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Pegasys

Generic name: peginterferon alfa-2a

What is Pegasys?

Pegasys is a prescription medicine that is:

  • used with other hepatitis C virus (HCV) antiviral medicines to treat adults who have chronic (lasting a long time) hepatitis C infection and compensated liver disease.
  • used alone to treat adults with chronic hepatitis C (CHC) and compensated liver disease, and who are not able to take other HCV antiviral medicines.
  • used with Ribavirin to treat children 5 years of age and older who have CHC and compensated liver disease.

Pegasys should not be used alone or with Ribavirin, without taking other HCV antiviral medicines, to treat people with CHC who have taken interferon-alfa and it did not work.

Pegasys should not be used to treat people with CHC who have received an organ transplant.

Pegasys is a prescription medicine that is:

  • used alone to treat adults and children 3 years and older with chronic hepatitis B (CHB) virus who show signs that the virus is damaging the liver

It is not known if Pegasys is safe and effective in:

  • children with CHC under 5 years of age or children with CHB under 3 years of age.
  • people with Hepatitis B virus (HBV) who also have HCV or HIV infection
  • people with HCV who also have HBV, or HIV infection and their CD4+ cell count is less than 100 cells/mm3

What is the most important information I should know about Pegasys?

  • Ribavirin in combination with Pegasys may cause birth defects or death of your unborn baby. If you are pregnant or your sexual partner is pregnant or plans to become pregnant, do not take Pegasys and Ribavirin combination therapy. You or your sexual partner should not become pregnant during treatment with Pegasys and Ribavirin combination therapy and for 6 months after treatment is over. You must use 2 effective forms of birth control, one of which should be a condom with spermicide during treatment with Pegasys and Ribavirin combination therapy, and for the 6 months after you stop treatment.
    • Females must have a pregnancy test before starting Pegasys and Ribavirin combination therapy, every month while being treated, and every month for the 6 months after stopping treatment with Pegasys and Ribavirin combination therapy.
    • If you or your female sexual partner becomes pregnant during treatment with Pegasys and Ribavirin or within 6 months after you stop taking Pegasys and Ribavirin, tell your healthcare provider right away. You or your healthcare provider should contact the Ribavirin Pregnancy Registry by calling 1-800-593-2214. The Ribavirin Pregnancy Registry collects information about the health of you and your baby if you take Pegasys and Ribavirin during pregnancy or if you become pregnant within 6 months after you stop taking Pegasys and Ribavirin.
  • Mental health problems and suicide. Pegasys may cause you to develop mood or behavioral problems, including:
    • irritability (getting upset easily)
    • depression (feeling low, feeling bad about yourself or feeling hopeless) and anxiety
    • aggressive behavior
    • former drug addicts may fall back into drug addiction or overdose
    • thoughts of hurting yourself or others, or suicide
  • Heart problems. Pegasys may cause heart problems, including:
    • high blood pressure
    • fast heart rate or abnormal heart beat
    • chest pain
    • heart attacks
    • trouble breathing
  • 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.
  • New or worsening autoimmune problems. Some people taking Pegasys develop autoimmune problems (a condition where the body's immune cells attack other cells or organs in the body), such as rheumatoid arthritis, systemic lupus erythematosus, and psoriasis. In some people who already have an autoimmune problem, it may get worse during your treatment with Pegasys.
  • Infections. Symptoms may include:
    • fever
    • chills
    • burning and painful urination
    • urinating often
    • coughing up yellow or pink mucus (phlegm)

      Call your healthcare provider right away if you get any of these symptoms during treatment with Pegasys:

Before and during treatment with Pegasys you will need to see your healthcare provider regularly and have blood tests to make sure that your treatment is working and to check for side effects.

Pegasys can cause serious side effects. Some of these side effects may cause death. Tell your healthcare provider right away if you have any of these symptoms during treatment with Pegasys.

For more information about side effects, see "What are the possible side effects of Pegasys?"

Important: If you are taking Pegasys with other medicines for treatment of hepatitis C, you should also read the Medication Guides or Patient Information that comes with the other medicines.

Who should not take Pegasys?

Do not take Pegasys if you:

  • have had a serious allergic reaction to another alpha-interferon medicine or to any of the ingredients in Pegasys. Symptoms of a serious allergic reaction to alpha-interferon may include itching, swelling of your face, tongue, throat, trouble breathing, feeling dizzy or faint, and chest pain. See the end of this Medication Guide for a list of the ingredients in Pegasys.
  • have certain types of hepatitis caused by your immune system attacking your liver (autoimmune hepatitis)
  • have certain other liver problems

Do not give Pegasys to a baby under 1 year of age. Pegasys contains benzyl alcohol. Benzyl alcohol can cause nervous system problems and other problems which may lead to death.

