Final answer:
Carisoprodol is metabolized into the controlled substance meprobamate, which is known for its anxiolytic and sedative effects.
Step-by-step explanation:
Carisoprodol is metabolized into the controlled substance meprobamate. This occurs through hepatic enzyme conversion, and meprobamate is known for its anxiolytic and sedative properties. It's important to be aware of this metabolite because it contributes to the effects (and potential for abuse) associated with carisoprodol, which is typically prescribed as a muscle relaxant. Options such as pregabalin, alprazolam, and barbital are not products of carisoprodol metabolism; these are other distinct controlled substances used for various therapeutic purposes.