Updated December 29, 2014.

What Is Peginterferon:

Peginterferon is an injectable drug used for treating chronic hepatitis infections (hepatitis C, hepatitis B) and some cancers. It's a man-made version of a human protein (interferon alpha) that your body makes to fight viral infections.

Peginterferon is a shortened word for pegylated interferon, which is interferon that's engineered to only need one injection every week. The original version of the drug (regular interferon) required up to three injections every week.

Due to the pegylation, peginterferon is more convenient, more effective and has nearly replaced regular interferon as a therapy.

What Are Other Names for Peginterferon:

There are basically two types of peginterferon: Pegasys (also known as peginterferon alfa-2a) and PegIntron (also known as peginterferon alfa-2b). These drugs are very similar and have only minor differences between them.

Does Peginterferon Effectively Treat Chronic Hepatitis C:

The most effective way to treat hepatitis C is with a combination of peginterferon and ribavirin. Treating hepatitis C with just peginterferon is rarely done. Successful treatment (sustained virologic response) depends on the type of hepatitis C and the characteristics of the patient being treated. For example, a healthy patient with a genotype 2 infection will usually have a successful treatment; however, a patient with diabetes HIV infection and genotype 1 has less than a 35% chance of successful treatment.

Does Peginterferon Effectively Treat Chronic Hepatitis B:

Peginterferon is rarely used for treating hepatitis B in the United States. Treatment with peginterferon works somewhere between 15% and 40% of the time, depending on your infection. Some people relapse after treatment stops, which means that the virus starts replicating again. Unlike hepatitis C, though, other treatments are available for hepatitis B.

How Do I Take Peginterferon:

Peginterferon must be injected, usually under the skin. Your nurse will teach you how to correctly do the injections, and you'll quickly be able to do it by yourself. You also need to keep the medicine refrigerated.

How Much Peginterferon Do I Need to Take:

You take one injection of peginterferon every week. Your exact dose will depend on many factors, including which type of peginterferon you take and your particular viral infection.

How Much Does Peginterferon Cost:

A full course of peginterferon treatment is expensive, almost $20,000 for a year. As a drug for chronic hepatitis C, it's the only effective treatment available, especially when combined with ribavirin. In the United States, most health insurance will cover the cost of peginterferon and ribavirin for hepatitis C treatment.

For chronic hepatitis B, there are other more effective treatment drugs available that are also much cheaper, but peginterferon remains a useful therapy for some people.

What Are the Side Effects of Peginterferon:

There are many side effects from taking peginterferon. Here is a list of the most common side effects.

Who Should Not Take Peginterferon:

Some people should not take peginterferon. Here are examples of medical conditions that may keep you from using this medication:

• Advanced liver, heart, kidney or lung disease
• Autoimmune disease
• Severe depression or other psychiatric conditions
• Pregnancy
• Breast-feeding

<sub>Sources:

Dienstag, JL. Chronic Hepatitis. In: AS Fauci, E Braunwald, DL Kasper, SL Hauser, DL Longo, JL Jameson, J Loscaizo (eds), Harrison’s Principles of Internal Medicine, 17e. New York, McGraw-Hill, 2008.

Friedman, LS. Liver, Biliary Tract, & Pancreas: Chronic Viral Hepatitis. In: LM Tierney, SJ McPhee, MA Papadakis (eds), 2007 Current Medical Diagnosis and Treatment, 46e. New York, McGraw-Hill, 2007.

Katzung, BG. Basic and Clinical Pharmacology, 10e. New York, McGraw-Hill, 2007.

Pegasys Medication Guide. http://www.rocheusa.com/products/pegasys/PEGASYS_MedGuide.pdf.

PegIntron Medication Guide. http://www.spfiles.com/pipeg-intron.pdf#page=8.</sub>