PegIntron treats hepatitis C infection. Inject this medication at bedtime to help reduce flu-like symptoms. Your doctor may also recommend Tylenol to reduce flu like symptoms.

PegIntron Overview

Reviewed: September 14, 2012

PegIntron is a prescription medication used to treat chronic hepatitis C. PegIntron belongs to a group of drugs called interferons. PegIntron treats hepatitis by activating the immune system to attack the hepatitis virus.

This medication comes in an injectable form to be given just under the skin once a week.
Common side effects of PegIntron include flu-like symptoms (fever, headaches, chills), tiredness, appetite problems, and redness or swelling at the injection site. 

How was your experience with PegIntron?

First, a little about yourself

Tell us about yourself in a few words?

What tips would you provide a friend before taking PegIntron?

What are you taking PegIntron for?

Choose one
  • Other
  • Brain Neoplasms
  • Carcinoma, Hepatocellular
  • Carcinoma, Renal Cell
  • Colorectal Neoplasms
  • Cryoglobulinemia
  • Hemangioma
  • Hepatitis C, Chronic
  • Hepatitis D
  • Hypereosinophilic Syndrome
  • Ileal Neoplasms
  • Leukemia, Hairy Cell
  • Macular Degeneration
  • Melanoma
  • Multiple Myeloma
  • Mycosis Fungoides
  • Sezary Syndrome
  • Skin Neoplasms
  • Skin Ulcer
  • Thrombocythemia, Essential
  • Thrombocytopenia
  • Warts

How long have you been taking it?

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  • Less than a week
  • A couple weeks
  • A month or so
  • A few months
  • A year or so
  • Two years or more

How well did PegIntron work for you?

Did you experience many side effects while taking this drug?

How likely would you be to recommend PegIntron to a friend?

PegIntron Cautionary Labels


Uses of PegIntron

PegIntron is a prescription medicine that is used:

  • with ribavirin and an approved hepatitis C virus (HCV) protease inhibitor to treat chronic (lasting a long time) hepatitis C infection in adults.
  • with ribavirin to treat chronic (lasting a long time) hepatitis C infection in people 3 years and older with stable liver problems.
  • alone, sometimes to treat adults who have chronic (lasting a long time) hepatitis C infection with stable liver problems and who can not take ribavirin.

This medication may be prescribed for other uses. Ask your doctor or pharmacist for more information.



PegIntron Drug Class

PegIntron is part of the drug class:

Side Effects of PegIntron

PegIntron may cause serious side effects including:

  • See "Drug Precautions".
  • Serious eye problems. PegIntron may cause eye problems that may lead to vision loss or blindness. You should have an eye exam before you start taking PegIntron. If you have eye problems or have had them in the past, you may need eye exams while you are taking PegIntron. Tell your healthcare provider or eye doctor right away if you have any vision changes while taking PegIntron.
  • Blood problems. PegIntron can affect your bone marrow and cause low white blood cell and platelet counts. In some people, these blood counts may fall to dangerously low levels. If your blood counts become very low, you can get infections, and problems with bleeding and bruising.
  • Swelling of your pancreas (pancreatitis) or intestines (colitis).
    Symptoms may include:
    • severe stomach area (abdomen) pain
    • severe back pain
    • nausea and vomiting
    • bloody diarrhea
    • fever
  • Lung problems including:
    • trouble breathing
    • pneumonia
    • inflammation of lung tissue
    • new or worse high blood pressure of the lungs (pulmonary hypertension). This can be severe and may lead to death.
You may need to have a chest X-ray or other tests if you develop fever, cough, shortness of breath or other symptoms of a lung problem during treatment with PegIntron.
  • Severe liver problems, or worsening of liver problems, including liver failure and death. Symptoms may include:
    • nausea
    • loss of appetite
    • tiredness
    • diarrhea
    • yellowing of your skin or the white part of your eyes
    • bleeding more easily than normal
    • swelling of your stomach area (abdomen)
    • confusion
    • sleepiness
    • you cannot be awakened (coma)
  • Thyroid problems. Some people develop changes in their thyroid function. Symptoms of thyroid changes include:
    • problems concentrating
    • feeling cold or hot all of the time
    • weight changes
    • skin changes
  • Blood sugar problems. Some people may develop high blood sugar or diabetes. If you have high blood sugar or diabetes that is not controlled before starting PegIntron, talk to your healthcare provider before you take PegIntron. If you develop high blood sugar or diabetes while taking PegIntron, your healthcare provider may tell you to stop PegIntron and prescribe a different medicine for you. Symptoms of high blood sugar or diabetes may include:
    • increased thirst
    • tiredness
    • urinating more often than normal
    • increased appetite
    • weight loss
    • your breath smells like fruit
  • Serious allergic reactions and skin reactions. Symptoms may include:
    • itching
    • swelling of the face, eyes, lips, tongue, or throat
    • trouble breathing
    • anxiousness
    • chest pain
    • feeling faint
    • skin rash, hives, sores in your mouth, or your skin blisters and peels
  • Growth problems in children. Weight loss and slowed growth are common in children during treatment with PegIntron.
  • Nerve problems. People who take PegIntron or other alpha interferon products with telbivudine (Tyzeka) can develop nerve problems such as continuing numbness, tingling, or burning sensation in the arms or legs (peripheral neuropathy). Call your healthcare provider if you have any of these symptoms.
  • Dental and gum problems.

