Which of the following drug products must be purchased using a DEA Form 222?

The requirement to purchase drugs using a DEA Form 222 is applicable to controlled substances listed in Schedule I and Schedule II of the Controlled Substances Act. This form is designed to ensure proper tracking and management of these potent medications to prevent misuse and illegal distribution.

All of the drugs listed, including methadone, methylphenidate, and fentanyl, are classified as controlled substances. Methadone is a Schedule II drug commonly used in pain management and for treating opioid dependence. Methylphenidate, though primarily known for treating ADHD, is also classified as a Schedule II due to its potential for abuse. Fentanyl, a powerful synthetic opioid, is classified as a Schedule II narcotic with a high potential for addiction and overdose.

Since each of these substances falls under the regulations for Schedule II drugs, a DEA Form 222 is required for their purchase to ensure compliance with federal law. This requirement highlights the strict control measures implemented for drugs with a significant risk of abuse, emphasizing the importance of proper documentation in the handling of such substances. Thus, the inclusion of all three drugs in the answer indicates that they all necessitate the use of this specific form for their procurement.