What is zanubrutinib (Brukinsa®)?

Zanubrutinib (Brukinsa®) is a type of drug called a tyrosine kinase inhibitor (TKI). It belongs to a group of targeted therapy drugs known as cancer growth inhibitors. Tyrosine kinases are proteins in the body that help cancer cells grow and divide.

Zanubrutinib blocks the proteins (kinases) from sending signals to the cancer cells to grow. Blocking the signals causes the cells to die. This may help to stop or slow down the cancer.

It is best to read this information with our general information about the type of cancer you have. 

Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment. 

More information about this treatment

This information is correct at time of publishing. But sometimes the types of cancer this treatment is used for, or treatment side effects, may change between revision dates.

You can talk to your cancer team if you want more detailed information about this treatment. Or visit the electronic Medicines Compendium (eMC) website, which has patient information leaflets (PIL) for individual drugs.

How zanubrutinib is given

You will be given zanubrutinib as capsules to take at home.

During treatment, you usually see a:

  • cancer doctor
  • cancer nurse or specialist nurse
  • specialist pharmacist.

This is who we mean when we mention doctor, nurse or pharmacist in this information.

You will have regular blood tests during your treatment. This is to check your general health and that your blood cells are at a safe level to have treatment.

You will speak to a doctor, nurse or pharmacist regularly during your treatment. They will ask you how you have been feeling. A nurse or pharmacist will give you the zanubrutinib capsules to take at home.

Your course of treatment

You usually keep taking zanubrutinib every day for as long as it keeps the cancer under control and any side effects can be managed. Sometimes the dose might need to be reduced or treatment stopped for a while to manage side effects.

Your nurse or pharmacist may also give you some anti-sickness drugs and other medicines to take home. Take all your medicines exactly as they have been explained to you. 

Taking zanubrutinib

Your doctor, nurse or pharmacist will explain how to take your capsules. 

Always take zanubrutinib exactly as explained to you. This is important to make sure it works as well as possible for you.

Zanubrutinib comes as 80mg capsules. The usual dose of zanubrutinib is 320mg a day. 

You can either take zanubrutinib as: 

  • 4 capsules (320mg) once a day 
  • 2 capsules (160mg) in the morning and 2 capsules (160mg) in the evening. 

You should try and take the capsules at the same times each day. Swallow the capsules whole with a glass of water. They should not be chewed, broken, or opened. You can take the capsules with or without food.

If you forget to take a dose

If you take zanubrutinib once a day and forget to take a dose, take your next dose as usual the following day. 

If you take zanubrutinib twice a day and you forget to take it in the morning, take your next dose as usual in the evening. If you forget to take your evening dose, take your next dose as usual the following morning. 

If you forget a dose, do not take a double dose to make up for the forgotten one.

If you are not sure, contact your doctor, pharmacist or nurse about when to take your next dose.

Here are some other things to remember about your capsules:

  • Do not have grapefruit or Seville oranges (bitter oranges) while you are taking zanubrutinib. This includes eating these fruits, drinking the juice, or taking supplements that might contain them. These fruits can increase the amount of zanubrutinib in your blood. 
  • Wash your hands after taking your capsules.
  • Other people should avoid direct contact with the capsules. 
  • Keep the capsules in the original package and at room temperature, away from moisture, heat and direct sunlight.
  • Keep the capsules safe, somewhere children cannot see or reach them. 
  • If you are sick just after taking the capsules, contact the hospital. Do not take another dose.
  • If your treatment is stopped, return any unused capsules to the pharmacist. 

About side effects

We explain the most common side effects of this treatment here. We also include some that are less common. 

You may get some of the side effects we mention, but you are unlikely to get all of them. And you may have some side effects, including rarer ones, that we have not listed here. 

Other cancer treatments may cause different side effects. If you are also having other cancer treatment, you may have other side effects.

Always tell your doctor, nurse or pharmacist about any side effects you have. They can give you: 

  • drugs to help control some side effects 
  • advice about managing side effects. 

It is important to take any drugs exactly as explained. This means they will be more likely to work for you.

Serious and life-threatening side effects

Some cancer treatments can cause serious side effects. Sometimes, these may be life-threatening. Your doctor, nurse or pharmacist can explain the risk of these side effects to you.

Contact the hospital

Your doctor, nurse or pharmacist will give you 24-hour contact numbers for the hospital. If you feel unwell or need advice, you can call at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

Common side effects

Risk of infection

This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is sometimes called neutropenia.

Your doctor may give you antibiotics and other drugs to try to stop you getting an infection. These are called prophylactic medicines.

