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Ai J, Li J, Chang AK, Pei Y, Li H, Liu K, Li R, Xu L, Wang N, Liu Y, Su W, Liu W, Wang T, Jiang Z, Chen L, Liang X. Toxicokinetics and bioavailability of indoxacarb enantiomers and their new metabolites in rats. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2024; 203:106024. [PMID: 39084783 DOI: 10.1016/j.pestbp.2024.106024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2024] [Revised: 07/03/2024] [Accepted: 07/10/2024] [Indexed: 08/02/2024]
Abstract
Indoxacarb is a chiral insecticide that consists of two enantiomers, S-(+)-indoxacarb and R-(-)-indoxacarb, of which only S-(+)-indoxacarb has insecticidal activity. Previous enantioselective toxicology studies of indoxacarb focused mostly on simple environmental model organisms. The lack of a toxicology evaluation of indoxacarb conducted in a mammalian system could mean that the extent of the potential health risk posed by the insecticide to humans is not adequately known. In this study, we reported on a new pair of enantiomers, S-IN-RM294 and R-IN-RM294, derived from the metabolic breakdown of S-(+)-indoxacarb and R-(-)-indoxacarb, respectively, in rats. The toxicokinetics of S-(+)-indoxacarb, R-(-)-indoxacarb, S-IN-RM294, and R-IN-RM294 in rats were evaluated to provide a more comprehensive risk assessment of these molecules. The bioavailability and excretion rates of both S-(+)-indoxacarb and R-(-)-indoxacarb were relatively low, which may be due to their faster metabolism and accumulation in the tissues. In addition, there were significant differences in the metabolism and distribution between the two indoxacarb enantiomers and their metabolites in vivo. S-(+)-Indoxacarb was found to be more easily metabolized in the blood compared with R-(-)-indoxacarb, as shown by the differences in pharmacokinetic parameters between oral and intravenous administration. Analysis of their tissue distribution showed that S-(+)-indoxacarb was less likely to accumulate in most tissues. The results obtained for the two metabolites were consistent with those of the two parent compounds. S-IN-RM294 was more readily cleared from the blood and less likely to accumulate in the tissues compared with R-IN-RM294. Therefore, whether from the perspective of insecticidal activity or from the perspective of mammalian and environmental friendliness, the application of optically pure S-(+)-indoxacarb in agriculture may be a more efficient and safer strategy.
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Affiliation(s)
- Jiao Ai
- School of Pharmaceutical Sciences, Liaoning University, 66 Chongshan Road, Shenyang 110036, Liaoning Province, PR China
| | - Jianxin Li
- School of Pharmaceutical Sciences, Liaoning University, 66 Chongshan Road, Shenyang 110036, Liaoning Province, PR China
| | - Alan Kueichieh Chang
- College of Life and Environmental Sciences, Wenzhou University, Wenzhou 325035, Zhejiang Province, PR China
| | - Ying Pei
- School of Pharmaceutical Sciences, Liaoning University, 66 Chongshan Road, Shenyang 110036, Liaoning Province, PR China
| | - Haoran Li
- School of Pharmaceutical Sciences, Liaoning University, 66 Chongshan Road, Shenyang 110036, Liaoning Province, PR China
| | - Kai Liu
- School of Pharmaceutical Sciences, Liaoning University, 66 Chongshan Road, Shenyang 110036, Liaoning Province, PR China
| | - Ruiyun Li
- School of Pharmaceutical Sciences, Liaoning University, 66 Chongshan Road, Shenyang 110036, Liaoning Province, PR China
| | - Liuping Xu
- School of Pharmaceutical Sciences, Liaoning University, 66 Chongshan Road, Shenyang 110036, Liaoning Province, PR China
| | - Nan Wang
- School of Pharmaceutical Sciences, Liaoning University, 66 Chongshan Road, Shenyang 110036, Liaoning Province, PR China
| | - Yuhui Liu
- School of Pharmaceutical Sciences, Liaoning University, 66 Chongshan Road, Shenyang 110036, Liaoning Province, PR China
| | - Weiping Su
- School of Pharmaceutical Sciences, Liaoning University, 66 Chongshan Road, Shenyang 110036, Liaoning Province, PR China
| | - Wenbao Liu
- School of Pharmaceutical Sciences, Liaoning University, 66 Chongshan Road, Shenyang 110036, Liaoning Province, PR China
| | - Tingting Wang
- School of Pharmaceutical Sciences, Liaoning University, 66 Chongshan Road, Shenyang 110036, Liaoning Province, PR China
| | - Zhen Jiang
- Department of Analytical Chemistry, College of Pharmacy, Shenyang Pharmaceutical University, 103 Wenhua Road, Shenyang 110016, Liaoning Province, PR China
| | - Lijiang Chen
- School of Pharmaceutical Sciences, Liaoning University, 66 Chongshan Road, Shenyang 110036, Liaoning Province, PR China.
