Which of the following medications is classified as a Schedule IV substance?

The classification of medications under the Controlled Substances Act designates Schedule IV substances as having a lower potential for abuse compared to substances in Schedules I, II, and III. Products in this schedule generally have accepted medical uses in the United States and are considered to have a low potential for physical or psychological dependence.

Phenobarbital, which is the correct answer, is a barbiturate that is commonly used as an anticonvulsant and for sedation. Its placement as a Schedule IV controlled substance reflects its recognized medical utility along with its relatively low potential for abuse and dependence when compared to substances classified in higher schedules.

Testosterone is classified as a Schedule III substance due to its potential for abuse and the effects it can have. Phentermine, often used as an appetite suppressant, is classified as a Schedule IV drug as well, which could lead to confusion; however, in the context of the question focusing on Phenobarbital, it is important to note that while Phentermine is also Schedule IV, it is not the correct focus here. Hydrocodone, on the other hand, is considered a higher-risk substance classified as Schedule II due to its potential for abuse and risk of severe dependence.

Understanding the definitions and classifications under the