Hepatitis B virus (HBV) viral load is closely related to necroinflammation and the outcome of chronic hepatitis B. The available treatment options to reduce viral load, and hence improve outcome, are either based on IFN or on nucleoside/nucleotide analogue antiviral agents, which inhibit HBV DNA replication. Use of IFN alfa or pegylated IFN alfa-2a for periods longer than 48 weeks is limited by their side-effects. The antiviral agents have much more acceptable side-effect profiles, and lamivudine, the first antiviral to become available, was widely used until it became apparent that it carries a high potential for resistance to emerge, which rapidly negates its benefit. A new antiviral agent, telbivudine, has been approved in the USA and Europe and appears to be very rapid and potent against HBV, with an excellent safety profile. (C) 2007 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.