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.
Behind the numbers One factor behind the decline in overdose deaths may be wider availability of the opioid overdose reversal drug naloxone. — Theresa Gaffney, STAT, 3 Sep. 2026 But naloxone should be the first step, not the end of the road. — Joel Teron, New York Daily News, 31 Aug. 2026 For example, when the medication is taken as directed, under the tongue or inside the cheek, relatively little naloxone reaches the bloodstream. — Encyclopedia Britannica, 28 Aug. 2026 If preban trends had continued, there would have been over 150 naloxone kits distributed weekly by one program, on average. — Paul Christine, The Conversation, 25 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 5 Sep. 2026.

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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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