| | - Xiao Liang
- School of Pharmaceutical Sciences, Liaoning University, 66 Chongshan Road, Shenyang 110036, Liaoning Province, PR China.
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Sprega G, Di Giorgi A, Poyatos L, Papaseit E, Pérez-Mañá C, Tini A, Pichini S, Busardò FP, Lo Faro AF, Farré M. Usefulness of Oral Fluid for Measurement of Methylone and Its Metabolites: Correlation with Plasma Drug Concentrations and the Effect of Oral Fluid pH. Metabolites 2023; 13:metabo13040468. [PMID: 37110127 PMCID: PMC10143603 DOI: 10.3390/metabo13040468] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2023] [Revised: 03/07/2023] [Accepted: 03/22/2023] [Indexed: 04/29/2023] Open
Abstract
The aim of this study was to investigate methylone and its metabolites concentration in oral fluid following controlled increasing doses, focusing on the effect of oral fluid pH. Samples were obtained from a clinical trial where twelve healthy volunteers participated after ingestion of 50, 100, 150 and 200 mg of methylone. Concentration of methylone and its metabolites 4-hydroxy-3-methoxy-N-methylcathinone (HMMC) and 3,4-methylenedioxycathinone in oral fluid were measured using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Pharmacokinetic parameters were estimated, and the oral fluid-to-plasma ratio (OF/P) at each time interval was calculated and correlated with the oral fluid pH using data from our previous study in plasma. Methylone was detected at all time intervals after each dose; MDC and HMMC were not detectable after the lowest dose. Oral fluid concentrations of methylone ranged between 88.3-503.8, 85.5-5002.3, 182.8-13,201.8 and 214.6-22,684.6 ng/mL following 50, 100, 150 and 200 mg doses, respectively, peaked between 1.5 and 2.0 h, and were followed by a progressive decrease. Oral fluid pH was demonstrated to be affected by methylone administration. Oral fluid is a valid alternative to plasma for methylone determination for clinical and toxicological studies, allowing for a simple, easy and non-invasive sample collection.
