Pharmacology: Acyclovir is an antiviral agent which is highly active in vitro against herpes simplex virus (HSV) types I and II and varicella zoster virus. Toxicity to mammalian host cells is low.
Acyclovir is phosphorylated after entry into herpes infected cells to the active compound Acyclovir triphosphate. The first step in this process is dependent on the presence of the HSV-coded thymidine kinase. Acyclovir triphosphate acts as an inhibitor of, and substrate for, the herpes-specified DNA polymerase, preventing further viral DNA synthesis without affecting normal cellular processes.
Pharmacokinetics: Pharmacology studies have shown only minimal systemic absorption of Acyclovir following repeated topical administration of Acyclovir cream.