Acyclovir is an antiviral drug from the group of synthetic analogues of acyclic purine nucleoside-deoxyguanidine, which is a component of DNA.
Acyclovir is highly specific for the virus Herpes simplex 1 and 2 types; a virus that causes varicella and herpes zoster (Varicella zoster); the Epstein-Barr virus. Moderately active against the causative agent of cytomegalovirus infection.
Acyclovir penetrates directly into virus-infected cells. Cells infected with the virus produce viral thymidine kinase, which phosphorescrates acyclovir to acyclovir triphosphate. The latter interacts with the viral DNA polymerase, which is synthesized for new viruses. Thus, "defective" viral DNA is formed, which leads to suppression of replication of new generations of viruses.