Assessment of the stability of mephedrone in ante-mortem and post-mortem blood specimens

The effect of mephedrone on human neuroblastoma and astrocytoma cells

Mephedrone is an illegal drug that is used recreationally. Few studies have been conducted to investigate the mechanisms by which mephedrone is harming cells. In this research, we investigated the effect of mephedrone using toxicology coupled with LC-MS/MS based metabolomics in the two CNS derived cell lines. Methods of assessment such as neutral red (NR) assay, dimethylthiazolyl diphenyltetrazolium bromide (MTT), lactose dehydrogenase (LDH) measurement, and morphology were performed to identify the effect on cell viability and to identify the best concentration to be used in a metabolomics study. A concentration of 100 μM of mephedrone was used in the metabolomic experiment because at this concentration mephedrone had induced several intracellular changes. Although there no clear indicators of cellular damage caused by mephedrone. In astrocytes there was a clear indication that cell membrane function might be impaired by depletion of ether lipids.

3-Methylmethcathinone Intoxication: Discrepancies Between Blood Concentrations and Clinical Outcomes-A Short Communication

BACKGROUND

The absence of a correlation between the blood concentration of 3-methylmethcathinone (3-MMC) and clinical outcomes in intoxication cases has been attributed to stability issues. Indeed, a loss of more than 50%, 70%, and even 95% of 3-MMC in whole blood after 2 weeks of storage at 20°C, 4°C, and room temperature, respectively, has been reported in the past. Here, the authors report the case of a 43-year-old man who was hospitalized with generalized convulsive status epilepticus related to 3-MMC use with a plasma concentration of 9600 ng/mL (delay between sampling and analysis <72 hours). The stability of 3-MMC was evaluated in several biological specimens.

METHODS

Three quality control samples (human plasma, whole blood, and postmortem blood) spiked with 3-MMC were stored at -20°C and 4°C for 14 days. The initial analysis was performed on day 1 to establish the initial concentration of 3-MMC in each specimen type, and the samples were divided into 2 aliquots for storage under both conditions. Further analyses were performed on days 7 and 14 for each specimen, and the results were compared with those obtained on day 1.

RESULTS

3-MMC appeared relatively stable in whole and postmortem blood when stored at -20°C for 1 week, with losses of <3% in both matrices (0% and 2.5%, respectively). At +4°C, 3-MMC losses ranged from 25% to 53%.

CONCLUSIONS

These results differ from others reported in the literature. Hence, it may be hypothesized that other elements should be considered to explain the discrepancy between the concentration and toxicity pointed out by the Toxicology community, especially the development of tolerance.

Development and validation of a chiral LC-MS/MS method for the separation and quantification of four synthetic cathinones in human whole blood and its application in stability analysis

Synthetic cathinones, a subclass of new psychoactive substances, have gained high popularity on the recreational drugs market over the past years. These drugs typically have a chiral center, so they may exist as two stereoisomers. Therefore the pharmacological, pharmacokinetic or metabolic properties of their enantiomers are expected to differ. However, these drugs are often synthesized and sold as a racemic mixture, and as a consequence, differentiation of their (R)- and (S)- enantiomers is relevant in clinical and forensic toxicology. Information about single enantiomers of synthetic cathinones is relatively scarce due to challenges of their chiral analysis. Hence, a sensitive and reliable liquid chromatography-tandem mass spectrometry method was developed and validated for the chiral separation and quantification of four synthetic cathinones in human whole blood samples. The method was fully validated in terms of linearity, limit of detection, limit of quantification, bias, precision, carryover, interferences, matrix effects, recovery and processed sample stability and successfully applied to evaluate the stability as well as enantioselective degradation of synthetic cathinones enantiomers under various storage conditions. For most of the analytes, significant enantioselective degradation was observed when stored at room temperature or refrigerated, with the E2-enantiomers observed to more rapidly degrade under both conditions. This is the first report concerning the stability and enantioselective degradation of synthetic cathinone enantiomers in whole blood. Moreover, the inversion study demonstrated enantiomeric inversion of R-(-)- and S-(+)-methylenedioxypyrovalerone (MDPV) in human whole blood and methanolic solution.

