What does acyclovir mean?
Acyclovir is a synthetic antiviral medication used to treat infections caused by herpes viruses, including genital and oral herpes (herpes simplex), chickenpox, and shingles (varicella-zoster). First developed in the 1970s by researchers including Nobel laureate Gertrude Elion, it was a landmark in antiviral medicine because it selectively targets virus-infected cells: once inside a herpes-infected cell, it is converted into an active form that blocks viral DNA replication while leaving healthy cells largely unharmed. Acyclovir is available as an oral tablet, topical cream, and intravenous formulation; it does not cure herpes infections, which remain latent in the body, but it can shorten outbreaks, reduce severity, and lessen contagiousness. In medical writing it appears in phrases such as oral, topical, or intravenous acyclovir, and it is closely associated with its prodrug valacyclovir, which the body converts into acyclovir for improved absorption.
nounA synthetic antiviral drug used to treat infections caused by herpes viruses, including herpes simplex, varicella-zoster (chickenpox and shingles), and Epstein-Barr virus. It works by interfering with viral DNA replication, thereby slowing the spread of the infection.
- A synthetic nucleoside analogue (9-(2-hydroxyethoxymethyl)guanine) that inhibits herpesviral DNA polymerase, used to treat herpes simplex, varicella-zoster, and related viral infections.
"The doctor prescribed acyclovir to shorten the duration of her shingles outbreak."
"Patients with recurrent cold sores often keep a supply of acyclovir on hand to start treatment at the first sign of tingling."
"Intravenous acyclovir is the standard therapy for herpes simplex encephalitis in hospitalized patients."
Rarely pluralized; acyclovir is typically treated as a mass noun referring to the drug substance. A plural may appear when discussing different formulations or brands collectively.
"The pharmacy stocked several generic acyclovirs alongside the brand-name version."
Acyclovir was the first truly effective treatment for herpes, developed in the 1970s by Gertrude Elion — a Nobel laureate who helped pioneer it without ever earning a formal doctorate.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of acyclovir
Acyclovir was coined in the 1970s as a contraction of 'acyclic guanosine analogue', reflecting its chemical structure: unlike natural nucleosides such as guanosine, whose sugar ring forms a closed cycle, acyclovir's side chain is open or 'acyclic'. The name combines 'a-' (without), 'cyclo-' (ring, from Greek kyklos meaning circle or wheel), and '-vir' (from Latin virus). It belongs to a family of similarly named antivirals, including valacyclovir, ganciclovir, and penciclovir, all built on the same '-clovir' naming pattern.
How acyclovir is actually used
Acyclovir is a pharmaceutical trade name as well as a generic drug name; it is used almost exclusively in medical and scientific contexts rather than everyday conversation. The brand name Zovirax is well known in many countries.
Easily confused with acyclovir
Valacyclovir is a prodrug of acyclovir that converts into acyclovir in the body and offers better oral absorption.
Ganciclovir is a structurally similar but distinct antiviral used mainly against cytomegalovirus, whereas acyclovir targets herpes simplex and varicella-zoster viruses.