How do nucleoside/nucleotide analogues work?
Hepatitis B virus reproduces by making copies of its viral DNA nucleosides and nucleotides. The nucleoside/nucleotide analogues fool the hepatitis B virus into thinking they are normal building blocks for DNA. Essentially, the virus is unable to reproduce. Nucleoside/nucleotide analogues do not prevent all viral reproduction, but they can substantially lower the amount of virus in the body. Over time, the hepatitis B virus can become resistant to nucleoside/nucleotide analogues. Once this happens, the viral load rises again, and the doctor may recommend switching to a different medication. Lamivudine has been used for more than 10 years and has a good side effect profile, but HBV often becomes resistant over months or years. It is estimated that 15% to 30% of hepatitis B viruses will become resistant to lamivudine after one year of treatment and that more than 70% will be resistant after five years of treatment. Newer analogues like adefovir, entecavir, and telbivudine are less likely
