Pharmacotherapeutic group: Antiviral agents.
Acyclovir is active in vitro against Herpes simplex virus (HSV) types I and II and varicella-zoster virus (VZV).
This activity is due to intracellular conversion of acyclovir to acyclovir triphosphate by viral thymidine kinase. Acyclovir triphosphate inhibits viral DNA synthesis and replication.