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Generic name: niraparib [ nih-RAP-a-rib ]
Brand name: Zejula
Dosage form: oral capsule (100 mg)
Drug class: PARP inhibitors

Medically reviewed by on Jul 21, 2022. Written by Cerner Multum.

What is niraparib?

Niraparib is used as a "maintenance" treatment in adults to keep certain types of cancer from coming back. This includes cancers of the ovary, fallopian tube, or peritoneum (the membrane that lines the inside of your abdomen and covers some of your internal organs).

Niraparib is given after you have received chemotherapy (with cisplatin, oxaliplatin, carboplatin, or similar) and your cancer has responded to that medicine.

Niraparib is sometimes used only if your cancer has a specific genetic marker (an abnormal "BRCA" gene) or other gene mutations. Your doctor will test you for this gene.

Niraparib may also be used for purposes not listed in this medication guide.


Stop taking niraparib and call your doctor at once if you have fever, frequent infections, weakness, tiredness, shortness of breath, weight loss, blood in your urine or stools, easy bruising or bleeding. These may be symptoms of bone marrow disorder and may lead to death.

Before taking this medicine

Tell your doctor if you have ever had:

You may need to have a negative pregnancy test before starting this treatment.

Do not use niraparib if you are pregnant. It could harm the unborn baby or cause a miscarriage. Use effective birth control to prevent pregnancy while you are using this medicine and for at least 6 months after your last dose.

This medicine may affect fertility (the ability to have children) in men. Talk with your doctor about your individual risk.

Do not breastfeed while using this medicine and for at least 1 month after your last dose.

Niraparib is not approved for use by anyone younger than 18 years old.

How should I take niraparib?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

Do not share niraparib with another person, even if they have the same symptoms you have.

Take the medicine at the same time each day, with or without food.

Niraparib is usually taken once a day until your body no longer responds to the medication.

Niraparib may be taken at bedtime if it upsets your stomach.

Swallow the capsule whole and do not crush, chew, break, or open it.

If you vomit shortly after taking niraparib, do not take another dose. Wait until your next scheduled dose time to take the medicine again.

Niraparib can lower your blood cell counts. Your blood will need to be tested often. Your cancer treatments may be delayed based on the results.

Your blood pressure and heart rate will also need to be checked often.

Store at room temperature away from moisture and heat.

What happens if I miss a dose?

Skip the missed dose and use your next dose at the regular time. Do not use two doses at one time.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while taking niraparib?

Follow your doctor's instructions about any restrictions on food, beverages, or activity.

Niraparib side effects

Get emergency medical help if you have signs of an allergic reaction: hives; difficult breathing; swelling of your face, lips, tongue, or throat.

Stop taking niraparib and call your doctor at once if you have signs of a bone marrow disorder: fever, frequent infections, weakness, tiredness, feeling short of breath, weight loss, blood in your urine or stools, easy bruising or bleeding.

Niraparib may cause serious side effects. Call your doctor at once if you have:

  • pounding heartbeats or fluttering in your chest;

  • sores or white patches in or around your mouth, trouble swallowing or talking, dry mouth, bad breath, altered sense of taste;

  • pain or burning when you urinate; or

  • severe headache, blurred vision, pounding in your neck or ears.

Your cancer treatments may be delayed or permanently discontinued if you have certain side effects.

Common side effects of niraparib may include:

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect niraparib?

Other drugs may affect niraparib, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell your doctor about all your current medicines and any medicine you start or stop using.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use this medication only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.