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Imatinib 333

Imatinib 333

This leaflet provides information on a course of treatment known as Imatinib.  The leaflet will explain what this is and when and how it is given.  It will also tell you about common side effects that you may experience.  Contact telephone numbers and details of how to obtain further information on Imatinib are given at the end of the leaflet.

What is Imatinib treatment?

Imatinib is a cancer treatment which is given as tablets.  It works by stopping a particular type of cancer cell from growing.

Why am I having Imatinib?

Your doctor has recommended Imatinib because it has been found to be effective in treating your type of cancer.

How should I take the Imatinib tablets?

You should take your tablets once a day with a meal and a large glass of water.  You can choose what time of the day to take your tablets but it is important to take them at about the same time each day. If your dose is altered, you may need to take the tablets at slightly different time intervals, but this will be labelled on the box.

Taking your Imatinib tablets with food and water will help stop them upsetting your stomach.  It is best not to have drinks containing caffeine, such as tea, coffee or cola, for an hour before and after you take your Imatinib tablets.  You should also not have grapefruit and grapefruit juice during your treatment with Imatinib.

How many tablets will I need to take?

This will vary for each person.  There are 2 different strength tablets which are different sizes.  The bigger tablets are 400mg and the smaller tablets are 100mg.  The amount you need to take will be clearly marked on the box.  

What should I do if I forget to take my tablets?

  • If it’s within 2 hours of the normal time take them now.
  • If it’s more than 2 hours late, miss this dose.

Do not take the extra tablets when your treatment should have finished.  It is important that even if you have missed any doses you should finish the treatment at the planned time.  

What if I take too many tablets?

Please contact Velindre Cancer Centre immediately for advice.  The telephone numbers are at the end of the leaflet.

How should I store my Imatinib tablets?

You should store your tablets in their original packaging in a safe place away from children.  They should be kept in a cool dry place.  

Any unused tablets should be returned to the hospital Pharmacy or your local chemist for safe disposal.  

How long will I need to take my Imatinib?

Your doctor will discuss with you how long you need to take Imatinib.  You will usually take Imatinib for as long as it is helpful. This could be for many months or years.

How often will I be seen in clinic?

You will be reviewed regularly in clinic.  Your doctor will discuss how often you will need to be reviewed.

How will my doctor know if the treatment is working?

You will have scans at regular intervals during your treatment so that we can see if your treatment is working.  

Can I bring relatives and friends with me? 

You are welcome to bring someone to stay with you during your treatment. Space is limited so there is not usually room for more than one person.  Treatment areas are not suitable for young children.

Are there any side effects to Imatinib?

As with all medicines some patients can get side effects when taking Imatinib.  Usually these side effects are mild or moderate.  It is unusual to have to stop taking Imatinib because of any side effects.  The doctors, nurses and pharmacists can give you advice or answer any questions you may have.

Fluid retention (oedema)

Some patients notice puffiness around their eyes or swelling of their ankles and legs.  If you develop fluid retention you should tell your doctor or nurse at your next clinic visit.  Your doctor may prescribe tablets which can help.


Some patients have diarrhoea when taking Imatinib.  This is usually mild but it is important to tell your doctor or nurse if this happens.

If you have four or more bowel movements in 24 hours above what is normal for you please contact Velindre Cancer Centre immediately.  The telephone numbers are at the end of the leaflet.


Nausea and vomiting can usually be avoided by taking your Imatinib tablets with a meal and a large glass of water.  We will give you anti-sickness tablets to take in case you need them.  

If you are sick more than once in 24 hours despite taking regular anti-sickness medicine contact Velindre Cancer Centre for advice.  The telephone number is at the end of the leaflet.

Muscle cramps and joint pains.

These are usually mild but please tell your doctor or nurse if these happen.  You may find it helpful to take a mild painkiller, for example what you take for a headache.  If your normal painkiller doesn’t help please contact us for further advice. The telephone number is at the end of the leaflet.  