Tell your healthcare provider right away if you have any of the symptoms listed above.

The most common side effects of PegIntron include:

  • Flu-like symptoms. Symptoms may include: headache, muscle aches, tiredness, and fever. Some of these symptoms may be decreased by injecting your PegIntron dose at bedtime. Talk to your healthcare provider about which over-the-counter medicines you can take to help prevent or decrease some of these symptoms.
  • Tiredness. Many people become very tired during treatment with PegIntron.
  • Appetite problems. Nausea, loss of appetite, and weight loss can happen with PegIntron.
  • Skin reactions. Redness, swelling, and itching are common at the site of injection.
  • Hair thinning.

Tell your healthcare provider if you have any side effect that bothers you or that does not go away.

These are not all of the possible side effects of PegIntron. For more information, ask your healthcare provider or pharmacist.

Call your doctor for medical advice about side effects. You may report side effects to FDA at 1–800–FDA–1088.

PegIntron Interactions

Tell your doctor about all the medicines you take including prescription and non-prescription medicines, vitamins, and herbal supplements. Especially tell your doctor if you take:

This is not a complete list of PegIntron drug interactions. Ask your doctor or pharmacist for more information.

PegIntron Precautions

PegIntron can cause serious side effects that:

  • may cause death, or
  • may worsen certain serious diseases that you may already have.

Tell your healthcare provider right away if you have any of the symptoms listed below while taking PegIntron. If symptoms get worse, or become severe and continue, your healthcare provider may tell you to stop taking PegIntron permanently. In many, but not all people, these symptoms go away after they stop taking PegIntron.

1.  Mental health problems and suicide. PegIntron may cause you to develop mood or behavior problems that may get worse during treatment with PegIntron or after your last dose, including:
  • irritability (getting upset easily)
  • depression (feeling low, feeling bad about yourself, or feeling hopeless)
  • aggressive behavior
  • thoughts of hurting yourself or others, or suicide
  • former drug addicts may fall back into drug addiction or overdose
If you have these symptoms, your healthcare provider should carefully monitor you during treatment with PegIntron and for 6 months after your last dose.
2.  Heart problems. Some people who take PegIntron may get heart problems, including:
  • low blood pressure
  • fast heart rate or abnormal heart beat
  • trouble breathing or chest pain
  • heart attacks or heart muscle problems (cardiomyopathy)
3. Stroke or symptoms of a stroke. Symptoms may include weakness, loss of coordination, and numbness. Stroke or symptoms of a stroke may happen in people who have some risk factors or no known risk factors for a stroke.
4.  New or worsening autoimmune problems. Some people taking PegIntron develop autoimmune problems (a condition where the body's immune cells attack other cells or organs in the body), including rheumatoid arthritis, systemic lupus erythematosus, and psoriasis. In some people who already have an autoimmune problem, it may get worse during your treatment with 
5.  Infections. Some people who take PegIntron may get an infection. Symptoms may include:
  • fever
  • chills
  • bloody diarrhea
  • burning or pain with urination
  • urinating often
  • coughing up mucus (phlegm) that is discolored (for example, yellow or pink)

Do not take PegIntron with ribavirin if you are pregnant or planning to get pregnant or breastfeeding.

While taking PegIntron, you should see a healthcare provider regularly for check-ups and blood tests to make sure that your treatment is working, and to check for side effects.

Do not take PegIntron:

  • if you have had a serious allergic reaction to another alpha interferon or to any of the ingredients in PegIntron. Ask your healthcare provider if you are not sure.
  • if you have certain types of hepatitis (autoimmune hepatitis).
  • if you have certain other liver problems.
  • with ribavirin if you are pregnant, planning to get pregnant, or breastfeeding.

Talk to your healthcare provider before taking PegIntron if you have any of these conditions.

PegIntron Food Interactions

Medicines can interact with certain foods. In some cases, this may be harmful and your doctor may advise you to avoid certain foods. In the case of PegIntron there are no specific foods that you must exclude from your diet when receiving PegIntron.

