Peg-interferon (Pegetron)


Pegetron is a medication used to treat hepatitis C. It is a combination of two hepatitis C medications—peg-interferon and ribavirin—that are sold together in a box and called Pegetron. It is used along with other medications to cure people of the hepatitis C virus. Peg-interferon is taken by injection once a week, while ribavirin comes in the form of pills that are taken twice daily. This fact sheet is primarily about the peg-interferon medication that is included in Pegetron. Common side effects include fever, headache, tiredness, irritability and sometimes depression. Peg-interferon must be stored in the fridge. Hepatitis C treatment can cure a person from hepatitis C. However, a person could become infected again if they are exposed to the hepatitis C virus in the future.

What is Pegetron?

Pegetron is a medication used to treat hepatitis C (Hep C). It is used by itself or in combination with other medications to cure people of the hepatitis C virus.

Pegetron is commonly referred to as peg-interferon. It is a specific type called peg-interferon alpha-2b and it is sold together with ribavirin. This fact sheet is primarily about the peg-interferon medication that is included in Pegetron.

How does peg-interferon work?

Hep C is a disease of the liver that is caused by a virus. A virus is a very tiny germ that makes copies of itself to survive by a process called replication. The Hep C virus has at least six different strains, which are also known as genotypes.

Peg-interferon is the name of a long-lasting form of alpha interferon. Alpha interferon is a chemical messenger that is made by the body. It protects your cells from infection by Hep C and helps your immune system fight Hep C.

Hep C treatment can cure a person from Hep C. However, a person could get infected again if they are exposed to the Hep C virus in the future. Being cured from Hep C does not make you immune from getting the Hep C virus again.

How do people use peg-interferon?

Peg-interferon is taken as an injection once a week. It must be used in combination with ribavirin, which are pills that are taken twice a day. It can also be taken with some direct-acting antiviral medications (DAAs). DAAs are a group of medications that directly attack the ability of a virus, such as hepatitis C, to make copies of itself. In Canada, peg-interferon is approved for use with the following drug combinations:

For more information on the medications that are taken with peg-interferon, see the drug fact sheet by clicking on the drug name.

The combination a person takes depends on which genotype they have, whether they have been treated before, the amount of liver damage and other issues. Peg-interferon does not need to be taken with food.

Peg-interferon is approved in Canada for people with genotype 1, 2, 3, 4, 5 or 6 hepatitis C virus.

How long is treatment?

As access to newer Hep C treatments improves in Canada, it will be less likely that a person with chronic Hep C would take peg-interferon and ribavirin without an additional DAA. To find out the length of treatment for a DAA taken with peg-interferon and ribavirin, see the drug fact sheet for the DAAs listed above.

When peg-interferon and ribavirin are prescribed without DAAs they are taken for either 24 or 48 weeks.

How is peg-interferon taken?

Peg-interferon is injected under the skin once a week. This drug is usually taken at bedtime.

Your nurse will teach you how to inject peg-interferon under the skin. The best places on the body to inject peg-interferon include the following:

  • upper leg or thigh
  • outer part of the upper arm
  • abdomen (not the belly button or waist)

Do not inject peg-interferon into the same place all the time. You should change injection sites in a regular pattern. If you prefer, some clinics or health centres may let you come in once a week so a nurse can inject you. Speak to your hepatitis nurse or doctor to find out if this option is available.

Ribavirin is always taken with peg-interferon. It is taken in pill form every day. Your doctor will tell you how many pills to take.

Sticking to treatment

All medications work best when they are taken exactly as prescribed and directed. This means taking the medications in the right amount and at the right time for the entire time that your treatment lasts. Skipping doses or stopping treatment altogether means that the treatment may not work as well and the chance of being cured is lower.

What can you do if you forget to take your medication?

If you miss taking a dose of peg-interferon and remember within two days of when you were supposed to take it, take it as soon as possible. If it is more than two days past when you were supposed to take your dose, ask your doctor what you should do.

If you find that you are not able to take your medication as prescribed and directed, talk to your nurse or doctor. You can also check out the section “Tips for staying on track with treatment” in CATIE’s Hepatitis C: An in-depth guide.

How likely is a cure from treatment that includes peg-interferon?

Hep C treatment can cure a person from Hep C.

In late-stage clinical trials of peg-interferon and ribavirin, cure rates ranged from 45% to 80% depending on the genotype of the participants. In clinical trials of peg-interferon and ribavirin in people who have both Hep C and HIV, the cure rates are lower compared to people who are mono-infected with Hep C.

When peg-interferon and ribavirin are tested with other DAAs in clinical trials, the cure rates are higher than for peg-interferon and ribavirin. For more information on the cure rates for different DAA combinations, see the fact sheets for the individual drugs.

