Opioid antagonists, specific agents naloxone

A study of the effect of several opioid antagonists on food intake and their ability to block opioid agonist-induced behaviors, demonstrates a degree of specificity which suggests that the mechanisms for these two activities may differ. Naloxone, naltrexone, diprenorphine, Mr 1452 (16) and Mr 2266 (17) decrease food intake whereas WIN 44,441 (18) does not. Diprenorphine is the most potent of these agents in blocking the antinociceptive effect of morphine, whereas (lb), (]J) and (lb) are weaker antagonists in this test. ... 

Basic and advanced life support measures should be initiated immediately. Activated charcoal may be utilized to adsorb illicit fentanyl derivatives following ingestion. Naloxone is the specific pharmacologic antagonist for fentanyl derivatives. Naloxone displaces these agents at the opioid receptor and reverses their clinical effects however, higher than customary doses may be needed to successfully overcome the opioid receptor. 

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