What are the classes of opioids in opioid abuse?

Updated: Mar 23, 2020
  • Author: David W Dixon, DO; Chief Editor: Glen L Xiong, MD  more...
  • Print

Opioids are defined by their ability to bind to and influence opiate receptors on cell membranes. They can be divided into 3 classes:

  • Naturally occurring opioids: The following 6 opium alkaloids occur naturally: morphine, narcotine, codeine, thebaine, papaverine and narceine. Opium is extracted from the plant Papaver somniferum (the opium poppy), and morphine is the primary active component of opium. Endogenous neural polypeptides such as endorphins and enkephalins are also natural opioids.

  • Semi-synthetic opioids: Semisynthesis is a type of chemical synthesis that uses compounds isolated from natural sources (eg, plants) as starting materials. Semi-synthetic opioids include heroin, oxycodone, oxymorphone, and hydrocodone.

  • Synthetic opioids: Synthetic opioids are made using total synthesis, in which large molecules are synthesized from a stepwise combination of small and inexpensive (petrochemical) building blocks. Synthetic opioids include buprenorphine, methadone, fentanyl, alfentanil, levorphanol, meperidine, and propoxyphene (withdrawn from US market).

The terms opiate and narcotic are generally used interchangeably with the term opioid.

Did this answer your question?
Additional feedback? (Optional)
Thank you for your feedback!