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Affiliation(s)
- Giorgia Sprega
- Department of Excellence-Biomedical Sciences and Public Health, Università Politecnica delle Marche, 60126 Ancona, Italy
| | - Alessandro Di Giorgi
- Department of Excellence-Biomedical Sciences and Public Health, Università Politecnica delle Marche, 60126 Ancona, Italy
| | - Lourdes Poyatos
- Department of Clinical Pharmacology, Hospital Universitari Germans Trias i Pujol and Institut de Recerca Germans Trias i Pujol (HUGTiP-IGTP), 08916 Badalona, Spain
- Department of Pharmacology, Therapeutics and Toxicology and Department of Psychiatry and Forensic Medicine, Universitat Autònoma de Barcelona (UAB), 08193 Cerdanyola del Vallés, Spain
| | - Esther Papaseit
- Department of Clinical Pharmacology, Hospital Universitari Germans Trias i Pujol and Institut de Recerca Germans Trias i Pujol (HUGTiP-IGTP), 08916 Badalona, Spain
- Department of Pharmacology, Therapeutics and Toxicology and Department of Psychiatry and Forensic Medicine, Universitat Autònoma de Barcelona (UAB), 08193 Cerdanyola del Vallés, Spain
| | - Clara Pérez-Mañá
- Department of Clinical Pharmacology, Hospital Universitari Germans Trias i Pujol and Institut de Recerca Germans Trias i Pujol (HUGTiP-IGTP), 08916 Badalona, Spain
- Department of Pharmacology, Therapeutics and Toxicology and Department of Psychiatry and Forensic Medicine, Universitat Autònoma de Barcelona (UAB), 08193 Cerdanyola del Vallés, Spain
| | - Anastasio Tini
- Department of Excellence-Biomedical Sciences and Public Health, Università Politecnica delle Marche, 60126 Ancona, Italy
| | - Simona Pichini
- National Centre on Addiction and Doping, Istituto Superiore di Sanità, 00161 Rome, Italy
| | - Francesco Paolo Busardò
- Department of Excellence-Biomedical Sciences and Public Health, Università Politecnica delle Marche, 60126 Ancona, Italy
| | - Alfredo Fabrizio Lo Faro
- Department of Excellence-Biomedical Sciences and Public Health, Università Politecnica delle Marche, 60126 Ancona, Italy
| | - Magí Farré
- Department of Clinical Pharmacology, Hospital Universitari Germans Trias i Pujol and Institut de Recerca Germans Trias i Pujol (HUGTiP-IGTP), 08916 Badalona, Spain
- Department of Pharmacology, Therapeutics and Toxicology and Department of Psychiatry and Forensic Medicine, Universitat Autònoma de Barcelona (UAB), 08193 Cerdanyola del Vallés, Spain
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Aldubayyan AA, Castrignanò E, Elliott S, Abbate V. Influence of long-term storage temperatures and sodium fluoride preservation on the stability of synthetic cathinones and dihydro-metabolites in human whole blood. Forensic Toxicol 2023; 41:81-93. [PMID: 36652059 PMCID: PMC9849191 DOI: 10.1007/s11419-022-00634-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Accepted: 07/16/2022] [Indexed: 01/22/2023]
Abstract
PURPOSE Synthetic cathinones, one of the largest groups of new psychoactive substances, represent a large analytical and interpretative challenge in forensic laboratories. Of these is the synthetic cathinones' instability in different biological samples, which may lead to drug concentration discrepancies when interpreting toxicological findings. In this study, the stability of a panel of synthetic cathinones and their dihydro-metabolites (n = 26) together with internal standard was monitored in human whole blood stored at various temperatures over 6 months. The influence of sodium fluoride as a preservative in blood collection tubes was also investigated. METHODS Samples were extracted using a two-step liquid-liquid extraction technique, and analyzed using a validated liquid chromatography-tandem mass spectrometry method following recommendations of published guidelines. RESULTS The influence of temperature over analytes' stability was an important element in whole blood samples, with - 40 °C being the best storage temperature for all tested analytes. Sodium fluoride did not significantly affect the stability of cathinones except at room temperature. Dihydro-metabolites displayed better stability in whole blood samples and remained detectable for a longer period of time under all tested conditions. CONCLUSIONS The data suggest that samples containing synthetic cathinones should be analyzed immediately, if possible. Alternatively, whole blood samples should be stored frozen (at - 40 °C or lower); however, (quantitative) results should be interpreted with caution after long-term storage. The data also promote the use of dihydro-metabolites as biomarkers for synthetic cathinones intake, as these reduced metabolites may be detected for longer period of time when compared with parent drugs in whole blood samples.
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Affiliation(s)
- Abdulaziz A Aldubayyan
- Department of Analytical, Environmental and Forensic Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
- Department of Toxicology, Central Military Laboratory and Blood Bank, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
| | - Erika Castrignanò
- Department of Analytical, Environmental and Forensic Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
| | - Simon Elliott
- Department of Analytical, Environmental and Forensic Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK
- Elliott Forensic Consulting, Birmingham, UK
| | - Vincenzo Abbate
- Department of Analytical, Environmental and Forensic Sciences, Faculty of Life Sciences and Medicine, King's College London, London, UK.
