NCIt definition : A diacetyl 6-deoxy prodrug analog of the antiviral agent penciclovir. Orally administered,
famciclovir in vivo is converted to penciclovir triphosphate, which is active against
the Herpes viruses, including herpes simplex 1 and 2 and varicella-zoster. This agent
inhibits the replication of viral DNA by interfering competitively with DNA polymerase.
(NCI04);