An infection can be very serious when the number of white blood cells is low. It is important to get any infection treated as soon as possible. Contact the hospital straight away on the 24-hour contact number you have been given if:

  • your temperature goes over 37.5°C (99.5°F)
  • you suddenly feel unwell, even with a normal temperature
  • you have symptoms of an infection
  • your temperature goes below 36°C (96.8°F).

Symptoms of an infection include:

  • feeling shivery and shaking
  • a sore throat
  • a cough 
  • breathlessness
  • diarrhoea
  • needing to pass urine (pee) a lot, or discomfort when you pass urine.

It is important to follow any specific advice your cancer treatment team gives you.

You will have regular blood tests during treatment. If your white blood cell count is low, your doctor may reduce or stop your treatment for a while, until your cell count increases.

Anaemia (low number of red blood cells)

This treatment can reduce the number of red blood cells in your blood. 

Red blood cells carry oxygen around the body. If the number of red blood cells is low, this is called anaemia. You may have symptoms such as:

  • pale skin 
  • lack of energy
  • feeling breathless 
  • feeling dizzy and light-headed. 

Tell your doctor or nurse if you have these symptoms. 

Sometimes, if you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.

Bruising and bleeding

Zanubrutinib can increase the risk of bleeding and reduce the number of platelets in your blood. Platelets are cells that help the blood to clot. 

Tell your doctor or pharmacist if you are taking any medicines that can affect bleeding. This includes: 

  • tablets such as aspirin and ibuprofen
  • treatment to prevent blood clots such as warfarin, apixaban or rivoroxiban,  
  • supplements such as fish oil, vitamin E or flaxseed 

If you have a low number of platelets in your blood, you may bruise or bleed easily. You may have:

  • nosebleeds
  • bleeding gums
  • heavy periods
  • tiny red or purple spots on your skin that may look like a rash.

Tell your doctor if you have any unexplained bruising or bleeding. Sometimes, you may need a drip to give you extra platelets. This is called a platelet transfusion. 

You should contact your doctor straight away if you have any heavy or unusual bleeding. This includes: 

  • vomiting or coughing up blood
  • unexpected vaginal bleeding
  • blood in your urine (pee) or stools (poo)

If you need surgery or dental treatment, your doctor may ask you to stop taking zanubrutinib for a few days before and after the treatment.


This treatment may cause diarrhoea. Diarrhoea means passing more stools (poo) than is normal for you, or having watery or loose stools. You may also have stomach cramps. If you have a stoma, it may be more active than usual. 

If you are passing loose stools 3 or more times a day and this is not normal for you, contact the hospital as soon as possible on the 24-hour number. Follow the advice they give you about:

  • taking anti-diarrhoea medicines 
  • drinking enough fluids to keep you hydrated and to replace lost salts and minerals
  • any changes to your diet that might help. 

They might also ask you for a specimen of your stool to check for infection.


This treatment can cause constipation. Constipation means that you are not able to pass stools (poo) as often as you normally do. It can become difficult or painful. Here are some tips that may help:

  • Drink at least 2 litres (3½ pints) of fluids each day.
  • Eat high-fibre foods, such as fruit, vegetables and wholemeal bread.
  • Do regular gentle exercise, like going for short walks.

If you have constipation, contact the hospital on the 24-hour number for advice. They can give you drugs called laxatives to help. 

If you have not been able to pass stools for over 2 days and are being sick, contact the 24-hour number straight away. 

Feeling tired (fatigue)

Feeling tired is a common side effect. Try to pace yourself and plan your day so you have time to rest between activities.

Being physically active can help to manage tiredness and give you more energy. It also:

  • helps you sleep better
  • reduces stress
  • improves your bone health.

If you feel sleepy, do not drive or operate machinery.

Muscle or joint pain

You may get pain in your muscles or joints for a few days after treatment. If this happens, tell your doctor, nurse or pharmacist. They can give you painkillers and advice. They can also tell you if any of the painkillers you usually take are suitable. 

Tell them if the pain does not get better. Having warm baths and resting regularly may help. 


Zanubrutinib can cause a cough. Tell your doctor or nurse if you notice this.

Feeling dizzy

You may feel dizzy while taking zanubrutinib. Tell your doctor or nurse if this happens. Do not drive or operate machinery if you feel dizzy.

Skin changes

Zanubrutinib may affect your skin It may cause a rash, which might be itchy. Your doctor or nurse can tell you what to expect. If your skin feels dry, try using an unperfumed moisturising cream every day.

Always tell your doctor, nurse or pharmacist about any skin changes. They can give you advice and may prescribe creams or medicines to help. 

Build-up of fluid

You may put on weight or your ankles and legs may swell because of fluid building up. Tell your doctor or nurse if you notice this. If your ankles and legs swell, it can help to put your legs up on a foot stool or cushion.