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Aknouche F, Ameline A, Gheddar L, Maruejouls C, Kintz P. Fatal Rectal Injection of 3-MMC in a Sexual Context. Toxicological Investigations Including Metabolites Identification Using LC-HRMS. J Anal Toxicol 2022; 46:949-955. [PMID: 35767277 DOI: 10.1093/jat/bkac048] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Revised: 06/16/2022] [Accepted: 06/28/2022] [Indexed: 11/13/2022] Open
Abstract
The dead body of a 59-year-old man was found at his home by his father. The subject was naked in the corridor, wearing a black hood and a collar around the neck where a dog leash was attached. An empty syringe was discovered in the decedent's rectal vein. The autopsy revealed marked asphyxia signs with no indication of violence or trauma. Femoral blood, urine and hair (4 cm, brown) were collected and submitted for comprehensive toxicological investigation. Initial screening did not indicate the presence of ethanol or any other over-the-counter or prescription pharmaceuticals. Routine toxicology screening by liquid chromatography-tandem mass spectrometry (LC-MS-MS) tentatively identified only the cathinone stereoisomer(s), 3-methylmethcathinone (3-MMC) or mephedrone (4-MMC). Analysis by GC-MS to distinguish between the isomers revealed the presence of 3-MMC, which was subsequently quantified by LC-MS-MS. Femoral blood and urine concentrations were 1437 ng/mL and 16733 ng/mL, respectively. In 4 x 1 cm hair segments, 3-MMC was detected at less than 10 pg/mg (LOQ). Further analysis by high-resolution mass spectrometry (LC-HRMS) allowed identification of two metabolites in both blood and urine: desmethyl-3-MMC and hydroxyl-3-MMC. The pathologist established the cause of death in this case as acute 3-MMC poisoning in the context of ChemSex.
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Affiliation(s)
| | - Alice Ameline
- Institut de médecine légale, 11 rue Humann, F-67000 Strasbourg, France
| | - Laurie Gheddar
- Institut de médecine légale, 11 rue Humann, F-67000 Strasbourg, France
| | | | - Pascal Kintz
- Institut de médecine légale, 11 rue Humann, F-67000 Strasbourg, France.,X-Pertise Consulting, 42 rue principale, F-67206 Mittelhausbergen, France
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Poyatos L, Torres A, Papaseit E, Pérez-Mañá C, Hladun O, Núñez-Montero M, de la Rosa G, Torrens M, Fuster D, Muga R, Farré M. Abuse Potential of Cathinones in Humans: A Systematic Review. J Clin Med 2022; 11:1004. [PMID: 35207278 PMCID: PMC8878365 DOI: 10.3390/jcm11041004] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/11/2022] [Accepted: 02/13/2022] [Indexed: 01/09/2023] Open
Abstract
Introduction and objective: Assessing the abuse potential of new substances with central nervous system activity is essential for preventing possible risks of misuse and addiction. The same methodology is recommended for the evaluation of the abuse potential of recreational drugs. This systematic review aims to assess the pharmacological effects related to the abuse potential and pharmacokinetics of cathinones, which are evaluated in both experimental and prospective observational studies in humans. Materials and Methods: A systematic search of the published literature was conducted to retrieve studies that had administered cathinone, mephedrone, methylone, and diethylpropion to evaluate their acute pharmacological effects related to abuse potential. Results: The search yielded 583 results, 18 of which were included to assess the abuse potential of cathinone (n = 5), mephedrone (n = 7), methylone (n = 1), and diethylpropion (n = 5). All four substances induce stimulant and euphorigenic effects that resemble those of amphetamines and MDMA, and their different intensities may be associated with varying levels of abuse potential. Conclusions: Cathinone, mephedrone, methylone, and diethylpropion induce a range of desirable and reinforcing effects that may, to some extent, result in abuse potential. Further investigation is needed to minimize and prevent their impact on society and public health.
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Affiliation(s)
- Lourdes Poyatos
- Department of Clinical Pharmacology, Hospital Universitari Germans Trias i Pujol and Institut de Recerca Germans Trias i Pujol (HUGTiP-IGTP), 08916 Badalona, Spain; (L.P.); (C.P.-M.); (O.H.); (M.N.-M.); (G.d.l.R.)
