De kaldes dog begge generelt for NRTI' er, og de virker ved at gribe ind i den normale måde, som et enzym (revers transkriptase) arbejder på, og som er nødvendigt for at virus kan reproducere sig selv.
However, both are generally known as NRTIs and they work by interfering with the normal working of an enzyme (reverse transcriptase) that is essential for the virus to reproduce itself.