Lapatinib (Tyverb) | Cancer Research UK
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What lapatinib is

Lapatinib is also known by its brand name Tyverb. In North America it is called Tykerb. It is a treatment for advanced breast cancer.

Lapatinib may be given with the chemotherapy drug capecitabine (Xeloda) or a biological therapy called trastuzumab (Herceptin). It is also sometimes used with hormone therapies called aromatase inhibitors. Researchers are looking at using it to treat other types of cancer.


How lapatinib works

Lapatinib is a type of biological therapy called a protein tyrosine kinase inhibitor (TKI). It is a targeted treatment used for cancers that have large amounts of a protein called HER2 (human epidermal growth factor receptor 2). Some breast cancers have large amounts of HER2 and they are called HER2 positive cancers. 

HER2 makes the cancer cells grow and divide. Lapatinib switches off HER2 to make the cells stop growing or die.


How you have lapatinib

Lapatinib comes as tablets. You take them once a day with a glass of water, either an hour before or an hour after food. 

It is very important that you take tablets according to the instructions your doctor or pharmacist gives you. For example, whether you have a full or empty stomach can affect how much of a drug gets into your bloodstream. You should take the right dose, not more or less. And never stop taking a cancer drug without talking to your specialist first.

If you miss a dose, don't take an extra dose to catch up. Just take your next dose at the scheduled time.


Tests during treatment

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


About side effects

We've listed the side effects associated with lapatinib. You can use the links to find out more about each side effect. Where there is no link, please go to our information about cancer drug side effects or use the search box at the top of the page.

You may have a few side effects. They may be mild or more severe. A side effect may get better or worse through your course of treatment. Or more side effects may develop as the course goes on. This depends on

  • How many times you've had the drug before
  • Your general health
  • The amount of the drug you have (the dose)

The side effects may be different if you are having lapatinib with other medicines.

Tell your doctor or nurse straight away if any of the side effects get severe.


Common side effects

More than 10 in every 100 people have one or more of these.

  • Diarrhoea affects more than 3 out of 10 people (30%). Drink plenty of fluids and tell your doctor or nurse if you have diarrhoea as you may need treatment
  • Skin changes – about 3 out of 10 people (30%) have a rash or red, dry, itchy skin
  • Feeling sick and being sick happen in about 1 in 4 people (25%). This is usually well controlled with anti sickness medicines
  • Tiredness and weakness (fatigue) affects 1 out of 4 people (25%) during and after treatment. Most people find their energy levels are back to normal a few months after treatment ends
  • Some people develop soreness, redness and peeling on the palms of the hands and soles of the feet (hand-foot syndrome). This may cause tingling, numbness, pain and dryness
  • Loss of appetite
  • Indigestion
  • Headaches
  • Difficulty sleeping
  • Muscle and joint pain or back pain – this can usually be helped with mild painkillers
  • Loss of fertility – you may not be able to become pregnant or father a child after this treatment. Talk to your doctor before starting treatment if you think you may want to have a baby in the future. Men may be able to store sperm before starting treatment
  • A mild effect on the liver – this is unlikely to cause symptoms. Your liver will almost certainly go back to normal after the treatment ends
  • Heart problems including chest pain – contact your doctor or nurse as soon as possible if you have any pain. If you have had heart problems you may not be able to have lapatinib
  • Nose bleeds
  • Hot flushes and sweats
  • A cough and breathlessness due to lung inflammation
  • A sore mouth
  • Tummy (abdominal) pain

Occasional side effects

Between 1 and 10 in every 100 people have one or more of these.

  • Some people have an allergic reaction while having lapatinib treatment, usually at the first or second treatment. Let your nurse know if you feel hot or have any skin rashes, itching, dizziness, headaches, or shivering. Also let them know if you have breathlessness, anxiety, flushing of the face, or a sudden need to pass urine
  • Constipation – drink plenty of fluids if you have constipation. Tell your doctor or nurse if it lasts for more than 3 days as they can give you laxatives
  • Brittle, chipped and ridged nails – some people have infection around the nail
  • Higher levels of bilirubin in your blood – you will have blood tests during and after treatment

Important points to remember

Talk to your doctor, pharmacist or nurse about all your side effects so they can help you manage them. They can give you advice or reassure you. Your nurse will give you a contact number to ring if you have any questions or problems. If in doubt, call them.

Other medicines

Tell your doctor about any other medicines you are taking, including vitamins, herbal supplements and over the counter remedies. Some drugs can react together.

Grapefruit and grapefruit juice

You should not eat grapefruit or drink grapefruit juice when you are taking lapatinib because it can react with the drug.


This drug may harm a baby developing in the womb. It is important not to become pregnant or father a child while you are having treatment and for a few months afterwards. Talk to your doctor or nurse about effective contraception before starting treatment.


Don't breastfeed during this treatment because the drug may come through in the breast milk.



You should not have immunisations with live vaccines while you are having treatment or for at least 6 months afterwards. In the UK, these include rubella, mumps, measles (usually given together as MMR), BCG, yellow fever and Zostavax (shingles vaccine).

You can have other vaccines, but they may not give you as much protection as usual until your immune system has fully recovered from your treatment. It is safe to have the flu vaccine.

It is safe for you to be in contact with other people who've had live vaccines as injections. There can be problems with vaccines you take by mouth (oral vaccines), but not many people in the UK have these now. So there is usually no problem in being with any baby or child who has recently had any vaccination in the UK. You might need to make sure that you aren't in contact with anyone who has had oral polio, cholera or typhoid vaccination recently, particularly if you live abroad.


More information on lapatinib

This page does not list all the very rare side effects of this treatment that are very unlikely to affect you. For further information look at the Electronic Medicines Compendium website at

If you have a side effect not mentioned here that you think may be due to this treatment you can report it to the Medicines Health and Regulatory Authority (MHRA) at

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Updated: 24 August 2015