Antagonist substitution: naltrexone

• What is an antagonist?

  • chemical that binds to a receptor but blocks its function, preventing the effects of opioids.
• What is naltrexone used for?

  • Opioid addiction: Blocks pleasurable effects, reducing motivation to use.

  • Alcohol addiction: Given post-withdrawal to prevent relapse.
  • Problem gambling: May help, but more research is needed.
• When is naltrexone prescribed for opioid addiction?

  • After detoxification, for individuals who are highly motivated to stay drug-free.
• What forms is naltrexone available in?

  • Oral tablet (UK-approved)
  • Implant or depot injection (approved in USA & Russia)