How does it work?

Pegasys injection contains the active ingredient peginterferon alfa-2a, which is a type of medicine called an immunomodulator. It is a man-made form of a natural substance called interferon.

Interferons are a family of small protein molecules that are produced naturally by cells in response to viral infections or various synthetic and biological inducers. Three major classes of interferons have been identified: alfa, beta and gamma. They work in a complicated way that is not fully understood, but are thought to boost the immune system, causing it to attack infected or abnormal cells.

Interferons can be used to treat a range of diseases. Interferon alfa can be used in the treatment of chronic hepatitis B or C, which are liver diseases caused by the hepatitis B and C viruses. It works by helping to prevent these viruses from multiplying in the liver cells.

The peginterferon alfa-2a in Pegasys injection is a form of interferon alfa that has been combined with a chemical called polyethylene glycol. It is sometimes referred to as pegylated interferon alfa-2a. This form of interferon alfa remains in the body for longer then standard interferon alfa and allows for the medicine to be given less frequently.

Pegasys injection is given once weekly to treat hepatitis B and C. When treating hepatitis C it is most effective if used in combination with another medicine called ribavirin.

The injection should be administered under the skin (subcutaneously) of the abdomen or thigh.

What is it used for?

• Chronic hepatitis B.
• Chronic hepatitis C, preferably in combination with ribavirin (Copegus).

Warning!

• This medicine may reduce your ability to drive or operate machinery safely. Do not drive or operate machinery until you know how this medicine affects you and you are sure it won't affect your performance.
• This medicine can cause flu-like symptoms such as aches and pains, fever, chills, sweating, headache, fatigue and nausea. These tend to be worse at the start of treatment and improve with continued treatment. You may want to take a medicine to reduce these symptoms, for example, paracetamol. Ask your doctor or pharmacist for advice.
• During treatment with this medicine you will need to have regular blood tests. This is to monitor various things, including your liver function, thyroid function, blood cells and levels of lipids in your blood.
• This medicine may decrease the number of blood cells in your blood. Tell your doctor immediately if you experience any of the following symptoms during your treatment, as they may indicate problems with your blood cells: unexplained bruising or bleeding, purple spots, sore mouth or throat, mouth ulcers, high temperature (fever) or other signs of infection, or suddenly feeling tired, breathless, or generally unwell.
• This medicine has been associated with psychiatric side effects, particularly depression, which can occur at any time during treatment and even after treatment has finished. You should discuss this with your doctor before starting treatment. It is important to talk to your doctor immediately if you have any distressing thoughts or feelings, thoughts about suicide or self-harm, mood changes, confusion, aggressive behaviour or any other unusual change in behaviour while having treatment with this medicine. It may be necessary to stop treatment.
• Lung inflammation and pneumonia can occur rarely in people treated with this medicine. For this reason it is important to tell your doctor if you get a fever, cough or shortness of breath during treatment. Your doctor will need to take a chest X-ray to make sure there are no problems with your lungs.
• This medicine has rarely been associated with side effects on the eyes. You should have an eye examination before starting treatment. Tell your doctor if you experience any disturbances in your vision during treatment. If you have any existing eye disorders you should have regular eye examinations throughout treatment with this medicine.
• If you experience signs of a severe allergic reaction (such as difficulty in breathing, wheezing, swelling of the face, tongue or throat, or hives) while on this medication, seek medical help immediately.
• Teeth and gum disorders, which may lead to loss of teeth, have been reported when this medicine is used in combination with ribavirin. If you are taking ribavirin with this medicine it is important to have regular dental checks and follow a good dental care routine during treatment. Teeth should be brushed thoroughly twice daily. If you experience vomiting as a side effect of this medicine it is important to rinse out the mouth thoroughly afterwards.
• The safety and effectiveness of this medicine have not been established in people who have had a liver transplant.

Use with caution in

• People with current depression, or a history of depression or other severe psychiatric disorders.
• Diabetes.
• Heart disease.
• High blood pressure (hypertension).
• Overactive or underactive thyroid gland.
• Psoriasis.
• Sarcoidosis.
• Diseases caused by the immune system attacking the body's own tissues (autoimmune diseases).
• People co-infected with HIV, particularly if also receiving Highly Active Anti-Retroviral Therapy (HAART) or with a low CD4 count.
• Decreased kidney function.
• Decreased liver function.
• People with low numbers of white blood cells, red blood cells, haemoglobin or platelets in their blood.
• People taking other medicines that can lower the numbers of blood cells in the blood, eg immunosuppressants.

