Treatment of chronic hepatitis B: Who to treat, what to use, and for how long?

Chronic hepatitis B infection continues to be a major public health concern worldwide. The natural history of the disease can be divided into 4 different phases: immune tolerance, immune clearance, inactive carrier, and reactivation. The goals of treatment are sustained viral suppression, normalization of ALT, and improvement in liver histology. Antiviral agents in current use include standard interferon, lamivudine, and adefovir. With an improved understanding of the natural history of the disease and a growing repertoire of antiviral drugs, the important questions are: who should receive treatment, what is the best agent to use, and what is the optimal duration of therapy? Treatment is indicated for patients in the immune clearance and reactivation phases. Patients with high pretreatment ALT level, detectable HBV DNA in the serum, and active inflammation on liver biopsy are predicted to have the highest chance of response to treatment. The choice of a particular agent must balance long-term benefits such as the likelihood of a sustained response against long-term risks such as drug resistance. Interferon treatment leads to a more durable response but is associated with unpleasant side effects. Lamivudine is effective and well tolerated but requires long-term therapy and is associated with drug resistance. Adefovir has proven efficacy and a very low rate of drug resistance but is associated with a small risk of reversible nephrotoxicity. For HBeAG-positive chronic hepatitis B and HBeAG-negative chronic hepatitis B, the duration of interferon therapy is 4-6 months and 12 months, respectively. Duration of treatment is at least 1 year with lamivudine and adefovir; longer duration of treatment is needed in most patients, but the optimal duration of treatment and the criteria for stopping treatment have not been established.