Imatinib is a targeted therapy. It is used to treat some types of leukaemia, blood disorders and gastro-intestinal stromal tumours called GISTs.
Imatinib is a targeted therapy drug known as a tyrosine kinase inhibitor. It is used to treat some types of leukaemia, blood disorders and cancers. It is best to read this with our information about the type of cancer you have.
Tyrosine kinases are proteins in the body that control how cells grow and divide. Imatinib blocks (inhibits) signals in the leukaemia or cancer cells that make them grow and divide. Blocking the signals causes the cells to die.
Your doctor will talk to you about this treatment and its possible side effects before you agree (consent) to have treatment.
When imatinib is given
Imatinib may be used to treat:
- chronic myeloid leukaemia (CML), a cancer of white blood cells
- a type of acute lymphoblastic leukaemia (ALL) called Philadelphia chromosome positive (Ph+ALL)
- blood disorders, such as myelodysplastic and myeloproliferative conditions
- blood disorders, such as advanced hypereosinophilic syndrome and chronic eosinophilic leukaemia.
Imatinib may also be used to treat:
- gastro-intestinal stromal tumours (GISTs), a rare cancer that affects the supporting tissue of the bowel or stomach
- dermatofibrosarcoma protuberans (DFSP), a rare cancer that affects the tissue under the skin.
Your doctor can tell you if it is suitable for you. Some people may be given imatinib as part of a clinical trial.
Imatinib comes as tablets. The nurse or pharmacist will give you the tablets to take home. Always take them exactly as explained. This is important to make sure they work as well as possible for you.
During treatment you will see a haematologist (doctor who treats blood cancers) or a cancer doctor, a specialist nurse and a specialist pharmacist. This is who we mean when we mention doctor, nurse or pharmacist in this information. You keep taking imatinib for as long as your doctor tells you. Do not stop taking it without talking to your doctor.
Taking imatinib tablets
You usually take imatinib once or twice a day, depending on the dose your doctor prescribes. You should take the tablets with a meal. They must be swallowed whole with a glass of water. They should not be chewed, opened or crushed. Take them at the same time every day.
If you find it hard to swallow the tablets, tell your doctor, nurse or pharmacist. They may suggest that you dissolve them in still water or apple juice. They will give you clear instructions on how to do this.
If you are sick just after taking the tablets, contact the hospital. You may need to take another dose.
If you forget to take the tablets, you should take the missed dose as soon as possible within the same day. If a full day has gone by, let your doctor or nurse know. Do not take a double dose unless your doctor tells you to.
Other things to remember about your tablets:
- Keep them in the original package and at room temperature, away from heat and direct sunlight.
- Keep them safe and out of sight and reach of children.
- IIf you are sick just after taking the capsules or tablets, contact the hospital. Do not take another dose.
- If your treatment is stopped, return any unused tablets to the pharmacist.
We explain the most common side effects of this treatment here. We also include some less common side effects.
You may get some of the side effects we mention, but you are unlikely to get all of them. If you are also having treatment with other cancer drugs, you may have some side effects that we have not listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.
Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse will give you advice about managing your side effects. After your treatment is over, most side effects start to improve.
Serious and life-threatening side effects
Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.
Contact the hospital
Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.
We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) for more detailed information.
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 called neutropenia.
If you have an infection, it is important to treat it as soon as possible. Contact the hospital straight away on the 24-hour contact number you have 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.
Symptoms of an infection include:
- feeling shivery
- a sore throat
- a cough
- needing to pass urine often.
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 delay your treatment for a short time.
Bruising and bleeding
This treatment can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot.
Tell your doctor if you have any bruising or bleeding that you cannot explain. This includes:
- bleeding gums
- tiny red or purple spots on the skin that may look like a rash.
Some people may need a drip to give them extra platelets. This is called a platelet transfusion.
Anaemia (low number of red blood cells)
This treatment can reduce the number of red blood cells in your blood. These cells carry oxygen around the body. If the number of red blood cells is low, you may be tired and breathless. Tell your doctor or nurse if you feel like this. If you are very anaemic, you may need a drip to give you extra red blood cells. This is called a blood transfusion.
This is usually mild. Your doctor can prescribe anti-sickness (anti-emetic) drugs to prevent or reduce sickness and vomiting. Taking imatinib with food also helps. Tell your doctor if the sickness isn't controlled or if it continues. They can give you other anti-sickness drugs that may work better for you.
