naloxone

noun

nal·​ox·​one na-ˈläk-ˌsōn How to pronounce naloxone (audio)
: a synthetic potent antagonist of narcotic drugs (such as morphine and fentanyl) that is administered especially in the form of its hydrochloride C19H21NO4·HCl

Note: Naloxone is administered by injection or as a nasal spray to reverse the effects of opioids especially in the emergency treatment of opioid overdose. It is also administered in combination with buprenorphine in the form of a dissolvable tablet placed under the tongue or a film placed inside the cheek to treat opioid dependence.

Examples of naloxone in a Sentence

Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
During the year that free doses of the overdose-reversal drug naloxone have been publicly available at five Red Line stops, none appear to have been put into use at the stations, the MBTA said in a report to the Legislature this month. State House News Service, Boston Herald, 21 Oct. 2025 For The People that distributes huge amounts of naloxone. Brian Mann, NPR, 8 Oct. 2025 The Shamashes have also launched a nonprofit called the Drug Awareness Foundation to encourage schools to keep naloxone on hand to reverse opioid overdoses as well as educate kids about avoiding addiction and teach groups about overdose prevention, among other efforts. Jillian Frankel, PEOPLE, 4 Oct. 2025 Agents do suggest carrying naloxone, an opioid reversal drug. Craig Shoup, Nashville Tennessean, 24 Sep. 2025 See All Example Sentences for naloxone

Word History

Etymology

N-allyl + hydroxy- + -one

First Known Use

1964, in the meaning defined above

Time Traveler
The first known use of naloxone was in 1964

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Cite this Entry

“Naloxone.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/naloxone. Accessed 29 Oct. 2025.

Medical Definition

naloxone

noun
: a potent synthetic antagonist of narcotic drugs (as morphine and fentanyl) that is administered especially in the form of its hydrochloride C19H21NO4·HCl

Note: Naloxone is administered by injection or as a nasal spray to reverse the effects of opioids and especially in the emergency treatment of opioid overdose. It is also administered in combination with buprenorphine in the form of a dissolvable tablet placed under the tongue or a film placed inside the cheek to treat opioid dependence. Trademarks for preparations containing naloxone include Bunavail, Evzio, Narcan, Suboxone, and Zubsolv.

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