Which of the following is classified as a Sedative/Tranquilizer but not a controlled substance?

• A. Alprazolam (Xanax)
• B. Gabapentin
• C. Acepromazine
• D. Fentanyl

Answer: (C)

The main idea is identifying a drug that acts as a sedative or tranquilizer in animals but isn’t a controlled substance. Acepromazine fits this role well: it’s a phenothiazine tranquilizer used to calm patients and provide mild sedation, and it does not carry federal scheduling as a controlled substance. It calms without providing analgesia and isn’t subject to the DEA scheduling that applies to many other sedatives.

In contrast, alprazolam is a benzodiazepine and is a controlled substance due to potential abuse. Fentanyl is a potent opioid analgesic and also tightly controlled. Gabapentin isn’t a classic sedative or tranquilizer, and while its regulatory status varies by jurisdiction, it’s not typically classified as a sedative/tranquilizer in the same sense as acepromazine. So acepromazine is the best fit for a sedative/tranquilizer that is not a controlled substance.