Niraparib

Say it: nye-RAP-a-rib · Brand names: Zejula, Akeega

Niraparib is a targeted therapy pill called a PARP inhibitor that stops cancer cells from repairing their damaged DNA.

What it is

Cells use proteins called PARP to fix damaged DNA. When niraparib blocks PARP, cancer cells that already have trouble fixing DNA cannot repair themselves and die. It is often used to help keep cancer from growing after chemotherapy has worked.

Often used for

• ovarian, fallopian tube, or primary peritoneal cancer, to help keep it from growing after chemotherapy
• prostate cancer with a BRCA gene change, in a combination pill with abiraterone (Akeega)

How you get it

Niraparib is a pill you take by mouth at home, once a day, with or without food. Taking it at bedtime may help with nausea. Your schedule may be different.

Common side effects and what helps

• Low platelets, which can cause easy bruising or bleeding. You will have blood tests to check.
• Low red blood cells (anemia), which can make you tired or short of breath.
• Low white blood cells, which raise your chance of infection. Wash your hands often.
• Feeling sick to your stomach or throwing up. Eat small meals and ask your team about anti-nausea medicine.
• Feeling tired or weak. Rest when you need to, and try short walks.
• Constipation. Drink fluids and eat fiber.
• Trouble sleeping. Keep a regular bedtime and limit caffeine.
• Headache. Ask your team which pain medicines are safe.

Call your care team right away if you have

• A fever of 100.4 degrees Fahrenheit (38 degrees Celsius) or higher, or chills
• Unusual bruising or bleeding, feeling very weak or tired, or getting infections often
• A very bad headache, confusion, seizure, or changes in your eyesight
• Chest pain or pressure, or a racing or pounding heartbeat

Before you start, tell your team

• If you are pregnant, may become pregnant, or are breastfeeding
• If you have high blood pressure or heart problems
• If you have liver problems
• All the medicines, vitamins, and herbal products you take, since some can change how this medicine works

Good to know

• You will have blood tests to check your blood counts every week for the first month, then every month.
• It can raise blood pressure and heart rate. Your team will check these often, and you may be asked to check at home.
• Rarely, it can cause a serious blood or bone marrow cancer. Tell your team if you feel very tired, lose weight, bruise easily, or get fevers or infections often.
• This medicine can harm an unborn baby. Use birth control during treatment and for some time after. Ask your team how long.

At home

• Take it at about the same time each day.
• Swallow the pills whole.
• If you miss a dose or throw up after taking it, ask your team what to do. Do not take extra pills to make up for it.
• Store the pills at room temperature in the original bottle, away from children and pets.

Questions to ask

• How long will I take this medicine?
• Should I check my blood pressure at home?
• When will I have blood tests?
• Which side effects should I call about right away, and which can wait until my next visit?

Side effect guides

• Fatigue (tiredness)
• Nausea and vomiting
• Constipation
• Low white blood cells and infection risk
• Anemia (low red blood cells)
• Low platelets and bleeding
• Shortness of breath
• Sleep problems
• Pain

Last updated: 2026-10-27. Medically reviewed by Veli Bakalov, MD, medical oncologist (October 2026). General education from Step by Step, the patient portal of HemeOncBuddy.