Imatinib is a chemotherapy medicine used to treat certain types of cancer. This page from Great Ormond Street Hospital (GOSH) explains what imatinib is, how it is given and some of the possible side effects. Imatinib is available in the form of tablets in 100mg and 400mg doses. The 100mg tablet can be halved but the 400mg tablet should be taken whole. Both types of tablets should be taken with a large glass of still water or apple juice once or twice a day.

What are the side effects?

If your child experiences the following side effects, contact your doctor immediately as the dose may need to be reduced or stopped.

Water retention

Imatinib can make your child retain more water than usual, which might show as pain in the eyes, vision problems or shortness of breath. Imatinib can also cause a rapid increase in weight due to water retention.

Changes in liver function

Imatinib may change how well your child’s liver works. These changes may happen rapidly. Blood tests will be taken to monitor your child’s liver function (LFTs) during treatment. Please contact your doctor immediately if your child complains of pain in their right side or the whites of their eyes or the skin develops a yellow tinge.

Bone marrow suppression

There will be a temporary reduction in how well your child’s bone marrow works. This means your child may become anaemic (reduced red blood cells), bruise or bleed more easily than usual, and have a higher risk of infection.

Your child’s blood counts will be checked regularly to see how the bone marrow is working. Please tell your doctor if your child seems unusually tired, has bruising or bleeding, or any signs of infection, especially a high temperature.


Your child may suffer from headaches while taking imatinib. If they are a problem, simple pain relief can be given.

Nausea and vomiting

Taking imatinib with food will help this side effect. If this is not helpful, anti-sickness medicines can be given to reduce or prevent these symptoms. Please tell your doctor or nurse if your child’s sickness is very bad or continues for more than a few days.

Abdominal pain or diarrhoea

These side effects are usually mild and will often improve over time.

Muscle cramps

If these are a problem, your child can take simple pain relief to help.


Imatinib can sometimes cause a rash. Please tell your doctor or nurse if your child develops a rash. They will advise you on the appropriate treatment to use.

Interactions with other medicines

Some medicines can interact with imatinib altering how well it works. Always check with your doctor or pharmacist before giving your child any other medicine, including medicines on prescription from your family doctor (GP), medicines bought from a pharmacy (chemist) or any herbal or complementary medicines.

  • Your child should avoid grapefruit juice while taking imatinib as it stops the medicine working properly.
  • If your child needs to take paracetamol, follow the instructions carefully and do not exceed the recommended dose.

Giving imatinib in a mixture at home

If your child cannot swallow the tablets, they can be made into a mixture to be given by mouth as follows:

  • Empty the required number of tablets into a glass of still water or apple juice, stir well with a spoon and give immediately to your child when the tablet has dispersed.
  • Each 100mg of imatinib should be dispersed in 50ml of still water or apple juice. Dispersing tablets in a large volume of water or juice will reduce the chance of stomach irritation. If your child cannot tolerate large volumes of liquid, please reduce this amount but be aware that this could cause stomach irritation.
  • If you see a white residue in the glass, do not worry, this is not the imatinib, just part of the ingredient of the tablet that does not dissolve. As long as the tablets have been added slowly and stirred well, the imatinib will have dissolved.
  • If you see a yellow residue, this means that the imatinib has not dissolved properly. Do not repeat the dose but when the next dose is due ensure that the tablets are added in small portions and stirred well.
  • Other drinks such as milk, orange juice or cola must not be used as they react with the medicine.
Children with nasogastric tubes should be given imatinib by mouth if possible. However if this is not possible, the mixture should be made up with still water as described above and then given immediately down the nasogastric tube.

Accidental spillages

  • If you accidentally spill the tablets or mixture medicines on the work surface or floor, wearing gloves, cover the spillage with kitchen paper. Wipe the area with water then clean with household cleaner and water. 
  • If the mixture gets onto your skin, you must wash the area immediately, using plenty of water. If the skin is sore you should contact your GP (family doctor) for advice.
  • If the mixture accidentally gets into your eyes, wash with plenty of running water for at least 10 minutes. If your eyes are sore after this, you should go to your nearest Accident and Emergency (A&E) department.
  • If the mixture is spilt on clothing, the spill should be blotted dry with kitchen paper. Clothing should be removed immediately and washed separately from other items. Used kitchen paper should be disposed of as above.
  • Used paper towels, masks, vomit and dirty disposable nappies should be placed inside two rubbish bags and disposed of along with your normal rubbish.
If any type of spillage occurs you should contact GOSH for advice immediately.


  • Keep all medicines in a safe place where children cannot reach them.
  • Imatinib should be kept in a cool, dry place away from direct sunlight or heat.
  • You should handle these medicines with care, avoiding touching them where possible. If you are pregnant or think you could be pregnant, please discuss handling instructions with your doctor, nurse or pharmacist. Please see our Special handling requirements information sheet for further details.
  • If your child vomits straight after taking the dose, inform your local doctor or nurse, as your child may need to take another one. Do not give them another dose without informing the doctor or nurse.
  • If you forget to give your child a dose, do not give a double dose. Inform your doctor or nurse and keep to your child’s regular schedule.
  • Sometimes it is necessarily to halve tablets to get the correct dose. A tablet cutter may be used for this but you should keep it only for cutting chemotherapy tablets.
  • If your doctor decides to stop treatment with imatinib or the medicine passes its expiry date, return any remaining tablets to the pharmacist. Do not flush them down the toilet or throw them away.
Compiled by:
The Pharmacy team in collaboration with the Child and Family Information Group
Last review date:
October 2019