Print this page    •   Back to Web version of article

An Overview of Peginterferon Alfa-2a (Pegasys)

March 10, 2015

Other Names: Pegasys, pegIFN alfa-2a, PEG-interferon alfa-2a, pegylated-interferon alfa 2a
Drug Class: Opportunistic Infections and Coinfections

Chemical Image

peginterferon alfa-2a chemical image

peginterferon alfa-2a
Molecular Weight: 348.3734

What Is Peginterferon Alfa-2a?

Peginterferon alfa-2a is an antiviral prescription medicine approved by the U.S. Food and Drug Administration (FDA) for the treatment of chronic hepatitis B virus (HBV) infection and chronic hepatitis C virus (HCV) infection. HBV and HCV infections are HIV-related opportunistic infection. An opportunistic infection is an infection that occurs more frequently or is more severe in people with weakened immune systems -- such as those infected with HIV -- than in people with healthy immune systems.

The Guidelines for the Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents, prepared by the Centers for Disease Control and Prevention (CDC), the National Institutes of Health (NIH), and the HIV Medicine Association of the Infectious Diseases Society of America (IDSA-HIVMA), includes recommendations on the use of peginterferon alfa-2a to treat HBV and HCV infections in people also infected with HIV.

In addition to recommendations for the medicine's use in treating chronic HBV and HCV infections, the guidelines include recommendations on the "off-label" use of peginterferon alfa-2a to treat acute HCV infection in HIV-infected individuals. "Off-label" use refers to use of an FDA-approved medicine in a manner different from that described on the medicine label. Good medical practice and the best interests of a patient sometimes require that a medicine be used "off-label."

The above may not include all of the HIV-related uses of peginterferon alfa-2a recommended in the Guidelines for the Prevention and Treatment of Opportunistic Infections in HIV-Infected Adults and Adolescents. Some recommended uses, such as uses in certain rare circumstances, may have been omitted.


What Should I Tell My Health Care Provider Before Taking Peginterferon Alfa-2a?

Before taking peginterferon alfa-2a, tell your health care provider:

Ask your health care provider about possible side effects from peginterferon alfa-2a. Your health care provider will tell you what to do if you have side effects.

How Should I Take Peginterferon Alfa-2a?

Take peginterferon alfa-2a according to your health care provider's instructions. Your health care provider will tell you how much peginterferon alfa-2a to take and when to take it. Before you start peginterferon alfa-2a and each time you get a refill, read any printed information that comes with your medicine.

How Should Peginterferon Alfa-2a Be Stored?

Where Can I Find More Information About Peginterferon Alfa-2a?

More information about peginterferon alfa-2a is available:

The above Patient Version drug summary is based on the following FDA label(s): Injection (solution), kit.

This article was provided by AIDSinfo. You can find this article online by typing this address into your Web browser:

General Disclaimer: is designed for educational purposes only and is not engaged in rendering medical advice or professional services. The information provided through should not be used for diagnosing or treating a health problem or a disease. It is not a substitute for professional care. If you have or suspect you may have a health problem, consult your health care provider.