U-47700

Last updated
U-47700
U-47700 fixedstructure.svg
U-47700.png
Legal status
Legal status
Identifiers
  • 3,4-Dichloro-N-[(1R,2R)-2-(dimethylamino)cyclohexyl]-N-methylbenzamide
CAS Number
PubChem CID
ChemSpider
UNII
KEGG
ChEMBL
CompTox Dashboard (EPA)
Chemical and physical data
Formula C16H22Cl2N2O
Molar mass 329.27 g·mol−1
3D model (JSmol)
  • ClC1=C(C=CC(=C1)C(=O)N(C)[C@@H]2CCCC[C@H]2N(C)C)Cl
  • InChI=1S/C16H22Cl2N2O/c1-19(2)14-6-4-5-7-15(14)20(3)16(21)11-8-9-12(17)13(18)10-11/h8-10,14-15H,4-7H2,1-3H3/t14-,15-/m1/s1
  • Key:JGPNMZWFVRQNGU-HUUCEWRRSA-N
 X mark.svgNYes check.svgY  (what is this?)    (verify)

U-47700, also known as U4, pink heroin, pinky, and pink, is an opioid analgesic drug developed by a team at Upjohn in the 1970s [1] which has around 7.5 times the potency of morphine in animal models. [2] [3] [4]

Contents

Physical Sample of U-47700 Sample of U-47700.png
Physical Sample of U-47700

U-47700 is a structural isomer of the earlier opioid AH-7921 [6] and the result of a great deal of work elucidating the quantitative structure–activity relationship of the scaffold. Upjohn looked for the key moieties which gave the greatest activity [7] and posted over a dozen patents on related compounds, each optimizing one moiety [8] [9] [10] [11] [12] [13] [14] [15] until they discovered that U-47700 was the most active. [16]

U-47700 became the lead compound of selective kappa-opioid receptor ligands such as U-50488, U-51754 (containing a pyrrolidine rather than a dimethylamine substituent) and U-69,593, which share very similar structures. [17] [18] Although not used medically, the selective kappa ligands are used in research. [19] [20]

Pharmacology

U-47700 is an agonist of the μ-opioid receptor (Ki11.1 ± 0.4 nM) and possesses significantly lower affinity for the κ-opioid receptor (Ki = 287 ± 24 nM) and δ-opioid receptor (Ki = 1220 ± 82 nM). U-47700 is approximately 10-fold more potent than morphine in rats, although the binding of U-47700 is 2–4 times weaker than morphine at all three opioid receptors. [21]

The metabolism of U-47700 in humans involves mono- and didesmethylation followed by hydroxylation. [22] The desmethyl metabolites of U-47700 have negligible affinity for the opioid receptors and are not thought to contribute to the activity of U-47700. [23] [24]

Side effects

U-47700 has never been studied in humans, but it would be expected to produce effects similar to those of other potent opioid agonists, including strong analgesia, sedation, euphoria, constipation, itching and respiratory depression which could be harmful or fatal. [25] [26] [27] [28] [29] [30] [31] [32] Tachycardia was another side effect encountered with U-47700 use. [32] Tolerance and dependence would be expected to develop. [33]

Deaths

Combined consumption of U-47700 with fentanyl and flubromazepam caused one fatality each in Belgium and Germany, respectively. [34] [35] [36] One death was reported in Ireland [37] and another one in Italy. [38] 17 opioid overdoses and several deaths in the United States had initially been associated with U-47700 in April 2016. [39] As of September 2016 at least 15 fatalities were confirmed. By December 2017, at least 46 fatalities had been associated with the use of U-47700. [40] [41] [42] [43] [44] [45] [46]

U-47700 was found in combination with fentanyl during the autopsy of the American artist Prince in 2016. [47]

Detection in biological fluids

U-47700 may be measured in serum, plasma, blood or urine to monitor for abuse, confirm a diagnosis of poisoning, or assist in a medicolegal death investigation. Serum or blood U-47700 concentrations are expected to be in a range of 10–250 μg/L in intoxicated patients and 100–1,500 μg/L in deceased victims of acute overdosage. The detection usually involves analysis by liquid chromatography-mass spectrometry. [48]

