Which of the following drugs is NOT classified as Schedule II?

Hydrocodone combined with acetaminophen is classified as a Schedule II controlled substance due to the potential for abuse and the risk of psychological or physical dependence. However, the question is asking for the drug that does NOT fall under Schedule II classification.

In this context, while hydrocodone itself is a Schedule II substance, when it is combined with acetaminophen in a combination product, it is classified as Schedule III. This distinction is critical as it indicates a lower potential for abuse and dependence compared to Schedule II drugs.

On the other hand, meperidine, hydromorphone, and methylphenidate are all classified as Schedule II controlled substances due to their high potential for abuse, which can lead to severe psychological or physical dependence. Thus, recognizing the specific combination and its scheduling is key to understanding why hydrocodone with acetaminophen stands apart from the other drugs in this question.