Definition of naltrexone in English:

Share this entry


Pronunciation: /nalˈtreksōn/


A synthetic drug, similar to morphine, that blocks opiate receptors in the nervous system and is used chiefly in the treatment of heroin addiction.
Example sentences
  • In addition, this research group also determined that naloxone, an opiate antagonist similar to naltrexone, prevented the action of both marijuana and heroin on dopamine transmission.
  • Thus, the researchers proposed the hypothesis that alcohol releases endogenous opioids and that naltrexone blocks the opioid receptor.
  • Small studies have suggested that the opiate antagonist naltrexone is effective as an adjuvant therapy for treating alcohol addiction.


1970s: from a contraction of N-al(lylnoroxymorph)one (see naloxone), with the insertion of the arbitrary element -trex-.

For editors and proofreaders

Syllabification: nal·trex·one

Share this entry

What do you find interesting about this word or phrase?

Comments that don't adhere to our Community Guidelines may be moderated or removed.