Sometimes in real life the cure rates can be lower than in clinical trials.

A cure for Hep C is also known as a sustained virological response (SVR). This is when the Hep C virus is no longer detected in the blood 12 or 24 weeks after treatment ends.


Below is a list of warnings about conditions that may or may not occur while you are taking peg-interferon. This list is not a complete list of warnings. Talk to your doctor, nurse and pharmacist about possible side effects and other issues that you may experience while you are taking peg-interferon.

1. Mental health

Some people who take peg-interferon find that it has an impact on their mental health. For example, some people may experience irritability, brain fog, anxiety or hallucinations.

Depression is also a possible side effect of treatment with peg-interferon. People who have a history of depression can talk to their doctor about the possibility of starting antidepressants prior to treatment with peg-interferon. Let your doctor know if you have a history of depression or anxiety. Talk to your doctor about treatment options for depression.

Once you have started treatment, if you notice any of the following problems, talk to your doctor right away:

  • you become easily upset or angry
  • you have unexpected feelings of sadness
  • you feel hopeless
  • you have thoughts about harming yourself or others
  • you have thoughts about suicide

2. Pregnancy

If you are pregnant or think that you may be pregnant and you are taking peg-interferon and ribavirin, talk to your doctor right away. Peg-interferon should not be used by the following people:

  • pregnant people
  • people who could become pregnant and their sex partners

This is because the combination of peg-interferon and ribavirin can severely damage the fetus. Pregnancy should not be planned while you or your partner are on this therapy. If you are planning to have a baby, you should wait until six months after therapy has been stopped. Ribavirin can also be toxic to sperm.

3. Breastfeeding/nursing

People with infants who are taking peg-interferon should not breastfeed or nurse their children.

4. Heart, stroke and blood problems

Although this is rare, some people who have used peg-interferon have developed heart problems, including low blood pressure, rapid heart beats and chest pain.

Peg-interferon can also lower levels of white blood cells, increasing the risk of developing infections. As well, this drug can reduce levels of platelets in your blood. Because platelets are needed to help your blood clot, having lower-than-normal levels of platelets increases the risk of bleeding. Tell your doctor right away if you have any problems with blood clotting or are getting regular infections.

Some people who have used peg-interferon have developed bleeding in the brain or a disruption of blood flow to the brain (a stroke). Signs and symptoms of a stroke include the following:

  • sudden numbness or weakness of the face, arm or leg, especially on one side of the body
  • sudden confusion or trouble speaking or understanding speech
  • sudden trouble seeing in one or both eyes
  • sudden trouble walking, dizziness or loss of balance or coordination
  • sudden severe headache with no known cause

If you have any of these problems, go to your nearest emergency department immediately.

5. Thyroid problems

Some people who use peg-interferon have developed changes in their thyroid hormones. The thyroid gland makes hormones that control the speed of different activities in the body, such as how fast calories are burned and how quickly the heart beats. Thyroid hormones affect your ability to maintain a normal body temperature and have sufficient energy and also help to stabilize your mood. During treatment with peg-interferon your doctor may monitor your thyroid hormone levels.

6. Infections

A temporary fever is a normal reaction to peg-interferon treatment. However, a high fever or a fever that does not go away needs to be investigated to ensure that there is not some other cause, such as an infection. If you have a high or persistent fever while using peg-interferon, tell your nurse and doctor.

7. Skin rash

Rash can occur in people using peg-interferon. In rare cases the rash may be serious. If you have a severe rash with blisters, fever or sores in your mouth, nose or eyes (or your eyes become red), contact your doctor right away.

8. Inflammation of the pancreas (pancreatitis)

Some people who use peg-interferon may develop inflammation of the pancreas. People who have pancreatitis may develop abdominal pain, nausea, vomiting, unexpected sweating, fever and anxiety. If this happens, tell your doctor right away.

9. Lung problems

In rare cases, people taking peg-interferon have developed lung problems, such as lung infection (pneumonia), high blood pressure that affects the lungs and heart (pulmonary hypertension), and inflammation of the lung tissue (pneumonitis). If you experience chest pain, shortness of breath, coughing up blood, having your skin, fingernails or toenails turn blue or dark, dizziness, fainting, swelling in the legs and ankles, fatigue or racing heart rate, seek medical attention immediately.

10. Autoimmune disease

Some people have been reported to develop autoimmune diseases while taking peg-interferon. Autoimmune diseases occur when your immune system does not differentiate between healthy cells and infectious cells and destroys both kinds of cells. People with autoimmune diseases may experience fatigue, fever, bone and/or joint pain and rash. If you are having any of these symptoms, talk to your doctor.

