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

Medically reviewed by P. Thornton, DipPharm Last updated on Apr 9, 2019.

What is PegIntron?

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 damage, or if you are allergic to any type of interferon alfa. 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 10 days after the final dose.

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.

Tell your doctor about any new or worsening mood symptoms, such as feeling irritable, hostile, aggressive, depressed, or having thoughts about suicide or hurting yourself.

Before taking this medicine

You should not use PegIntron if:

  • you are pregnant;

  • you are allergic to any type of interferon alfa; or

  • you have autoimmune hepatitis, or severe liver damage.

PegIntron can worsen a medical condition you already have.

To make sure PegIntron is safe for you, tell your doctor if you have:

You may need to have a negative pregnancy test before starting this treatment.

Peginterferon alfa-2b may harm an unborn baby. Use effective birth control to prevent pregnancy while using this medicine and for at least 10 days after your last dose. Tell your doctor if you become pregnant.

This medicine may affect fertility (ability to have children) in women. However, it is important to use birth control to prevent pregnancy because peginterferon alfa-2b can harm an unborn baby.

You should not use PegIntron if you are pregnant, or if you are a man and your sexual partner is pregnant.

It may not be safe to breastfeed while using peginterferon alfa-2b. Ask your doctor about any risk.

How should I use PegIntron?

Use PegIntron exactly as directed. Follow all directions on your prescription label and read all medication guides or instruction sheets. PegIntron is often used with other medicines. Use all medications exactly as directed.

PegIntron is injected under the skin, usually once per week. 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. Ask your doctor or pharmacist if you don't understand all instructions.

Prepare an 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.

Your doctor may recommend you take a fever-reducer medication at bedtime to help prevent flu-like symptoms. Use this medicine for as long as your doctor has prescribed.

Pay special attention to your dental hygiene and have regular dental exams while using peginterferon alfa-2b. Rinse your mouth well if you vomit at any time while using PegIntron.

You may need frequent medical tests.

Store PegIntron vials (bottles) in their original package at room temperature (25°C (77°F)), away from moisture and heat. Do not freeze. After mixing, the solution should be used immediately but may be stored up to 24 hours in a refrigerator at 2-8°C (36-46°F).

Store the PegIntron Redipen (injection pen) in a refrigerator (2-8°C (36-46°F)). 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.

Each Redipen is for one use only. Do not reuse a vial or injection pen. Throw the vial or Redipen away after one use, even if there is still medicine left inside.

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?

Call your doctor for instructions if you miss a dose.

What happens if I overdose?

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

Overdose symptoms may include headache, extreme tiredness, muscle pain, fever, sore throat, trouble breathing, bruising or bleeding.

What should I avoid while using PegIntron?

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

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

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.

Tell your doctor right away if you have unusual changes in mood or behavior, such as: depression, irritability, feeling hostile or aggressive, hallucinations, thoughts about hurting yourself, or falling back into a previous pattern of drug addiction. These symptoms may occur during treatment and up to 6 months after your last dose.

Peginterferon alfa-2b may cause serious or fatal side effects. Call your doctor at once if you have:

  • fever, chills, cough with mucus;

  • chest pain, fast heartbeats, trouble breathing;

  • a light-headed feeling, like you might pass out;

  • sudden numbness or weakness, loss of coordination, slurred speech;

  • vision problems;

  • easy bruising, unusual bleeding;

  • upper stomach pain, loss of appetite;

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

  • bloody diarrhea, burning when you urinate;

  • yellowing of the skin or eyes;

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

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

Combination treatment with PegIntron and ribavirin can affect growth in children. Tell your doctor if you think your child is not growing at a normal rate while using this combination.

Common PegIntron side effects may include:

  • flu-like symptoms, weakness, feeling tired;

  • mild depression or sadness;

  • nausea, 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:

  • telbivudine.

This list is not complete. Other drugs may affect 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.