Society and culture

Common street names for U-47700 include pinky, pink, and U4. [49]

Following its sale as a designer drug, U-47700 was made illegal in Sweden on January 26, 2016. [50]

U-47700 was emergency scheduled in Ohio on May 3, 2016, by executive order of Governor John Kasich. [51]

U-47700 was emergency scheduled in Florida on September 27, 2016, by an emergency rule of Florida Attorney General Pam Bondi. [52]

Responding to a perceived threat to public health and safety, the U.S. Drug Enforcement Administration has placed U-47700 into Schedule I of the Controlled Substances Act, effective November 14, 2016. [53] In April 2018, U-47700 was placed into Schedule I indefinitely. [54]

U-47700 was placed into Schedule 1 of South Dakota's Controlled Substance Schedule. It was signed by Governor Daugaard on February 9, 2017. [55]

U-47700 was made a Class A, Schedule 1 drug under the Misuse of Drugs Act in the UK in 2017. [56]

U-47700 is the title of a 2021 Dutch sci-fi short film by director Erasmo de la Parra. [57] In the film, the characters are addicted to a new drug containing the substance U-47700.

See also

Related Research Articles

<span class="mw-page-title-main">Carfentanil</span> Synthetic opioid analgesic

Carfentanil or carfentanyl, sold under the brand name Wildnil, is an extremely potent opioid analgesic used in veterinary medicine to anesthetize large animals such as elephants and rhinoceroses. It is typically administered in this context by tranquilizer dart. Carfentanil has also been used in humans to image opioid receptors. It has additionally been used as a recreational drug, typically by injection, insufflation, or inhalation. Deaths have been reported in association with carfentanil.

<span class="mw-page-title-main">JTC-801</span> Chemical compound

JTC-801 is an opioid analgesic drug used in scientific research.

<span class="mw-page-title-main">U-50488</span> Chemical compound

U-50488 is a drug which acts as a highly selective κ-opioid agonist, but without any μ-opioid antagonist effects. It has analgesic, diuretic and antitussive effects, and reverses the memory impairment produced by anticholinergic drugs. U-50488 was one of the first selective kappa agonists invented and research on its derivatives has led to the development of a large family of related compounds. This compound has never received FDA approval and there are no reported human cases in the literature involving an U-50488 overdose.

<span class="mw-page-title-main">Arylcyclohexylamine</span> Class of chemical compounds

Arylcyclohexylamines, also known as arylcyclohexamines or arylcyclohexanamines, are a chemical class of pharmaceutical, designer, and experimental drugs.

<span class="mw-page-title-main">Bromadoline</span> Opioid analgesic drug

Bromadoline (U-47931E) is an opioid analgesic selective for the μ-opioid receptor developed by the Upjohn company in the 1970s. The drug has a potency lying between that of codeine and morphine, being slightly stronger than pentazocine. Bromadoline is related to AH-7921 and U-47700.

<span class="mw-page-title-main">AH-7921</span> Opioid analgesic

AH-7921 (Doxylam) is an opioid analgesic drug selective for the μ-opioid receptor, having around 90% the potency of morphine when administered orally. It was discovered in the 1970s by a team at Allen and Hanburys located in the United Kingdom. The drug is considered a new psychoactive substance (NPS) in which it is synthetically created in laboratories to mimic that of controlled substances. The substance has also been sold on the internet since 2012 as a "research chemical". When sold online it may be called the alternative name doxylam, not to be confused with doxylamine. AH-7921 has never progressed to clinical trials. The DEA is not aware of any medical usage in the United States, and has not insisted the Health and Human Services department (HHS) to conduct any medical research of the substance's uses.

