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Harvesting the poppy pod.

Opiate is a 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 in the brain (including antagonists).[1] Opiates are alkaloid compounds naturally found in the opium poppy plant Papaver somniferum.[2] The psychoactive compounds found in the opium plant include morphine, codeine, and thebaine. All opioids, like opiates, are considered drugs of high abuse potential and are listed on various "Substance-Control Schedules" under the Uniform Controlled Substances Act of the United States.

In 2013, between 13 and 20 million people used opiates recreationally (0.3% to 0.4% of the global population between the ages of 15 and 65).[3]

Contents

OverviewEdit

 
Chemical structure of morphine

Opiates belong to the large biosynthetic group of benzylisoquinoline alkaloids, and are so named because they are naturally occurring alkaloids found in the opium poppy. The major psychoactive opiates are morphine, codeine, and thebaine. Papaverine, noscapine, and approximately 24 other alkaloids are also present in opium but have little to no effect on the human central nervous system, and as such are not considered to be opiates. Very small quantities of hydrocodone and hydromorphone are detected in assays of opium on rare occasions; it appears to be produced by the plant under circumstances and by processes which are not understood at this time and may include the action of bacteria.[citation needed] Dihydrocodeine, oxymorphol, oxycodone, oxymorphone, metopon and possibly other derivatives of morphine and/or hydromorphone also are found in trace amounts in opium.[citation needed]

Despite morphine being the most medically significant opiate, larger quantities of codeine are consumed medically, most of it synthesized from morphine. Codeine has greater and more predictable oral bioavailability, making it easier to titrate the dose. Codeine also has less abuse potential than morphine, and because it is milder, larger doses of codeine are required.[4]

 
Morphine addiction cure advertisement in the year 1900

Opiate withdrawal syndrome effects are associated with the abrupt cessation or reduction of prolonged opiate usage.

SynthesisEdit

While the full synthesis of opioids from naphthoquinone (Gates synthesis) or other simple organic starting materials is possible, they are tedious and uneconomical processes. Therefore, most of the opiate-type analgesics in use today are either extracted from Papaver somniferum or synthesized from those opiates, especially thebaine.[5]

In 2015 researches reported successful biosynthesis of thebaine and hydrocodone using genetically modified yeast. Once scaled for commercial use the process would cut production time from a year to several days and could reduce costs by 90%.[6][7]

Esters of morphineEdit

Global estimates of illegal drug users in 2014
(in millions of users)[8]
Substance Best
estimate
Low
estimate
High
estimate
Amphetamine-
type stimulants
35.65 15.34 55.90
Cannabis 182.50 127.54 233.65
Cocaine 18.26 14.88 22.08
Ecstasy 19.40 9.89 29.01
Opiates 17.44 13.74 21.59
Opioids 33.12 28.57 38.52

Heroin is one of several semi-synthetic opioids derived from the morphine. Although sometimes not considered opiates, as they are not directly derived from natural opium, they are commonly referred to as opiates.[citation needed] Heroin (diacetylmorphine) is a morphine prodrug; it is metabolized by the liver into morphine after administration. One of the major metabolites of heroin, 6-monoacetylmorphine (6-MAM), is also a morphine prodrug. Nicomorphine (morphine dinicotinate), dipropanoylmorphine (morphine dipropionate), desomorphine (di-hydro-desoxy-morphine), methyldesorphine, acetylpropionylmorphine, dibenzoylmorphine, diacetyldihydromorphine, and several others are also derived from morphine.[9]

See alsoEdit

ReferencesEdit

  1. ^ Hemmings, Hugh C.; Egan, Talmage D. (2013). Pharmacology and Physiology for Anesthesia: Foundations and Clinical Application: Expert Consult - Online and Print. Elsevier Health Scienc,es. p. 253. ISBN 1437716792. 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). 
  2. ^ "Opiate - Definitions from Dictionary.com". dictionary.reference.com. Retrieved 2008-07-04. 
  3. ^ "Status and Trend Analysis of Illict [sic] Drug Markets". World Drug Report 2015 (pdf). Retrieved 26 June 2015. 
  4. ^ "Canadian Guideline for Opioid Use for Pain — Appendix B-8: Opioid Conversion and Brand Availability in Canada". nationalpaincentre.mcmaster.ca. Retrieved 2016-04-18. 
  5. ^ Synthesis of morphine alkaloids Presentation School of Chemical Sciences, University of Illinois at Urbana-Champaign retrieved 12-02-2010
  6. ^ Galanie, Stephanie; Thodey, Kate; Trenchard, Isis J.; Interrante, Maria Filsinger; Smolke, Christina D. (2015-09-04). "Complete biosynthesis of opioids in yeast". Science. 349 (6252): 1095–1100. doi:10.1126/science.aac9373. ISSN 0036-8075. PMC 4924617 . PMID 26272907. 
  7. ^ Mobley, Emily (2015-08-13). "Yeast cells genetically modified to create morphine-like painkiller". The Guardian. ISSN 0261-3077. Retrieved 2016-04-17. 
  8. ^ "Statistical tables". World Drug Report 2016 (pdf). Vienna, Austria: United Nations Office on Drugs and Crime. 2016. ISBN 9789210578622. Retrieved 1 August 2016. 
  9. ^ "Esters of Morphine". www.unodc.org. United Nations Office on Drugs and Crime. Retrieved 10 March 2012. 

External linksEdit