Which medications are opioid antagonists?

Which medications are opioid antagonists?

• A. Naloxone, Naltrexone, Nalmefene
• B. Morphine, Fentanyl
• C. Hydromorphone, Oxycodone
• D. Methadone, Buprenorphine

Answer: (A)

Opioid antagonists block the effects of opioids by binding to mu receptors without activating them, effectively displacing opioid agonists and reversing opioid-induced respiratory depression and analgesia. The drugs that fit this profile are naloxone, naltrexone, and nalmefene. Naloxone acts quickly to reverse an overdose but has a short duration, making it ideal for acute management. Naltrexone is longer-acting and is used for relapse prevention in opioid use disorder. Nalmefene shares the same antagonistic mechanism with a duration longer than naloxone, useful in reversal contexts where a longer window is helpful. The other options are opioid agonists or partial agonists, which activate receptors and therefore are not antagonists.

Opioid antagonists block the effects of opioids by binding to mu receptors without activating them, effectively displacing opioid agonists and reversing opioid-induced respiratory depression and analgesia. The drugs that fit this profile are naloxone, naltrexone, and nalmefene. Naloxone acts quickly to reverse an overdose but has a short duration, making it ideal for acute management. Naltrexone is longer-acting and is used for relapse prevention in opioid use disorder. Nalmefene shares the same antagonistic mechanism with a duration longer than naloxone, useful in reversal contexts where a longer window is helpful. The other options are opioid agonists or partial agonists, which activate receptors and therefore are not antagonists.