Talzenna (talazoparib) is a prescription drug that’s used to treat certain kinds of breast cancer and prostate cancer. Talzenna can cause side effects that range from mild to serious. Examples include fatigue, nausea, and vomiting.

The active ingredient in Talzenna is talazoparib. (An active ingredient is what makes a drug work.) The drug comes as a capsule that you swallow.

Keep reading to learn about the common, mild, and serious side effects that Talzenna can cause. For a general overview of the drug, including details about its uses, see this article.

Some people may experience mild to serious side effects during Talzenna treatment. Examples of Talzenna’s 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 Talzenna include:

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

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

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

Talzenna can cause serious side effects. Some of these side effects are common.

Serious side effects that have been reported with Talzenna include:

If you develop serious side effects while taking Talzenna, 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.

* To learn more about this side effect, see the “Side effects explained” section below.
† An allergic reaction is possible after taking Talzenna, but this side effect wasn’t reported in studies.

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

Myelodysplastic syndrome or acute myeloid leukemia

Myelodysplastic syndrome (MDS) is a kind of cancer involving atypical blood cells formed in the bone marrow. Acute myeloid leukemia (AML), another cancer of the blood and bone marrow, may develop in some people with MDS.

In studies of Talzenna, MDS was not a common side effect. And people who developed MDS experienced treatment with certain chemotherapy drugs (traditional drugs used to treat cancer) before taking Talzenna.

Some people have a higher risk of MDS. Risk factors for MDS include:

  • taking certain chemotherapy drugs
  • being age 60 years or older
  • being male*
  • having certain inherited gene differences
  • smoking tobacco
  • having been exposed to certain industrial chemicals or radiation
  • having a family history of MDS

* In this article, we use the term “male” to refer to someone’s sex assigned at birth. For information about the difference between sex and gender, see this article.

Symptoms of MDS include:

What might help

Before you start taking Talzenna, talk with your doctor about your health history. Also, tell them about other cancer treatments you may have had.

If you’ve received chemotherapy or radiation, your doctor will likely recommend that you don’t start Talzenna for a certain period of time. This is to make sure that you’ve recovered from those treatments.

Also, you’ll have blood tests to help monitor your blood cell counts while you take Talzenna. If you have atypical levels of certain blood cells, your doctor may pause your Talzenna treatment and order weekly blood tests for you. The results will help them determine when it’s safe for you to resume Talzenna treatment.

If you develop MDS or AML, your doctor will likely discontinue your Talzenna treatment.


Fatigue (low energy) is a common side effect of Talzenna. During treatment with this drug, you may feel extremely tired or weak even when you get enough sleep.

Fatigue can be caused by certain factors, such as some side effects of the drug. An example is anemia (low red blood cell level).

Physical fatigue can lead to mental fatigue. With mental fatigue, you may have decreased concentration and memory.

Other causes of cancer fatigue include:

What might help

It’s important to try to describe the following aspects of your fatigue to your doctor:

  • when it started
  • how severe it is
  • whether your level of fatigue changes
  • what makes it better or worse
  • whether it affects your mood or thoughts

As part of your Talzenna treatment, your doctor will order regular blood tests. The results will help them to determine whether your fatigue is related to anemia or other serious side effects of the drug.

Your doctor can also suggest ways to manage your fatigue. They may recommend certain lifestyle changes or medications.

Here are a few tips you can try that may help ease fatigue:

If you have fatigue that is bothersome or does not go away, talk with your doctor.


Headaches are a common side effect of Talzenna. The headaches may be throbbing or sharp, or they may be dull and constant.

What might help

To help your doctor better assess your headaches, try keeping a headache journal. Write down when they happened, what kind of pain you felt, how long they lasted, and what may have triggered them.

Here are a few things you might try to help prevent headaches:

  • Take steps to reduce physical and emotional stress with relaxation techniques or progressive muscle relaxation.
  • Get a good night’s sleep.
  • Eat meals on a regular schedule.

To ease a headache, try using an ice pack on the area where you’re feeling pain. Or place a cool washcloth on your forehead or neck. Taking a warm shower or sitting for a while in a dimly lit room may also help.

If you’re having headaches while taking Talzenna, let your doctor know. They can give you more tips on how you can manage them at home. They may also recommend certain medications to ease your symptoms.


Anemia (low red blood cell level) is a common side effect of Talzenna. While anemia caused by Talzenna is usually temporary, it can be serious. In a study, anemia usually occurred in the first 3–4 months of treatment.

Symptoms of anemia include:

What might help

Before you start taking Talzenna, your doctor will order blood tests to check your level of red blood cells. You’ll continue to have these blood tests each month during treatment.

If you have anemia, your doctor may have you temporarily stop taking Talzenna until your red blood cell level improves. Then when you restart treatment, they may have you take a lower dosage of the drug. In the case of severe anemia, you might need medication or a blood transfusion.

If you have symptoms of anemia, talk with your doctor. They may recommend that you come in for a checkup and order another blood test.

Nausea and vomiting

Talzenna commonly causes nausea and vomiting. In studies, nausea occurred more often than vomiting.

Vomiting can cause dehydration, in which you have a low level of fluid in your body. This can lead to serious problems.

These side effects may be temporary or lessen over time during treatment.