This treatment may cause diarrhoea. Diarrhoea means passing more stools (poo) than is usual for you, or having watery or loose stools. If you have a stoma, it will be more active than usual.
If you have diarrhoea:
- try to drink at least 2 litres (3½ pints) of fluids each day
- avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods
- contact the hospital for advice.
Some people have indigestion when taking imatinib. They may also have acid reflux, which is when acid comes up from the stomach and into the gullet. If this happens, tell your doctor.
Loss of appetite
If you lose your appetite try to eat smaller meals more often. If you find it difficult to eat enough, ask to speak to a nurse or dietitian. They can give you advice on getting more calories and protein in your diet. They may give you food supplement drinks to try. Your doctor can prescribe these and you can buy them from chemists.
This treatment may cause headaches. If this happens, tell your doctor or nurse. They can give you painkillers.
Muscle and bone pain
Some people have pain or cramps in their muscles, or pain in their bones while having treatment. Tell your doctor if this happens. They can prescribe painkillers to help.
Build-up of fluid
You may gain weight or develop swelling around the eyes and ankles because of fluid build-up. Your doctor may prescribe drugs that make you pass more urine (diuretics) to help get rid of some fluid. But it often improves by itself.
If you put on weight very quickly it is important to let your doctor know straightaway.
Cough or breathlessness
You may feel breathless or develop a cough. Contact your doctor for advice if you develop these symptoms. If you have any difficulty breathing contact your doctor immediately.
Effects on the eyes
Imatinib can cause eye pain, dry or watery eyes, or blurred vision. If your eyes are affected, tell your doctor. You should be careful when driving or operating machinery if your vision has changed.
Some people develop an itchy rash. If this happens, it is important to let your doctor know. They can advise you about creams or lotions to use, or prescribe medicines to relieve itching.
If you have a severe rash or any blistering or peeling contact your doctor immediately.
Your skin may be more sensitive to sun while taking imatinib. Use a sun cream with a sun protection factor (SPF) of at least 30 when you are in the sun. Cover up with clothing and a hat.
This treatment can cause sleeplessness (insomnia) in some people. If you are finding it difficult to sleep, talk to your doctor or specialist nurse.
You may feel more tired than usual. Try to pace yourself and get as much rest as you need. It can help to do some gentle exercise, such as taking short walks. If you feel sleepy, don’t drive or operate machinery.
You may feel dizzy. Tell your doctor if this happens.
Effects on the liver
Imatinib may cause changes in the way that your liver works. Your doctor will take blood samples to check your liver is working properly.
Effects on the heart
Some people may notice a change to their heartbeat. Let your doctor know if this happens. Less commonly, imatinib may have other effects on the heart. Contact a doctor immediately if you:
- have pain or a tightness in your chest
- feel breathless or dizzy
- feel your heart is beating too fast or too slowly.
Other conditions can cause these symptoms, but it is important to get them checked by a doctor.
Some medicines can be harmful when you are taking imatinib. This includes medicines you can buy in a shop or chemist. They may make imatinib less effective or increase the side effects it can cause. Tell your doctor and check with your pharmacist about any medicines you are taking, including over-the-counter drugs such as paracetamol, complementary therapies and herbal drugs.
If you have had Hepatitis B (a liver infection) in the past, imatinib can make it active again. Your doctor or nurse will talk to you about this and test you for Hepatitis B. It is important to let your doctor know straight away if you feel unwell or have any severe side effects, even if they are not mentioned above.
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. Your doctor, nurse or pharmacist can tell you more about this.
Women are advised not to become pregnant during their treatment. This is because imatinib may harm a developing baby. It is important to use contraception during treatment and for several months afterwards. You can talk to your doctor or nurse about this.
Women are advised not to breastfeed while having this treatment. This is because the drugs could be passed to the baby through breast milk.
Some brands of imatinib contain a small amount of lactose. If you have a lactose intolerance, talk to your doctor before you start taking this.
If you need medical treatment for any other reason, always tell the doctors and nurses that you are having treatment with imatinib. Give them the contact details for your haematologist or cancer doctor so they can ask for advice.
If you think you need dental treatment, talk to your cancer doctor or nurse. Always tell your dentist you are having cancer treatment.