Definition of "narcotic antagonist" [narcotic antagonist]

• An antagonist used to counteract the effects of narcotics (especially to counteract the depression of respiration) (noun)

WordNet. Princeton University. 2010.

• "He also knew of the work of J. J. Jacob and his colleagues in France who had found that the narcotic antagonist naloxone increased the effect of painful stimuli, leading to the assumption that it was blocking a naturally occurring, opiate-like substance in the brain, inhibiting its painkilling power.14"
• "In a test of his hypothesis, he found that the narcotic antagonist naloxone, applied either before or after the addition of “X” or normorphine, blocked or reversed the inhibitory action of both compounds."