famciclovir

noun

fam·​ci·​clo·​vir ˌfam-ˈsī-klō-ˌvir 

: a precursor C₁₄H₁₉N₅O₄ of the antiviral agent penciclovir that after oral administration is converted to penciclovir by cellular kinases and that is used especially to treat shingles and herpes genitalis see famvir