A PARP inhibitor used as maintenance treatment in ovarian cancer
Niraparib
A targeted cancer tablet used as maintenance treatment to keep ovarian cancer under control after chemotherapy.
What is Niraparib?
Niraparib is a specialist targeted cancer medicine belonging to a group called PARP inhibitors. It is mainly used as maintenance treatment in ovarian cancer, taken after chemotherapy has worked to help keep the cancer under control for longer. It is taken by mouth as a daily capsule. Its most important effects are on the blood: it can lower platelets, red cells and white cells, so blood counts are checked regularly, especially in the first months. It can also raise blood pressure and cause tiredness. Rarely, it carries a risk of serious bone-marrow conditions (MDS or leukaemia). It is harmful to a developing baby, so reliable contraception is important.
Education and reference only. This is a plain-language guide to Niraparib — it deliberately contains no doses. Doses depend on the person, the brand and the reason for treatment, and belong with your prescriber. Always check the BNF, the product labelling (SmPC) and follow medical advice.
What it is
Niraparib is a targeted cancer treatment in a group of medicines called PARP inhibitors. It is used mainly as maintenance treatment in ovarian cancer, meaning it is taken after chemotherapy has shrunk or controlled the cancer, to help keep it from coming back as quickly. It is taken by mouth as a capsule, usually once a day. It works particularly well in cancers that already have difficulty repairing their DNA. It is prescribed and closely monitored by a specialist cancer team, with regular blood tests, especially during the first few months of treatment.
How it works
Cancer cells, like all cells, must repair damage to their DNA to survive. PARP is one of the tools cells use for these repairs. Niraparib blocks PARP, so cancer cells can no longer fix certain types of DNA damage. In cancers that are already poor at DNA repair, blocking this backup tool tips them over so they die. Healthy cells, which usually have better repair systems, are affected less. Because it is taken every day, it keeps PARP blocked continuously, which is why it suits ongoing maintenance treatment.
Company & origin
Originated / developed by: Specialist manufacturer.
A specialist targeted cancer medicine used in the UK, mainly as maintenance treatment to keep ovarian cancer under control after it has responded to chemotherapy.
Practical use
How to take Niraparib
General, dose-free guidance — always follow your prescriber's and the leaflet's specific instructions.
- Take it by mouth once a day, at about the same time, with or without food; bedtime can help with nausea.
- Attend your blood tests, which are frequent at first, so blood counts can be watched and the dose adjusted if needed.
- Have your blood pressure checked as advised, as it can rise during treatment.
- Report unusual bruising, bleeding, signs of infection or marked tiredness to your team promptly.
- Use reliable contraception during treatment and for the time your team advises, as it is harmful to a developing baby.
Weighing it up
Advantages & disadvantages of Niraparib
Advantages
- Helps keep ovarian cancer under control for longer after chemotherapy, as maintenance treatment.
- Taken as a convenient daily capsule rather than an infusion.
- Works well in cancers that are poor at repairing their own DNA.
Disadvantages
- Can lower blood counts, raising the risk of bleeding, anaemia and infection, needing regular checks.
- Can raise blood pressure and commonly causes tiredness, nausea and constipation.
- Carries a rare but serious risk of bone-marrow conditions such as MDS or leukaemia.
Practical use
Good to know
The effect that matters most with niraparib is on the bone marrow and blood: it can lower platelets (raising the risk of bruising and bleeding), red cells (causing anaemia and tiredness) and white cells (raising infection risk), so blood counts are checked often, particularly in the first months, and the dose may be adjusted. It can also raise blood pressure, which is monitored, and commonly causes tiredness, nausea and constipation. A rare but serious risk shared by this group of medicines is a bone-marrow condition (called MDS) or a type of leukaemia, which is part of why long-term blood monitoring continues. It can be taken with or without food, and taking it at bedtime can help with nausea. It is harmful to a developing baby, so reliable contraception is needed during treatment and for a time afterwards.
Who should not take it / use with caution
- People who have had a serious allergic reaction to niraparib should not take it.
- It is used with care in people with existing low blood counts, which are checked before and during treatment.
- It is not used in pregnancy or breastfeeding because it is harmful to a developing baby, and contraception is needed.
- It should only be used under a specialist cancer team with regular blood monitoring.
Monitoring
- Regular blood counts, frequent at first, to watch platelets, red cells and white cells.
- Regular blood pressure checks during treatment.
- Long-term watching for bone-marrow problems, and scans to see how the cancer is responding.
Side effects
- Low platelets, red cells or white cells, causing bruising, bleeding, anaemia, tiredness or infections.
- Raised blood pressure, which is monitored during treatment.
- Nausea, constipation, tiredness and trouble sleeping.
- Rarely but seriously, bone-marrow conditions such as MDS or a type of leukaemia.
Key interactions
- It can add to the effects of other medicines that lower blood counts, so these are reviewed.
- Medicines for blood pressure or heart rate may need reviewing, as blood pressure can rise.
- Give a full medicines list, including supplements, to your specialist team.
Available as: Capsules taken by mouth.
Answers
Niraparib: frequently asked questions
What is niraparib used for?
It is used mainly as maintenance treatment in ovarian cancer, taken after chemotherapy has worked, to help keep the cancer under control for longer.
Why do I need so many blood tests?
Niraparib can lower platelets, red cells and white cells, so blood counts are checked often, especially in the first months, and the dose may be adjusted.
Can it affect my blood pressure?
Yes. It can raise blood pressure, so this is monitored during treatment and may need treating if it rises.
Is there a risk of another cancer?
Rarely, this group of medicines carries a risk of serious bone-marrow conditions such as MDS or leukaemia, which is why blood monitoring continues long term.
Do I need contraception?
Yes. Niraparib is harmful to a developing baby, so reliable contraception is needed during treatment and for the time your team advises afterwards.
Authoritative sources
- BNF
- NICE CKS
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