Zejula (niraparib) is a brand-name drug prescribed for certain types of ovarian, fallopian tube, or primary peritoneal cancers in adults. As with other drugs, Zejula can cause side effects, such as nausea and fatigue.

Zejula can cause certain side effects, some of which are more common than others. These side effects may be temporary, lasting a few days to weeks. However, 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 Zejula for ovarian cancer in clinical trials:

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

Mild side effects that people taking Zejula have reported include:

These side effects may be temporary, lasting a few days to weeks. However, 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 and reviews side effects of the medication. If you develop a side effect while taking Zejula and want to tell the FDA about it, visit MedWatch.

Zejula may cause serious side effects, but they’re not common. The list below may not include all possible serious side effects of the drug. For more information, you can refer to the Zejula prescribing information.

If you develop serious side effects while taking Zejula, 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:

ALLERGIC REACTION

For some people, Zejula can cause an allergic reaction. But it’s not clear whether this side effect occurred in the drug’s clinical trials.

In general, symptoms of allergic reaction can be mild or serious.

Ways to manage

For mild allergic reaction symptoms, such as a mild rash, call your doctor right away. They may recommend treatments to help manage your symptoms. They’ll also let you know whether you should keep taking the medication.

For severe allergic reaction symptoms, such as swelling or trouble breathing, call 911 or your local emergency number right away. These symptoms require immediate medical care because they can become life threatening. If you’ve had a serious allergic reaction to Zejula, your doctor may recommend taking a different medication instead.

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

Does Zejula cause long-term side effects?

Yes, it’s possible. Long-term side effects include those that can start at anytime during Zejula treatment, even if you’ve been taking it for a long time. It also includes side effects that don’t go away even after you stop taking the drug. Long-term side effects reported in clinical trials of Zejula include:

  • kidney problems, including kidney failure
  • posterior reversible encephalopathy syndrome
  • bone marrow or blood cancers, such as AML or MDS
  • bone marrow suppression
  • high blood pressure

For details about bone marrow suppression and high blood pressure, see “Side effect specifics.” To learn more about the other side effects listed, refer to the “Serious side effects of Zejula” section.

Keep in mind that you’ll likely take Zejula until your cancer worsens or you have side effects that can’t be managed. If you’re concerned or have questions about the drug’s long-term side effects, talk with your doctor or pharmacist.

Does Zejula cause weight gain?

Weight gain wasn’t reported as a side effect in clinical trials of Zejula. In fact, treatment with Zejula can decrease your appetite, which may cause weight loss in some people.

Weight loss is also a side effect of certain bone marrow problems, such as MDS, that can occur with Zejula. Talk with your doctor if you experience weight loss along with any of the following symptoms:

  • shortness of breath
  • weakness
  • blood in your urine or stool
  • bleeding or bruising more easily than usual
  • fever

Talk with your doctor if you have concerns about weight changes while taking Zejula.

Learn more about some of the side effects that Zejula may cause. To find out how often side effects occurred in clinical trials, see the drug’s prescribing information.

Bone marrow suppression

Zejula can cause bone marrow suppression, which is a decreased level of certain blood cells. This was a common side effect reported in the drug’s clinical trials. The most common conditions that people reported were thrombocytopenia (low platelets), anemia (low red blood cells), and neutropenia (low white blood cells). Sometimes, the level of all blood cells is reduced, which is known as pancytopenia.

Your blood needs platelets to clot as usual. Symptoms of a low platelet count may include:

  • bruising more easily
  • petechiae (small purple or red spots in the skin)
  • bleeding gums
  • bleeding that doesn’t stop

Red blood cells (RBCs) carry oxygen throughout your body. With a low RBC count, your body doesn’t receive as much oxygen as usual. Symptoms may include:

  • weakness or fatigue
  • paleness
  • shortness of breath
  • lightheadedness

White blood cells (WBCs) help fight off infections. A low WBC count may not cause symptoms but can increase your risk of infection. Symptoms of an infection may include fever, cough, and sore throat.

You may have a higher risk of bone marrow suppression if you’re also receiving other treatments, such as chemotherapy.

What you can do

Your doctor will order a blood test (a complete blood count) before you start treatment with Zejula to check your blood cell levels. After you start treatment, they’ll likely order the blood test every week for the first month, then once a month for a year.

Zejula can rarely cause certain bone marrow and blood cancers, including AML or MDS. These cancers have occurred from 3 months to 6 years after starting treatment with Zejula. AML and MDS can have the same symptoms as low blood cell levels.

If you have symptoms of bone marrow suppression, contact your doctor right away. They’ll likely want to check your blood count. If you have low blood cell levels, your doctor may recommend that you stop taking Zejula until they return to previous levels. Sometimes, your doctor may refer you to a blood specialist for further evaluation.

High blood pressure

High blood pressure was a common side effect reported by people taking Zejula in clinical trials. This condition typically doesn’t cause any symptoms, but sometimes, it may become severe. Symptoms of severely high blood pressure may include:

  • headache
  • dizziness
  • nosebleed
  • shortness of breath
  • vision changes

What you can do

Your doctor will likely monitor your blood pressure and heart rate once a week during your first 2 months of treatment with Zejula. After that, they’ll continue to monitor these monthly during the first year of treatment.

If you already have high blood pressure or other heart problems, such as an irregular heart rhythm, your doctor will monitor your blood pressure more closely while you’re taking Zejula.

If you experience any of these symptoms while taking Zejula, call your doctor right away. Your doctor may prescribe medication to lower your blood pressure and may need to change your Zejula dose. If you feel your symptoms are life threatening, call 911 or your local emergency number.

Below is important information you should consider before starting Zejula.

Before taking Zejula, discuss your health history with your doctor. Zejula may not be right for you if you have certain medical conditions or other factors affecting your health. Be sure to talk with your doctor if any of the following apply to you:

  • high blood pressure
  • heart problems, including an irregular heart rhythm
  • liver problems
  • previous allergic reaction to this or a similar drug
  • pregnancy
  • breastfeeding
  • alcohol consumption

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.