Not to be used in

• Allergy to alfa interferons.
• History of severe heart disease, such as unstable or uncontrolled heart failure, heart attack or severe irregular heartbeats (arrhythmias) in the previous six months.
• Severely decreased liver function or, liver cirrhosis with complications (decompensated cirrhosis).
• Hepatitis caused by the body's immune system attacking the liver (autoimmune hepatitis).
• People co-infected with hepatitis C and HIV who have liver cirrhosis and moderate to severely decreased liver function.
• Uncontrolled thyroid disease.
• This medicine contains benzyl alcohol and is not suitable for children under the age of three years. The manufacturer states that the safety and efficacy of this medicine have not been established in children less than 18 years of age.

This medicine should not be used if you are allergic to one or any of its ingredients. Please inform your doctor or pharmacist if you have previously experienced such an allergy.

If you feel you have experienced an allergic reaction, stop using this medicine and inform your doctor or pharmacist immediately.

Pregnancy and breastfeeding

Certain medicines should not be used during pregnancy or breastfeeding. However, other medicines may be safely used in pregnancy or breastfeeding providing the benefits to the mother outweigh the risks to the unborn baby. Always inform your doctor if you are pregnant or planning a pregnancy, before using any medicine.

• The safety of this medicine for use during pregnancy has not been established. It should only be used during pregnancy if the expected benefit to the mother is greater than any possible risk to the foetus. Women who could get pregnant should use effective methods of contraception to prevent pregnancy while having treatment with this medicine. Seek medical advice from your doctor.
• Women taking this medicine in combination with ribavirin must use a highly effective method of contraception (such as an injected or implanted form) to prevent pregnancy, because ribavirin can be harmful to an unborn baby. Contraception should be started before your treatment begins and continued all the time you are taking ribavrin with this medicine. You should continue to use contraception to prevent pregnancy for at least seven months after your treatment is finished. See the Copegus factsheet for more details.
• Men taking this medicine in combination with ribavirin should use condoms to avoid fathering a child, both during treatment and for seven months after treatment is finished. See the Copegus factsheet for more details.
• It is not known if this medicine passes into breast milk. The manufacturer states that breastfeeding should be stopped before treatment is started and women should not breastfeed if having treatment with this medicine.

Side effects

Medicines and their possible side effects can affect individual people in different ways. The following are some of the side effects that are known to be associated with this medicine. Just because a side effect is stated here does not mean that all people using this medicine will experience that or any side effect.

• Headache.
• Dizziness.
• Pain and swelling at injection site.
• Fatigue, weakness or loss of strength (asthenia).
• Loss of appetite.
• Pain in the muscles or joints.
• Fever or chills.
• Emotional problems or mood changes, for example irritability, depression, anxiety, aggression, suicidal thoughts (see warning above).
• Difficulty sleeping (insomnia).
• Impaired concentration or memory.
• Disturbances of the gut such as diarrhoea, nausea, vomiting, indigestion or abdominal pain.
• Dry mouth, mouth ulcers, bleeding gums.
• Shortness of breath (dyspnoea), cough.
• Skin reactions such as rash, itching, dry skin, hair loss, increased sweating.
• Weight loss.
• Changes in sensation, eg tingling or numb sensations.
• Decrease in the number of white blood cells, haemoglobin or platelets in the blood (see warning above).
• Eye problems, such as blurred vision, eye inflammation or pain, visual disturbances (see warning above).
• Heart problems such as increased heart rate, irregular heart beats, chest pain, palpitations.
• Liver, kidney, thyroid or lung disorders.

The side effects listed above may not include all of the side effects reported by the medicine's manufacturer.

For more information about any other possible risks associated with this medicine, please read the information provided with the medicine or consult your doctor or pharmacist.

How can this medicine affect other medicines?

It is important to tell your doctor or pharmacist what medicines you are already taking, including those bought without a prescription and herbal medicines, before you start treatment with this medicine. Similarly, check with your doctor or pharmacist before taking any new medicines while having treatment with this one, to ensure that the combination is safe.

There may be an increased chance of side effects on the blood cells if this medicine is used in combination with other medicines that can affect the blood cells, for example immunosuppressants or chemotherapy.

There may be an increased risk of side effects if this medicine is used in combination with medicines used to treat HIV infection.

Peginterferon alfa-2a may increase the blood level of methadone, which is prescribed for injecting drug users. This can increase the risk of side effects such as drowsiness or slow breathing in people who are taking large amounts of methadone.

Peginterferon alfa-2a can increase the amount of theophylline in the blood, by preventing its breakdown. If this medicine and theophylline are used in combination it is necessary to have regular blood tests to check the amount of theophylline in your blood. Your doctor may need to reduce your dose of theophylline.

Other medicines containing the same active ingredient

There are currently no other medicines available in the UK that contain peginterferon alfa-2a as the active ingredient.