Aciclovir is an antiviral medication commonly used to treat viral infections such as herpes simplex virus, varicella-zoster virus, and Epstein-Barr virus. It can also be used as a prophylactic treatment for these viruses. In addition to its primary name, aciclovir is sold under various synonyms such as acyclovir, acyclovirum, aciclovirum, acyclovirax, and acyclovirax. Whatever its name, the drug works by inhibiting the replication of the viral DNA, thereby preventing the virus from multiplying and spreading. Aciclovir and its synonymous names are widely used in the medical industry and have proved to be effective in treating viral infections in many patients who have taken this medication.