Which of the following drugs is NOT classified as a Schedule III drug?

Fioricet is the correct choice as it is not classified as a Schedule III drug. It contains butalbital, acetaminophen, and caffeine, and is generally considered to be a combination medication used for relieving tension headaches. Importantly, Fioricet does not contain any controlled substances, which differentiates it from Schedule III medications.

Schedule III drugs are typically substances that have a potential for abuse but less than those in Schedule I or II. They include certain narcotics like codeine when in combination with other medications, as well as barbiturates like butalbital, which is a Schedule III drug on its own. These drugs are regulated due to their potential for addiction and abuse.

In contrast, Fiorinal, which contains butalbital and aspirin with codeine, does fall under the Schedule III classification due to the presence of codeine. This highlights the importance of understanding the specific formulations and their classifications under the Controlled Substances Act when preparing for the MPJE examination.