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.
All five inmates affected were administered two doses of naloxone (Narcan) to reverse the overdose effects, the office said. — Carlos E. Castañeda, CBS News, 17 Aug. 2026 Jail staff began lifesaving measures and administered naloxone, commonly known by the brand name Narcan, which can reverse an opioid overdose. — Sacramento Bee Contributor, Sacbee.com, 17 Aug. 2026 Drop by the Los Gatos library and get trained on how to use Narcan (the trade name for naloxone) to help someone experiencing an opioid overdose. — Hema Sivanandam, Mercury News, 10 Aug. 2026 Kerr said the best approach would be to continue to promote the use of test strips while also continuing to give out lifesaving medications like naloxone. — Scott Maucione, NPR, 8 Aug. 2026 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

Rhymes for naloxone

See All Rhymes for naloxone

Browse Nearby Words

nalorphine
naloxone
naltrexone
See all Nearby Words

Cite this Entry

“Naloxone.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/naloxone. Accessed 24 Aug. 2026.

Copy Citation

Medical Definition

naloxone

noun
nal·​ox·​one nal-ˈäk-ˌsōn How to pronounce naloxone (audio) ˈnal-ək-ˌsōn How to pronounce naloxone (audio)
: 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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