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Side effects of Ibrutinib

Find out about the side effects of the targeted cancer drug ibrutinib.

Tell your doctor or nurse if you have any side effects so they can help you manage them. Your nurse will give you a contact number to ring if you have any problems or questions. If in doubt, call them. 

Contact your doctor or nurse immediately if any of your side effects get severe, or if you have signs of an infection, including a temperature above 38C.

The side effects might be different if you are having ibrutinib with other cancer treatments. 

Common side effects

Each of these effects happens in more than 1 in 10 people (10%). You might have one or more of them. 

Signs of an infection include headaches, aching muscles, a cough, a sore throat, pain passing urine, or feeling cold and shivery.

Contact your treatment centre straight away if you have any of these signs or if your temperature goes above 37.5C. Severe infections can be life threatening.

Cancer treatments can reduce the number of white blood cells in the blood. This increases your risk of infections. White blood cells help fight infections.

When the level is very low it is called neutropenia (pronounced new-troh-pee-nee-ah).

You have antibiotics if you develop an infection. You might have them as tablets or as injections into the bloodstream (intravenously). To have them into your bloodstream you need to go into hospital.

You might notice you:

  • bruise more easily
  • have nosebleeds
  • have bleeding gums when you brush your teeth

This is due to a drop in the number of platelets that help clot your blood.

If your platelets get very low you may have lots of tiny red spots or bruises on your arms or legs called petechiae.

Tell your doctor or nurse straight away if you have petechiae.

You'll have a platelet transfusion if your platelet count is very low. It is a drip of a clear fluid containing platelets. It takes about 15 to 30 minutes. The new platelets start to work right away. 

Let your doctor or nurse know if you have headaches. They can give you painkillers such as paracetamol to help.

Tell your doctor or nurse if you have diarrhoea. They can prescribe medicine to help you. 

Drink at least 2.5 litres of fluid a day. This helps to keep you hydrated.

Ask your nurse about soothing creams to apply around your back passage (rectum). The skin in that area can get very sore and even break if you have severe diarrhoea.

Contact your doctor or nurse immediately if you have diarrhoea 4 or more times a day, or any diarrhoea at night.

Constipation is easier to sort out if you treat it early. Drink plenty of fluids and eat as much fresh fruit and vegetables as you can. Try to take gentle exercise, such as walking.

Tell your doctor or nurse if you are constipated for more than 3 days. They can prescribe a laxative.

You might feel sick or be sick. Anti sickness injections and tablets can control it. Tell your doctor or nurse if you feel sick. You might need to try different anti sickness medicines to find one that works.


  • Avoid eating or preparing food when you feel sick.
  • Avoid hot fried foods, fatty foods or foods with a strong smell.
  • Eat several small meals and snacks each day.
  • Relaxation techniques help control sickness for some people.
  • Ginger can help – try it as crystallised stem ginger, ginger tea or ginger ale.
  • Try fizzy drinks.
  • Sip high calorie drinks if you can’t eat.

Your mouth might get sore. It may be painful to swallow drinks or food. You will have mouth washes to keep your mouth healthy.

You can have painkillers to reduce the soreness. Take them half an hour before meals to make eating easier.

A rash can also be itchy. Tell your doctor or nurse if you have a skin rash. They can prescribe medicine to stop the itching and soothe your skin.

You might have muscle pain during treatment with this drug. Let your treatment team know so they can advise you on how to reduce it.

Swelling of hands and feet is due to fluid build up. This is called oedema. Let your doctor or nurse know if you have any swelling.

Occasional side effects

Each of these effects happens in more than 1 in 100 people (1%). You might have one or more of them.

You have an increased risk of developing non melanoma skin cancers. For example, basal cell skin cancers or squamous cell skin cancers. Your medical team will check you regularly for possible signs and tell you what to look out for. These skin cancers are usually very easy to treat. 

You might develop changes to your lungs that cause breathlessness. This includes inflammation or fluid on the lungs.

Let your doctor or nurse know if you suddenly feel short of breath, or your breathlessness is getting worse.

High uric acid levels in the blood are due to the breakdown of tumour cells (tumour lysis syndrome). You will have regular blood tests to check your uric acid levels and may have a tablet called allopurinol to take. Drinking plenty of fluids helps to flush out the excess uric acid.

Don’t drive or operate machinery if you have this.

Do not drive or operate machinery if you have this symptom and speak to your doctor. 

You may have changes to how your heart works. This can cause changes to your heart rhythm. 

Your doctor might ask you to have tests to check your heart, such as an electrocardiogram (ECG).

Tell your doctor or nurse if you have headaches, nose bleeds, blurred or double vision or shortness of breath. Your nurse will check your blood pressure regularly.

Some people have bleeding that collects between the surface of the brain and the skull. This is called a subdural haematoma. This is a serious condition that needs immediate treatment. 

You, or your friend or relative should contact a doctor if you:

  • have a headache that is getting worse
  • are feeling or being sick
  • are feeling dizzy
  • are confused or behaving differently 
  • are drowsy or unconscious 

Rare side effects

Each of these effects happens in fewer than 1 in 100 people (1%). You might have one or more of them.

A small number of people have an allergic reaction to ibrutinib. Contact a doctor immediately if you have any of these symptoms:

  • swelling of the face, lip, mouth, tongue or throat
  • difficulty swallowing or breathing
  • itchy rash

A small number of people might have swelling of the skin (angioedema). For example, swelling around the eyes, lips and tongue, hands and feet. Let your doctor know if this happens to you. 

Rarely, a person's white blood cell count could become very high (leukostatis syndrome). If this happens you might become unwell quite quickly causing:

  • breathlessness
  • a high temperature
  • headaches, dizziness, and problems with vision 
  • confusion 

Contact a doctor immediately if you have these symptoms so you can be treated as soon as possible.

About ibrutinib

More information about this treatment

We haven't listed all the very rare side effects of this treatment. For further information look at the Chemo care website.

You can report any side effect you have that isn’t listed here to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.

Information and help

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