Abstract
The antihelminthic drug Levamisole can enhance cocaine effects by conversion into the amphetamine-like drug aminorex. We describe an LC-MS method for the determination of levamisole and its metabolite aminorex in human urine. Selectivity is given, calibration curves were linear within the calibration range 2.5–250 ng/mL; limits of the method were LoD 0.51 ng/mL, LoQ 1.02 ng/mL for levamisole and LoD 0.65 ng/mL, LoQ 0.76 ng/mL for aminorex. Precision data was in accordance with the guidelines (intraday precision for aminorex ranged between 5.75 and 11.0 % for levamisole between 8.36 and 10.9 %; interday precision for levamisole 10.9–16.9 % and for aminorex 7.64–12.7 %; accuracy data for levamisole −1.96 to –14.3 % and for aminorex−11.9 to–18.5 %). The validated method was successfully applied to study the urinary excretion of levamisole after the administration of 100 mg of levamisole orally. Levamisole and aminorex could be detected in post-administration urine samples. Levamisole could be detected up to 39 h after ingestion, while aminorex was detectable up to 54 h. Maximum aminorex concentrations were 45 ng/mL urine. Further metabolites of levamisole after oral ingestion by means of liquid chromatography hybrid quadrupole time-of-flight high-resolution mass spectrometry (LC-QTOF-HRMS) were identified. Only 0.5 % of the ingested drug was quantified as unchanged levamisole in urine. Besides aminorex, five isomers of aminorex and 4 hydroxy-metabolites of aminorex or its isomers were found. Furthermore, levamisole is also hydroxylated and eliminated free or conjugated with sulfate or glucuronide into urine.
Similar content being viewed by others
References
Dillman RO (2011) Cancer immunotherapy. Cancer Biother Radiopharm 26:1–64
Schneider S, Meys F (2011) Analysis of illicit cocaine and heroin samples seized in Luxembourg from 2005–2010. Forensic Sci Int 212:242–246
Larocque A, Hoffman RS (2012) Levamisole in cocaine: unexpected news from an old acquaintance. Clin Toxicol (Phila) 50:231–241
Bertol E, Mari F, Milia MG, Politi L, Furlanetto S, Karch SB (2011) Determination of aminorex in human urine samples by GC-MS after use of levamisole. J Pharm Biomed Anal 55:1186–1189
Ho EN, Leung DK, Leung GN et al (2009) Aminorex and rexamino as metabolites of levamisole in the horse. Anal Chim Acta 638:58–68
Karch SB, Mari F, Bartolini V, Bertol E (2012) Aminorex poisoning in cocaine abusers. Int J Cardiol 158:344–346
Zhu NY, Legatt DF, Turner AR (2009) Agranulocytosis after consumption of cocaine adulterated with levamisole. Ann Intern Med 150:287–289
Wolford A, McDonald TS, Eng H et al (2012) Immune-mediated agranulocytosis caused by the cocaine adulterant levamisole: a case for reactive metabolite(s) involvement. Drug Metab Dispos 40:1067–1075
Buchanan JA, Lavonas EJ (2012) Agranulocytosis and other consequences due to use of illicit cocaine contaminated with levamisole. Curr Opin Hematol 19:27–31
Walsh NM, Green PJ, Burlingame RW, Pasternak S, Hanly JG (2010) Cocaine-related retiform purpura: evidence to incriminate the adulterant, levamisole. J Cutan Pathol 37:1212–1219
Farhat EK, Muirhead TT, Chaffins ML, Douglass MC (2010) Levamisole-induced cutaneous necrosis mimicking coagulopathy. Arch Dermatol 146:1320–1321
Wolford A, McDonald TS, Eng H et al (2012) Immune-mediated agranulocytosis caused by the cocaine adulterant levamisole: a case for reactive metabolite(s) involvement. Drug Metab Dispos 40:1067–1075
