Virzaf contains Adefovir, which is used to treat chronic hepatitis B infection in adults and children 12 years of age and older. Adefovir is in a class of medications called nucleotide analogs, which work by reducing the amount of hepatitis B virus (HBV) in the body. However, Virzaf or Adefovir will not cure hepatitis B, spread the disease to others, and may not prevent complications of hepatitis B.