Which drug is NOT derived from the opium poppy?

Marinol is the correct choice as it is not derived from the opium poppy. Marinol, or dronabinol, is a synthetic form of THC, the active compound found in marijuana, and is used primarily to treat nausea and vomiting associated with chemotherapy, as well as to stimulate appetite in patients with AIDS.

In contrast, the other options are all derived from the opium poppy or are closely related to its derivatives. Codeine, for instance, is a naturally occurring alkaloid found in the opium poppy, and is used for its analgesic properties. Dilaudid, which is a brand name for hydromorphone, is a semi-synthetic opioid derived from morphine, another natural product of the opium poppy. Oxycodone is also a semi-synthetic opioid, derived from thebaine, another compound found in the opium poppy. Thus, Marinol stands apart as it originates from cannabis rather than the opium poppy.