Adefovirdiphosphat hæmmer virale polymeraser ved at konkurrere med det naturlige substrat (deoxyadenosintriphosphat) om den direkte binding, og udløser (efter indføjelse i viral DNA) DNA- kædeterminering.
Adefovir diphosphate inhibits viral polymerases by competing for direct binding with the natural substrate (deoxyadenosine triphosphate) and, after incorporation into viral DNA, causes DNA chain termination.