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Interferon 406

Interferon 406

This leaflet provides information on a course of treatment called interferon.  The leaflet will explain what interferon is and when and how it is given.  It will also tell you about common side effects that you may experience.  Contact telephone numbers and details of how to obtain further information on interferon are given at the end of the leaflet.

What is interferon? 

Interferon is a protein which occurs naturally in the body in small amounts.  It is not chemotherapy.  It helps your own immune system kill the cancer cells.

Why am I having interferon?

Interferon is a drug treatment used after surgery to reduce the risk of the cancer returning.  

How often will I see the specialist team?

You will see the specialist team in the outpatient clinic each week during your treatment.  You will need to have blood tests taken at least once a week to monitor your white blood cells and liver function.  Sometimes the treatment is temporarily stopped if any of your blood results are abnormal.  Treatment can be restarted when the blood results are back to normal.

How often will I receive interferon?

Interferon is given daily for five days a week (Monday – Friday) for four weeks.  It is given through a drip into a vein in the back of your hand or arm.  Alternatively it may be suggested that a fine tube called a PICC is inserted into a large vein in your upper arm.  This will remain in place throughout the course of your treatment.  Your doctor or nurse will discuss this further with you.  

We have a leaflet that tells you more about PICC lines.  Please ask if you would like a copy. 

How long will my appointment take?

The treatment will take about an hour.  Please allow an extra 30 minutes for your first treatment.

Can I bring relatives and friends with me? 

You are welcome to bring someone to stay with you during your treatment. Space is limited so there is not usually room for more than one person.  Treatment areas are not suitable for young children.

Reactions during treatment

Although it is rare, some people can experience a reaction during the treatment.  If you experience any of the following during your 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

If any of these occur we will stop the treatment until you feel better.  The treatment can then start again, usually without any further problems.

What are the possible side effects?

Many people tolerate interferon treatment very well, with very few side effects.  However, there are a number of side effects which can occur.  The doctors, nurses and pharmacists can give you advice or answer any questions you may have.

Flu like symptoms

One of the most common side effects of interferon is flu-like symptoms.  These occur in 80-90% of patients.  Symptoms include a high temperature, chills and muscle and joint pains.  They may start after the drug is given and last for a few days.  They usually become less of a problem as the treatment continues.

We will give you paracetamol to take approximately one hour before your treatment to reduce these symptoms.  You can take paracetamol at home if needed to control these symptoms (do not take more than 8 tablets in 24 hours).

Tiredness and fatigue

A feeling of tiredness can also be a problem during the treatment.  This can sometimes worsen over the four weeks.  It is important to listen to your body and rest if you need to, but carry out your normal activities if you feel able.  Some people find it beneficial to take gentle exercise as well as taking rest.


Nausea and vomiting are not common with this treatment. We will give you anti-sickness medicine to take if needed.

If you are sick more than once in 24 hours despite taking regular anti-sickness medicine when you are at home, then please contact Velindre Cancer Centre for advice.  The telephone number is at the end of the leaflet.

Less common side effects

Other less common side effects with interferon are listed below.  Please tell your doctor or nurse at your next hospital visit if you develop any of these side effects:

  • Loss of appetite
  • Depression
  • Dizziness
  • Skin rash, inflammation with dry skin 
  • Pins and needles in your hands and toes
  • Effects on circulation - interferon may alter the rhythm of the heart or affect your blood pressure.  This will go back to normal when the drug is stopped
  • Temporary reduction in the production of blood cells – we will check this through your regular blood tests.  Tell your doctor or nurse of any signs of infection, bruising or bleeding
  • Hair thinning, this is temporary and your hair will grow back once treatment has finished
  • Blurred vision or blood spots in the eyes

Other information

It is important that you do not become pregnant or father a child whilst receiving interferon treatment. 

Is it ok to take other medication with interferon?

Tell your doctor or pharmacist if you take phenytoin or phenobarbitone as interferon affects the way these drugs work.

Do not have live vaccines such as those for a foreign holiday during treatment or for at least 3 months after. 

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

Velindre leaflets provide information about very common and commonly reported side-effects (we are unable to list all of the common side effects), for more information regarding these and the less common side-effects please refer to the manufacturers patient information leaflets, obtained from Velindre pharmacy and/or on the internet at Sometimes patients may find these leaflets difficult to read however. Please ask if you would like a copy from your doctor or from Velindre pharmacy

Contact telephone numbers

Velindre Cancer Centre 029 2061 5888

Ask for the treatment helpline if you are unwell at home and need immediate advice at any time of the day or night. 

Pharmacy department 029 2061 5888 ext 6223

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

Tenovus freephone 0808 808 1010

cancer helpline 


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.

Prepared March 2011