Imatinib is a medicine used to treat certain types of cancer and leukaemia.
How is imatinib given?
Imatinib (brand name Glivec®) 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 of imatinib?
If your child experiences the following side effects, contact your doctor immediately as the dose may need to be reduced or stopped.
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 his or her right side or develops a yellow skin 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, 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.
Abdominal pain or diarrhoea
These side effects are usually mild and will often improve over time.
If these are a problem, your child can take simple pain relief to help.
Imatinib can sometimes cause a rash.
Imatinib and interactions with other medicines
Some medicines can react 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.
Important information you should know about imatinib
- 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.
- 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.
- 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.
Please read this information sheet from GOSH alongside the patient information leaflet (PIL) provided by the manufacturer. If you do not have a copy of the manufacturer’s patient information leaflet please talk to your pharmacist. A few products do not have a marketing authorisation (licence) as a medicine and therefore there is no PIL.
For children in particular, there may be conflicts of information between the manufacturer’s patient information leaflet (PIL) and guidance provided by GOSH and other healthcare providers. For example, some manufacturers may recommend, in the patient information leaflet, that a medicine is not given to children aged under 12 years. In most cases, this is because the manufacturer will recruit adults to clinical trials in the first instance and therefore the initial marketing authorisation (licence) only covers adults and older children.
For new medicines, the manufacturer then has to recruit children and newborns into trials (unless the medicine is not going to be used in children and newborns) and subsequently amend the PIL with the approved information. Older medicines may have been used effectively for many years in children without problems but the manufacturer has not been required to collect data and amend the licence. This does not mean that it is unsafe for children and young people to be prescribed such a medicine ‘off-licence/off-label’. However, if you are concerned about any conflicts of information, please discuss with your doctor, nurse or pharmacist.