Which of the following is NOT included in a Prescription Narcotic according to its definition?

A Prescription Narcotic is defined in legislation and pharmacy regulations as a controlled substance that is subject to specific restrictions and regulations. This category typically includes substances that have a high potential for abuse and are strictly regulated under drug control laws.

Lidocaine, being a local anesthetic, is not classified as a narcotic. It is used for pain relief in medical procedures and is not known for having narcotic effects such as sedation or euphoria associated with the other substances listed. Instead, it functions primarily as a numbing agent without the abuse potential that characterizes narcotics.

On the other hand, hydrocodone, methadone, and diacetylmorphine (heroin) are all examples of narcotics that are classified for their psychoactive properties and potential for abuse. These substances are controlled under various legislative frameworks, requiring special prescriptions and monitoring. Hence, identifying lidocaine as the substance not included in the definition of a Prescription Narcotic aligns with the understanding of how these medications are classified and regulated.