Norcocaine
{{Short description|Chemical compound}}
{{distinguish|Nocaine}}
{{Drugbox
| verifiedrevid = 449585349
| IUPAC_name = methyl (1R,2R,3S,5S)-3-(benzoyloxy)-8-azabicyclo[3.2.1]octane-2-carboxylate
| image = Cocaine analog 218 (norcocaine).svg
| image_class = skin-invert-image
| width = 220
| tradename =
| legal_US = Schedule II
| addiction_liability = High
| routes_of_administration =
| CAS_number_Ref = {{cascite|correct|??}}
| CAS_number = 18717-72-1
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 3SL7BR2M1E
| ATC_prefix = none
| ATC_suffix =
| PubChem = 644007
| ChemSpiderID_Ref = {{chemspidercite|correct|chemspider}}
| ChemSpiderID = 559083
| C = 16
| H = 19
| N = 1
| O = 4
| smiles = COC(=O)[C@@H]1[C@H]2CC[C@H](N2)C[C@@H]1OC(=O)C3=CC=CC=C3
| StdInChI_Ref = {{stdinchicite|correct|chemspider}}
| StdInChI = 1S/C16H19NO4/c1-20-16(19)14-12-8-7-11(17-12)9-13(14)21-15(18)10-5-3-2-4-6-10/h2-6,11-14,17H,7-9H2,1H3/t11-,12+,13-,14+/m0/s1
| StdInChIKey_Ref = {{stdinchicite|correct|chemspider}}
| StdInChIKey = AYDBLCSLKNTEJL-RFQIPJPRSA-N
}}
Norcocaine is a minor metabolite of cocaine. It is the only confirmed pharmacologically active metabolite of cocaine,{{Cite web |url=http://mass-spec.chem.cmu.edu/VMSL/cocaine/ch_bg3.htm |title=Virtual Mass Spectrometry Laboratory: Cocaine in Hair |access-date=2008-01-14 |archive-url=https://web.archive.org/web/20070901210916/http://mass-spec.chem.cmu.edu/VMSL/cocaine/ch_bg3.htm |archive-date=2007-09-01 |url-status=dead }} although salicylmethylecgonine is also speculated to be an active metabolite. The local anesthetic potential of norcocaine has been shown to be higher than that of cocaine,{{cite journal | vauthors = Wang Q, Simpao A, Sun L, Falk JL, Lau CE | title = Contribution of the active metabolite, norcocaine, to cocaine's effects after intravenous and oral administration in rats: pharmacodynamics | journal = Psychopharmacology | volume = 153 | issue = 3 | pages = 341–52 | date = January 2001 | pmid = 11271407 | doi = 10.1007/s002130000568 | s2cid = 10708670 | url = http://www.cocaine.org/norcocaine/index.html }}{{cite journal | vauthors = Just WW, Hoyer J | title = The local anesthetic potency of norcocaine, a metabolite of cocaine | journal = Experientia | volume = 33 | issue = 1 | pages = 70–1 | date = January 1977 | pmid = 836425 | doi = 10.1007/BF01936761 | publisher = Birkhäuser | s2cid = 32483810 }} however cocaine continues to be more widely used. Norcocaine used for research purposes is typically synthesized from cocaine. Several methods for the synthesis have been described.{{cite journal| vauthors = Stenberg VI, Narain NK, Singh SP, Parmar SS |date=April 1976|title=An improved synthesis of norcocaine|journal=Journal of Heterocyclic Chemistry|volume=13|issue=2|pages=363–364|doi=10.1002/jhet.5570130231}}{{cite journal | vauthors = Lazer ES, Aggarwal ND, Hite GJ, Nieforth KA, Kelleher RT, Spealman RD, Schuster CR, Wolverton W | display-authors = 6 | title = Synthesis and biological activity of cocaine analogs I: N-alkylated norcocaine derivatives | journal = Journal of Pharmaceutical Sciences | volume = 67 | issue = 12 | pages = 1656–8 | date = December 1978 | pmid = 102759 | doi = 10.1002/jps.2600671204 }}
Legal status
The legal status of norcocaine is somewhat ambiguous. The US DEA does not list norcocaine as a controlled substance.{{cite web |url=http://www.deadiversion.usdoj.gov/schedules/orangebook/c_cs_alpha.pdf |title=Controlled Substances |author= |date=9 September 2014 |website=dea.gov |publisher=United States Drug Enforcement Administration, United States Department of Justice |access-date=8 December 2014 |archive-date=17 April 2016 |archive-url=https://web.archive.org/web/20160417085659/http://www.deadiversion.usdoj.gov/schedules/orangebook/c_cs_alpha.pdf |url-status=dead }} However, some suppliers of norcocaine, like Sigma-Aldrich, consider the drug to be a Schedule II drug (same as cocaine) for the purpose of their own sales.{{Cite web |last=B.S |first=Amanda Stevens |date=2022-06-05 |title= Symptoms & Risks Of Cocaine Use & Abuse |url=https://www.ascendantny.com/cocaine-overdose/ |access-date=2023-04-15 |language=en-US}}{{cite web |url=http://www.sigmaaldrich.com/catalog/product/sigma/n2279?lang=en®ion=US |title=Norcocaine |author= |website=sigmaaldrich.com |publisher=Sigma-Aldrich Co. LLC |access-date=8 December 2014}}