- Department of Pharmacology, Therapeutics and Toxicology, Universitat Autònoma de Barcelona (UAB), 08913 Cerdanyola del Vallés, Spain;
| | - Adrián Torres
- Department of Pharmacology, Therapeutics and Toxicology, Universitat Autònoma de Barcelona (UAB), 08913 Cerdanyola del Vallés, Spain;
| | - Esther Papaseit
- Department of Clinical Pharmacology, Hospital Universitari Germans Trias i Pujol and Institut de Recerca Germans Trias i Pujol (HUGTiP-IGTP), 08916 Badalona, Spain; (L.P.); (C.P.-M.); (O.H.); (M.N.-M.); (G.d.l.R.)
- Department of Pharmacology, Therapeutics and Toxicology, Universitat Autònoma de Barcelona (UAB), 08913 Cerdanyola del Vallés, Spain;
| | - Clara Pérez-Mañá
- Department of Clinical Pharmacology, Hospital Universitari Germans Trias i Pujol and Institut de Recerca Germans Trias i Pujol (HUGTiP-IGTP), 08916 Badalona, Spain; (L.P.); (C.P.-M.); (O.H.); (M.N.-M.); (G.d.l.R.)
- Department of Pharmacology, Therapeutics and Toxicology, Universitat Autònoma de Barcelona (UAB), 08913 Cerdanyola del Vallés, Spain;
| | - Olga Hladun
- Department of Clinical Pharmacology, Hospital Universitari Germans Trias i Pujol and Institut de Recerca Germans Trias i Pujol (HUGTiP-IGTP), 08916 Badalona, Spain; (L.P.); (C.P.-M.); (O.H.); (M.N.-M.); (G.d.l.R.)
- Department of Pharmacology, Therapeutics and Toxicology, Universitat Autònoma de Barcelona (UAB), 08913 Cerdanyola del Vallés, Spain;
| | - Melani Núñez-Montero
- Department of Clinical Pharmacology, Hospital Universitari Germans Trias i Pujol and Institut de Recerca Germans Trias i Pujol (HUGTiP-IGTP), 08916 Badalona, Spain; (L.P.); (C.P.-M.); (O.H.); (M.N.-M.); (G.d.l.R.)
- Department of Pharmacology, Therapeutics and Toxicology, Universitat Autònoma de Barcelona (UAB), 08913 Cerdanyola del Vallés, Spain;
| | - Georgina de la Rosa
- Department of Clinical Pharmacology, Hospital Universitari Germans Trias i Pujol and Institut de Recerca Germans Trias i Pujol (HUGTiP-IGTP), 08916 Badalona, Spain; (L.P.); (C.P.-M.); (O.H.); (M.N.-M.); (G.d.l.R.)
- Department of Pharmacology, Therapeutics and Toxicology, Universitat Autònoma de Barcelona (UAB), 08913 Cerdanyola del Vallés, Spain;
| | - Marta Torrens
- Institut de Neuropsiquiatria i Adiccions (INAD), Parc de Salut Mar, 08003 Barcelona, Spain;
- Department of Psychiatry and Legal Medicine, Universitat Autònoma de Barcelona (UAB), 08913 Cerdanyola del Vallés, Spain
| | - Daniel Fuster
- Department of Internal Medicine, Hospital Universitari Germans Trias i Pujol and Institut de Recerca Germans Trias i Pujol (HUGTiP-IGTP), 08916 Badalona, Spain; (D.F.); (R.M.)
- Department of Medicine, Universitat Autònoma de Barcelona (UAB), 08913 Cerdanyola del Vallés, Spain
| | - Robert Muga
- Department of Internal Medicine, Hospital Universitari Germans Trias i Pujol and Institut de Recerca Germans Trias i Pujol (HUGTiP-IGTP), 08916 Badalona, Spain; (D.F.); (R.M.)
