Opioid Classifications

Although the term “opiate” is often used as a synonym for “opioid”, the term opiate is properly limited to the natural alkaloids found in the resin of the opium poppy (Papaver somniferum).

The opium poppy was cultivated as early as 3400 BC in Mesopotamia. The term opium refers to a mixture of alkaloids from the poppy seed. Opiates are naturally occurring alkaloids such as morphine or codeine. Opioid is the term used broadly to describe all compounds that work at the opioid receptors. The term narcotic (from the Greek word for stupor) originally was used to describe medications for sleep, then was used to describe opioids, but now is a legal term for drugs that are abused as well.

Morphine Meperidine Diamorphine Endorphins Tramadol
Codeine Fentanyl Dihydrocodeine Enkephalins Tapentadol
Papavarine Remifentanil Hydromorphone Dynorphins
Thebaine Alfentanil Hydrocodone Endomorphins
Mitragyna Speciosa Sufentanil Oxycodone
Salvinorin A Methadone Oxymophone
Dextropropoxyphene Ethylmorphine
Butorphanol Buprenorphine
Levorphanol Diamorphine
Pentazocine Nalbuphine