What might help

To help prevent or reduce nausea and vomiting, try eating small meals regularly throughout the day. Avoid foods that are greasy or have lots of sugar. Drinking beverages containing ginger or peppermint tea may also help.

Generally, Talzenna can be taken with or without food. Taking your dose around the time of eating a meal or snack may help reduce nausea.

To help prevent dehydration, drink plenty of water. If you become seriously dehydrated from vomiting, you may need to receive fluids intravenously (given by injection into a vein over time) in a hospital.

Resting or avoiding strenuous physical activity may also help reduce your symptoms.

If you vomit after taking a dose of Talzenna, you should not take another dose. Take your next dose at your usual time.

If your nausea or vomiting is bothersome or does not go away, talk with your doctor. They can offer more tips that you can try at home. They may also recommend certain medications to ease these side effects.

Allergic reaction

Like most drugs, Talzenna can cause an allergic reaction in some people. But this side effect wasn’t reported in studies.

Symptoms can be mild to serious and may 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. They may suggest a treatment to manage your symptoms. Examples include:

  • an over-the-counter antihistamine that you take by mouth, such as Benadryl (diphenhydramine)
  • a product that you apply to your skin, such as hydrocortisone cream

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

Keeping track of side effects

During Talzenna treatment, consider taking 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 the drug you were taking when you had the side effect
  • how soon you had the side effect after starting that dose
  • what your symptoms were
  • 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 Talzenna affects you. They can then use this information to adjust your treatment plan if needed.

Talzenna 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 Talzenna. The list below includes factors to consider.

Increased risk of myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). In studies, MDS or AML occurred in some people taking Talzenna. These cases were rare, and they primarily occurred in people who had previously undergone platinum-based chemotherapy, radiation, or similar cancer treatments that can affect DNA. If you’ve had these types of treatment in the past, you may be at an increased risk of MDS and AML with Talzenna treatment.

If you have an increased risk of MDS* or are uncertain whether you do, talk with your doctor. They’ll likely monitor you more closely for MDS during treatment.

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

Blood cell disorders. Talzenna can decrease the activity of your bone marrow, resulting in decreased levels of certain blood cells. This is called myelosuppression. People with myelosuppression may have an increased risk of bleeding, anemia, and infections.

Before taking Talzenna, tell your doctor if you have any existing blood cell disorders. They’ll monitor your blood cell levels closely to determine whether it’s safe for you to take Talzenna. If certain blood cell levels decrease during your treatment with Talzenna, your doctor may temporarily stop your treatment until those levels improve. And they may lower your dose when you restart Talzenna.

* For a list of some factors that increase the risk of MDS, see the “Side effects explained” section above.

Alcohol and Talzenna

It’s unknown whether alcohol can interact with Talzenna. But your risk of certain side effects may increase if you drink alcohol during treatment.

Both alcohol and Talzenna can cause some of the same side effects, such as:

  • nausea
  • vomiting
  • diarrhea
  • fatigue (low energy)

Consuming alcohol while taking Talzenna may worsen such side effects.

If you drink alcohol, talk with your doctor about the safety of drinking alcohol during Talzenna treatment.

Pregnancy and breastfeeding while taking Talzenna

If you’re pregnant or breastfeeding, your doctor likely won’t recommend Talzenna as a treatment option.


You should not take Talzenna during pregnancy. Taking Talzenna while pregnant can harm a fetus.

If you’re able to become pregnant, your doctor will likely have you take a pregnancy test before you start Talzenna treatment. In addition, it’s recommended that you use birth control during Talzenna treatment and for at least 7 months after your last dose.

If your sexual partner is able to become pregnant, you also should use birth control during Talzenna treatment and for at least 4 months after your last dose.

Your doctor can suggest safe and effective birth control options to use during Talzenna treatment.

If you’re pregnant or plan to become pregnant, talk with your doctor. They may recommend a treatment option other than Talzenna for your condition.


It’s not known whether breastfeeding while taking Talzenna is safe. Due to the risk of harm to a child who is breastfed, your doctor will likely recommend that you not breastfeed during Talzenna treatment. It’s also recommended that you wait at least 1 month after your last dose to breastfeed.

If you’re breastfeeding or planning to breastfeed, talk with your doctor about safe ways to feed your child while taking Talzenna.

Talzenna can cause mild or serious side effects. Some of these are common, though not everyone will experience them. Before you start Talzenna treatment, talk with your doctor about its side effects. This can help you and your doctor decide whether this medication is a good treatment option for you. Below are some questions to help you get the conversation started.

  • What happens if I become pregnant during treatment with Talzenna?
  • Do my side effects have an effect on whether my Talzenna treatment is long term or not?
  • If I have certain other health conditions, am I at a higher risk of side effects?
  • What are the most common serious side effects that Talzenna can cause?

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If I have side effects from Talzenna, will my doctor change my treatment?



If you have side effects that are serious or bothersome, your doctor may adjust your dose of Talzenna. Depending on your side effects, they might temporarily stop your treatment. When you resume taking Talzenna, your doctor may lower your dose of the drug.

Here are a few examples of side effects that may result in changes to your Talzenna treatment:

If your dose needs to be reduced more than three times, your doctor will likely recommend that you stop taking Talzenna.

For more information about how side effects may change your treatment, talk with your doctor.

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