Which of the following is NOT a Schedule III drug?

In the context of controlled substances, Schedule III drugs are those that have a potential for abuse but are considered to have a lower risk compared to Schedule I and II drugs. They are often utilized for medical purposes.

Butalbital, testosterone, and dronabinol are classified as Schedule III substances. Butalbital is often used in combination with other medications for treating headaches, testosterone is utilized in hormone replacement therapy, and dronabinol is a synthetic form of THC used to treat nausea and vomiting in patients undergoing chemotherapy. These drugs are recognized for their medical utility while also being regulated due to their potential for misuse.

Methadone, on the other hand, is classified as a Schedule II substance. It is primarily used for pain management and for treatment in drug dependency programs. The higher potential for abuse associated with methadone reasons for its classification as a Schedule II controlled substance under federal law.

Thus, the correct answer identifies methadone as the drug that is not classified as Schedule III, differentiating it from the other options which are indeed in that category.