One of the autoimmune diseases that may develop from taking peg-interferon is inflammation of the colon (colitis). People who develop colitis typically experience abdominal pain, bloody diarrhea and fever. If this happens, tell your doctor right away. Colitis usually goes away one to three weeks after peg-interferon is discontinued.

11. Diabetes

Some people who use peg-interferon have developed diabetes. Diabetes occurs when the body does not use the insulin it produces (insulin controls the amount of sugar in the blood). This can result in blood sugar that is higher than normal, causing symptoms such as thirst, fatigue, weight loss, frequent urination, hunger, regular infections, irritability, blurred vision and sores that take a long time to heal. If you are taking peg-interferon and have any of these symptoms, tell your doctor.

12. Changes in vision

Some people who use peg-interferon may develop blurred vision or other problems seeing. If this happens, tell your doctor right away.

13. Hearing problems

Some people who use peg-interferon may develop hearing loss. If this happens, tell your doctor right away.

14. Special populations

Peg-interferon has not been tested in the following populations:

  • people over the age of 65
  • people under the age of 18
  • people who are organ transplant recipients
  • people with hepatitis B

People who are in the following groups should not take peg-interferon:

  • people who have epilepsy
  • people who are hypersensitive to alpha interferons, E. coli-derived products or polyethylene glycol
  • people with autoimmune hepatitis (AH) or a history of AH
  • people with severe liver damage (decompensated cirrhosis)
  • people with chronic obstructive pulmonary disease (COPD)
  • people who have severe mental health issues or a history of severe mental health issues
  • people who have diabetes that is not controlled by medication
  • people who are breastfeeding or chest-feeding
  • people with severe kidney problems
  • people with advanced liver disease that is not controlled by medication and is caused by a disease other than hepatitis C

Side effects

Common side effects of peg-interferon include:

This is not a complete list of side effects of peg-interferon.

Drug interactions

Always consult your doctor and pharmacist about taking other prescription and non-prescription drugs, including methadone or opiate substitution therapies, herbs, supplements and street drugs.

Drug interactions occur when one medication affects how another is absorbed, used or flushed out of the body. Some drugs can interact with peg-interferon, increasing or decreasing the level of one or both drugs in the body. Increased levels can lead to new or more severe side effects. Decreased levels may mean that the drug(s) won’t be as effective.

Taking peg-interferon and ribavirin with the following medications could potentially cause significant drug interactions:

  • the HIV medicines d4T (stavudine, Zerit), ddI (didanosine, Videx EC), AZT (zidovudine, Retrovir), 3TC (lamivudine), abacavir (Ziagen), Triumeq (dolutegravir + abacavir + 3TC), Combivir (AZT + 3TC ), Trizivir (abacavir + AZT + 3TC)
  • the hepatitis B medicine telbivudine (Sebivo)
  • the Chinese herbal medicine sho-saiko/Xiao-Chai-Hu

Peg-interferon can temporarily weaken the bone marrow. Use of the HIV medicine AZT (zidovudine, Retrovir and also found in the combination pills Combivir and Trizivir) may make this worse.

When peg-interferon is combined with any HIV medicine, also known as antiretroviral therapy (ART), there is a risk of developing lactic acidosis. Lactic acidosis is the name given to a condition where high levels of lactic acid build up in the blood. The symptoms of lactic acidosis are tiredness, nausea, vomiting, abdominal pain and shortness of breath. If you have these symptoms, talk to your doctor right away.

This is not a complete list of possible drug interactions with peg-interferon and ribavirin.

Talk to your nurse, doctor and pharmacist if you are taking any of the above medicines.

One way to manage drug interactions is to make sure that your doctor and pharmacist know about everything you are taking, including prescription drugs, over-the-counter drugs, street drugs, herbal medications, supplements or anything else. If you have more than one doctor or pharmacist, it is possible for drug interactions to get missed. If more than one doctor is writing prescriptions for you, let each one know about everything you are taking. If possible, use the same pharmacy for all your prescriptions.


The dose of peg-interferon normally used is 1.5 micrograms (mcg) per kilogram of body weight, once a week. Your doctor will tell you how much to take. The drug is injected under the skin at bedtime. Keep peg-interferon in your refrigerator.

The dose of ribavirin used with peg-interferon will be adjusted depending on your weight. It usually ranges between 800 and 1,200 mg/day. Ribavirin is taken orally with meals twice per day.


Pegetron, which includes peg-interferon and ribavirin, has been approved by Health Canada and is available in Canada. Pegetron is manufactured by Merck Canada Inc.

Your nurse, doctor or pharmacist can tell you more about availability and coverage of Pegetron in your region.

CATIE’s online Treatment coverage in your region section of Hepatitis C: An in-depth guide contains information about provincial and territorial drug coverage.


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Author(s): Anderson S, Hosein SR

Published: 2015