The chemical Famciclovir has a designated molecular formula of C14H19N5O4 and a molecular weight of 321.337 g/mol. Synonyms may include: Famciclovirum [INN-Latin], Famvir, Famciclovirum, UNII-QIC03ANI02, HSDB 8121 (ChemID). Famciclovir has been assigned a MeSH pharmacological action of: Antivirals, Nucleic Acid Synthesis Inhibitor.