acy·​clo·​vir (ˌ)ā-ˈsī-klō-ˌvir How to pronounce acyclovir (audio)
: a cyclic synthetic nucleoside C8H11N5O3 used especially to treat the symptoms of chicken pox, shingles, and the genital form of herpes simplex

Examples of acyclovir in a Sentence

Recent Examples on the Web There are a variety of genital and oral herpes treatments that can help prevent outbreaks, alleviate symptoms, and lower the risk of transmission, including antiviral medication like valacyclovir and acyclovir, acyclovir cream for cold sores, lidocaine pain cream, Cover Up! Danielle Sinay, Glamour, 5 Mar. 2024 Taken daily, drugs like acyclovir (Zovirax) and valacyclovir (Valtrex) can significantly reduce the risk of herpes transmission—but not 100%. Amanda Gardner, Health, 3 Sep. 2023 Antiviral medications: Antiviral medicines like acyclovir, valacyclovir, and famciclovir can treat shingles, shorten the length and severity of the illness, and minimize a patient’s chances of developing complications, Szema said. Alyssa Hui, Verywell Health, 25 May 2023 If caught early, there are antiviral medications, including acyclovir, valacyclovir and famciclovir, that can shorten the length and severity of the illness. Sandee Lamotte, CNN, 10 Mar. 2023 Suspecting varicella-zoster, Grant had already prescribed acyclovir, an antiviral remedy. Claire Panosian Dunavan, Discover Magazine, 15 Oct. 2012 The most common course of antiviral medications has been seven to 10 days of acyclovir, valacyclovir, or famciclovir, although some studies have suggested that a longer 21-day course may be more effective. Bruce Y. Lee, Forbes, 12 June 2022 At time, antiviral medicines that help with the herpes family, such as acyclovir or valacyclovir may be prescribed. Sandee Lamotte, CNN, 11 June 2022 Treatment options can include anti-inflammatory and antiviral medications such as prednisone, acyclovir and valacyclovir. CBS News, 10 June 2022

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'acyclovir.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History


acycl(ic) + -o- + vir(us); from its containing less cyclic structure than its naturally occurring analogue guanosine

First Known Use

1979, in the meaning defined above

Time Traveler
The first known use of acyclovir was in 1979

Dictionary Entries Near acyclovir

Cite this Entry

“Acyclovir.” Dictionary, Merriam-Webster, Accessed 24 May. 2024.

Medical Definition


acy·​clo·​vir ˌā-ˈsī-klō-ˌvir How to pronounce acyclovir (audio)
: a cyclic nucleoside C8H11N5O3 used especially to treat shingles, genital herpes, and chicken pox see zovirax

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