<span class="mw-page-title-main">MT-45</span> Chemical compound

MT-45 (IC-6) is an opioid analgesic drug invented in the 1970s by Dainippon Pharmaceutical Co. It is chemically a 1-substituted-4-(1,2-diphenylethyl) piperazine derivative, which is structurally unrelated to most other opioid drugs. Racemic MT-45 has around 80% the potency of morphine, with almost all opioid activity residing in the (S) enantiomer. It has been used as a lead compound from which a large family of potent opioid drugs have been developed, including full agonists, partial agonists, and antagonists at the three main opioid receptor subtypes. Fluorinated derivatives of MT-45 such as 2F-MT-45 are significantly more potent as μ-opioid receptor agonists, and one of its main metabolites 1,2-diphenylethylpiperazine also blocks NMDA receptors.

<span class="mw-page-title-main">Butyrfentanyl</span> Synthetic opioid analgesic

Butyrfentanyl or butyrylfentanyl is a potent short-acting synthetic opioid analgesic drug. It is an analog of fentanyl with around one quarter of its potency. One of the first mentions of this drug can be found in document written by The College on Problem of Drug Dependence, where it is mentioned as N-butyramide fentanyl analog. This document also states that the article describing its clinical effects was published in 1987. It is an agonist for the μ-opioid receptors.

<span class="mw-page-title-main">U-77891</span> Chemical compound

U-77891 is an opioid analgesic drug that was first synthesized in 1983 by the Upjohn company. It was originally synthesized to prove that the removal of a single methylene spacer of the benzamide would alter a κ-opioid receptor agonist such as U-50488 into an μ-opioid receptor agonist, as well as producing a semi-rigid derivative of U-47700. This would help elucidate the relative positions of the hydrogen-bond acceptors and substituted aromatic system to find the compound with the lowest Ki value in a series of benzamide opioids dating back to the 1970s. The original work found a mixture of agonists and antagonists.

<span class="mw-page-title-main">Furanylfentanyl</span> Opioid analgesic

Furanylfentanyl (Fu-F) is an opioid analgesic that is an analog of fentanyl and has been sold as a designer drug. It has an ED50 value of 0.02 mg/kg in mice. This makes it approximately one fifth as potent as fentanyl.

<span class="mw-page-title-main">Acrylfentanyl</span> Opioid analgesic

Acrylfentanyl (also known as acryloylfentanyl) is a highly potent opioid analgesic that is an analog of fentanyl and has been sold online as a designer drug. In animal studies the IC50 (the half maximal inhibitory concentration for acrylfentanyl to displace naloxone) is 1.4 nM, being slightly more potent than fentanyl itself (1.6 nM) as well as having a longer duration of action.

<span class="mw-page-title-main">Bucinnazine</span> Opioid analgesic drug

Bucinnazine is an opioid analgesic drug that was widely used in China to treat pain in cancer patients as of 1986. It is one of the most potent compounds among a series of piperazine-amides first synthesized and reported in Japan in the 1970s. Bucinnazine has analgesic potency comparable to that of morphine but with a relatively higher therapeutic index.

<span class="mw-page-title-main">4-Fluoroisobutyrfentanyl</span> Chemical compound

4-Fluoroisobutyrylfentanyl (also known as 4-FIBF and p-FIBF) is an opioid analgesic that is an analog of butyrfentanyl and structural isomer of 4-Fluorobutyrfentanyl and has been sold online as a designer drug. It is closely related to 4-fluorofentanyl, which has an EC50 value of 4.2 nM for the human μ-opioid receptor. 4-fluoroisobutyrylfentanyl is a highly selective μ-opioid receptor agonist whose analgesic potency is almost ten times of that reported for morphine.

<span class="mw-page-title-main">Metonitazene</span> Chemical compound (analgesic drug)

Metonitazene is an analgesic compound related to etonitazene, which was first reported in 1957, and has been shown to have approximately 1000 times the potency of morphine by central routes of administration, but if used orally it has been shown to have approximately 10 times the potency of morphine.

<span class="mw-page-title-main">Butyrylnorfentanyl</span> Synthetic opioid analgesic metabolite

Butyrnorfentanyl or butyrylnorfentanyl is an inactive synthetic opioid analgesic drug precursor. It is an analog of fentanyl.

