Which of the following drugs is listed as Schedule IV in the material?

• A. Butorphanol
• B. Morphine
• C. Hydromorphone
• D. Fentanyl

Answer: (A)

Scheduling classes drugs by their abuse potential, medical use, and dependence risk. Schedule IV indicates lower potential for abuse than Schedule III, with accepted medical use and tighter controls. Butorphanol is a mixed opioid receptor agonist-antagonist with primarily mu antagonism and kappa agonism, which gives analgesia but a relatively lower risk of abuse and a ceiling effect on some adverse effects like respiratory depression. This combination makes it fit Schedule IV. The other three choices—morphine, hydromorphone, and fentanyl—are full mu‑opioid agonists with higher abuse potential and greater dependence risk, so they’re placed in Schedule II.