Hepatitis - Hepatitis B and D

Treatments for Chronic Hepatitis B

Four drugs are currently approved in the United States for treatment of chronic hepatitis B: interferon-alfa-2b (Intron), adefovir (Hepsera), lamivudine (Epivir), and entecavir (Baraclude). These drugs block the replication of HBV in the body. A doctor will decide which drug to prescribe based on a patient?s age, disease severity, and other factors. Each drug has various advantages and disadvantages in terms of cost, efficacy, and likelihood of drug resistance. A combination of drugs may also be prescribed.

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Interferon Alpha. For many years, interferon alfa-2b (Intron) was the standard drug for hepatitis B. The drug is usually taken by injection every day for 16 weeks. (It does not appear to be effective for hepatitis D.) Unfortunately, even in hepatitis B, the virus recurs in almost all cases, although this recurring mutation may be weaker than the original strain. Administering the drug for longer periods may produce sustained remission in more patients while still being safe. Interferon is also effective in eligible children, although long-term effects are unclear.

Lamivudine and Entecavir. These two drugs are classified as nucleoside analogs. Lamivudine (Epivir or 3TC) is an antiretroviral drug that is used to treat human immunodeficiency virus (HIV) as well as hepatitis B. Lamivudine has reduced viral count in over half of hepatitis B patients who have taken it as sole therapy for about a year. It is less expensive than interferon-alfa and has fewer side effects, but may not be as effective as interferon-alfa for long-term therapy. A major problem with lamivudine is the development of mutated viral strains that become resistant to the drug, particularly in areas where the virus is common. In 2005, the FDA approved entecavir (Baraclude) for treatment of adults with chronic hepatitis B. In clinical trials, entecavir was more effective than lamivudine for treating HBV. However, questions have been raised about the drug?s possible cancer risks. Ongoingstudies are assessingthis risk.

Adefovir. Adefovir (Hepsera) belongs to a class of antiviral agents called nucleotide analogs. (Nucleotides are related to nucleosides but have a slightly different chemical structure.) Nucleotide analogs block an enzyme involved in the replication of viruses. Adefovir costs more than lamivudine, but may be effective against lamivudine-resistant strains of HBV.

Drug Warnings. In 2004, the FDA issued two drug warnings for patients with HBV. The HIV drug tenofovir (Viread) should not be used to treat patients who are co-infected with HBV as the drug may increase hepatitis severity. The lymphoma drug rituximab (Rituxan) may reactivate HBV. Patients with lymphoma should be screened for HBV.