What is interferon?

Interferon alpha is a biological therapy that may be used to treat kidney cancer, melanoma, carcinoid tumours and some types of lymphoma and leukaemia.

During treatment, you will see a cancer doctor and a cancer nurse. This is who we mean when we mention doctor or nurse in this information.

How interferon works

Interferon is a protein the body makes in very small amounts. It can also be made outside the body and used as a drug.

Interferon stimulates the body’s immune system to fight some types of cancer. The immune system is the body’s defence against infection and disease.

Interferon may:

  • slow down or stop the cancer cells dividing
  • reduce the ability of the cancer cells to protect themselves from the immune system
  • strengthen the immune system.

How is interferon given?

Interferon is given as an injection into the fatty tissue under the skin (subcutaneously). You can be taught how to give yourself the injections, or you may want a relative or carer to learn so they can help you. A district nurse or GP practice nurse can also give them to you. Your doctor or nurse will explain how often you will have the drug and how long treatment will last.

There are some important things to remember about interferon:

  • If you forget to take your injection, tell your doctor – don’t take a double dose.
  • Store it in the fridge and follow any instructions given by your pharmacist.
  • If your treatment is finished, return any remaining injections to the pharmacist.

About side effects

We explain the most common side effects of this treatment here. We also include some less common side effects. You may get some of the side effects we mention, but you are unlikely to get all of them.

If you are also having treatment with other cancer drugs, you may have some side effects that we have not listed here. Always tell your doctor, nurse or pharmacist about any side effects you have.

Your doctor can give you drugs to help control some side effects. It is important to take them exactly as your nurse or pharmacist explains. This means they will be more likely to work for you. Your nurse will give you advice about managing your side effects. After your treatment is over, most side effects start to improve.

Serious and life-threatening side effects

Some cancer treatments can cause severe side effects. Rarely, these may be life-threatening. Your cancer doctor or nurse can explain the risk of these side effects to you.

Contact the hospital

Your nurse will give you telephone numbers for the hospital. If you feel unwell or need advice, you can call them at any time of the day or night. Save these numbers in your phone or keep them somewhere safe.

More information

We cannot list every side effect for this treatment. There are some rare side effects that are not listed. You can visit the electronic Medicines Compendium (eMC) for more detailed information.

Common side effects

Flu-like symptoms

These include a high temperature, chills, headaches, and muscle and joint pains. You may get these symptoms soon after you start treatment. These symptoms can be quite severe at the start of your treatment with interferon, but usually become milder. Your doctor may advise you to take paracetamol to help with them.

Feeling tired

Feeling tired is a common side effect. Try to pace yourself and plan your day so you have time to rest. Gentle exercise, like short walks, can give you more energy. If you feel sleepy, do not drive or operate machinery.

Changes to your mood

Some people may have mood changes. These could be depression, anxiety, mood swings, restlessness or difficulty sleeping. If you feel depressed or have other changes to your mood, it is important to tell your doctor straight away.

Risk of infection

This treatment can reduce the number of white blood cells in your blood. These cells fight infection. If the number of white blood cells is low, you are more likely to get an infection. A low white blood cell count is called neutropenia.

If you have an infection, it is important to treat it as soon as possible. Contact the hospital straight away on the 24-hour contact number you have if:

  • your temperature goes over 37.5°C (99.5°F)
  • you suddenly feel unwell, even with a normal temperature
  • you have symptoms of an infection.

Symptoms of an infection include:

  • feeling shaky
  • a sore throat
  • a cough
  • diarrhoea
  • needing to pass urine a lot.

It is important to follow any specific advice your cancer treatment team gives you.

The number of white blood cells will usually return to normal before your next treatment. You will have a blood test before having more treatment. If your white blood cell count is low, your doctor may delay your treatment for a short time.

Feeling sick

Your doctor can give you anti-sickness drugs to help prevent or control sickness. If you still feel sick, tell your doctor. They can prescribe other anti-sickness drugs that may work better for you.

Loss of appetite

This treatment can affect your appetite. Do not worry if you do not eat much for a day or two. But if your appetite does not come back after a few days, tell your nurse or dietitian. They will give you advice. They may give you food or drink supplements.

