Share this entry
naltrexone Syllabification: nal·trex·one
Pronunciation: /nalˈtreksōn/

Definition of naltrexone in English:


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-.

Definition of naltrexone in:
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.

Subscribe to remove ads and access premium resources