Opioid

Opioid
Drug class
Chemical structure of morphine, the prototypical opioid.[1]
Class identifiers
UsePain relief
ATC codeN02A
Mode of actionOpioid receptor
External links
MeSHD000701
Legal status
In Wikidata

Opioids are a class of drugs that derive from, or mimic, natural substances found in the opium poppy plant. Opioids work in the brain to produce a variety of effects, including pain relief. As a class of substances, they act on opioid receptors to produce morphine-like effects.[2][3]

The terms 'opioid' and 'opiate' are sometimes used interchangeably, but there are key differences based on the manufacturing processes of these medications.[4]

Medically they are primarily used for pain relief, including anesthesia.[5] Other medical uses include suppression of diarrhea, replacement therapy for opioid use disorder, reversing opioid overdose, and suppressing cough.[5] Extremely potent opioids such as carfentanil are approved only for veterinary use.[6][7][8] Opioids are also frequently used recreationally for their euphoric effects or to prevent withdrawal.[9] Opioids can cause death and have been used for executions in the United States.

Side effects of opioids may include itchiness, sedation, nausea, respiratory depression, constipation, and euphoria. Long-term use can cause tolerance, meaning that increased doses are required to achieve the same effect, and physical dependence, meaning that abruptly discontinuing the drug leads to unpleasant withdrawal symptoms.[10] The euphoria attracts recreational use, and frequent, escalating recreational use of opioids typically results in addiction. An overdose or concurrent use with other depressant drugs like benzodiazepines commonly results in death from respiratory depression.[11]

Opioids act by binding to opioid receptors, which are found principally in the central and peripheral nervous system and the gastrointestinal tract. These receptors mediate both the psychoactive and the somatic effects of opioids. Opioid drugs include partial agonists, like the anti-diarrhea drug loperamide and antagonists like naloxegol for opioid-induced constipation, which do not cross the blood–brain barrier, but can displace other opioids from binding to those receptors in the myenteric plexus.

Because opioids are addictive and may result in fatal overdose, most are controlled substances. In 2013, between 28 and 38 million people used opioids illicitly (0.6% to 0.8% of the global population between the ages of 15 and 65).[12] In 2011, an estimated 4 million people in the United States used opioids recreationally or were dependent on them.[13] As of 2015, increased rates of recreational use and addiction are attributed to over-prescription of opioid medications and inexpensive illicit heroin.[14][15][16] Conversely, fears about overprescribing, exaggerated side effects, and addiction from opioids are similarly blamed for under-treatment of pain.[17][18]

