Final answer:
The anti-HSV drugs that inhibit viral DNA synthesis are trifluridine, penciclovir, acyclovir, and valacyclovir. Acyclovir and its prodrug valacyclovir are particularly notable for their selective activation by herpesvirus-thymidine kinase and specificity for viral DNA polymerase, resulting in terminated viral DNA chains. Docosanol works differently by blocking the virus from entering host cells.
Step-by-step explanation:
The anti-HSV drugs that can inhibit viral DNA synthesis are trifluridine, penciclovir, acyclovir, and valacyclovir. Specifically, acyclovir and its derivatives are widely used antivirals that target viral DNA replication. Acyclovir, a synthetic analog of guanosine, requires activation by the viral enzyme thymidine kinase and is incorporated into the growing viral DNA chain, leading to chain termination. It is especially effective against herpesvirus infections because it has a higher affinity for the viral DNA polymerase compared to the host's DNA polymerase and relies on a viral enzyme for its activation. Valacyclovir is a prodrug of acyclovir, meaning it is converted into acyclovir in the body. It offers the advantage of increased oral bioavailability. Trifluridine and penciclovir work similarly by integrating into the viral DNA and causing premature termination of the replication process.
On the other hand, docosanol does not inhibit viral DNA synthesis. Instead, it interferes with the fusion between the herpesvirus and the host cell membrane, preventing the virus from entering cells and starting the replication cycle.