Synthesis of emerging cathinones and validation of a SPE GC-MS method for their simultaneous quantification in blood

Over the past 15 years, synthetic cathinones have emerged as an important class of new psychoactive substances (NPS) worldwide. The proliferation of these psychostimulants and their sought-after effects among recreational drug users pose a serious threat to public health and enormous challenges to forensic laboratories. For forensic institutions, it is essential to be one step ahead of covert laboratories, foreseeing the structural changes possible to introduce in the core skeleton of cathinones while maintaining their stimulating activity. In this manner, it is feasible to equip themselves with standards of possible new cathinones and validated analytical methods for their qualitative and quantitative detection. Therefore, the aim of the work herein described was to synthesize emerging cathinones based on the evolving patterns in the illicit drug market, and to develop an analytical method for their accurate determination in forensic situations. Five so far unreported cathinones [4'-methyl-N-dimethylbuphedrone (4-MDMB), 4'-methyl-N-ethylbuphedrone (4-MNEB), 4'-methyl-N-dimethylpentedrone (4-MDMP), 4'-methyl-N-dimethylhexedrone (4-MDMH), and 4'-methyl-N-diethylbuphedrone (4-MDEB)] and a sixth one, 4'-methyl-N-ethylpentedrone, already reported to EMCDDA and also known as 4-MEAP, were synthesized and fully characterized by nuclear magnetic resonance (NMR) spectroscopy and mass spectrometry (MS). An analytical method for the simultaneous quantification of these cathinones in blood, using solid phase extraction (SPE) combined with gas chromatography-mass spectrometry (GC-MS) was developed and validated. The results prove that this methodology is selective, linear, precise, and accurate. For all target cathinones, the extraction efficiency was higher than 73%, linearity was observed in the range of 10 (lower limit of quantification, LLOQ) to 800 ng/mL, with coefficients of determination higher than 0.99, and the limits of detection (LODs) were 5 ng/mL for all target cathinones. The stability of these cathinones in blood matrices is dependent on the storage conditions; 4-MNEB is the most stable compound and 4-MDMH is the least stable compound. The low limits obtained allow the detection of the compounds in situations where they are involved, even if present at low concentrations.

Influence of long-term storage temperatures and sodium fluoride preservation on the stability of synthetic cathinones and dihydro-metabolites in human whole blood

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.

A Review of Synthetic Cathinone-Related Fatalities From 2017 to 2020

BACKGROUND

Synthetic cathinones (SCs) are designer analogs of the natural active principle of khat. Since their appearance on the black market in 2003, their popularity has increased annually, and they have become the most seized class of new psychoactive substances reported to the UNODC Early Warning Advisory system. The constant introduction of newly synthesized molecules makes this issue difficult to monitor. The authors reviewed the most recent SC-related fatalities worldwide to highlight new trends of consumption, reporting acute pharmacological and toxicological symptoms, scene investigations, analytical methods, and reported SC concentrations in diverse biological matrices.

METHODS

A literature search was performed using scientific databases such as PubMed, Scopus, Science Direct, Web of Science, and Research Gate to identify relevant scientific publications from 2017 to 2020. In addition, a search was conducted through the EU EWS.

RESULTS

From 2017 to 2020, 31 different SCs were identified in 75 reported fatal intoxications in the literature, alone or in combination with other substances. The most abused SCs were N-ethylpentylone, N-ethylhexedrone, and 4-chloromethcathinone. The EU EWS included less detail on 72 additional SC-related fatalities from 2017 to 2020.