Do not take Pegasys in combination with Ribavirin if you:

  • are pregnant, or plan to get pregnant during treatment, or during the 6 months after treatment
  • are a male with a female sexual partner who is pregnant or plans to become pregnant at any time during treatment with Ribavirin or during the 6 months after your treatment has ended.

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

What should I tell my healthcare provider before taking Pegasys?

Before taking Pegasys tell your healthcare provider about all of your medical conditions, including if you :

  • have or ever had any problems with your heart, including heart attack
  • have high blood pressure
  • have liver problems (other than hepatitis B or C)
  • have lung problems
  • have thyroid problems
  • have diabetes
  • have colitis (inflammation of your intestine)
  • have any kind of autoimmune disease (where the body's immune system attacks the body's own cells), such as psoriasis, systemic lupus erythematosus, or rheumatoid arthritis
  • have or ever had low blood cell counts
  • have cancer
  • have or had blood disorders (bleeding problems or a blood clot, thalassemia major or sickle-cell anemia)
  • hepatitis B or C infection
  • have Human Immunodeficiency Virus -1 (HIV-1) infection
  • have kidney problems
  • have high blood triglyceride levels (fat in your blood)
  • have had an organ transplant
  • have ever been addicted to drugs or alcohol
  • are being treated for a mental illness or had treatment in the past for any mental illness, including depression and suicidal behavior.
  • are pregnant or plan to become pregnant. It is not known if Pegasys will harm your unborn baby. Tell your healthcare provider if you become pregnant during treatment with Pegasys.
  • are breastfeeding or plan to breastfeed. It is not known if Pegasys passes into your breast milk. You and your healthcare provider should decide if you will use Pegasys or breastfeed. You should not do both.
    • If you have HIV-1 infection and are being treated with Pegasys, you should not breastfeed because of the risk of passing HIV-1 to your baby.

Tell your healthcare provider about all the medicines you take, including prescription and over-the-counter medicines, vitamins and herbal supplements. Pegasys and certain other medicines may affect each other and cause side effects.

Especially tell your healthcare provider if you take:

  • telbivudine (Tyzeka)
  • theophylline (Theo-24, Elixophyllin, Uniphyl, Theolair). Your healthcare provider may need to monitor the amount of theophylline in your body and make changes to your theophylline dose.
  • any anti-HIV medicines
  • methadone hydrochloride (Methadose, Dolophine hydrochloride)

Keep a list of your medicines and show it to your healthcare provider and pharmacist when you get a new medicine.

Do not start a new medicine without telling your healthcare provider. Your healthcare provider can tell you if it is safe to take Pegasys with other medicines.

How should I take Pegasys?

  • Pegasys is given by injection under the skin (subcutaneous injection).
  • Your healthcare provider will decide on your dose of Pegasys and when you will take it. Pegasys is usually injected 1 time each week. For children 3 years of age and older infected with hepatitis B virus or 5 years of age and older infected with hepatitis C virus, your healthcare provider will prescribe the dose of Pegasys based on your child's height and weight.
  • If your healthcare provider decides that you can inject Pegasys for your condition, inject it exactly as prescribed.
  • See the Instructions for Use that comes with your Pegasys for detailed instructions about how to prepare and inject a dose of Pegasys.
  • Your healthcare provider may change your dose of Pegasys if needed. Do not change your dose unless your healthcare provider tells you to change it.
  • Do not switch to another brand of interferon without talking to your healthcare provider.
  • Take your prescribed dose of Pegasys 1 time each week, on the same day of each week and at approximately the same time.
  • Do not take more than your prescribed dose.
  • Pegasys comes as a liquid:
    • in a single-dose vial
    • in a prefilled syringe
    • in an autoinjector
    Your healthcare provider will decide which one is best for you.
  • Your healthcare provider should show you how to prepare and measure, and inject your dose of Pegasys before you use the single-dose vial, prefilled syringe or autoinjector for the first time.
  • When you get your prescription from the pharmacy, ask your pharmacist for the syringe and needle that you need to use to prepare and inject a dose of Pegasys from the single-dose vial.
  • If you will be injecting a child with Pegasys, you will need a special syringe called a tuberculin syringe, which can measure doses of Pegasys that are 1 milliliter (1mL) or less.
  • Do not reuse Pegasys single-dose vials, prefilled syringes, autoinjectors, and needles.
  • If you miss your dose:
    • If you remember within 2 days of when you should have taken Pegasys, give yourself an injection of Pegasys as soon as you remember. Take your next dose on the day you would usually take it.
    • If more than 2 days have passed, ask your healthcare provider what you should do.
  • If you take more than the prescribed amount of Pegasys, call your healthcare provider right away. Your healthcare provider may want to examine you and do blood tests.

