Which of the following drugs has antagonistic effects at delta and kappa sites?

Question

Quizplus · Accepted Answer

Naloxone is a pure opioid antagonist that acts at all three opioid receptors (mu, delta, and kappa). It binds to the same receptor sites as opioids like morphine, fentanyl, and codeine, but does not activate them, effectively reversing their effects. It has antagonistic effects at both delta and kappa sites. Buprenorphine is a partial agonist at mu receptors and has weak antagonist effects at kappa receptors, but it does not have significant activity at delta receptors. Fentanyl and codeine are agonists at mu receptors, with no significant activity at delta or kappa receptors.

Which of the Following Drugs Has Antagonistic Effects at Delta