Inform MD

Before you take PegIntron, tell your healthcare provider if you:

  • See "Drug Precautions".
  • are being treated for a mental illness or had treatment in the past for any mental illness, including depression and suicidal behavior
  • have or ever had any problems with your heart, including heart attack or high blood pressure
  • have any kind of autoimmune disease (where the body's immune system attacks the body's own cells), such as psoriasis, systemic lupus erythematosus, rheumatoid arthritis
  • have or ever had bleeding problems or a blood clot
  • have or ever had low blood cell counts
  • have ever been addicted to drugs or alcohol
  • have liver disease (other than hepatitis C infection)
  • have or had lung disease such as chronic obstructive pulmonary disease (COPD)
  • have thyroid problems
  • have diabetes
  • have colitis (inflammation of your intestine)
  • have a condition that suppresses your immune system, such as cancer
  • have hepatitis B infection
  • have HIV infection
  • have kidney problems
  • have high blood triglyceride levels (fat in your blood)
  • have an organ transplant and are taking medicine that keeps your body from rejecting your transplant (suppresses your immune system)
  • have any other medical conditions
  • are pregnant or plan to become pregnant. It is not known if PegIntron will harm your unborn baby. You should use effective birth control during treatment with PegIntron. Talk to your healthcare provider about birth control choices for you during treatment with PegIntron. Tell your healthcare provider if you become pregnant during treatment with PegIntron.
  • are breastfeeding or plan to breastfeed. It is not known if PegIntron passes into your breast milk. You and your healthcare provider should decide if you will use PegIntron or breastfeed.

Tell your healthcare provider about all the medicines you take, including prescription and non-prescription medicines, vitamins, and herbal supplements.

PegIntron and Pregnancy

Tell your doctor if you are pregnant or plan to become pregnant. It is not known if PegIntron will harm your unborn baby.

PegIntron and Lactation

Tell your doctor if you are breastfeeding or plan to breastfeed. You and your healthcare provider should decide if you should use PegIntron or breastfeed. You should not do both.

PegIntron Usage

  • Take PegIntron exactly as your healthcare provider tells you to.
  • PegIntron is given as an injection under your skin (subcutaneous injection). Your healthcare provider should show you how to prepare and measure your dose of PegIntron, and how to inject yourself before you use PegIntron for the first time.
  • Do not take more than your prescribed dose. Call your healthcare provider right away if you take too much PegIntron.
  • Inject PegIntron one time each week unless instructed differently by your healthcare provider. Call your healthcare provider for instructions if you miss a dose.
  • If you miss a dose of PegIntron, take the missed dose as soon as possible during the same day or the next day, then continue on your regular dosing schedule. If several days go by after you miss a dose, check with your healthcare provider about what to do.
  • Do not inject more than 1 dose of PegIntron in one week without talking to your healthcare provider.
  • If you take too much PegIntron, call your healthcare provider right away. Your healthcare provider may examine you more closely, and do blood tests.
  • Your healthcare provider should do regular blood tests before you start PegIntron, and during treatment to see how well the treatment is working and to check you for side effects.
  • Expect to get "flu-like" symptoms when taking PegIntron. To help reduce flu-like symptoms:
    • Follow your healthcare provider's instructions about taking acetaminophen before future doses of PegIntron.
    • Inject PegIntron at bedtime to help reduce flu-like symptoms.

It is important for you to keep all appointments with your healthcare provider. Call your healthcare provider if you miss an appointment. There may be special instructions for you.

PegIntron Dosage

Take this medication exactly as prescribed by your doctor. Follow the directions on your prescription label carefully.
The dose your doctor recommends may be based on the following:

  • the condition being treated
  • other medical conditions you have
  • other medications you are taking
  • how you respond to this medication
  • your weight
  • your height
  • your age
  • your gender

Chronic Hepatitis C treatment (PegIntron formulation)

  • Adults dose: 1.5 mcg/kg/week
  • Pediatric dose: 60 mcg/m2/week

PegIntron Overdose

If you take too much PegIntron, call your local Poison Control Center or seek emergency medical attention right away.

Other Requirements

  • Store PegIntron vials in the carton at 59°F to 86°F (15°C to 30°C).
  • After mixing, use PegIntron right away or store it in the refrigerator for no longer than 24 hours at 36°F to 46°F (2°C to 8°C).
  • Do not freeze PegIntron.

Keep PegIntron and all medicines out of the reach of children.

PegIntron FDA Warning


The risk of serious depression, with suicidal ideation and completed suicides, and other serious neuropsychiatric disorders are increased with alpha interferons, including peginterferon alfa-2b. Permanently discontinue PegIntron in patients with persistently severe or worsening signs or symptoms of depression, psychosis, or encephalopathy. These disorders may not resolve after stopping PegIntron.