Which type of analgesic is classified as a controlled substance?

Opioid analgesics are classified as controlled substances due to their potential for abuse, dependence, and addiction. This classification reflects the need for strict regulations regarding their prescription and distribution. Opioids work by binding to specific receptors in the brain and spinal cord to block the perception of pain, providing effective relief for moderate to severe pain, but they also carry a significant risk for misuse.

In contrast, nonopioid analgesics, such as acetaminophen and nonsteroidal anti-inflammatory drugs (NSAIDs), are not classified as controlled substances because they have a lower potential for abuse and are commonly available over the counter. Adjuvant analgesics, which include certain anticonvulsants and antidepressants, are not controlled substances either. Similarly, over-the-counter analgesics are widely accessible and do not require special prescriptions, reinforcing their classification outside controlled substances.