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Trastuzumab (Herceptin)

Find out what trastuzumab is, how you have it and other important information about having trastuzumab.

What it is

Trastuzumab has the brand name Herceptin. It's a monoclonal antibody. Monoclonal antibodies attach to proteins on or in cancer cells.

Diagram showing a monoclonal antibody attached to a cancer cell

How it works

It is a type of targeted treatment.

It is used for cancers that have large amounts of a protein called HER2 (human epidermal growth factor receptor 2).

Some breast cancers and stomach cancers have large amounts of HER2 and they are called HER2 positive cancers. HER2 makes the cancer cells grow and divide. When Herceptin attaches to HER2 it can make the cells stop growing and die.

Doctors use trastuzumab to treat some types of:

  • early breast cancer in adults
  • advanced breast cancer in adults
  • advanced stomach cancer in adults

When you have it

For early breast cancer 

Trastuzumab may be used alongside chemotherapy used before or after surgery and radiotherapy.

For advanced breast cancer 

As a first treatment for breast cancer that has spread you may have trastuzumab with the chemotherapy drugs paclitaxel (Taxol) or docetaxel (Taxotere) or hormone therapies called aromatase inhibitors.

Trastuzumab may be used as a treatment on its own for people who have had at least two types of chemotherapy for breast cancer that has spread and where hormone therapy has not worked.

For advanced stomach cancer 

Trastuzumab may be used as a first treatment for a type of stomach cancer called adenocarcinoma of the stomach. You also have chemotherapy with the drug capecitabine (Xeloda) or a combination of fluorouracil and cisplatin. 

Trastuzumab is also used for cancer of the area where where the food pipe meets the stomach (gastro oesophageal cancer).

How you have trastuzumab

You might have trastuzumab into your bloodstream or as an injection under the skin.

Into your bloodstream (an infusion)

You may have trastuzumab by drip into your bloodstream (an infusion). Each treatment takes between 30 and 90 minutes. You have the first treatment over 90 minutes and your team will check you for any side effects. 

Depending on the effects you have, the infusion might be shorter next time.

You can have trastuzumab through a thin short tube (a cannula) that goes into a vein in your arm each time you have treatment.

You can also have it through a long line: a central line, a PICC line or a portacath. These are long plastic tubes that give the drug into a large vein in your chest. The tube stays in place throughout the course of treatment.

Under the skin (subcutaneous injection)

You might have trastuzumab as an injection under the skin, on the upper, outer part of your leg. The injection takes about 2 to 5 minutes.

It is important that your nurse changes which leg you have your injection in each time, to stop the area getting sore. They will check you for side effects for a few hours after the injection.

Tests during treatment

You have blood tests before starting treatment 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.

You will also have a heart trace test (ECG) and a heart scan before you start your treatment. You will have heart tests every few months while you are having trastuzumab and for some time after.

Side effects

Important information

Other medicines

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.

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 are having treatment and for 7 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 your breast milk.

Do not breastfeed for 7 months after treatment.


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.

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.


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
  • be in contact with other people who've had live vaccines as injections

Avoid contact with people who’ve had live vaccines taken by mouth (oral vaccines). This includes the rotavirus vaccine given to babies. The virus is in the baby’s urine for up to 2 weeks and can 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 also need to avoid anyone who has had oral polio or typhoid vaccination recently.

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.

Last reviewed: 
04 Aug 2014
  • Electronic medicines compendium, SPC and PILs (Powder for concentrate for solution for infusion). Accessed August 2014

  • Electronic medicines compendium, SPC and PILs (Soultion for injection in vial). Accessed August 2014

Information and help

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