Find out what lapatinib is, how you have it and other important information about taking lapatinib.

Lapatinib is a targeted cancer drug (biological therapy) and is also known by its brand name, Tyverb. In North America it is called Tykerb.

It is a treatment for advanced breast cancer. Researchers are also looking at using it to treat other types of cancer. 

How it works

Lapatinib is a type of targeted cancer drug (biological therapy) called a protein 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. 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 it

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

Taking your tablets

You should take the right dose, not more or less.

Never stop taking a cancer drug without talking to your specialist first.

When you have it

You take the tablets once a day. 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 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.

Side effects

Important information

Other medicines, foods and drink

Cancer drugs can interact with some other medicines and herbal products. Tell your doctor or pharmacist about any medicines you are taking. This includes vitamins, herbal supplements and over the counter remedies.

Grapefruit and grapefruit juice

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

Pregnancy and contraception

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

Fertility

You may not be able to become pregnant or father a child 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 may be able to store sperm before starting treatment. Women may be able to store eggs or ovarian tissue but this is rare.

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 if you need treatment for anything else, including teeth problems.

Immunisations

Don’t have immunisations with live vaccines while you’re having treatment and for at least 6 months afterwards.

In the UK, live vaccines include rubella, mumps, measles, BCG, yellow fever and shingles vaccine (Zostavax).

You can:

• have other vaccines, but they might not give you as much protection as usual
• have the flu vaccine (as an injection)
• be in contact with other people who've had live vaccines as injections

Avoid close contact with people who’ve recently had live vaccines taken by mouth (oral vaccines) such as oral polio or the typhoid vaccine.

This also includes the rotavirus vaccine given to babies. The virus is in the baby’s poo for up to 2 weeks and could make you ill. So, avoid changing their nappies for 2 weeks after their vaccination if possible. Or wear disposable gloves and wash your hands well afterwards.

You should also avoid close contact with children who have had the flu vaccine nasal spray if your immune system is severely weakened. 

More information about this treatment

For further information about this treatment go to the electronic Medicines Compendium (eMC) website.

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