reaction” below.

What might help

Talk with your doctor if you develop a rash while taking Pomalyst. They can help determine if it’s a sign of a more serious reaction.

If your rash is mild, your doctor may recommend treatment or waiting to see if it goes away on its own. Most people who get a mild rash are able to keep taking Pomalyst.

Upper respiratory infection

Upper respiratory infections (URIs) are among the most common side effects of Pomalyst reported in studies. The common cold is an example of a URI.

Other medications sometimes used with Pomalyst, such as dexamethasone, can also increase your risk of infections, including URIs. Symptoms of a URI can include:

What might help

Contact your doctor if you have symptoms of a respiratory infection while taking Pomalyst. They can recommend treatments to help relieve the symptoms until the infection clears. They may also prescribe an antibiotic or antiviral to treat the infection.

Severe skin reactions

Severe and sometimes life threatening skin reactions have been reported with Pomalyst.
While these are extremely rare, they do require immediate treatment.

Examples of severe skin reactions that can be side effects of Pomalyst include:

Symptoms of a severe skin reaction can include:

  • blisters on your eyes, lips, mouth, or other areas of skin
  • fever
  • flu-like symptoms
  • severe rash or rash that continues to get worse
  • reddened or otherwise discolored skin
  • skin burning or pain
  • skin peeling

What might help

Contact your doctor immediately if you think you’re having a severe skin reaction during treatment with Pomalyst. These reactions can be life threatening and may require treatment in a hospital. If your symptoms feel life threatening, seek emergency medical attention right away.

Your doctor may have you stop taking Pomalyst if you have a severe skin reaction. They can discuss other treatment options for your condition with you.

Allergic reaction

Like most drugs, Pomalyst can cause an allergic reaction in some people. Symptoms can 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.

They may suggest the following to help you manage your symptoms:

If your doctor confirms that you’ve had a mild allergic reaction to Pomalyst, they’ll decide if you should keep 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’ve had a serious allergic reaction to Pomalyst, they may have you switch to a different treatment.

Keeping track of side effects

Consider taking notes about any side effects you’re having during your Pomalyst treatment. You can then share this information with your doctor. This is especially helpful when you first start taking a new medication 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 you experienced it after starting that dosage
  • what your symptoms were
  • how they affected your daily activities
  • any other medications you were taking
  • any other information you feel is important

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

Treatment with Pomalyst may not be right for you if you have certain medical conditions or other factors that affect your health.

Pomalyst also carries two boxed warnings, which must be considered before taking it.

Boxed warnings

Pomalyst has boxed warnings about fetal harm and blood clots. Boxed warnings are the most serious warnings from the Food and Drug Administration (FDA).

  • Fetal harm. Treatment with Pomalyst is known to cause fetal harm. Due to this risk, doctors typically will not prescribe Pomalyst if you’re pregnant. To learn more, see “Pregnancy and breastfeeding while taking Pomalyst” below.
  • Blood clots. Treatment with Pomalyst can cause blood clots. To learn more, see the “Side Effects Explained” section above.

Other warnings

Pomalyst 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 treatment with Pomalyst. The list below includes factors to consider.

Blood clots in the past. Treatment with Pomalyst can result in blood clots as a side effect. Your risk of blood clots is higher if you’ve had one in the past. Your doctor can help determine if Pomalyst is safe for you.

High blood pressure. Having high blood pressure can increase your risk of blood clots if you take Pomalyst. Your doctor can help determine if Pomalyst is safe for you if you have high blood pressure.

High cholesterol. Having high cholesterol can increase your risk of blood clots if you take Pomalyst. Your doctor can help determine if Pomalyst is safe if you have this condition.

Severe kidney problems that require dialysis. Dialysis may remove Pomalyst from your blood. If you’re on dialysis, you’ll need to have your dosage adjusted. Your doctor can provide more information about taking Pomalyst if you have kidney problems.