Heykants JMW&VPA. Levamisole pharmacokinetics in healthy volunteers and in cancer patients. A review of the data available until January 1990. Unpublished Report Serial No. R12564/117 from Janssen Research Foundation. Submitted to WHO by Janssen Pharmaceutica, Beerse, Belgium. 1990
Ho EN, Leung DK, Leung GN et al (2009) Aminorex and rexamino as metabolites of levamisole in the horse. Anal Chim Acta 638:58–68
Lynch KL, Dominy SS, Graf J, Kral AH (2011) Detection of levamisole exposure in cocaine users by liquid chromatography-tandem mass spectrometry. J Anal Toxicol 35:176–178
Bertol E, Mari F, Milia MG, Politi L, Furlanetto S, Karch SB (2011) Determination of aminorex in human urine samples by GC-MS after use of levamisole. J Pharm Biomed Anal 55:1186–1189
Ho EN, Leung DK, Leung GN et al (2009) Aminorex and rexamino as metabolites of levamisole in the horse. Anal Chim Acta 638:58–68
Trehy ML, Brown DJ, Woodruff JT et al (2011) Determination of levamisole in urine by gas chromatography–mass spectrometry. J Anal Toxicol 35:545–550
Woestenborghs R, Michielsen L, Heykants J (1981) Determination of levamisole in plasma and animal tissues by gas chromatography with thermionic specific detection. J Chromatogr 224:25–32
Kouassi E, Caille G, Lery L, Lariviere L, Vezina M (1986) Novel assay and pharmacokinetics of levamisole and p-hydroxylevamisole in human plasma and urine. Biopharm Drug Dispos 7:71–89
Shea JL (2012) Bioanalytical methods for quantitation of levamisole, a widespread cocaine adulterant. Clin Chem Lab Med 1–8
Ho EN, Leung DK, Leung GN et al (2009) Aminorex and rexamino as metabolites of levamisole in the horse. Anal Chim Acta 638:58–68
Peters FT, Drummer OH, Musshoff F (2007) Validation of new methods. Forensic Sci Int 165:216–224
Broecker S, Herre S, Wust B, Zweigenbaum J, Pragst F (2011) Development and practical application of a library of CID accurate mass spectra of more than 2,500 toxic compounds for systematic toxicological analysis by LC-QTOF-MS with data-dependent acquisition. Anal Bioanal Chem 400:101–117
Broecker S, Koch M, Pragst F (2011) Detection of metabolites in the general unknown screening of hair by LC-QTOF-MS. Ann Tox Anal 23:S1–S12
Peters F, Drummer O, Musshoff F. Anhang B zur Richtlinie der GTFCh zur Qualitätssicherung bei forensich-toxikologischen Untersuchungen: Anforderung an die Validierung von Analysensystemen. https://www.gtfch.org/cms/files/GTFCh_Richtlinie_Anhang%20B_Validierung_Version%201.pdf, accessed 12.12.2011: 2011
Matuszewski BK, Constanzer ML, Chavez-Eng CM (1998) Matrix effect in quantitative LC/MS/MS analyses of biological fluids: A method for determination of finasteride in human plasma at picogram per milliliter concentrations. Anal Chem 70:882–889
DIN EN ISO/IEC 32645. 1994
Lynch KL, Dominy SS, Graf J, Kral AH (2011) Detection of levamisole exposure in cocaine users by liquid chromatography-tandem mass spectrometry. J Anal Toxicol 35:176–178
Bertol E, Mari F, Milia MG, Politi L, Furlanetto S, Karch SB (2011) Determination of aminorex in human urine samples by GC-MS after use of levamisole. J Pharm Biomed Anal 55:1186–1189
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Hess, C., Ritke, N., Broecker, S. et al. Metabolism of levamisole and kinetics of levamisole and aminorex in urine by means of LC-QTOF-HRMS and LC-QqQ-MS. Anal Bioanal Chem 405, 4077–4088 (2013). https://doi.org/10.1007/s00216-013-6829-x
Received:
Revised:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00216-013-6829-x