Which of the following is not a Schedule III drug?

Alprazolam is classified as a Schedule IV controlled substance, distinguishing it from Schedule III drugs. In the context of controlled substances, Schedule III includes drugs that have a moderate to low potential for physical and psychological dependence. Ketamine, paregoric, and butalbital all fall under Schedule III due to their acceptable medical uses and moderate risk factors associated with abuse or dependence.

Ketamine, originally used as an anesthetic, has gained recognition for its therapeutic applications in various mental health disorders, while paregoric is a preparation of opium used primarily for diarrhea. Butalbital is a barbiturate often used in combination products for headaches. Each of these drugs meets the criteria set for Schedule III, whereas alprazolam, being a benzodiazepine, is placed in the lower schedule with stricter regulations due to its higher potential for abuse and dependency. This classification highlights the importance of understanding the nuances in drug scheduling for safe and effective pharmacy practice.