Which substance is classified as a Schedule II drug?

Methadone is classified as a Schedule II drug primarily due to its recognized medical use along with its potential for abuse and severe psychological or physical dependence. Schedule II substances are considered to have a high potential for abuse, which may lead to severe psychological or physical dependence. Methadone is commonly utilized in the treatment of opioid addiction and as a pain management option, indicating its legitimate use in medical settings. However, the controls surrounding its prescription and distribution reflect the serious risks associated with its misuse.

Ketamine, while sometimes used for procedures or treatment-resistant depression, is classified as a Schedule III drug. Lyrica, which is often prescribed for nerve pain and fibromyalgia, falls under Schedule V, indicating a lower potential for abuse. Soma, a muscle relaxant, is not scheduled under the Controlled Substances Act, making it outside the classifications for drugs with significant abuse potential. Thus, only methadone aligns with the criteria for Schedule II classification among the provided choices.