Data are beginning to come in from testing of acyclovir (9-[(2-hydroxyethoxy)methyl] guanine), a potential new antiviral agent, against a variety of herpes virus infections.
"This agent differs from other antiviral drugs in that it is activated only while in an infected cell," Jonathan H. Lass, MD, told a Research to Prevent Blindness seminar in Los Angeles. "The virus in the cell produces an enzyme that in turn activates acyclovir to block viral replication. Uninfected cells go about their normal processes undisrupted by the acyclovir because there is no activation of the drug within these cells."
Deborah Pavan-Langston, MD, with whom Lass worked at Harvard Medical School, Boston, before going to Case Western Reserve University School of Medicine, Cleveland, says that, specifically, herpes simplex virus-coded thymidine kinase starts a phosphorylation chain reaction with acyclovir. This results in production of an acyclovir triphosphate that has a much greater affinity (about 30-fold) for