The term “Opioids” is a blanket term used for any drug, including opiates, which are active by binding to the C.N.S. or gastrointestinal tract opioid receptors, thus having an action comparable to that of opiates.

It is a broad class of narcotics whose activity comes from their receptor binding action, and includes natural opiates coming from the opium poppy (codeine, morphine) morphines ( heroin or diacetyl-morphine) semi-synthetic opiates (hydromorphone, oxycodone) and fully synthetic opiates (methadone, fentanyl) and endogenous opioid peptides produced in the body (endorphins, endomorphins)