CONCLUSIONS

New SCs continuously replace older natural and synthetic stimulant drugs, making determining the cause of death difficult. Analytical methods and high-performance mass spectrometry instruments are essential to detect the low concentrations of these potent new SCs. Little data are available on the pharmacology of these new drugs; the evaluation of toxicological antemortem and postmortem findings provides critical data on the drug's pharmacology and toxicology and for the interpretation of new SC cases.

Acute Pharmacological Effects of Oral and Intranasal Mephedrone: An Observational Study in Humans

Mephedrone (4-methylmethcathinone) is a synthetic cathinone with psychostimulant properties which remains one of the most popular new psychoactive substances (NPS). It is frequently used orally and/or intranasally. To date, no studies have evaluated the acute effects and pharmacokinetics after self-administration of mephedrone orally (ingestion) and intranasally (insufflation) in naturalistic conditions. An observational study was conducted to assess and compare the acute pharmacological effects, as well as the oral fluid (saliva) concentrations of mephedrone self-administered orally and intranasally. Ten healthy experienced drug users (4 females and 6 males) self-administered a single dose of mephedrone, orally (n = 5, 100–200 mg; mean 150 mg) or intranasally (n = 5, 50–100 mg, mean 70 mg). Vital signs (blood pressure, heart rate, and cutaneous temperature) were measured at baseline (0), 1, 2, and 4 h after self-administration. Each participant completed subjective effects questionnaires: A set of Visual Analogue Scales (VAS), the 49-item Addiction Research Centre Inventory (ARCI), and Evaluation of the Subjective Effects of Substances with Abuse Potential (VESSPA-SSE) at baseline, 1, 2, and 4 h after self-administration. Oral fluid and urine were collected during 4 h. Both routes of mephedrone self-administration enhanced ratings of euphoria and well-being effects and increased cardiovascular effects in humans. Although it was at times assessed that the oral route produced greater and larger effects than the intranasal one, concentrations of mephedrone in oral fluid and also the total amount of mephedrone and metabolites in urine showed that concentrations of mephedrone are considerably higher when self-administered intranasally in comparison to orally. Controlled clinical trials are needed to confirm our observational results.

Stability of synthetic cathinones in clinical and forensic toxicological analysis-Where are we now?

Understanding the stability of analyzed drugs in biological samples is a crucial part for an appropriate interpretation of the analytical findings. Synthetic cathinones, as psychoactive stimulants, belong to a major class of new psychoactive substances. As they are subject to several degradation pathways, they are known to clinical and forensic toxicologists as unstable analytes in biological samples. When interpreting analytical data of synthetic cathinones in biological samples, analysts must be aware that the concentration of analytes may not accurately reflect the levels at the time they were acquired owing to many factors. This review provides (i) an overview of the current scientific knowledge on the stability of synthetic cathinones and/or metabolites in various human biological samples with a focus on factors that may deteriorate their stability-such as storage temperature, length of storage, matrix, pH, type of preservatives, concentration of analytes, and the chemistry of the analytes-and (ii) possible solutions on how to avoid such degradation. The PubMed database as well as Google Scholar was thoroughly searched to find published studies on the stability of synthetic cathinones since 2007 by searching specific keywords. A total of 23 articles met the inclusion criteria and were included in this review. Synthetic cathinones that carry methylenedioxy or N-pyrrolidine ring showed higher degradation resistance over other substituted groups. Acidification of samples pH plays a crucial role at increasing the stability of cathinones even with analytes that were frequently considered as poorly stable. This review also provides several recommendations for best practice in planning the experimental design, preservation, and storage conditions in order to minimize synthetic cathinones' degradation in human biological samples.

