Nalmefene characteristics include which of the following?

Nalmefene characteristics include which of the following?

• A. Pure opioid antagonist analogue of naltrexone, blocking opioid effects without intrinsic agonist activity.
• B. It has intrinsic agonist activity.
• C. It shortens duration of action compared to naloxone.
• D. It is a mu receptor agonist.

Answer: (A)

Nalmefene is a pure opioid receptor antagonist with no intrinsic agonist activity. This means it binds to the same receptors (mu, kappa, delta) and blocks opioid effects but does not produce opioid-like effects on its own. That lack of intrinsic activity explains why it reverses opioid effects without causing any agonist-related action. Its profile as an analogue of naltrexone is characterized by high receptor affinity and a longer duration of action than naloxone, which helps prevent re-narcotization after reversal. It is not a mu receptor agonist, and stating that it has intrinsic agonist activity or that it shortens the duration of action would be incorrect.

Nalmefene is a pure opioid receptor antagonist with no intrinsic agonist activity. This means it binds to the same receptors (mu, kappa, delta) and blocks opioid effects but does not produce opioid-like effects on its own. That lack of intrinsic activity explains why it reverses opioid effects without causing any agonist-related action.

Its profile as an analogue of naltrexone is characterized by high receptor affinity and a longer duration of action than naloxone, which helps prevent re-narcotization after reversal. It is not a mu receptor agonist, and stating that it has intrinsic agonist activity or that it shortens the duration of action would be incorrect.