The word “narcotic” refers to an agent capable of inducing sleep, which includes opioids. Over time the term “narcotic” has become a derogatory term for opioids and other drugs of abuse. Naming police units that deal with illicit drugs “narcotics divisions” and the name of the group “narcotics anonymous” both place negative implications on the word.
Moreover, the slang term “narc” or “nark” is associated with a person that reports any misbehavior to an authority, similar to “tattletale” or “squealer.”
Therefore, the term “opioid” is now preferred. The term “opioid” is also more accurate, as the term “narcotics” may apply to many agents other than opioids.