Adefovir Dipivoxil Alone or in Combination with Lamivudine for Three Months in Patients with Lamivudine Resistant Compensated Chronic Hepatitis B

We studied clinical and laboratory effects of 3 months of lamivudine with adefovir combination and adefovir dipivoxil (AD) alone in the treatment of patients with lamivudine-resistant hepatitis B virus (HBV) infection. Eligible patients were hepatitis B surface antigen-positive men and women with compensated liver disease who were given lamivudine at least more than 6 months and had HBV polymerase gene mutation. Patients were assigned to receive adefovir 10 mg/day (Group 1) or adefovir 10 mg once daily and lamivudine 100 mg once daily combination during first 3 months, and then stopped lamivudine and continued adefovir (Group 2).

Median age was 48 years (34 males and 20 females, and 35 were HBeAg-negative). Baseline median ALT, AST, and HBV DNA levels were 66 IU/l, 49 IU/l, and 6.7 log₁₀ copy/ml, respectively. Median adefovir therapy time and ALT normalization time were 9 and 3.5 months, respectively. There was no significant difference between groups according to the baseline HBV DNA, ALT, HBe Ag status, age, gender, and lamivudine resistance time. Virological and biochemical responses were similar in both groups during therapy. Two patients (8%) had ALT flare more than five times upper limit of normal without any clinical decompensation in Group 1. Mild ALT elevation according to baseline levels were found in 8 (27.6%) and 4 (17.4%) patients, respectively, in Group 2 and Group 1, and no statistically significance between two groups.

In conclusion, this study showed that it is not necessary to continue lamivudine therapy while switching to AD therapy. Adefovir alone is effective in the treatment of patients with lamivudine resistant HBV infection and compensated liver disease, without significant clinical and laboratory flares. However, it is not easy to say that switching to AD with cessation of lamivudine is safe, because the study population is not enough for precise conclusion and resistance may be a considerable problem against AD in patients using long-term treatment.