Effect on your blood cells

The normal production of blood cells can be affected by taking Imatinib.  This may lead to an increased risk of bruising or bleeding.  Please contact Velindre Cancer Centre immediately if you experience any of these problems.  The telephone number is at the end of the leaflet.


You are at an increased risk of picking up infections because your white blood cells which help fight infections can be reduced by this treatment.  

If you develop an infection whilst your white blood cells are low, you are at risk of sepsis, this can be life threatening. 

Contact Velindre Cancer Centre immediately if you develop any signs of infection, for example flu like symptoms or a temperature above 37.5°centigrade or below 35.5°centigrade.  The telephone number is at the end of this leaflet.

Blood clots

A diagnosis of cancer can increase your risk of developing a blood clot (thrombosis), and having cancer treatment may increase this risk further.  It is important to tell your doctor immediately if you have symptoms such as pain, redness and swelling in your leg, or breathlessness and chest pain.  

Blood clots can be very serious.  However, most clots can usually be successfully treated with drugs to thin the blood.  Your doctor or nurse can give you more information.

Other possible side effects

Imatinib may also cause:-

  • dry skin
  • dry eyes or eye infections
  • difficulty sleeping
  • heartburn, reflux and wind
  • Rarely Imatinib can cause intestinal bleeding.  If you cough or vomit blood, please go to your local Accident and Emergency Department.

Please tell your doctor or nurse at your next clinic visit if you experience any of the following:

  • Abdominal pain 
  • Pains in your muscles, joints or bones
  • Skin rash
  • Headache
  • Tiredness
  • Watery eyes

Other information

It is important you do not become pregnant or father a child whilst taking Imatinib.  

Women should not breast feed whilst taking Imatinib.

Can I drive whilst taking Imatinib?

Some people can feel very tired, slightly dizzy or have some blurred vision when they first start taking Imatinib.  You should not drive if you experience any of these side effects.  If these persist or cause any problems please talk to your doctor or nurse. 

Admission to another hospital whilst taking Imatinib

If you are admitted to hospital it is important that you tell them you are taking Imatinib tablets.  You should take your Imatinib tablets with you to the hospital. 

It is also important that you let us know that you have been admitted to another hospital.  If this is within normal working hours ask the hospital to contact your consultant’s secretary at Velindre Cancer Centre.  At any other time ask them to contact the chemotherapy pager.  The telephone numbers are at the end of this leaflet.  

Sometimes cancer drugs can have very serious side effects which rarely can be life threatening. It is important to inform Velindre cancer centre if you are concerned about any side-effects

Is it alright to take other medicines with Imatinib?

It is important to tell us about any other medicines you are taking.  There are a number of medications that you must not take with Imatinib, including over the counter medicines, such as St.John’s Wort.  You should also tell your GP and your pharmacist that you are taking Imatinib, if you are prescribed medication or wish to buy over the counter.

Manufacturer’s patient information leaflets

Velindre leaflets provide information about very common and commonly reported side-effects (we are unable to list all of the common side effects), for more information regarding these and the less common side-effects please refer to the manufacturers patient information leaflets, obtained from Velindre pharmacy and/or on the internet at Sometimes patients may find these leaflets difficult to read however. Please ask if you would like a copy from your doctor or from Velindre pharmacy

Useful websites:

Contact telephone numbers

Velindre Cancer Centre 029 2061 5888

Ask for the treatment helpline if you are unwell at home and need immediate advice at any time of the day or night.  For example you should phone if you:

  • Are sick more than once in 24 hours
  • Have a temperature of 37.5°C or above or below 35.5°centigrade
  • Have 4 or more bowel movements in 24 hours above what is normal for you

If you need to let us know that you have been admitted to another hospital ask switchboard to transfer you to your consultant’s secretary

Pharmacy department 029 2061 5888 ext 6223

Monday – Friday 9am – 5pm for queries about your medicines

Tenovus freephone 0808 808 1010

cancer helpline 


This leaflet has been written by health professionals.  The information contained in the leaflet is evidence based.  It has been approved by doctors, nurses and patients.  It is reviewed and updated every 2 years.

Reviewed June 2016