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Important Note

The following information is intended to supplement, not substitute for, the expertise and judgment of your physician, pharmacist or other healthcare professional. It should not be construed to indicate that use of the drug is safe, appropriate, or effective for you. Consult your healthcare professional before using this drug.


(peg-in-ter-FEER-on alfa)


WARNING: This medication can cause or worsen some serious medical conditions including psychiatric conditions (e.g., depression), immune system problems (autoimmune conditions such as lupus or rheumatoid arthritis), circulation problems (e.g., cardiovascular disease/blood clots), or infections (bone marrow suppression). If your medical history includes these conditions, inform your doctor promptly. Also, tell your doctor immediately if any serious symptoms or side effects occur (see Side Effects section). These conditions occur infrequently, but some can be fatal. This medicine is frequently combined with ribavirin. Ribavirin may cause fetal harm/death should you be pregnant. Women must avoid pregnancy while using ribavirin, or if their male partner is using it. Ribavirin is a potential cancer-causing agent. Ribavirin also may infrequently cause a blood disorder (hemolytic anemia), which can worsen heart disease (e.g., angina).


Peginterferon alfa is used to treat chronic hepatitis C, a viral infection of the liver.



Peginterferon alfa may also be used to treat certain types of cancer (e.g., leukemia).

How To Use

Learn all preparation and usage instructions in the product package. If any of the information is unclear, consult your doctor or pharmacist. Inject this medication under the skin (subcutaneously or "sub- q") usually once weekly; or as directed by your doctor. The dose should be given on the same day of each week. The dosage is based on your weight, medical condition, and response to therapy. Before using, check this product visually for particles or discoloration. If either is present, do not use the liquid. Learn how to store and discard needles and medical supplies safely. Consult your pharmacist. Drink plenty of water/clear fluids while using this medication. Taking fever/pain-reducing medications (e.g., acetaminophen, ibuprofen) may be needed to help treat common side effects. Consult your doctor or pharmacist.

Side Effects

Flu-like symptoms (e.g., fever, headache, nausea, cough, vomiting, chills, fatigue, muscle aches/pain, stomach pain), hair loss, diarrhea, flushing, dizziness, or redness/swelling/pain at the injection site may occur. If any of these effects persist or worsen, notify your doctor promptly. Tell your doctor immediately if any of these serious side effects occur: trouble sleeping, weight loss, loss of appetite, severe stomach/abdominal pain. Tell your doctor immediately if any of these unlikely but serious side effects occur: persistent sore throat or fever, unusual fatigue, easy bruising or bleeding, black stools. Tell your doctor immediately if any of these highly unlikely but very serious side effects occur: increased thirst, increased urination, vision problems, chest pain, unusually fast/slow or irregular heartbeat, yellowing eyes or skin, dark urine, change in amount of urine, seizures, one-sided weakness. If you notice any of the following unlikely but serious side effects, stop your treatment with peginterferon and consult your doctor immediately: unusual or severe mental/mood changes (e.g., suicidal thoughts or severe depression), bloody diarrhea. An allergic reaction to this drug is unlikely, but seek immediate medical attention if it occurs. Symptoms of an allergic reaction include rash, itching, swelling, severe dizziness, trouble breathing. If you notice other effects not listed above, contact your doctor or pharmacist.


This medication is not recommended for use if you have the following medical conditions: other severe liver conditions (e.g., autoimmune hepatitis, decompensated liver disease), immune system suppression for organ transplants. Tell your doctor your medical history, especially of: psychiatric conditions (e.g., depression), low blood counts (e.g., red cells, white cells, or platelets), heart problems, thyroid problems, lung diseases (e.g., COPD, asthma, pneumonia), intestinal disease (e.g., colitis), pancreatitis, immune system diseases (e.g., lupus, rheumatoid arthritis), eye problems, diabetes, kidney disease, high blood pressure, brain tumors, seizures, any allergies. This drug may make you dizzy; use caution engaging in activities requiring alertness such as driving or using machinery. Limit alcoholic beverages. This medicine may cause stomach/intestinal bleeding. Daily use of alcohol and this medicine may increase your risk for stomach/intestinal bleeding. Because this medication can lower your body's ability to fight an infection, do not touch your eyes or the inside of your nose without first washing your hands. Do not have immunizations/vaccinations without the consent of your doctor. Use caution with sharp objects (e.g., razors, nail cutters) and avoid activities that would increase your risk of getting bruised, cut, or injured. A preservative (benzyl alcohol) which may be found in this product or in the liquid used to mix this product (diluent) can infrequently cause serious problems (sometimes death) if given by injection to an infant during the first months of life (neonatal period). The risk is greater with lower birth weight infants and is greater with increased amounts of benzyl alcohol. Symptoms include sudden gasping, low blood pressure, or a very slow heartbeat. Report these symptoms to the doctor immediately should they occur. If possible, a preservative-free product should be used when treating neonates. Caution is advised when using this drug in the elderly because they may be more sensitive to the effects of the drug. This medication is not recommended for use during pregnancy due to the risk of serious side effects for a pregnant woman. Consult your doctor for more details. It is not known whether this drug passes into breast milk. Because of the potential risk to the infant, breast-feeding while using this drug is not recommended. Consult your doctor before breast-feeding.

Drug Interactions

Tell your doctor of all prescription and nonprescription medication you may use, especially: zidovudine, vidarabine, theophylline, barbiturates (e.g., phenobarbital), drugs that can depress the immune system (e.g., anti-cancer type). This product can affect the results of certain lab tests (e.g., thyroid, blood counts). Make sure laboratory personnel and your doctors know you use this drug. Do not start or stop any medicine without doctor or pharmacist approval.


If overdose is suspected, contact your local poison control center or emergency room immediately.


Do not share this medication with others. Laboratory and/or medical tests (e.g., blood tests, thyroid tests, virus levels) may be performed to monitor your progress. You should receive an eye exam before using this medication. If you have an eye disease or are at risk for eye disease (e.g., diabetics), you should then have periodic eye exams thereafter while using this drug.

Missed Dose

If you miss a dose, contact your doctor or pharmacist to establish a new dosing schedule.


If you are using the dry powder brand: before mixing, store the dry powder at room temperature (77 degrees F or 25 degrees C) away from light and moisture. Brief storage is permitted from 59-86 degrees F (15-30 degrees C). Once mixed, the solution should be used immediately but may be stored up to 24 hours refrigerated (36 to 46 degrees F and 2 to 8 degrees C). Do not freeze. Discard any unused portion of the vial. If you are using the liquid brand: Store this in the refrigerator at 36-46 degrees F (2-8 degrees C). Do not freeze or shake the liquid, and protect it from light. This vial is for single-use only; discard any unused portion.

Medical Alert

Your condition can cause complications in a medical emergency. For enrollment information call MedicAlert at 1-800-854-1166 (USA), or 1-800-668-1507 (Canada).