ri·​to·​na·​vir | \ ˌrī-ˈtō-nə-ˌvir How to pronounce ritonavir (audio) , -ˈtä-, ri- \

Definition of ritonavir

: an antiviral protease inhibitor C37H48N6O5S2 administered orally to treat HIV infection and AIDS

Examples of ritonavir in a Sentence

Recent Examples on the Web The pill is made up of two medications: ritonavir, commonly used to treat HIV and AIDS, and nirmatrelvir, an antiviral that Pfizer developed to boost the strength of the first drug. Mary Kekatos, ABC News, 9 Mar. 2022 The potential drug is designed to counter possible viral resistance to Paxlovid, and to work without the aid of the antiviral ritonavir that is given with Paxlovid but carries safety risks for patients taking some common medications. Matt Grossman, WSJ, 8 Feb. 2022 In its fact sheet about Paxlovid, the FDA has published a detailed list of medications that may interact harmfully with ritonavir, including those that should not be paired with the Covid antivirals. NBC News, 22 Dec. 2021 According to the agreement, the companies will be able to take out sublicenses to produce raw ingredients of nirmatrelvir, co-package it with ritonavir or both steps. Mary Kekatos, ABC News, 18 Mar. 2022 Paxlovid combines a new antiviral drug named nirmatrelvir and an older one called ritonavir and is administered as three pills given twice a day for five days. Helen Regan And Adam Renton, CNN, 23 Dec. 2021 To be sure, Pfizer’s recent license to the Medicines Patent Pool for another antiviral, ritonavir (Paxlovid), similarly excludes middle-income countries, many of which have been devastated by Covid-19, like Brazil. Merith Basey, STAT, 20 Dec. 2021 Paxlovid is taken twice a day together with another pill called ritonavir. Peter Landers, WSJ, 7 Feb. 2022 Patients take three pills at a time: two of Pfizer’s pills and one of a low-dose H.I.V. drug known as ritonavir, which helps Pfizer’s drug remain active in the body longer. New York Times, 22 Dec. 2021 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'ritonavir.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of ritonavir

1995, in the meaning defined above

History and Etymology for ritonavir

rito- (perhaps by shortening & alteration from protease) + -navir (as in saquinavir)

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The first known use of ritonavir was in 1995

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Last Updated

16 Apr 2022

Cite this Entry

“Ritonavir.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/ritonavir. Accessed 19 May. 2022.

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More Definitions for ritonavir


ri·​to·​na·​vir | \ ˌrī-ˈtō-nə-ˌvir, -ˈtän-ə-, ri- How to pronounce ritonavir (audio) \

Medical Definition of ritonavir

: an antiviral protease inhibitor C37H48N6O5S2 administered orally to treat HIV infection and AIDS — see norvir


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