Imatinib

Imatinib comes as tablets or capsules. The nurse or pharmacist will give you them 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.

Before or on the day of treatment, a nurse or person trained to take blood (phlebotomist) will take a blood sample from you. This is to check that your blood cells are at a safe level for you to have your treatment. 

You keep taking imatinib for as long as your doctor tells you. Do not stop taking it without talking to your doctor.

You usually take imatinib once or twice a day, depending on the dose your doctor prescribes. You should take it with a meal. The tablets or capsules 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 or capsules, 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 forget to take imatinib, you should take the missed dose as soon as possible. If it is nearly time for your next dose, skip the missed dose and continue with your usual schedule and 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 or capsules:

• Keep them in the original package and at room temperature, away from heat.
• Keep them safe and out of sight and reach of children.
• If 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 imatinib to the pharmacist.

This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If your white blood cell count is low, you may be more likely to get an infection. A low white blood cell count is called neutropenia.

An infection can be very serious when the number of white blood cells is low. It is important to get any infection treated as soon as possible. If you have any of the following symptoms, contact the hospital straight away on the 24-hour number:

• a temperature above 37.5°C 
• a temperature below 36°C
• you feel unwell, even with a normal temperature
• you have symptoms of an infection.

Symptoms of an infection include:

• feeling shivery and shaking
• a sore throat
• a cough
• breathlessness
• diarrhoea
• needing to pass urine (pee) often, or discomfort when you pass urine.

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 stop your treatment for a short time, until your cell count increases. Sometimes they will reduce the dose of your treatment.

This treatment can reduce the number of platelets in your blood. Platelets are cells that help the blood to clot.

If the number of platelets is low, you may bruise or bleed easily. You may have:

• nosebleeds
• bleeding gums
• heavy periods
• blood in your urine (pee) or stools (poo)
• tiny red, brown or purple spots that may look like a rash – these spots can be harder to see if you have black or brown skin. 

If you have any unexplained bruising or bleeding, contact the hospital straight away on the 24-hour number. You may need a drip to give you extra platelets. This is called a platelet transfusion.

This treatment can reduce the number of red blood cells in your blood. Red blood cells carry oxygen around the body. If the number of red blood cells is low, this is called anaemia. You may feel:

• very low in energy
• breathless 
• dizzy and light-headed. 

If you have these symptoms, contact the hospital straight away on the 24-hour number. You may need treatment for anaemia. 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 normal for you, or having watery or loose stools. You may also have stomach cramps. If you have a stoma, it may be more active than usual. 

If you are passing loose stools 3 or more times a day and this is not normal for you, contact the hospital as soon as possible on the 24-hour number. Follow the advice they give you about:

• taking anti-diarrhoea medicines 
• drinking enough fluids to keep you hydrated and to replace lost salts and minerals
• any changes to your diet that might help. 

They might also ask you for a specimen of your stool to check for infection.

Some people have indigestion or wind 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.

This treatment may cause headaches. If you have headaches, tell your doctor, nurse or pharmacist. They can give you advice about painkillers that may help. Tell them if the headache does not get better, or gets worse.

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.

Some people develop an itchy rash. If this happens, it is important to tell your doctor. 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.  You should also tell them straight away if you feel any flu-like symptoms, for example, a high temperature or pain in your joints.

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.

Feeling tired is a common side effect. Try to pace yourself and plan your day so you have time to rest between activities.

Being physically active can help to manage tiredness and give you more energy. It also:

• helps you sleep better
• reduces stress
• improves your bone health.

If you feel sleepy, do not drive or operate machinery.

Cancer and some cancer treatments can increase the risk of a blood clot. Contact the hospital straight away on the 24-hour number if you have any of these symptoms during or after treatment:

• throbbing pain or swelling in a leg or arm
• reddening of the skin in the area – if you have black or brown skin, this can be harder to notice, but the skin might become darker
• suddenly feeling breathless or coughing.

Always call 999 if you have:

• chest pain
• difficulty breathing.

A blood clot is serious, but it can be treated with drugs called anticoagulants. These thin the blood. Your doctor, nurse or pharmacist can give you more information about preventing and treating blood clots.

Some medicines can affect how this treatment works or be harmful while you are having it. Always tell your cancer doctor, nurse or pharmacist about any drugs you are taking or planning to take, such as: 

• medicines you have been prescribed
• medicines you buy in a shop, pharmacy or online
• vitamins or supplements 
• herbal drugs and complementary or homeopathic therapies
• recreational drugs – for example, cannabis.

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 have had a liver infection called hepatitis B in the past, this treatment can make it active again. Your doctor or nurse will talk to you about this. They will test you for hepatitis B.

Doctors usually recommend that people with cancer have vaccinations for flu and for coronavirus (covid). These help reduce your risk of serious illness from these infections. Most people can have these vaccines, including people with weak immune systems.

If your immune system is weak, you should not have live vaccinations. Live vaccines can make you unwell because they contain a very weak version of the illness they will protect you against. Live vaccines include Zostavax^®, which is a shingles vaccine, and the yellow fever vaccine.

It is important to ask your doctor, nurse or pharmacist for advice about having vaccinations. They can explain what vaccines are right for you and when it is best to have them.

Some cancer drugs can affect whether you can get pregnant or make someone pregnant. If you are worried about this, it is important to talk with your doctor before you start treatment.

Your doctor, nurse or pharmacist will advise you not to get pregnant or make someone pregnant while having this treatment and for some time afterwards. The drugs may harm a developing baby. It is important to use contraception to prevent pregnancy. Follow their advice about:

• what types of contraception to use 
• how long after treatment you should continue to use contraception. 

You are advised not to breastfeed while having this treatment, or for some time after treatment ends. This is because the drugs could be passed to the baby through breast milk. 

Your doctor, nurse or pharmacist can give you more information.

If you need medical treatment for any reason other than cancer, always tell the healthcare professional that you are having cancer treatment. Give them the contact details for your cancer doctor or cancer team so they can ask for advice.

If you have appointments with a dentist, always tell them you are having cancer treatment. Talk to your cancer team before you have any dental treatment.