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Generic Name: peginterferon alfa-2b (peg in ter FEAR on AL fa 2 b)
Brand Names: PegIntron, Sylatron

Medically reviewed on Jul 4, 2018

What is PegIntron?

See also: Harvoni

PegIntron (peginterferon alfa-2b) is made from human proteins that help the body fight viral infections.

PegIntron is used to treat chronic hepatitis C in adults.

PegIntron is often used in combination with another medicine called ribavirin (Rebetol, Ribasphere).

Important Information

You should not use PegIntron if you have autoimmune hepatitis, or severe liver problems from causes other than hepatitis C. You should not use PegIntron with ribavirin if you have severe kidney disease, or a hemoglobin blood cell disorder (sickle-cell anemia, thalassemia).

Do not use PegIntron and ribavirin if you are pregnant, or if you are a man and your sexual partner is pregnant. Prevent pregnancy while using this medicine, and for at least 6 months after you stop using it.

PegIntron may cause serious or fatal side effects, and can worsen a medical condition you already have. Call your doctor if you have symptoms such as mood or behavior changes, chest pain, fast heartbeats, trouble breathing, numbness or weakness, loss of coordination, fever, chills, a cough with mucus, burning when you urinate, or bloody diarrhea.

Before taking this medicine

You should not use PegIntron if you are allergic to peginterferon alfa-2b or other alfa interferons, or if you have:

  • autoimmune hepatitis, or severe liver problems from causes other than hepatitis C.

You should not use PegIntron with ribavirin if you have:

  • severe kidney disease;

  • a hemoglobin blood cell disorder such as sickle-cell anemia or thalassemia; or

  • if you are pregnant, or if you are a man and your sexual partner is pregnant.

Tell your doctor if you have ever had:

Both men and women using PegIntron with ribavirin should use effective birth control to prevent pregnancy. Ribavirin can harm an unborn baby or cause birth defects if the mother or father is using this medicine.

If you are a woman, do not use PegIntron and ribavirin if you are pregnant. You may need to have a negative pregnancy test before using these two medications together, and every month during your treatment.

Use at least 2 effective forms of birth control while either sexual partner is using PegIntron with ribavirin. Keep using 2 forms of birth control for at least 6 months after treatment ends.

Tell your doctor right away if a pregnancy occurs while either the mother or the father is using PegIntron with ribavirin.

You should not breast-feed while you are using this medicine.

PegIntron should not be used in a child younger than 3 years old.

How should I use PegIntron?

Follow all directions on your prescription label and read all medication guides or instruction sheets. Use the medicine exactly as directed.

PegIntron is injected under the skin. A healthcare provider may teach you how to properly use the medication by yourself.

Read and carefully follow any Instructions for Use provided with your medicine. Do not use PegIntron if you don't understand all instructions for proper use. Ask your doctor or pharmacist if you have questions.

Prepare your injection only when you are ready to give it. Do not use if the medicine looks cloudy, has changed colors, or has particles in it. Call your pharmacist for new medicine.

Do not shake the injection pen or mixed medicine.

You may need frequent medical tests and eye exams.

Store the PegIntron Redipen in a refrigerator. Do not freeze. Mixed medicine may also be stored in the refrigerator but you must use it within 24 hours after mixing. Do not freeze or save any unused mixture.

Store PegIntron vials (bottles) at room temperature away from moisture and heat. Do not freeze. Do not reuse a vial or injection pen.

Use a needle and syringe only once and then place them in a puncture-proof "sharps" container. Follow state or local laws about how to dispose of this container. Keep it out of the reach of children and pets.

What happens if I miss a dose?

Use the medicine as soon as you remember, and then go back to your regular injection schedule. Do not use two doses at one time.

If you are more than 2 days late in using your injection, call your doctor for instructions.

What happens if I overdose?

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

What should I avoid while using PegIntron?

Using PegIntron will not prevent you from passing hepatitis to other people. Follow your doctor's instructions about how to prevent passing the disease to another person.

Avoid coffee, tea, cola, energy drinks, or other products that contain caffeine.

PegIntron side effects

Get emergency medical help if you have signs of an allergic reaction to PegIntron: hives, or a rash that spreads and causes blistering and peeling; chest pain, anxiety, difficult breathing; swelling of your face, lips, tongue, or throat.

PegIntron can cause life-threatening infections, autoimmune disorders, serious mood or behavior problems, or a stroke.

Stop using PegIntron and call your doctor at once if you have unusual changes in mood or behavior, such as: depression, irritability, aggression, hallucinations, thoughts about hurting yourself, or falling back into a previous pattern of drug addiction. Once you have had this type of reaction to peginterferon alfa-2b, you may not be able to use it again.

Call your doctor at once if you have other serious side effects, such as:

  • vision loss;

  • severe stomach pain with bloody diarrhea;

  • numbness, tingling, or burning pain in your arms or legs;

  • easy bruising, unusual bleeding;

  • sudden numbness or weakness (especially on one side of the body), slurred speech, problems with balance;

  • high blood sugar - increased thirst or urination, hunger, fruity breath odor, tiredness, weight loss;

  • lung problems - sudden chest discomfort, trouble breathing, cough with yellow or pink mucus;

  • new or worsened autoimmune disorders - skin problems, joint pain or swelling, cold feeling or pale appearance in your fingers or toes;

  • pancreas problems - severe pain in your upper stomach spreading to your back, vomiting, fever;

  • signs of infection - fever, chills, body aches, pain or burning when you urinate, increased urination;

  • heart problems - chest pain or pressure, fast heartbeats, sweating, feeling light-headed;

  • thyroid problems - weight changes, skin changes, thinking problems, feeling hot or cold all the time; or

  • worsening liver symptoms - upper stomach pain or swelling, loss of appetite, jaundice (yellowing of the skin or eyes).

PegIntron can affect growth in children. Talk with your doctor if you think your child is not growing at a normal rate while using this medication.

Common PegIntron side effects may include:

  • flu-like symptoms, weakness, feeling tired;

  • mild depression or sadness, feeling anxious or irritable;

  • nausea, vomiting, loss of appetite, weight loss;

  • thinning hair; or

  • redness, swelling, or itching where the medicine was injected.

This is not a complete list of side effects and others may occur. Call your doctor for medical advice about side effects. You may report side effects to FDA at 1-800-FDA-1088.

What other drugs will affect PegIntron?

Tell your doctor about all your other medicines, especially:

This list is not complete. Other drugs may interact with peginterferon alfa-2b, including prescription and over-the-counter medicines, vitamins, and herbal products. Not all possible drug interactions are listed here.

Further information

Remember, keep this and all other medicines out of the reach of children, never share your medicines with others, and use PegIntron only for the indication prescribed.

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.