Injecting the cancer medicine trastuzumab yourself

This guide gives you useful instructions and information about injecting the cancer medicine trastuzumab yourself. It covers:

The aim of this guide is to help you give yourself the medicine at home. It is not intended to replace the advice of your doctor or nurse.

Injecting trastuzumab yourself

A nurse has already shown you how to give yourself an injection under the skin (a subcutaneous injection). You and the nurse have agreed that:

  • you can inject the medicine yourself
  • you feel comfortable doing this

You have a phone appointment with a nurse on the day that you first need to inject trastuzumab. They check that you have successfully given yourself the injection.

If you have any questions not covered in this guide or are not sure how to inject trastuzumab, please contact your hospital team. They can support and help you.

Off-label use

Trastuzumab is officially approved (licensed) for use when a health professional gives you the medicine.

If you inject trastuzumab yourself, this is not an officially approved use of the medicine. It is called an off-label use of the medicine.

However, we believe that giving yourself the medicine at home is a safe and convenient way for you to have treatment. It will reduce the number of hospital visits that you need to make and save you time.

Please read the information that we give you about off-label use of the medicine. You can speak to your hospital team if you have any concerns.

About the medicine trastuzumab

Trastuzumab, which has the brand name Herceptin among others, is used to treat:

  • early and advanced breast cancer
  • advanced stomach cancer
  • cancer of where the food pipe (oesophagus) joins the stomach

How the medicine works

Trastuzumab is a type of targeted therapy. This means that the medicine is used to find and attack cancer cells.

Some cancer cells have large amounts of a protein called human epidermal growth factor receptor 2 (HER2). This substance encourages the cells to grow and survive. Trastuzumab attaches to the HER2 protein and:

  • stops the cancer cells from dividing and growing
  • encourages your body’s natural defence (immune) system to attack and kill the cancer cells

Side effects of trastuzumab

Your doctor, nurse or pharmacist explains the common side effects of trastuzumab treatment.

Contact us immediately if:

  • your temperature is very high, or you feel hot, shivery or shaky
  • you suddenly feel unwell, even if your temperature is normal
  • you have a sore throat, cough or diarrhoea, or need to pee a lot

You can call our acute oncology service on 020 7188 3754 (24 hours a day, 7 days a week).

If you get side effects or have any concerns that are not addressed in this guide, please contact your hospital.

Tips for using trastuzumab safely

Here is a list of general tips for how to use trastuzumab safely.



Resource number: 5346/VER1
Last reviewed: February 2023
Next review due: February 2026

A list of sources is available on request.

Trusted Information Creator. Patient Information Forum

Contact us

If you have any questions or equipment issues, or need information in a different format, please contact the chemotherapy day unit.

Phone: 020 7188 6452 (9am to 5pm, Monday to Friday)

Email: [email protected]

We aim to respond to emails within 1 working day.

Out of hours contact

Call the acute oncology service (AOS) on 020 7188 3754 (24 hours a day)

If you get any side effects from your treatment or feel unwell, please call the acute oncology service at any time.

Guy’s Cancer at Queen Mary’s Hospital

Please contact the Guy’s and St Thomas’ chemotherapy day unit if you have any questions or the acute oncology service out of hours.

Do you have any comments or concerns about your care?

Contact our Patient Advice and Liaison Service (PALS)

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