<span class="mw-page-title-main">3,4-MDO-U-47700</span> Opioid analgesic designer drug

3,4-MDO-U-47700 is an opioid analgesic which has been sold as a designer drug, first appearing in 2017 after U-47700 itself was banned in various jurisdictions. It is less potent than U-47700 but is still a full agonist at the μ-opioid receptor, with slightly higher potency than morphine. It is illegal in Virginia.

<span class="mw-page-title-main">U-48800</span> Chemical compound

U-48800 is an opioid analgesic which has been sold as a designer drug. Unlike U-47700, it is primarily active as a kappa opioid receptor agonist with only moderate affinity at the mu opioid receptor. Nevertheless, it has still appeared on the recreational drug market, often as a component of combinations with other drugs, and has been linked to numerous drug overdose cases.

Utopioids are a class of synthetic opioid analgesic drugs first developed in the 1970s by the pharmaceutical company Upjohn. However, they were never marketed for medical use. Some compounds from this class have been used for scientific research as model kappa opioid receptor agonists. In the mid-2010s, one mu opioid receptor selective compound from this class, U-47700, re-emerged as a designer drug and became widely sold around the world for several years before being banned in various jurisdictions from 2016 onwards. Following the prohibition of U-47700, a number of related compounds have continued to appear on illicit drug markets. They are often marketed online or included as components in mixtures sold under the guise of "street heroin." U-47700 itself is the most potent mu opioid agonist from this class, around 7-10x the potency of morphine. Some other compounds such as 3,4-MDO-U-47700 and N-Ethyl-U-47700 retain similar mu selectivity but with lower potency similar to that of morphine, or have a mixture of mu and kappa mediated effects, such as U-48800. Most utopioid derivatives are however selective kappa agonists, which may have limited abuse potential as dissociative hallucinogens, but do not alleviate withdrawal distress in opioid dependent individuals or maintain addiction in a typical sense. Nevertheless, this has not stopped them from being sold as designer drugs, and a number of these compounds are now banned in many jurisdictions alongside U-47700 itself.

