1. Hepatitis Slideshow Pictures
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Medical Author:

Mary D. Nettleman, MD, MS, MCAP

Medical Editor:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Medical Editor:

Jay W. Marks, MD

Jay W. Marks, MD

Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

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How interferons work

Interferons are naturally occurring proteins in the body that help the body's natural defense system fight viruses. Interferon alfa-2b and pegylated interferon alfa-2a are proteins specifically designed to attach to the surface of the hepatitis B virus. Once attached, the proteins start a cascade of events leading to increased viral cell death. Pegylated interferon works in the same way as interferon alfa-2b, but it has an added structure that enables it to stay in the body longer and does not need to be administered as often. For this reason, and because studies have shown increased effectiveness, pegylated interferon is usually the agent of choice when an interferon product is used.

Who should not use interferons?

• Individuals who have experienced an allergic reaction to interferons should not take this medication.
• A "black box" warning has been issued by the FDA warning patients and clinicians to watch for serious psychiatric, autoimmune, ischemic, or infectious disease disorders that may be side effects of interferons. Caution is especially urged if patients already have a history of depression or another serious psychiatric condition.
• Pegylated interferon is not used in newborn infants (it contains benzyl alcohol), in patients with autoimmune hepatitis, or in those with severe liver failure (it may cause a temporary increase in liver inflammation, which a failing liver could not handle).
• The safety and efficacy of pegylated interferon has not been established in patients under the age of 18.

Dosing of interferons

Interferons are administered by a subcutaneous injection into the thigh or abdomen at various dosage schedules. Interferon alfa-2b is approved for children as young as one year old as well as adults. Pegylated interferon alfa-2a is approved only in adults 18 years of age or older. While taking these medications, it is important to have routine blood work done to monitor for possible side effects.

Drug or food interactions of interferons

• Interferon increases theophylline (Theo-Dur, Respbid, Slo-Bid, Theo-24, Theolair, Uniphyl, Slo-Phyllin) levels by 100%.
• Interferon may increase levels of methadone in persons taking this drug.

Side effects of interferons

Common side effects of the interferons include flu-like symptoms such as muscle aches, fatigue, fevers, and chills.

Other common side effects include:

• headache,
• trouble sleeping or insomnia,
• hair loss,
• fatigue,
• nausea,
• irritability, and
• anxiety.

More serious side effects include:

• heart arrhythmias,
• diabetes mellitus,
• anemia,
• decreased white blood cell or platelet counts,
• liver failure, and
• serious depression.

Effectiveness of interferons

In patients who have hepatitis e antigen (HBeAg) in their blood, treatment with pegylated interferon eliminates the HBeAg and allows antibody formation in approximately 27% of patients. Treatment eliminates viral DNA from the blood in approximately 25% of patients with HBeAg. In patients who do not have HBeAg in their blood, treatment with pegylated interferon eliminates viral DNA from the blood 65% of the time. Again, viral DNA can rebound after the treatment is stopped.

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