High blood pressure

Tell your doctor or nurse if you have ever had any problems with your blood pressure. Your nurse will check it regularly during your treatment. Let them know if you have any headaches.

Less common side effects

Effects on the heart

This treatment can affect how the heart works. You may have tests to check how well your heart is working. These may be done before, during and after treatment.

If the treatment is causing heart problems, your doctor may change the type of treatment you are having.

Contact the hospital straight away on the 24-hour number if you have any of these symptoms during or after treatment:

  • breathlessness
  • dizziness
  • changes to your heartbeat
  • swollen feet and ankles.

Other conditions can cause these symptoms, but it is important to get them checked by a doctor. 

Always call 999 if you have:

  • chest pain, pressure, heaviness, tightness or squeezing across the chest
  • difficulty breathing.

Second cancer

Zanubrutinib can increase the risk of developing non-melanoma skin cancers called basal cell carcinoma or squamous cell skin cancer. The benefits of treatment usually far outweigh this risk. Your doctor can talk to you about this.

Take care to protect your skin in the sun. Use a sun cream with a sun protection factor (SPF) of at least 30 and cover up with clothing and a hat.

Other information

Blood clot risk

Cancer and some cancer treatments can increase the risk of a blood clot. Contact the hospital straight away on the 24-hour number if you have any of these symptoms during or after treatment:

  • throbbing pain or swelling in a leg or arm
  • reddening of the skin in the area – if you have black or brown skin, this can be harder to notice, but the skin might become darker
  • suddenly feeling breathless or coughing.

Always call 999 if you have:

  • chest pain
  • difficulty breathing.

A blood clot is serious, but it can be treated with drugs called anticoagulants. These thin the blood. Your doctor, nurse or pharmacist can give you more information about preventing and treating blood clots.

Hepatitis B reactivation

If you have had a liver infection called hepatitis B in the past, this treatment can make it active again. Your doctor or nurse will talk to you about this. They will test you for hepatitis B.

Other medicines

Some medicines can affect how this treatment works or be harmful while you are having it. Always tell your cancer doctor, nurse or pharmacist about any drugs you are taking or planning to take, such as: 


Doctors usually recommend that people with cancer have vaccinations for flu and for coronavirus (covid). These help reduce your risk of serious illness from these infections. Most people can have these vaccines, including people with weak immune systems.

If your immune system is weak, you should not have live vaccinations. Live vaccines can make you unwell because they contain a very weak version of the illness they will protect you against. Live vaccines include Zostavax®, which is a shingles vaccine, and the yellow fever vaccine.

It is important to ask your doctor, nurse or pharmacist for advice about having vaccinations. They can explain what vaccines are right for you and when it is best to have them.


Your doctor will advise you not to get pregnant or make someone pregnant while having this treatment. The drugs may harm a developing baby. It is important to use contraception during your treatment and for a while after treatment finishes. 

If you are on a hormonal contraception such as the pill, an injection or an implant, you will need to use a barrier type, such as a condom, as well. Your doctor, nurse or pharmacist can tell you more about this and advise you.


You are advised not to breastfeed while having this treatment, or for some time after treatment ends. This is because the drugs could be passed to the baby through breast milk. 

Your doctor, nurse or pharmacist can give you more information.


Some cancer drugs can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.

Medical and dental treatment

If you need medical treatment for any reason other than cancer, always tell the healthcare professional that you are having cancer treatment. Give them the contact details for your cancer doctor or cancer team so they can ask for advice.

If you have appointments with a dentist, always tell them you are having cancer treatment. Talk to your cancer team before you have any dental treatment.

About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert health professionals and people living with cancer.

    Our cancer information has been awarded the PIF TICK. Created by the Patient Information Forum, this quality mark shows we meet PIF’s 10 criteria for trustworthy health information.

The language we use

We want everyone affected by cancer to feel our information is written for them.

We want our information to be as clear as possible. To do this, we try to:

  • use plain English
  • explain medical words
  • use short sentences
  • use illustrations to explain text
  • structure the information clearly
  • make sure important points are clear.

We use gender-inclusive language and talk to our readers as ‘you’ so that everyone feels included. Where clinically necessary we use the terms ‘men’ and ‘women’ or ‘male’ and ‘female’. For example, we do so when talking about parts of the body or mentioning statistics or research about who is affected.

You can read more about how we produce our information here.

Date reviewed

Reviewed: 01 July 2023
Next review: 01 January 2026
Trusted Information Creator - Patient Information Forum
Trusted Information Creator - Patient Information Forum

Our cancer information meets the PIF TICK quality mark.

This means it is easy to use, up-to-date and based on the latest evidence. Learn more about how we produce our information.