References

  1. Szmuszkovicz J (4 July 1978). "Patent US4098904 - Analgesic N-(2-aminocycloaliphatic)benzamides".
  2. Cheney BV, Szmuszkovicz J, Lahti RA, Zichi DA (December 1985). "Factors affecting binding of trans-N-[2-(methylamino)cyclohexyl]benzamides at the primary morphine receptor". Journal of Medicinal Chemistry. 28 (12): 1853–1864. doi:10.1021/jm00150a017. PMID   2999404.
  3. Harper NJ, Veitch GB, Wibberley DG (November 1974). "1-(3,4-Dichlorobenzamidomethyl)cyclohexyldimethylamine and related compounds as potential analgesics". Journal of Medicinal Chemistry. 17 (11): 1188–1193. doi:10.1021/jm00257a012. PMID   4416926.
  4. Szmuszkovicz J, Von Voigtlander PF (October 1982). "Benzeneacetamide amines: structurally novel non-m mu opioids". Journal of Medicinal Chemistry. 25 (10): 1125–1126. doi:10.1021/jm00352a005. PMID   6128415.
  5. Alzghari SK, Fleming SW, Rambaran KA, Long JE, Burkhart S, An J, Furmaga J (October 2017). "U-47700: An Emerging Threat". Cureus. 9 (10): e1791. doi: 10.7759/cureus.1791 . PMC   5741271 . PMID   29282436.
  6. Brittain RT, Kellett DN, Neat ML, Stables R (September 1973). "Proceedings: Anti-nociceptive effects in N-substituted cyclohexylmethylbenzamides". British Journal of Pharmacology. 49 (1): 158P–159P. doi:10.1111/j.1476-5381.1973.tb08279.x. PMC   1776456 . PMID   4207044.
  7. Michalson ET, Szmuszkovicz J (1989). "Medicinal agents incorporating the 1,2-diamine functionality". Progress in Drug Research. Vol. 33. Birkhäuser Basel. pp. 135–149. doi:10.1007/978-3-0348-9146-2_6. ISBN   9783034891462. PMID   2687936.{{cite book}}: |journal= ignored (help)
  8. Mullins DD (28 June 1966). "Patent US US3258489 - N-(1-aminocyclohexylmethyl)anilines and N-(1-nitrocyclohexylmethyl)anilines".
  9. Harper NJ, Veitch GB (17 August 1976). "Patent US3975443 - 1-(3,4-dichlorobenzamidomethyl)-cyclohexyldimethylamine".
  10. Szmuszkovicz J (3 March 1970). "Patent US3499033 - Ethers of α-phenyl-2-aminocycloalkanemethanols".
  11. Szmuszkovicz J (5 May 1970). "Patent US3510492 - 2-anilino and 2-anilinomethyl cycloalkylamines".
  12. Rynbrandt RH, Skaletzky LL (7 March 1972). "Patent US3647804 - Cycloalkanecarboxamides".
  13. Roll W (23 July 1974). "Patent US3825595 - N-cyclopentyl-N-2-hydroxyalkyl-ring-substituted benzamides".
  14. Harper NJ, Veitch GB (20 September 1977). "Patent US4049663 - Ethylene diamine derivatives".
  15. Collins RJ, Kaplan LJ, Ludens JH, Von Voigtlander PF (9 April 1982). "Patent US4463013 - Oxygen substituted amino-cyclohexyl-benzeneacetamides and -benzamides as water diuretic drugs".
  16. Casy AF, Parfitt RT (1986). "Miscellaneous Groups of Analgesics". Opioid Analgesics. Springer US. pp. 385–403. doi:10.1007/978-1-4899-0585-7_11. ISBN   9781489905857.
  17. Szmuszkovicz J, Zhao S, Totleben MJ, Mizsak SA, Freeman JP (2000). "Phenanthridone Analogs of the Opiate Agonist U-47,700 in the trans-1,2-Diaminocyclohexane Benzamide Series". Heterocycles. 52 (1): 325–332. doi: 10.3987/com-99-s27 .
  18. Loew G, Lawson J, Toll L, Frenking G, Berzetei-Gurske I, Polgar W (1988). "Structure activity studies of two classes of beta-amino-amides: the search for kappa-selective opioids" (PDF). NIDA Research Monograph. 90: 144–151. PMID   2855852.
  19. Szmuszkovicz J (1999). "U-50,488 and the к receptor: A personalized account covering the period 1973 to 1990". Progress in Drug Research. Vol. 52. Birkhäuser Basel. pp. 167–195. doi:10.1007/978-3-0348-8730-4_4. ISBN   9783034887304. PMID   10396128.{{cite book}}: |journal= ignored (help)
  20. Tsibulnikov SY, Maslov LN, Mukhomedzyanov AV, Krylatov AV, Tsibulnikova MR, Lishmanov YB (October 2015). "Prospects of Using of κ-Opioid Receptor Agonists U-50,488 and ICI 199,441 for Improving Heart Resistance to Ischemia/Reperfusion". Bulletin of Experimental Biology and Medicine. 159 (6): 718–721. doi:10.1007/s10517-015-3057-8. PMID   26519268. S2CID   1046853.
