All anti-herpes medications share which primary mechanism?

• A. Inhibition of DNA polymerase
• B. Blockade of viral entry
• C. Inhibition of reverse transcription
• D. Inhibition of neuraminidase

Answer: (A)

All anti-herpes medications work by blocking the virus’s ability to copy its DNA. Herpesviruses need their DNA polymerase to replicate their genome, so these drugs act as DNA synthesis inhibitors. They’re typically nucleoside or nucleotide analogs that, after activation inside infected cells, resemble the normal building blocks and get incorporated into the viral DNA chain, causing termination or directly suppressing polymerase activity. Acyclovir and its prodrugs (valacyclovir, famciclovir) are activated by viral kinases, which helps target infected cells, and they ultimately inhibit viral DNA polymerase with chain termination. Ganciclovir acts similarly, though its activation and spectrum differ, and foscarnet directly inhibits viral DNA polymerase without needing activation. This shared mechanism explains why these drugs are effective against herpesviruses, whereas blockade of entry, reverse transcription, or neuraminidase inhibition are not the common features of herpes antivirals.