What are three features of narcotics that distinguish them pharmacologically from other drugs with sedative-hypnotic properties, such as barbiturates and benzodiazepines?

What will be an ideal response?

Narcotics (opiates) bind stereospecifically to endorphin/enkephalin receptors, produce profound analgesia without inducing sleep, and their effects are blocked with naloxone or naltrexone. Barbiturates and benzodiazepines induce actions via non-opioid receptors, and their effects are not blocked with naloxone or naltrexone. Barbiturates only produce significant analgesia with anesthetic-sleep, and benzodiazepines are not analgesics, nor can they produce a state of surgical anesthesia when used alone.