Cell metabolism of acyclovir phosphonate derivatives and antiherpesvirus activity of their combinations with alpha2-interferon.

The combinational use of acyclovir (ACV) phosphonate esters and alpha(2)-interferon was shown to produce a synergistic effect on inhibition of HSV-1 replication in Vero cell cultures. Unlike other acyclovir phosphonate derivatives studied earlier, ACV H-phosphonate is not an ACV prodrug. On penetrating into the cells, it may be directly converted into ACV monophosphate escaping dephosphonylation-phosphorylation steps.