Mutations in the hepatitis B virus DNA polymerase associated with antiviral resistance

The nucleoside analogues lamivudine, famciclovir, lobucavir, (-)-FTC, BMS 200,475 and the nucleotide analogue prodrug adefovir dipivoxil, are currently undergoing clinical trials, or are licenced (lamivudine) for treatment of hepatitis B virus (HBV) infection. Efficacy has been demonstrated for chronic HBV infection, human immunodeficiency virus (HIV)/HBV co-infection and as prophylaxis against re-infection following liver transplantation. However, viral resistance mutations have been observed with these compounds and their importance will increase as more compounds reach the clinic.