Naloxone (Brandname: Narcan) is an opioid antagonist used to block the effects of opioid agonists. It is most commonly used in opioid overdoses. Naloxone is also commonly combined with buprenorphine to form the combination medication Suboxone to decrease the risk of misuse.

  • Both naloxone and naltrexone are centrally-acting opioid receptor antagonists. They are both potent competitive inhibitors, with high affinity for the mu opioid receptor.
  • Naloxone is the most common choice in for emergency management of opioid overdose, while naltrexone is mainly used in more stabilized opioid and alcohol use disorders to maintain abstinence by decreasing cravings.
  • Naloxone is most commonly administered with 0.4mg to 2mg as initial dose, with repeated doses as necessary
  • The adverse effects of naloxone are all related to naloxone-induced opioid withdrawal