naltrexone

American

[nal-trek-sohn] / nælˈtrɛk soʊn /

noun

Pharmacology.

a nonaddictive substance, C 2 0 H 2 3 NO 4 , used in the treatment of heroin addiction and opiate overdose.

naltrexone British

/ nælˈtrɛksəʊn /

noun

a narcotic antagonist, similar to morphine, used chiefly in the treatment of heroin addiction

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Etymology

Origin of naltrexone

First recorded in 1970–75; by rearrangement of parts of its chemical name

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

See Examples For:

naltrexone

Low-dose naltrexone has been shown to reduce fatigue and lower platelet aggregation.

From Science Daily ● Jan. 8, 2026

I have been taking low-dose naltrexone for a couple of years.

From Seattle Times ● Apr. 24, 2024

Among the most popular are low-dose naltrexone, anticoagulants, antivirals, beta blockers, statins, antihistamines to calm overactive mast cells, and probiotics to improve gut health.

From Slate ● May 8, 2023

These elegant studies demonstrate that when opioid receptors are blocked – in one example by a drug called naltrexone – people still experienced euphoria and reduced pain and anxiety after exercise.

From Salon ● Jan. 4, 2022

The researchers gave depressed patients naltrexone to block the opioid receptor before administering ketamine, and found that this eliminated ketamine’s antidepressant effects but not its hallucinatory side effects.

From Scientific American ● Feb. 22, 2019

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Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023