Abstract: AIM: To evaluate the efficacy and safety of adefovir dipivoxil in treating patients with hepatitis B resistant to lamivudine. METHODS: 68 patients with hepatitis B resistant to lamivudine were administered 10 mg adefovir dipivoxil orally daily for over 1 years.The serum HBV-DNA levels were measured by quantitative PCR and liver function test, HBeAg anti-HBe and safety assessments were also performed at 0, 12, 24, 52 weeks after treatment. RESULTS: After 12, 24, 52 weeks of treatment, the mean HBV-DNA levels were reduced by 1.6 lg copies/mL (t=10.10, P<0.01), 2.9 lg copies/mL (t=13.01, P<0.01) and 4.5 lg copies/mL(t=14.08, P<0.01).The normalization rates of ALT levels were 19.12%, 48.53% and 70.59%.The HBeAg loss rates were 0%, 19.44%and 47.22%.The HBV-DNA undetectable rates were 4.41%, 19.12% and 54.41% respectively. CONCLUSION: Adefovir dipivoxil is effective and safe for treating chronic hepatitis B patients with lamivudine resistance.

Key words: chronic hepatitis B, lamivudine resistance, adefovir dipivoxil