Which of the following drugs is classified as a narcotic analgesic?

Codeine is classified as a narcotic analgesic because it belongs to the opioid class of drugs, which are primarily used for their pain-relieving properties. As an opioid, codeine binds to specific receptors in the brain and spinal cord to impede the perception of pain, making it effective for moderate pain relief.

Narcotic analgesics are characterized by their ability to alleviate pain both by affecting the brain’s pain perceptions and by inducing sedation. Codeine, in particular, can also be converted in the body to morphine, enhancing its analgesic effects.

The other drugs mentioned do not fit the classification of narcotic analgesics: Meth (methamphetamine) is a stimulant that can lead to increased energy and alertness, rather than pain relief; cocaine is also a stimulant and has different effects, primarily on the central nervous system; and secobarbital is a barbiturate that serves as a sedative and hypnotic but is not primarily used for pain management. Thus, codeine stands out as the only true narcotic analgesic among the options provided.