What should I avoid while taking Pegasys?

  • Avoid drinking alcohol. This may make your liver disease worse.
  • Avoid driving or operating machinery if you become dizzy, confused, very sleepy, or tired during treatment with Pegasys.

What are the possible side effects of Pegasys?

Pegasys can cause serious side effects including:

  • See "What is the most important information I should know about Pegasys?"
  • Blood problems. Pegasys can affect your bone marrow and cause low red blood cell, low white blood cell and low platelet counts. These blood counts may fall to dangerously low levels. If your blood cell counts become very low, you can get anemia, infections or have problems with bleeding and bruising.
  • Thyroid problems. Symptoms of thyroid changes include feeling cold or hot all the time, a change in your weight, and changes to your skin, trouble concentrating.
  • Blood sugar problems. Pegasys may cause low blood sugar (hypoglycemia), high blood sugar (hyperglycemia) or diabetes. If you have high blood sugar or diabetes before starting Pegasys, talk to your healthcare provider before you take Pegasys. If you develop high blood sugar or diabetes during treatment with Pegasys, your healthcare provider may tell you to stop Pegasys and prescribe a different medicine for you.
    Symptoms of low blood sugar may include:
    • feeling faint
    • headaches,
    • sweating
    • anxiousness
    • confusion
    • weakness
      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 eye problems. Pegasys may cause eye problems that may lead to vision loss or blindness. You should have an eye exam before you start taking Pegasys. If you have eye problems or have had them in the past, you may need eye exams during treatment with Pegasys. Tell your healthcare provider or eye doctor right away if you have any vision changes during treatment with Pegasys.
  • Serious liver problems, 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)
  • 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 Pegasys.
  • Inflammation of your intestines (colitis). Symptoms of inflammation of your intestines (colitis) may include:
    • severe stomach area (abdomen) pain
    • fever
    • bloody diarrhea or blood bowel movements
  • Inflammation of your pancreas (pancreatitis). Symptoms of inflammation of your pancreas (pancreatitis) may include:
    • severe stomach (abdomen) pain
    • severe back pain
    • nausea
    • vomiting
    • fever
  • Serious allergic reactions and skin reactions. Get medical help right away if you get any of the following symptoms:
    • itching
    • swelling of your face, eyes, lips, tongue, or throat
    • trouble breathing
    • skin rash, hives, sores in your mouth, or your skin blisters and peels
    • chest pain
    • feeling faint
  • Effect on growth in children. Children can experience a delay in weight gain and height increase during treatment with Pegasys. In children with hepatitis C, catch-up in growth happens after treatment stops, but some children may not reach the height that they were expected to have before treatment. In children with hepatitis B, it is not yet known if catch-up in growth happens after treatment stops. Talk to your healthcare provider if you are concerned about your child's growth during treatment with Pegasys.
  • Nerve problems. People who take Pegasys or other alfa interferon products with telbivudine (Tyzeka) for hepatitis B 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.

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

The most common side effects of Pegasys include:

  • flu-like symptoms. Symptoms may include: tiredness, weakness, fever, chills, muscle aches, joint pain, and headaches. Some of these symptoms may be decreased by injecting your Pegasys dose in the evening. Talk to your healthcare provider about which over-the-counter medicines you can take to help prevent or decrease some of the symptoms.

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 side effects of Pegasys.

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

You may also report side effects to Genentech at 1-888-835-2555.

General information about the safe and effective use of Pegasys

Medicines are sometimes prescribed for purposes other than those listed in a Medication Guide. Do not use Pegasys for a condition for which it was not prescribed. Do not give Pegasys to other people, even if they have the same symptoms that you have. It may harm them. You can ask your healthcare provider or pharmacist for information that is written for health professionals.

How should I store Pegasys?

  • Store Pegasys single-dose vials, prefilled syringes, and autoinjectors in a refrigerator at 36°F to 46°F (2°C to 8°C).
  • Do not leave Pegasys out of the refrigerator for more than 24 hours.
  • Do not freeze or shake Pegasys.
  • Protect Pegasys from light.

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

What are the ingredients in Pegasys?

Active ingredient: interferon alfa-2a

Inactive ingredients: acetic acid, benzyl alcohol, polysorbate 80, sodium acetate trihydrate, and sodium chloride.

Source: National Library of Medicine. Last updated October 31, 2017.