  21. Truver MT, Smith CR, Garibay N, Kopajtic TA, Swortwood MJ, Baumann MH (October 2020). "Pharmacodynamics and pharmacokinetics of the novel synthetic opioid, U-47700, in male rats". Neuropharmacology. 177: 108195. doi:10.1016/j.neuropharm.2020.108195. PMC   7554234 . PMID   32533977. S2CID   219559700.
  22. Krotulski AJ, Mohr AL, Papsun DM, Logan BK (January 2018). "Metabolism of novel opioid agonists U-47700 and U-49900 using human liver microsomes with confirmation in authentic urine specimens from drug users". Drug Testing and Analysis. 10 (1): 127–136. doi: 10.1002/dta.2228 . PMID   28608586.
  23. Nordmeier F, Cannaert A, Stove CP, Schmidt PH, Meyer MR, Schaefer N (April 2022). "Are the N-demethylated metabolites of U-47700 more active than their parent compound? In vitro μ-opioid receptor activation of N-desmethyl-U-47700 and N,N-bisdesmethyl-U-47700". Drug Testing and Analysis. 14 (4): 713–717. doi:10.1002/dta.3182. hdl: 1854/LU-8751266 . PMID   34669261.
  24. Truver MT, Smith CR, Garibay N, Kopajtic TA, Swortwood MJ, Baumann MH (October 2020). "Pharmacodynamics and pharmacokinetics of the novel synthetic opioid, U-47700, in male rats". Neuropharmacology. 177: 108195. doi:10.1016/j.neuropharm.2020.108195. PMC   7554234 . PMID   32533977. S2CID   219559700.
  25. Davis TL (9 March 2016). "New Synthetic Opioid Surfaces in North Texas". NBCDFW.
  26. Jones MJ, Hernandez BS, Janis GC, Stellpflug SJ (January 2017). "A case of U-47700 overdose with laboratory confirmation and metabolite identification". Clinical Toxicology. 55 (1): 55–59. doi:10.1080/15563650.2016.1209767. PMID   27549165. S2CID   27920117.
  27. Domanski K, Kleinschmidt KC, Schulte JM, Fleming S, Frazee C, Menendez A, Tavakoli K (January 2017). "Two cases of intoxication with new synthetic opioid, U-47700". Clinical Toxicology. 55 (1): 46–50. doi:10.1080/15563650.2016.1209763. PMID   27432224. S2CID   46228909.
  28. Ruan X, Chiravuri S, Kaye AD (September 2016). "Comparing fatal cases involving U-47700". Forensic Science, Medicine, and Pathology. 12 (3): 369–371. doi:10.1007/s12024-016-9795-8. PMID   27421264. S2CID   24201474.
  29. Elliott SP, Brandt SD, Smith C (August 2016). "The first reported fatality associated with the synthetic opioid 3,4-dichloro-N-[2-(dimethylamino)cyclohexyl]-N-methylbenzamide (U-47700) and implications for forensic analysis" (PDF). Drug Testing and Analysis. 8 (8): 875–879. doi:10.1002/dta.1984. PMID   27232154. S2CID   205762837.
  30. Armenian P, Olson A, Anaya A, Kurtz A, Ruegner R, Gerona RR (January 2017). "Fentanyl and a Novel Synthetic Opioid U-47700 Masquerading as Street "Norco" in Central California: A Case Report". Annals of Emergency Medicine. 69 (1): 87–90. doi:10.1016/j.annemergmed.2016.06.014. PMID   27473610.
  31. Helander A, Bäckberg M (January 2017). "New Psychoactive Substances (NPS) - the Hydra monster of recreational drugs". Clinical Toxicology. 55 (1): 1–3. doi:10.1080/15563650.2016.1217003. PMID   27549399. S2CID   35645218.
  32. 1 2 Rambaran KA, Fleming SW, An J, Burkhart S, Furmaga J, Kleinschmidt KC, et al. (October 2017). "U-47700: A Clinical Review of the Literature". The Journal of Emergency Medicine. 53 (4): 509–519. doi:10.1016/j.jemermed.2017.05.034. PMID   28911989.
  33. Kimergård A, Breindahl T, Hindersson P, Deluca P (October 2016). "Tampering of opioid analgesics: a serious challenge for public health?". Addiction. 111 (10): 1701–1702. doi: 10.1111/add.13436 . PMID   27273814.
  34. Coopman V, Blanckaert P, Van Parys G, Van Calenbergh S, Cordonnier J (September 2016). "A case of acute intoxication due to combined use of fentanyl and 3,4-dichloro-N-[2-(dimethylamino)cyclohexyl]-N-methylbenzamide (U-47700)". Forensic Science International. 266: 68–72. doi:10.1016/j.forsciint.2016.05.001. hdl: 1854/LU-8509152 . PMID   27235591.