- Department of Medicine, Universitat Autònoma de Barcelona (UAB), 08913 Cerdanyola del Vallés, Spain
| | - Magí Farré
- Department of Clinical Pharmacology, Hospital Universitari Germans Trias i Pujol and Institut de Recerca Germans Trias i Pujol (HUGTiP-IGTP), 08916 Badalona, Spain; (L.P.); (C.P.-M.); (O.H.); (M.N.-M.); (G.d.l.R.)
- Department of Pharmacology, Therapeutics and Toxicology, Universitat Autònoma de Barcelona (UAB), 08913 Cerdanyola del Vallés, Spain;
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Investigation of Biotransformation Products of p-Methoxymethylamphetamine and Dihydromephedrone in Wastewater by High-Resolution Mass Spectrometry. Metabolites 2021; 11:metabo11020066. [PMID: 33503865 PMCID: PMC7912097 DOI: 10.3390/metabo11020066] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 01/20/2021] [Accepted: 01/21/2021] [Indexed: 01/06/2023] Open
Abstract
There is a paucity of information on biotransformation and stability of new psychoactive substances (NPS) in wastewater. Moreover, the fate of NPS and their transformation products (TPs) in wastewater treatment plants is not well understood. In this study, batch reactors seeded with activated sludge were set up to evaluate biotic, abiotic, and sorption losses of p-methoxymethylamphetamine (PMMA) and dihydromephedrone (DHM) and identify TPs formed during these processes. Detection and identification of all compounds was performed with target and suspect screening approaches using liquid chromatography quadrupole-time-of-flight mass spectrometry. Influent and effluent 24 h composite wastewater samples were collected from Athens from 2014 to 2020. High elimination rates were found for PMMA (80%) and DHM (97%) after a seven-day experiment and degradation appeared to be related to biological activity in the active bioreactor. Ten TPs were identified and the main reactions were O- and N-demethylation, oxidation, and hydroxylation. Some TPs were reported for the first time and some were confirmed by reference standards. Identification of some TPs was enhanced by the use of an in-house retention time prediction model. Mephedrone and some of its previously reported human metabolites were formed from DHM incubation. Retrospective analysis showed that PMMA was the most frequently detected compound.
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Pharmacokinetics of Mephedrone Enantiomers in Whole Blood after a Controlled Intranasal Administration to Healthy Human Volunteers. Pharmaceuticals (Basel) 2020; 14:ph14010005. [PMID: 33374623 PMCID: PMC7822411 DOI: 10.3390/ph14010005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2020] [Revised: 12/21/2020] [Accepted: 12/22/2020] [Indexed: 11/26/2022] Open
Abstract
Mephedrone, which is one of the most popular synthetic cathinones, has one chiral centre and thus exists as two enantiomers: R-(+)-mephedrone and S-(−)-mephedrone. There are some preliminary data suggesting that the enantiomers of mephedrone may display enantioselective pharmacokinetics and exhibit different neurological effects. In this study, enantiomers of mephedrone were resolved via chromatographic chiral recognition and the absolute configuration was unambiguously determined by a combination of elution order and chiroptical analysis (i.e., circular dichroism). A chiral liquid chromatography tandem mass spectrometry method was fully validated and was applied to the analysis of whole blood samples collected from a controlled intranasal administration of racemic mephedrone hydrochloride to healthy male volunteers. Both enantiomers showed similar kinetics, however, R-(+)-mephedrone had a greater mean Cmax of 48.5 ± 11.9 ng/mL and a longer mean half-life of 1.92 ± 0.27 h compared with 44.6 ± 11.8 ng/mL and 1.63 ± 0.23 h for S-(−)-mephedrone, respectively. Moreover, R-(+)-mephedrone had a lower mean clearance and roughly 1.3 times greater mean area under the curve than S-(−)-mephedrone. Significant changes in the enantiomeric ratio over time were observed, which suggest that the analytes exhibit enantioselective pharmacokinetics. Even though the clinical significance of this finding is not yet fully understood, the study confirms that the chiral nature, and consequently the enantiomeric purity of mephedrone, can be a crucial consideration when interpreting toxicological results.
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