ZEFFIX, known generically as lamivudine, is an antiviral medication primarily used in the treatment of chronic hepatitis B virus (HBV) infection. It works by inhibiting the replication of the virus within the body, thereby reducing the viral load and the potential damage to the liver. ZEFFIX is taken orally and is suitable for adults and children, offering a therapeutic option to manage and control the progression of hepatitis B. It is important for patients to adhere to their prescribed regimen and consult healthcare providers for regular monitoring while on ZEFFIX, as it does not cure hepatitis B but helps in managing the symptoms and reducing the risk of complications associated with the virus.