Which substance on the list is a Schedule IV opioid analgesic with partial agonist activity?

Which substance on the list is a Schedule IV opioid analgesic with partial agonist activity?

• A. Pemoline
• B. Phentermine
• C. Zolpidem
• D. Pentazocine

Answer: (D)

The key idea here is recognizing a mixed opioid medication that provides pain relief through partial agonist activity. Pentazocine acts as an agonist at kappa receptors and as a partial agonist at mu receptors. That combination gives noticeable analgesia but with a ceiling effect on respiratory depression and a lower potential for abuse compared with full mu-agonist opioids. That partial agonist activity is what sets it apart from other drugs listed. Pemoline, phentermine, and zolpidem are not opioid analgesics. Pemoline is a stimulant, phentermine is an appetite suppressant stimulant, and zolpidem is a sedative-hypnotic. While they may be Schedule IV, they do not fit the description of an opioid analgesic with partial agonist activity, which is why pentazocine is the correct choice.

The key idea here is recognizing a mixed opioid medication that provides pain relief through partial agonist activity. Pentazocine acts as an agonist at kappa receptors and as a partial agonist at mu receptors. That combination gives noticeable analgesia but with a ceiling effect on respiratory depression and a lower potential for abuse compared with full mu-agonist opioids. That partial agonist activity is what sets it apart from other drugs listed.

Pemoline, phentermine, and zolpidem are not opioid analgesics. Pemoline is a stimulant, phentermine is an appetite suppressant stimulant, and zolpidem is a sedative-hypnotic. While they may be Schedule IV, they do not fit the description of an opioid analgesic with partial agonist activity, which is why pentazocine is the correct choice.