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Subcutaneous herceptin 786

subcutaneous Trastuzumab (Herceptin®) 786

This leaflet provides information for patients having treatment with the drug Trastuzumab.  Trastuzumab is also known by the name Herceptin®.  The leaflet will explain:

  • what Trastuzumab (Herceptin®) is
  • when and how it is given.
  • common side effects that you may experience.

What is Trastuzumab (Herceptin®) and why am I having it?

Your cancer showed a high level of a substance known as HER2 (Human Epidermal growth Receptor- factor 2).  HER2 is found on the outside of some cancer cells and it stimulates their growth.

Trastuzumab (Herceptin®) is one of a group of cancer drugs called monoclonal antibodies. Monoclonal antibodies are sometimes called targeted therapies because they work by ‘targeting’ specific proteins (receptors) on the surface of cells.  Trastuzumab (Herceptin®) locks onto the HER2 protein.  This blocks the receptor and stops the cells from dividing and growing.

How often will I receive Trastuzumab (Herceptin®)?

For Trastuzumab (Herceptin®) treatment to be most effective, it is given at 3 weekly time intervals.  For patients with early breast cancer it is usual to have Trastuzumab (Herceptin®) treatment every 3 weeks for a total of 18 treatments over 12 months.  For Metastatic Breast Cancer patients the exact number of treatments you will receive will be discussed with you by your doctor; however you will also receive your treatment at 3 weekly intervals.

How is Trastuzumab (Herceptin®) given?

Trastuzumab (Herceptin®) is available in two types for administration

  • Infusion into a vein in the back of hand or arm
  • Injection under the skin into the thigh.

Trastuzumab (Herceptin®) by subcutaneous injection is an injection under the skin on your thigh.  The administration of Trastuzumab (Herceptin®) by subcutaneous injection will take up to 5 minutes.  The injection site will change from left to right each treatment cycle.  In order for the nurse to give the injection to the leg it is advisable to wear comfortable loose-fitting clothing for example a skirt or trousers to enable access to your thigh for administration on the day of your treatment.

How often will I see the specialist team?

Your doctor will let you know how often you will need to be seen in the outpatient clinic.  At each visit the nurse who gives your Trastuzumab (Herceptin®) will check how you are feeling and discuss any problems you may have with treatment(s) or any other issues.

Where do I receive my treatment?

The first treatment will be administered in one of the day case treatment areas at Velindre Hospital or the District General Hospital closer to your home.

After the first treatment your Trastuzumab (Herceptin®) will be given by VCC trained nurses in Velindre Hospital or one of the Outreach Clinics. 

Other information

You are welcome to bring someone to stay with you during your treatment.  Space is limited in the waiting areas and treatment room so there is not usually room for more than one person.  Please be advised treatment areas are not suitable for young children.

It is important you do not become pregnant whilst having Trastuzumab (Herceptin®) treatment.

How long will my appointment take?

You will be required to spend a minimum of 2 ½ hours at the hospital for your first cycle and a minimum of 30 minutes for your second cycle of Trastuzumab (Herceptin®) treatment.  The reason for this period of observation is to ensure you are tolerating the treatment without any initial side effects 

Side effects during the treatment

Most people tolerate Trastuzumab (Herceptin®) treatment very well, with very few side effects.  However, as with all drugs, there are a number of known side effects which can occur.  Some of these are detailed below, the doctors, nurses and pharmacists can give you advice or answer any questions you may have.  

Most side effects which can occur with Trastuzumab (Herceptin®) occur at the time the drug is given.  A nurse will monitor you closely during the treatment.

If you experience any of the following during the treatment or immediately post treatment please tell your nurse straight away:

  • Feeling hot and feverish
  • Chills or shivering
  • Headache
  • Dizziness or faintness
  • Problems with breathing
  • Rash
  • Feeling sick or vomiting

Other common side effects you may experience in the first few days after treatment include:

  • Diarrhoea
  • Weakness
  • Skin rashes
  • Abdominal pain
  • Joint pain
  • Muscle pain

These side effects usually only last a few days.  Taking a mild painkiller, for example whatever you usually take for a headache, may help.  If you feel very unwell or want further advice please contact Velindre Cancer Centre – Chemotherapy Pager.

Heart problems

Trastuzumab (Herceptin®) treatment may cause some heart problems.  This is rare and the risk of developing serious heart problems is less than 1%.  Any problems which are caused by Trastuzumab (Herceptin®) will usually get better when the completed treatment cycles have finished.  Your doctor will discuss this with you and arrange for your heart function to be tested before you start Trastuzumab (Herceptin®).  Your heart function will be monitored usually every 4 months for the first year of treatment.  We will also check your blood pressure and monitor your weight regularly.

If you already have a heart condition or you take any heart medication, please tell your Velindre doctor before you start treatment with Trastuzumab (Herceptin®).  If you do develop heart problems whilst on Trastuzumab (Herceptin®) it can be treated with tablets.  It is very important not to stop taking any tablets you have been given for heart problems without discussing it with your Velindre doctor or specialist nurse.

If at any time during your treatment you become breathless, develop a cough, experience fluid retention (swelling) in your arms or legs, or palpitations (heart flutter or irregular heart beat) please contact Velindre Cancer Centre – chemotherapy Pager immediately.

Is it ok to take other medication with Trastuzumab (Herceptin®)?

Trastuzumab (Herceptin®) can remain in your body for up to 6 months after you finish treatment.  During this time you should tell your doctor and pharmacist that you have had Trastuzumab (Herceptin®) before starting any new medicines.

Who do I contact if I am unwell during my Trastuzumab (Herceptin®) treatment?

If you are unwell at home and need immediate attention at any time of the day or night phone Velindre Cancer Centre 029 2061 5888 ask for the chemotherapy pager

Sometimes cancer drugs can have very serious side effects which rarely can be life threatening. It is important to inform Velindre cancer centre if you are concerned about any side-effects

Manufacturer’s patient information leaflets 

This leaflet was written by VCC healthcare professionals in line with the approved VCC protocol. The information contained in this leaflet is evidence based. The leaflet has been approved by a Velindre Cancer Centre group of doctors, nurses, pharmacists and patient representatives. It will be reviewed and updated every 2 years. 

Copies of drug manufacturer’s patient information leaflets are available from the Velindre Pharmacy, your treatment centre or on the internet at These leaflets provide detailed information on individual drugs. We don’t give them out routinely as they can be difficult to read. Please ask if you would like a copy

Contact telephone numbers

Velindre Cancer Centre 029 2061 5888

Ask for the treatment helpline if you are unwell at home and need immediate attention at any time of the day or night. For example you should phone if you:

  • Are sick more than once in 24 hours
  • Have a temperature of 37.5°C or above or below 35.5°centigrade
  • Have diarrhoea

Pharmacy department 029 2061 5888 ext 6223

Monday – Friday 9am – 5pm for queries about your medicines

Tenovus freephone 0808 808 1010

cancer helpline 


This information is also available in Welsh

This leaflet was written by health professionals.  The information contained in this leaflet is evidence based.  It has been approved by doctors, nurses and patients.  It is reviewed and updated every 2 years.