Liver problems. Your body uses your liver to get rid of Pomalyst after you take a dose. Having liver problems, such as hepatitis, could affect how well your body can get rid of Pomalyst. This can increase your risk of side effects. Your doctor can provide more information about taking Pomalyst if you have liver problems.

Smoking. Smoking increases your risk of blood clots, which are a possible side effect of Pomalyst. Before you begin taking Pomalyst, let your doctor know if you smoke. They may want you to smoke less or quit smoking during the treatment.

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

Alcohol use and Pomalyst

There’s no known direct interaction between Pomalyst and alcohol.

But drinking alcohol could increase your risk of liver damage, which is also a rare side effect of Pomalyst.

Talk with your doctor if you drink alcohol. They can advise you how much, if any, may be safe for you during Pomalyst treatment.

Pregnancy and breastfeeding while taking Pomalyst

You should not take Pomalyst while pregnant. See “Fetal harm” just below for more information.

You also should not take Pomalyst while breastfeeding. It’s not known if the drug is present in human breast milk. But if it is, it could cause serious side effects in a breastfed child. Talk with your doctor about other feeding options for your child if you take Pomalyst.

Fetal harm

Pomalyst has a boxed warning about the risk of fetal harm if the drug is taken during pregnancy. A boxed warning is the most serious warning from the FDA.

A drug similar to Pomalyst, called thalidomide, is known to have caused severe problems with fetal development and miscarriage in pregnant people. Because of this risk, Pomalyst is not safe to take while you’re pregnant.

If you can become pregnant, you should use at least two forms of effective birth control:

  • for at least 4 weeks prior to starting treatment with Pomalyst
  • while taking Pomalyst
  • for at least 4 weeks after your last dose of the drug

If you’re capable of becoming pregnant, your doctor will order two pregnancy tests for you before you start Pomalyst. Both must be negative before they’ll prescribe Pomalyst to you. You’ll need to continue having negative pregnancy tests while taking this medication.

If you become pregnant while taking Pomalyst, stop taking the medication and immediately contact your doctor.

If you’re male* and have a sexual partner who can become pregnant, you should use condoms while taking Pomalyst and for at least 4 weeks after your last dose. This applies even if you’ve had a vasectomy. You should also not donate sperm while taking Pomalyst and for at least 4 weeks after your last dose.

Because of these risks, there are special safety requirements for people taking Pomalyst. Your doctor or pharmacist can provide more information.

* Sex and gender exist on spectrums. Use of the term “male” in this article refers to sex assigned at birth.

If you have certain types of cancer, your doctor may recommend treatment with Pomalyst. Like most drugs, taking Pomalyst can cause side effects, including some serious ones, in rare cases.

Pomalyst has several boxed warnings, the most serious warning a drug may be given by the Food and Drug Administration (FDA). See the “Side effects explained” section above for more information.

Talk with your doctor or pharmacist if you’re interested in learning more about taking Pomalyst for your condition. Ask questions to get the answers you need to feel confident about your cancer treatment. Some questions to consider are:

  • Are there ways I can reduce my risk of side effects from Pomalyst?
  • If I develop side effects while taking Pomalyst, can I take a lower dosage?
  • Do other medications I take increase my risk of side effects from Pomalyst?

Q:

Are there lab tests my doctor can order to check for side effects that Pomalyst may cause?

Anonymous

A:

There are many tests your doctor may order while you’re taking Pomalyst to see how your body is responding to it.

Your doctor may order blood tests to check your complete blood count. This can show if you’re having a negative response, such as an infection.

Other tests include those for kidney function and liver function. This is because both of these organs play a role in how Pomalyst is removed from your body. If your kidney or liver function decreases, Pomalyst could build up in your body. And this could increase your risk of side effects.

Depending on the results of these tests, your doctor may adjust your dosage of Pomalyst, or stop or change your treatment.

Elizabeth Scheffel, PharmDAnswers 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.