Imatinib is a targeted cancer drug. It is also known as Glivec (pronounced glee-vec).

It is a treatment for a number of different cancer types.

You pronounce imatinib as im-at-in-ib.

How does imatinib work?

Imatinib is a type of cancer growth blocker called a tyrosine kinase inhibitor (TKI). Tyrosine kinases are proteins that cells use to signal to each other to grow. They act as chemical messengers. There are a number of different tyrosine kinases and blocking them stops the cancer cells growing.

Imatinib targets different tyrosine kinases, depending on the type of cancer.

How do you have imatinib?

You have imatinib as a tablet that you swallow whole, with a glass of water after food. If you can’t swallow the tablets, you can dissolve them in a glass of water. Talk to your pharmacist about the best way to do this.

Taking your tablets

You must take tablets according to the instructions your doctor or pharmacist gives you.

Speak to your pharmacist if you have problems swallowing the tablets.

Whether you have a full or an empty stomach can affect how much of a drug gets into your bloodstream.

You should take the right dose, no more or less.

Talk to your healthcare team before you stop taking a cancer drug or if you miss a dose.

How often do you have imatinib?

You have imatinib either once or twice a day, depending on the condition you have. You usually continue taking imatinib for as long as it works, unless the side effects get too bad.

For acute lymphoblastic leukaemia that is Philadelphia chromosome positive, you may have imatinib on its own, or with chemotherapy.

Tests

You have blood tests before and during your treatment. They check your levels of blood cells and other substances in the blood. They also check how well your liver and kidneys are working.

What are the side effects of imatinib?

How often and how severe the side effects are can vary from person to person. They also depend on what other treatments you're having.

When to contact your team

Your doctor, nurse or pharmacist will go through the possible side effects. They will monitor you during treatment and check how you are at your appointments. Contact your advice line as soon as possible if:

  • you have severe side effects
  • your side effects aren’t getting any better
  • your side effects are getting worse

Early treatment can help manage side effects better.

Contact your advice line immediately if you have signs of infection, including a temperature above 37.5C or below 36C.

We haven't listed all the side effects here. Remember it is very unlikely that you will have all of these side effects. But you might have some of them at the same time.

Common side effects

These side effects happen in more than 10 in 100 people (more than 10%). You might have one or more of them. They include:

Increased risk of getting an infection

Increased risk of getting an infection

is due to a drop in white blood cells. Symptoms include a change in temperature, aching muscles, headaches, feeling cold and shivery and generally unwell. You might have other symptoms depending on where the infection is.

Infections can sometimes be life threatening. You should contact your advice line urgently if you think you have an infection.

Breathlessness and looking pale

You might be

breathless and look pale

due to a drop in red blood cells. This is called anaemia.

Bruising, bleeding gums or nosebleeds

This is due to a

drop in the number of platelets in your blood

. These blood cells help the blood to clot when we cut ourselves. You may have nosebleeds or bleeding gums after brushing your teeth. Or you may have lots of tiny red spots or bruises on your arms or legs (known as petechiae).

Tiredness and weakness (fatigue)

Tiredness and weakness (fatigue)

can happen during and after treatment. Doing gentle exercises each day can keep your energy up. Don't push yourself, rest when you start to feel tired and ask others for help.

Fluid build-up (oedema)

A build up of fluid may cause swelling in your arms, hands, ankles, legs, face, eyes and other parts of the body. Contact your healthcare team if this happens to you.

Feeling or being sick

Feeling or being sick

is usually well controlled with anti sickness medicines. Avoiding fatty or fried foods, try eating small meals and snacks, drinking plenty of water, and relaxation techniques can all help.

It is important to take anti sickness medicines as prescribed even if you don’t feel sick. It is easier to prevent sickness rather than treat it once it has started.

Diarrhoea

Contact your advice line if you have

diarrhoea

, such as if you've had 4 or more loose watery poos (stools) in 24 hours. Or if you can't drink to replace the lost fluid. Or if it carries on for more than 3 days.

Your doctor may give you anti diarrhoea medicine to take home with you after treatment. Eat less fibre, avoid raw fruits, fruit juice, cereals and vegetables, and drink plenty to replace the fluid lost.

Headaches

Tell your healthcare team if you keep getting headaches. They can give you painkillers to help.

Indigestion

Contact your doctor or pharmacist if you have indigestion or heartburn. They can prescribe medicines to help.

Skin rash

Skin problems

include a skin rash, dry skin and itching. This usually goes back to normal when your treatment finishes. Your healthcare team can tell you what products you can use on your skin to help.

Muscle and joint pain

You might feel some pain from your muscles and joints. Speak to your doctor or nurse about what painkillers you can take to help with this.