Changes to your taste

You may find that food tastes different. If you don’t have a sore mouth or ulcers, try using herbs and spices or strong-flavoured sauces to give your food more flavour. Taste changes usually get better after treatment finishes. Your nurse or dietician can give you more advice.


This treatment may cause headaches. If this happens, tell your doctor or nurse. They can give you painkillers.


If you have diarrhoea, contact the hospital for advice. Try to drink at least 2 litres (3½ pints) of fluids every day. It can help to avoid alcohol, caffeine, milk products, high-fat foods and high-fibre foods.

Increased sweating

This treatment can cause increased sweating in some people. Wearing natural fabrics, such as cotton, may be more comfortable if you are affected.

Hair thinning

Your hair may start to thin. Rarely, this treatment can cause complete hair loss. Effects on your hair are temporary. Hair usually begins to grow back and thicken a few weeks after treatment ends.

Sore mouth

Your mouth may become sore and you may get ulcers. This can make you more likely to get an infection in your mouth. Gently clean your teeth and/or dentures morning and night and after meals. Use a soft-bristled or children’s toothbrush. Your nurse might ask you to rinse your mouth regularly or use mouthwashes. It’s important to follow any advice you are given and to drink plenty of fluids.

Tell your nurse or doctor if you have any problems with your mouth. They can prescribe medicines to prevent or treat mouth infections and reduce any soreness.

Skin changes

Your skin may become dry or itchy. Tell your doctor or nurse about any skin changes. They can give you advice and may give you creams or medicines to help.

If you have psoriasis, it may get worse during treatment. Your doctor can tell you more about this.

Heart problems

Interferon may cause changes to your heartbeat or affect your blood pressure. If you notice any changes to your heartbeat, or have any pain or feel a tightness in your chest, tell your doctor straight away.

Less common side effects

Allergic reaction

Rarely, some people have an allergic reaction to interferon. Contact the hospital straight away if you develop:

  • red, warm and itchy bumps on the skin (like nettle rash)
  • swelling of the lips, tongue or throat
  • breathlessness, wheezing, a cough or sudden difficulty with breathing
  • a tight chest or chest pain.

Raised blood sugar levels

Interferon may raise your blood sugar levels. Symptoms of this include feeling thirsty, needing to pass urine more often and feeling tired. Tell your doctor or nurse if you have these symptoms.

If you have diabetes, your blood sugar levels may be higher than usual. Your doctor will talk to you about how to manage this.

Effects on the eyes

Your eyes may become sore, red or itchy (conjunctivitis). If this happens, tell your doctor. They can give you eye drops to help.

Interferon can sometimes cause blurred vision. Changes are usually mild, but rarely they can be more severe. If you notice any changes to your vision, contact your doctor so that they can check your eyes.

Effects on the lungs

Rarely, interferon can affect the lungs. If you have a cough or feel breathless, contact your doctor for advice. They may arrange for you to have a chest x-ray to check your lungs. If lung changes happen, they usually get better with treatment and after you stop having interferon.

Effects on the kidneys or liver

In some people, interferon can affect their kidneys or liver. This is usually mild and goes back to normal after treatment. You will have regular blood tests to check your kidneys and liver.

Other information about interferon

Other medicines

Some medicines can affect this treatment or be harmful when you are having it. This includes medicines you can buy in a shop or chemist. Tell your cancer doctor about any drugs you are taking, including vitamins, herbal drugs and complementary therapies.


Do not drive if you have dizziness or blurred vision, or if you feel tired or sleepy. Talk to your doctor if you are not sure whether it is safe for you to drive.


This treatment can affect whether you can get pregnant or father a child.

If you are worried about fertility, it is important to talk with your doctor before you start treatment. There may be ways to preserve fertility for men and women.


Your doctor will advise you not to get pregnant or make someone pregnant while having this treatment and for some time afterwards. The drugs may harm the developing baby. It is important to use effective contraception.


Women are advised not to breastfeed while having this treatment. This is because the drugs could be passed to the baby through breast milk.

Medical and dental treatment

If you need to go into hospital for any reason other than cancer, always tell the doctors and nurses you are taking this drug. Give them the name of your cancer doctor so they can ask for advice.

Talk to your cancer doctor or nurse if you think you need dental treatment. Always tell your dentist the names of your cancer medicines.

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