Pegasys

What is Pegasys

Pegasys is a long acting interferon. Interferons are proteins released in the body in response to viral infections. Interferons are important for fighting viruses in the body, for regulating reproduction of cells, and for regulating the immune system.

Pegasys is a specific interferon used to treat chronic hepatitis C.

Pegasys may also be used for purposes other than those listed in this medication guide.

General medical information about Pegasys

Call your doctor or seek emergency medical attention if you develop symptoms of depression or are contemplating suicide; become unusually irritable, anxious (nervous), or aggressive; or experience other mood or behavior changes. In some cases, Pegasys has caused serious mood or behavioral problems.

Problems with body organs such as the heart, lungs, and eyes have been experienced by people taking interferon alfa-2a. Contact your doctor immediately if you develop difficulty breathing, chest pain, blurred vision, or loss of vision.

Many patients using Pegasys have developed a drop in the number of white blood cells and platelets. If the number of these blood cells are too low, there is an increased risk of infection or bleeding. Contact your doctor immediately if you develop a fever, symptoms of an infection, or unusual bleeding or bruising.

Use caution when driving, operating machinery, or performing other hazardous activities. Pegasys may cause drowsiness or impair alertness. If you experience drowsiness or impaired alertness, avoid these activities.

What you should discuss with your doctor before using Pegasys

Do not use Pegasys if you have
- autoimmune hepatitis;
- decompensated liver disease; or
- had an allergic reaction to an alfa interferon in the past or if you are allergic to E. coli derived products.

Before using this medication, tell your doctor if you have:
- lung disease;
- diabetes;
- colitis;
- eye problems;
- pancreatitis;
- bone marrow suppression;
- low platelet counts;
- a history of cancer;
- kidney disease;
- liver problems other than hepatitis C;
- hepatitis B or HIV infection;
- an autoimmune disorder such as rheumatoid arthritis, systemic lupus erythematosus (SLE), or psoriasis;
- heart disease or previous heart attack;
- a history of drug or alcohol abuse;
- a history of depression, suicidal thoughts, anxiety, or another mental illness; or
- thyroid problems.

You may not be able to use Pegasys, or you may require a dosage adjustment or special monitoring during treatment if you have any of the conditions listed above.

Pegasys is in the FDA pregnancy category C. This means that it is not known whether Pegasys will be harmful to an unborn baby. Do not use this medication if you are pregnant or could become pregnant during treatment.

It is not known whether Pegasys passes into breast milk. Do not use this medication without first talking to your doctor if you are breast-feeding.

How should you use Pegasys

Use Pegasys exactly as directed by your doctor. If you do not understand these directions, ask your doctor, nurse, or pharmacist to explain them to you.

Pegasys is used as a subcutaneous injection only. Your doctor or nurse will give you detailed instructions on how and where to inject the medication. Do not inject this medication if you are unsure how.

Pegasys is given subcutaneously once a week. The dose should be administered on the same day each week.

Do not shake the vial of Pegasys. Shaking could cause the medication to not work properly.

Do not inject Pegasys if it is discolored or has particles in it.

Never reuse a needle or syringe. Dispose of all needles and syringes in an appropriate, puncture-resistant disposal container.

Do not stop using this medication without first talking to your doctor. Also, do not change the brand of Pegasys that you use without talking to your doctor.

Your doctor may want to you to have regularly scheduled blood tests during treatment with Pegasys.

Flulike symptoms including fever, chills, muscle aches, joint pain, and headaches are likely to occur. They are most common at the start of therapy and may decrease with continued use. Over-the-counter fever reducers such as acetaminophen (Tylenol, others), ibuprofen (Motrin, Advil, others), and naproxen (Aleve), plenty of fluid, and taking the medication at bedtime may help to alleviate these symptoms.

It is not known whether treatment with Pegasys will prevent the transmission of hepatitis C to others. It is also not known whether Pegasys will cure hepatitis C or prevent cirrhosis, liver failure, or liver cancer that may be the result of infection with hepatitis C virus.

Store Pegasys in the refrigerator at 36 to 46 degrees Fahrenheit (2 to 8 degrees Celsius) and protected from light. Do not leave Pegasys outside of the refrigerator for more than 24 hours. Do not allow the Pegasys solution to freeze.

If you miss a dose:

Use the missed dose as soon as you remember within 2 days of the missed dose. However, if more than 2 days have passed since the dose was missed, ask your healthcare provider what to do. Do not use a double dose of this medication.

What happens if you overdose:

Seek emergency medical attention.

Symptoms of a Pegasys overdose are not known.

What should you avoid while using Pegasys

Possible side effects of Pegasys

If you experience an allergic reaction (difficulty breathing; closing of the throat; swelling of the lips, tongue, or face; or hives), stop using Pegasys and seek emergency medical attention.

Flulike symptoms are likely to occur. They are most common at the start of therapy and may decrease with continued use. An over-the-counter fever reducer such as acetaminophen (Tylenol, others), ibuprofen (Motrin, Advil), or naproxen (Aleve); plenty of fluid; and using the medication at bedtime may help to alleviate these symptoms. Continue to use Pegasys and notify your doctor if you experience:
- fever or chills;
- headache;
- muscle aches or joint pain;
- nausea, vomiting, or loss of appetite;
- diarrhea;
- dizziness or drowsiness;
- difficulty sleeping;
- dry or itchy skin;
- temporary hair loss; or
- redness, swelling, or irritation at the injection site.

Side effects other than those listed here may also occur. Talk to your doctor about any side effect that seems unusual or that is especially bothersome.

What other drugs will affect Pegasys

Before using this medication, tell your doctor if you are taking theophylline (Theo-Dur, Theochron, Theolair, others). Pegasys may increase theophylline levels in the body, which could become dangerous.

Medications other than those listed here may also interact with Pegasys. Talk to your doctor and pharmacist before taking any prescription or over-the-counter medicines, including herbal products.