Weight gain

You may gain weight while having this treatment. You may be able to control it with diet and exercise. Tell your healthcare team if you are finding it difficult to control your weight.

Tummy (abdominal) pain

Tell your treatment team if you have this. They can check the cause and give you medicine to help.

Occasional side effects

These side effects happen in between 1 and 10 out of every 100 people (between 1 and 10%). You might have one or more of them. They include:

  • constipation
  • sore mouth
  • liver changes
  • taste changes
  • weight loss
  • dizziness
  • difficulty sleeping (insomnia)
  • sore eyes
  • blurred vision
  • loss of appetite
  • wind (flatulence)
  • numbness in hands or feet
  • high temperature (fever)
  • hair thinning
  • cough
  • nosebleeds
  • sensitive to light
  • feeling cold, shivers or shaking

Rare side effects

These side effects happens in fewer than 1 in 100 people (fewer than 1%). You might have one or more of them. They include:

  • fluid around the heart (pericardial effusion)
  • breast pain or pain in your nipples
  • high uric acid levels in your body due to the breakdown of tumour cells (tumour lysis syndrome) - you have regular blood tests to check for this and may have a tablet called allopurinol to take
  • palpitations or a fast heart beat
  • chest infection including pneumonia
  • depression
  • decreased libido or sex drive
  • memory problems
  • hearing problems including ringing in the ears (tinnitus)
  • changes to blood pressure
  • dizziness or vertigo
  • irregular periods (menstruation)
  • problems getting or maintaining an erection

Coping with side effects

We have more information about side effects and tips on how to cope with them.

What else do you need to know?

Other medicines, food and drink

Cancer drugs can interact with medicines, herbal products, and some food and drinks. We are unable to list all the possible interactions that may happen. An example is grapefruit or grapefruit juice which can increase the side effects of certain drugs.

Tell your healthcare team about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies. Also let them know about any other medical conditions or allergies you may have.

Pregnancy and contraception

This treatment might harm a baby developing in the womb. It is important not to become pregnant or get someone pregnant while you're having treatment and for a few months afterwards.

Talk to your doctor or nurse about effective contraception before starting treatment. Let them know straight away if you or your partner falls pregnant while having treatment.

Fertility

You may not be able to become pregnant or get someone pregnant after treatment with this drug. Talk to your doctor before starting treatment if you think you may want to have a baby in the future.

Men might be able to store sperm before starting treatment. And women might be able to store eggs or ovarian tissue. But these services are not available in every hospital, so you would need to ask your doctor about this.

Breastfeeding

Don’t breastfeed during this treatment because the drug may come through into your breast milk.

Treatment for other conditions

Always tell other doctors, nurses, pharmacists or dentists that you’re having this treatment. For example, if you need treatment for anything else, including teeth problems.

Hepatitis B reactivation

Tell your doctor 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 may test you for it.

Immunisations

Don’t have immunisations with live vaccines while you’re having treatment and for up to 12 months afterwards. The length of time depends on the treatment you are having. Ask your doctor or pharmacist how long you should avoid live vaccinations.

In the UK, live vaccines include rubella, mumps, measles, BCG, yellow fever and one of the shingles vaccines called Zostavax.

You can have:

  • other vaccines, but they might not give you as much protection as usual
  • the flu vaccine (as an injection)
  • the coronavirus (COVID-19) vaccine - talk to your doctor or pharmacist about the best time to have it in relation to your cancer treatment

Members of your household who are aged 5 years or over are also able to have the COVID-19 vaccine. This is to help lower your risk of getting COVID-19 while having cancer treatment and until your immune system Open a glossary item recovers from treatment.

Contact with others who have had immunisations - You can be in contact with other people who have had live vaccines as injections. Avoid close contact with people who have recently had live vaccines taken by mouth (oral vaccines) such as the oral typhoid vaccine. Sometimes people who have had the live shingles vaccine can get a shingles type rash. If this happens they should keep the area covered.

If your immune system is severely weakened, you should avoid contact with children who have had the flu vaccine as a nasal spray as this is a live vaccine. This is for 2 weeks following their vaccination.

Babies have the live rotavirus vaccine. The virus is in the baby’s poo for about 2 weeks and could make you ill if your immunity is low. Get someone else to change their nappies during this time if you can. If this isn't possible, wash your hands well after changing their nappy.

Children and adolescents

Some children and adolescents taking imatinib may have slower than normal growth. The treatment team will monitor this carefully.

More information about this treatment

For further information about this treatment and possible side effects go to the electronic Medicines Compendium (eMC) website. You can find the patient information leaflet on this website.

You can report any side effect you have to the Medicines Health and Regulatory Authority (MHRA) as part of their Yellow Card Scheme.