Which of the following is NOT a Schedule II drug used in veterinary medicine?

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

Answer: (C)

Understanding how controlled substances are scheduled helps here. Schedule II drugs have high abuse potential and accepted medical use with strict controls. Morphine, hydromorphone, and fentanyl are all Schedule II because they are potent full opioid agonists with high abuse risk and tight handling and prescribing rules. Buprenorphine, on the other hand, is a partial opioid agonist with a ceiling effect, which lowers abuse potential. Federa­l regulation places it in Schedule III, not Schedule II, so it’s the correct answer to the question. In veterinary practice, buprenorphine is widely used for analgesia but remains Schedule III, while the others listed are Schedule II.