  35. "Twee doden in België door overdosis met fentanylpleisters" (in Dutch). Deredactie. 29 January 2016.
  36. Koch K, Auwärter V, Hermanns-Clausen M, Wilde M, Neukamm MA (April 2018). "Mixed intoxication by the synthetic opioid U-47700 and the benzodiazepine flubromazepam with lethal outcome: Pharmacokinetic data". Drug Testing and Analysis. 10 (8): 1336–1341. doi:10.1002/dta.2391. PMID   29637722.
  37. "Young people playing Russian roulette with drugs, warns coroner". The Irish Times .
  38. "Torino, ucciso dalla droga comprata online: la prima vittima italiana dell'U47700". LaStampa.it (in Italian). Retrieved 2017-10-20.
  39. Zalkind S (11 April 2016). "Synthetic opiate makers stay step ahead of US drug laws as overdose cases rise". The Guardian. ISSN   0261-3077.
  40. Draper B (6 June 2016). "New synthetic drug U-47700 has states rushing to stop spread". Associated Press.
  41. Schneir A, Metushi IG, Sloane C, Benaron DJ, Fitzgerald RL (January 2017). "Near death from a novel synthetic opioid labeled U-47700: emergence of a new opioid class". Clinical Toxicology. 55 (1): 51–54. doi:10.1080/15563650.2016.1209764. PMID   27448790. S2CID   25206275.
  42. Mohr AL, Friscia M, Papsun D, Kacinko SL, Buzby D, Logan BK (November 2016). "Analysis of Novel Synthetic Opioids U-47700, U-50488 and Furanyl Fentanyl by LC-MS/MS in Postmortem Casework". Journal of Analytical Toxicology. 40 (9): 709–717. doi: 10.1093/jat/bkw086 . PMID   27590036.
  43. "19 Recent Deaths Associated With Synthetic Opioids; State Officials Urge Awareness". NC Department of Health and Human Services. 24 March 2016.
  44. Drug Enforcement Administration (DEA) (7 September 2016). "Proposed Rule: Schedules of Controlled Substances: Temporary Placement of U-47700 Into Schedule I". Federal Register.
  45. Krotulski AJ, Mohr AL, Papsun DM, Logan BK (January 2018). "Metabolism of novel opioid agonists U-47700 and U-49900 using human liver microsomes with confirmation in authentic urine specimens from drug users". Drug Testing and Analysis. 10 (1): 127–136. doi: 10.1002/dta.2228 . PMID   28608586.
  46. Moody MT, Diaz S, Shah P, Papsun D, Logan BK (September 2018). "Analysis of fentanyl analogs and novel synthetic opioids in blood, serum/plasma, and urine in forensic casework". Drug Testing and Analysis. 10 (9): 1358–1367. doi:10.1002/dta.2393. PMID   29633785. S2CID   4758125.
  47. "Furanyl Fentanyl Joins U-47,700 As The Second Illicit Opioid Banned By DEA In November". Forbes .
  48. Baselt, R. (2017) Disposition of Toxic Drugs and Chemicals in Man, 11th edition, Biomedical Publications, Foster City, CA, pp. 2208.
  49. "Pinky". pubchem.ncbi.nlm.nih.gov. National Library of Medicine. Retrieved 16 July 2020.
  50. "31 nya ämnen kan klassas som narkotika eller hälsofarlig vara" (in Swedish). Folkhälsomyndigheten. November 2015.
  51. Kasich JR (May 3, 2016). "Executive Order 2016-01K" (PDF). Governor of Ohio.
  52. "News Release - Attorney General Bondi Outlaws Deadly Synthetic Drug". www.myfloridalegal.com. Retrieved 2016-09-27.
  53. DEA Public Affairs (November 11, 2016). "46 confirmed deaths linked to dangerous opioid in '15 and '16 spark emergency action". DEA. Archived from the original on June 4, 2018. Retrieved November 11, 2016.
  54. "Schedules of Controlled Substances: Placement of Butyryl Fentanyl and U-47700 Into Schedule I". Federal Register. 20 April 2018.
  55. South Dakota Legislature. "House Bill No. 1041" (PDF). Governor Dauggard of South Dakota.
  56. "EXPLANATORY MEMORANDUM TO THE MISUSE OF DRUGS ACT 1971 (AMENDMENT) ORDER 2017" (PDF).
  57. Filmaffinity U-47700 (S) (2021) , retrieved 2022-05-16