Educational video on opioid dependence.
  1. ^ Ogura T, Egan TD (2013). "Chapter 15 – Opioid Agonists and Antagonists". Pharmacology and physiology for anesthesia : foundations and clinical application. Philadelphia, PA: Elsevier/Saunders. ISBN 978-1-4377-1679-5. Archived from the original on 26 March 2019. Retrieved 19 July 2017.
  2. ^ Hemmings HC, Egan TD (2013). Pharmacology and Physiology for Anesthesia: Foundations and Clinical Application: Expert Consult – Online and Print. Elsevier Health Sciences. p. 253. ISBN 978-1437716795. Opiate is the older term classically used in pharmacology to mean a drug derived from opium. Opioid, a more modern term, is used to designate all substances, both natural and synthetic, that bind to opioid receptors (including antagonists).
  3. ^ "Opioids". www.hopkinsmedicine.org. 11 May 2023. Archived from the original on 2 November 2023. Retrieved 2 November 2023.
  4. ^ "Alcohol and Drug Policy Commission : Opiates or Opioids — What's the difference? : State of Oregon". www.oregon.gov. Archived from the original on 2 November 2023. Retrieved 2 November 2023.
  5. ^ a b Stromgaard K, Krogsgaard-Larsen P, Madsen U (2009). Textbook of Drug Design and Discovery, Fourth Edition. CRC Press. ISBN 9781439882405.
  6. ^ Walzer C (2014). "52 Nondomestic Equids". In West G, Heard D, Caulkett N (eds.). Zoo Animal and Wildlife Immobilization and Anesthesia. Vol. 51 (2nd ed.). Ames, USA: John Wiley & Sons. pp. 723, 727. doi:10.1002/9781118792919. ISBN 9781118792919. PMC 2871358. Retrieved 8 July 2019. {{cite book}}: |journal= ignored (help)
  7. ^ "Carfentanil". www.drugbank.ca. Archived from the original on 6 August 2020. Retrieved 8 July 2019.
  8. ^ Sterken J, Troubleyn J, Gasthuys F, Maes V, Diltoer M, Verborgh C (October 2004). "Intentional overdose of Large Animal Immobilon". European Journal of Emergency Medicine. 11 (5): 298–301. doi:10.1097/00063110-200410000-00013. PMID 15359207.
  9. ^ Lembke A (2016). Drug Dealer, MD: How Doctors Were Duped, Patients Got Hooked, and Why It's So Hard to Stop. Johns Hopkins University Press. ISBN 978-1421421407.
  10. ^ "Drug Facts: Prescription Opioids". NIDA. June 2019. Archived from the original on 12 June 2019. Retrieved 5 July 2019.
  11. ^ "FDA requires strong warnings for opioid analgesics, prescription opioid cough products, and benzodiazepine labeling related to serious risks and death from combined use". FDA. 31 August 2016. Archived from the original on 23 April 2019. Retrieved 1 September 2016.
  12. ^ "Status and Trend Analysis of Illict [sic] Drug Markets" (PDF). World Drug Report 2015. Archived (PDF) from the original on 27 June 2015. Retrieved 26 June 2015.
  13. ^ "Report III: FDA Approved Medications for the Treatment of Opiate Dependence: Literature Reviews on Effectiveness & Cost- Effectiveness, Treatment Research Institute". Advancing Access to Addiction Medications: Implications for Opioid Addiction Treatment. p. 41. Archived from the original on 24 February 2021. Retrieved 14 February 2016.
  14. ^ Tetrault JM, Butner JL (September 2015). "Non-Medical Prescription Opioid Use and Prescription Opioid Use Disorder: A Review". The Yale Journal of Biology and Medicine. 88 (3): 227–33. PMC 4553642. PMID 26339205.
  15. ^ Tarabar AF, Nelson LS (April 2003). "The resurgence and abuse of heroin by children in the United States". Current Opinion in Pediatrics. 15 (2): 210–5. doi:10.1097/00008480-200304000-00013. PMID 12640281. S2CID 21900231.
  16. ^ Gray E (4 February 2014). "Heroin Gains Popularity as Cheap Doses Flood the U.S". TIME.com. Archived from the original on 2 December 2020. Retrieved 12 February 2016.
  17. ^ Maltoni M (January 2008). "Opioids, pain, and fear". Annals of Oncology. 19 (1): 5–7. doi:10.1093/annonc/mdm555. PMID 18073220. Archived from the original on 10 September 2015. Retrieved 14 February 2016. [A] number of studies, however, have also reported inadequate pain control in 40%–70% of patients, resulting in the emergence of a new type of epidemiology, that of 'failed pain control', caused by a series of obstacles preventing adequate cancer pain management.... The cancer patient runs the risk of becoming an innocent victim of a war waged against opioid abuse and addiction if the norms regarding the two kinds of use (therapeutic or nontherapeutic) are not clearly distinct. Furthermore, health professionals may be worried about regulatory scrutiny and may opt not to use opioid therapy for this reason.
  18. ^ McCarberg BH (March 2011). "Pain management in primary care: strategies to mitigate opioid misuse, abuse, and diversion". Postgraduate Medicine. 123 (2): 119–30. doi:10.3810/pgm.2011.03.2270. PMID 21474900. S2CID 25935364.