Toxicity
The LD50 of norcocaine has been studied in mice. When administered by the intraperitoneal route, the LD50 in mice was 40 mg/kg.{{cite journal | vauthors = Evans MA, Morarity T | title = Analysis of cocaine and cocaine metabolites by high pressure liquid chromatography | journal = Journal of Analytical Toxicology | volume = 4 | issue = 1 | pages = 19–22 | date = January 1980 | pmid = 6927046 | doi = 10.1093/jat/4.1.19 }}
Controversy
Some researchers have suggested that hair drug testing for cocaine use should include testing for metabolites like norcocaine.{{cite journal | vauthors = Cone EJ, Yousefnejad D, Darwin WD, Maguire T | title = Testing human hair for drugs of abuse. II. Identification of unique cocaine metabolites in hair of drug abusers and evaluation of decontamination procedures | journal = Journal of Analytical Toxicology | volume = 15 | issue = 5 | pages = 250–5 | date = 1991 | pmid = 1960975 | doi = 10.1093/jat/15.5.250 }} The basis for this suggestion is the potential for external contamination of hair during testing. There is considerable debate about whether current means of washing hair samples are sufficient for removing external contamination. Some researchers state the methods are sufficient,{{cite journal | vauthors = Koren G, Klein J, Forman R, Graham K | title = Hair analysis of cocaine: differentiation between systemic exposure and external contamination | journal = Journal of Clinical Pharmacology | volume = 32 | issue = 7 | pages = 671–5 | date = July 1992 | pmid = 1640006 | doi = 10.1002/j.1552-4604.1992.tb05780.x | s2cid = 39938511 }}{{cite news| vauthors = Baumgartner WA, Hill VA |title=Hair analysis for drugs of abuse: Decontamination issues.|agency=Recent Developments in Therapeutic Drug Monitoring and Clinical Toxicology|date=1992}} while others state, the residual contamination may result in a false positive test.{{cite journal| vauthors = Henderson GL, Harkey MR, Jones RT, Zhou C |title=Effect of External Contamination on the Analysis of Hair for Cocaine|journal=Paper Presented at the Joint Meeting of Forensic Toxicologists and the Canadian Society of Forensic Scientists, Montreal, Quebec, Canada|date=23 September 1991}}{{cite journal | vauthors = Welch MJ, Sniegoski LT, Allgood CC, Habram M | title = Hair analysis for drugs of abuse: evaluation of analytical methods, environmental issues, and development of reference materials | journal = Journal of Analytical Toxicology | volume = 17 | issue = 7 | pages = 389–98 | date = 1993 | pmid = 8309210 | doi = 10.1093/jat/17.7.389 }}{{cite journal | vauthors = Blank DL, Kidwell DA | title = External contamination of hair by cocaine: an issue in forensic interpretation | journal = Forensic Science International | volume = 63 | issue = 1–3 | pages = 145–56; discussion 157–60 | date = December 1993 | pmid = 8138216 | doi = 10.1016/0379-0738(93)90268-f }} Metabolites of cocaine, like norcocaine, in addition to cocaine, should be present in samples from drug users. Authors have stated that the metabolites should be present in any samples declared positive. Issues arise because the metabolites are present in only low concentrations. If the metabolites are present, it is possible for them to be from other contamination.{{cite journal | vauthors = Janzen K | title = Concerning norcocaine, ethylbenzoylecgonine, and the identification of cocaine use in human hair | journal = Journal of Analytical Toxicology |volume = 16 |issue = 6 |pages = 402 |date = 1992 |pmid = 1293409 |doi = 10.1093/jat/16.6.402 }}