Olaparib (Lynparza)

Olaparib is a targeted therapy. Targeted therapy is the name given to a group of drugs that block the growth and spread of cancer. They target and interfere with processes in the cells that help cancer grow.  

Olaparib belongs to a group of drugs called PARP inhibitors.

Olaparib is the drug’s non-branded name. Its brand name is Lynparza.

You may have olaparib if your breast cancer is:

• HER2 negative
• And you have an altered BRCA gene

Primary breast cancer

Olaparib can be given to treat primary breast cancer that has a high risk of returning.

You’ll have olaparib after other treatments such as chemotherapy, surgery and radiotherapy.

Locally advanced or metastatic breast cancer

Olaparib can be given to treat locally advanced or metastatic (secondary) breast cancer if you have already had:

• Chemotherapy with an anthracycline or a taxane, or both, unless these treatments were not suitable
• And hormone (endocrine) therapy if your breast cancer is hormone receptor positive, unless this was not suitable

Olaparib is a PARP inhibitor.

PARP is a protein that helps damaged cells repair themselves.

Cancer cells with altered BRCA genes are less able to repair themselves if they become damaged. PARP inhibitors stop these cancer cells from repairing themselves, so they become too damaged to survive.

You take olaparib as a tablet twice a day.

You can take it with or without food.

How long will I have olaparib for?

Primary breast cancer

You’ll take olaparib for around 1 year.

Locally advanced or metastatic breast cancer

You’ll take olaparib for as long as your treatment team feels you’re benefitting from the drug and any side effects are manageable.

Like any treatment, olaparib can cause side effects. Everyone reacts differently to drugs and some people have more side effects than others. These side effects can usually be managed and those described here will not affect everyone. 

If you’re worried about any side effects, regardless of whether they’re listed here, talk to your treatment team. 

Because olaparib may be given alongside other drugs, you may also have side effects from these. It’s sometimes difficult to know which drug causes which side effect.

Common side effects

Effects on the blood 

Olaparib can temporarily affect the number of blood cells in the body. Blood is made up of red cells, white cells and platelets. 

You’ll have regular blood tests. If these show the number of blood cells is too low, your next cycle of treatment may be delayed or the dose reduced.

Your treatment team may change the dose of a drug to suit you and help manage its side effects. This may help you stay on the treatment for longer. 

Risk of infection 

Not having enough white blood cells can increase your risk of getting an infection. 

Before starting treatment, you should be given a 24-hour contact number or told who to contact if you feel unwell at any time during your treatment, including overnight or at the weekends.

You may need treatment if you get an infection.

Anaemia

Having too few red blood cells is called anaemia. If you feel breathless, dizzy or particularly tired, let your treatment team know.

Bruising and bleeding 

Olaparib can reduce the number of platelets. Platelets help the blood to clot.

If your platelets are low, you may: 

• Bruise more easily 
• Have nosebleeds 
• Notice that your gums bleed when you brush your teeth 
• Take longer to stop bleeding if you cut yourself 

Tell your treatment team if you have any of these symptoms. 

Nausea and vomiting

You may feel sick (nausea) and be sick (vomit) at times during your treatment.

If nausea and vomiting affect you, let your treatment team know. They may prescribe anti-sickness drugs to help. 

Try to eat small meals throughout the day and drink often.

Extreme tiredness (cancer-related fatigue) 

Fatigue is extreme tiredness that does not go away with rest or sleep.

If you think you have fatigue, tell your GP or treatment team. They can assess you and offer advice on how to manage your energy levels. 

Find out more about managing fatigue.

Dizziness

Do not drive if you feel dizzy.

If dizziness carries on, speak to your treatment team or GP.

Diarrhoea

Contact your treatment team if you have diarrhoea 3 or more times in 24 hours, compared to what’s usual for you. 

Other common side effects

Other common side effects of olaparib include:

• Headaches
• Cough or shortness of breath
• Loss of appetite
• Taste changes
• Heartburn or indigestion
• Skin rash

Less common side effects

Liver and kidney changes

Olaparib can affect how the liver and kidneys work.

Your treatment team will arrange regular blood tests while you’re having treatment to check for this.

Other less common side effects

Other less common side effects of olaparib include:

• Tummy (abdominal) pain
• Sore mouth

Allergic reaction

Allergic reactions to olaparib are uncommon.

Call the 24-hour contact number you were given immediately if you notice any of the following:

• Breathlessness, wheezing, a bad cough or sudden difficulty breathing 
• Tight chest or chest pain 
• Swelling in your lips, tongue or throat 
• Itchy red or discoloured bumps on your skin (these may be harder to see on black or brown skin) 

Blood clots

People with breast cancer have a higher risk of blood clots. Having olaparib also increases the risk of blood clots such as a DVT (deep vein thrombosis). 

If you have a DVT, there’s a risk part of the blood clot could break away and travel to the lung. This is known as a pulmonary embolism (PE).  

Blood clots can be life-threatening and should be treated quickly. 

Medicines and food to avoid when having olaparib

Avoid grapefruit juice and Seville oranges while taking olaparib as these can affect how the drug works.

There are several drugs you should not take with olaparib. Tell your treatment team about any prescribed or over-the-counter medicines you’re taking.

Always ask your treatment team before taking any herbal medicines or supplements.

Sex and contraception

You can still have sex during treatment. It’s thought some drugs used to treat breast cancer cannot pass into vaginal fluids or semen, but this cannot be completely ruled out. 

Most treatment teams will advise women use barrier methods of contraception, like condoms or female condoms, during treatment and for 6 months after the last dose of olaparib.  

Men should use condoms during treatment and for 3 months after the last dose if their partner could get pregnant.

You’re advised not to become pregnant while having treatment because olaparib can harm a developing baby. If you have not been through the menopause, talk to your team about the most suitable method of contraception for you. It’s still possible to become pregnant even if your periods are irregular or have stopped naturally or because of treatment for breast cancer. 

Fertility

It’s not known if olaparib affects your ability to get pregnant (fertility).

Conversations about fertility can be hard. It’s important to discuss any fertility concerns with your treatment team before you begin your treatment. 

You can talk to your treatment team about fertility preservation options.

Breastfeeding

Breastfeeding is not recommended while having olaparib and for at least 1 month after the last dose. This is because there’s a risk the drugs could be passed on through breast milk.

Travel and vaccinations

If you’re planning a holiday or need to travel overseas, check with your treatment team first.  

You should not have any live vaccines while you’re having treatment. 

For more information about vaccines, including COVID-19 and flu vaccines, see our information on vaccines and breast cancer.

Being diagnosed with breast cancer can make you feel lonely and isolated.

Many people find it helps to talk to someone who has been through the same experience as them. You can ask questions and chat to other people on our online forum. 

And if you’ve been diagnosed with metastatic breast cancer, our Living with Secondary Breast Cancer services are also here for you. Choose the type of support that suits you and you’ll be able to talk, listen and learn with people who understand the challenges that metastatic breast cancer can bring. Find out more below.