Acyclovir is an antiviral medication that is used to treat a range of viral infections. It works by inhibiting the replication of the virus and preventing it from spreading. There are several other names for acyclovir, including Zovirax and Sitavig. These synonyms are often used interchangeably with acyclovir and are prescribed for similar indications. Some other synonyms for acyclovir include valacyclovir, famciclovir, and penciclovir. These medications are also antiviral agents that work in similar ways to acyclovir. While these drugs have similar effects, they may differ in terms of dosing, duration of therapy, and side effect profile.