Aciclovir or acyclovir, chemical name acycloguanosine, abbreviated as ACV, is a guanosine analogue antiviral drug, marketed under trade names such as Cyclovir, Herpex, Acivir, Acivirax, Zovirax, and Zovir. One of the most commonly used antiviral drugs, it is primarily used for the treatment of herpes simplex virus infections, as well as in the treatment of varicella zoster (chickenpox) and herpes zoster (shingles). Aciclovir was seen as the start of a new era in antiviral therapy, as it is extremely selective and low in cytotoxicity. It was co-discovered by Howard Schaffer following his work with Robert Vince, S...