Interferons for chronic hepatitis B

Examples

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Chemical Name

interferon alfa-2b (Intron A)

Chemical Name

pegylated interferon alfa-2a (Pegasys)

How It Works

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Interferon is a man-made copy of a protein that your body makes in response to infection. It helps the immune system fight disease and may slow or stop the growth of the hepatitis B virus in your body.

Interferon is given as a shot 3 times a week. A newer form of interferon, pegylated interferon (also known as peginterferon), is given as a shot once a week. Treatment with interferons can last 4 months to 1 year.

Why It Is Used

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Interferons are used to treat long-term (chronic) HBV infection in adults and children who are at risk for liver disease. The American Association for the Study of Liver Disease has made recommendations on who should receive treatment for hepatitis B based on the presence of hepatitis B antigen in your blood, the level of hepatitis B virus DNA (HBV DNA) in your blood, and the levels of your liver enzymes.¹

Treatment with interferons is not recommended if you are using illegal drugs or drinking too much alcohol. It is also not recommended if you have had an organ transplant or if you have advanced liver scarring (cirrhosis).

Interferons can cause or aggravate mental problems. Tell your doctor if you have a history of depression, suicidal thoughts, anxiety, drug or alcohol abuse, or mental illness.

How Well It Works

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It is important to weigh the benefits of treatment against the risks. Treatment for HBV infection is considered successful if blood tests show that the virus is no longer multiplying in the body, if liver enzyme levels return to normal, and if liver damage (such as inflammation and scarring) improves.

Interferons stop the growth of the virus in about 35% of people who use them.¹ Early studies suggest that peginterferon may work better than interferon.^{2, 3}

Interferons work best for people who have high levels of liver enzymes and in whom the virus is multiplying. They are also more likely to work in people who have a strong immune system, who have had hepatitis for a short amount of time, and who became infected after childhood.⁴

Relapse—when the virus starts to multiply again—is common after treatment is stopped.

Side Effects

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Interferons have common side effects, including:

• Headaches and muscle aches.
• Feeling very tired.
• Fever.
• Hair loss.
• Depression and other mental problems.
• Fewer platelets (cells that cause blood to clot).
• Fewer white blood cells.

Rare side effects include:

• Thyroid problems.
• Confusion.
• Too much protein in your urine, which may mean that you are having kidney problems.
• Heart problems.

See Drug Reference for a full list of side effects. (Drug Reference is not available in all systems.)

What To Think About

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• Drug resistance has not developed with interferon use. Resistance has developed with the use of other medicines to treat chronic hepatitis B. Drug resistance occurs when viruses change over time and can no longer be killed by medicines that used to kill them.
• Interferons are expensive. But you take interferons for just 4 to 12 months. You may need to take other medicines for longer periods of time.
• Peginterferon has to be given only once a week; interferon has to be given 3 times a week.
• Peginterferon was approved by the U.S. Food and Drug Administration (FDA) in 2005 to treat chronic hepatitis B, so its long-term effects are not yet known. But peginterferon has been used to treat chronic hepatitis C since 2002.
• Early studies suggest that peginterferon may work better than lamivudine to treat chronic hepatitis B.^{5, 3}
• Experts do not know if interferons are safe for pregnant women. They are not considered safe for women who are breast-feeding.

Complete the new medication information form (PDF) (What is a PDF document?) to help you understand this medication.

References

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Citations

1. Lok ASF, McMahon BJ (2004). Chronic hepatitis B: Update of recommendations. Hepatology, 39(3): 857–61.

2. Janssen, H (2005). Pegylated interferon alfa-2b alone or in combination with lamivudine for HBeAg-positive chronic hepatitis B: A randomised trial. Lancet, 365(9454): 123–129.

3. Lau GKK, et al. (2005). Peginterferon alfa-2a, lamivudine, and the combination for HBeAG-positive chronic hepatitis B. New England Journal of Medicine, 352(26): 2682–2695.

4. Malik AH, Lee WM (2000). Chronic hepatitis B virus infection: Treatment strategies for the next millennium. Annals of Internal Medicine, 132(9): 723–731.

5. Marcellin P, et al. (2004). Peginterferon alfa-2a alone, lamivudine alone, and the two in combination in patients with HBeAG-negative chronic hepatitis B. New England Journal of Medicine, 351(12): 1206–1217.

Credits

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Author	Colleen Cronin
Editor	Susan Van Houten, RN, BSN, MBA
Associate Editor	Michele Cronen
Associate Editor	Lisa Shaw
Associate Editor	Pat Truman
Primary Medical Reviewer	Kathleen Romito, MD - Family Medicine
Specialist Medical Reviewer	W. Thomas London, MD - Hepatology
Last Updated	November 4, 2005