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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.
When a study rated the states with the highest distribution of naloxone in 2023, Tennessee was in the top 20, according to the CDC's website. Beth Warren, Nashville Tennessean, 25 Nov. 2025 Similar to other opioids, naloxone can reverse a nitazene overdose. Elizabeth Yuko, Rolling Stone, 15 Nov. 2025 Now, programs that distribute overdose-reversing kits and train first responders in how to administer naloxone are slated to lose $56 million in annual grant funding under the federal spending bill. Natalie Eilbert, jsonline.com, 13 Nov. 2025 The agency has also started using Kloxxado, which delivers double the amount of naloxone per dose. Nathaniel Percy, Oc Register, 7 Nov. 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 Nov. 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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