Identification of Unique 4-Methylmethcathinone (4-MMC) Degradation Markers in Putrefied Matrices†

Drug degradation as a consequence of putrefactive bacterial activity is a well-known factor that affects the identification and quantitation of certain substances of forensic interest. Current knowledge on putrefaction-mediated degradation of drugs is, however, significantly lacking. This study aimed to investigate the degradation of 4-methylmethcathinone (4-MMC or mephedrone) and to detect its degradation products in putrefied biological matrices containing 4-MMC. The bacteria species Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae and Proteus vulgaris were grown in brain-heart infusion broth, spiked with 4-MMC and incubated at 37°C for 24 h. Postmortem human blood and fresh porcine liver macerate were also left to putrefy in sample tubes at room temperature for 1 week. Structural elucidation was based on modern spectroscopic analyses including the use of high-resolution mass spectrometry and nuclear magnetic resonance spectroscopy. All four putrefactive bacteria were capable of degrading 4-MMC extensively under the experimental conditions explored. Of particular interest was the discovery of a novel degradation product common to all four bacterial species, which was assigned as 2-hydroxy-1-(4-methylphenyl)propan-1-one (HMP) based on the spectroscopic data. This degradation product was detectable in both postmortem human blood and porcine liver samples. The stability of the identified degradation products, especially HMP, should be further investigated to assess their validity of serving as marker analytes for monitoring 4-MMC in postmortem toxicology.

Extended Stability Evaluation of Selected Cathinones

Understanding the stability of drugs in a forensic toxicology setting is critical for the evaluation of drug concentrations. Synthetic cathinones are new psychoactive substances structurally derived from cathinone, the psychoactive component of Catha edulis ("khat"), a shrub that is indigenous to the Middle East and East Africa. Previous research has evaluated the stability of synthetic cathinones in biological matrices, including blood preserved with the combination of NaF and K2C2O4 used in gray-top tubes. However, it does not assess their stability in blood preserved with Na2EDTA, used for some clinical samples. Further, stability in unpreserved urine samples was only studied for two weeks. This research evaluates the stabilities of four Schedule I synthetic cathinones: mephedrone, MDPV (3,4-methylenedioxypyrovalerone), naphyrone, and α-PVP (alpha-pyrrolidinopentiophenone) at 20°C (room temperature), 4°C (refrigerator), and -20°C (freezer). Stability was assessed in methanolic and acetonitrile solutions, as well as in Na2EDTA-preserved blood and unpreserved urine. Solutions (1 mg/L) of each drug in each matrix stored in aliquots (100 μL, solvents; 1.2 mL, biological samples; n = 12) at each of the three temperatures for triplicate analysis on days 3, 7, 14, and 30. On day 0 of each study, three additional aliquots of each solution were analyzed. Biological samples underwent solid-phase extraction before analysis. All samples were analyzed in full-scan by gas chromatography-mass spectrometry (GC-MS). The results of this study show that under room temperature and refrigerator storage conditions, mephedrone, naphyrone, and MDPV will degrade in methanol. This degradation starts are early as day 3. Additionally, all four drugs will degrade in Na2EDTA-preserved human whole blood samples in at least one evaluated storage environment. However, when in acetonitrile-based working solutions and unpreserved urine samples, they proved to be more stable. Methanolic working solutions and samples of Na2EDTA-preserved blood containing these cathinones should be stored in the freezer and used or tested with urgency to ensure that quantitative sample analysis is as accurate as possible in forensic casework.

The Stability of 4-Chloromethcathinone in Blood and Vitreous Humor

We present results of our study on the stability of 4-chloromethcathinone (4-CMC) in authentic postmortem peripheral blood and vitreous humor samples. The stability of 4-CMC was determined in postmortem blood samples (for a period of 90 days) and vitreous humor (30 days) at three different temperatures: -15°C, +4°C, and + 23°C. The analyses were carried out using ultra-high-performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UHPLC-QqQ-MS/MS). In both materials, the lowest 4-CMC stability was demonstrated at room temperature. The blood samples stored in a freezer (-15°C) showed stability for the entire study period (90 days), while in the case of the vitreous humor sample stored at the same temperature the concentration of the substance decreased by 53% after 30 days. The study carried out in authentic postmortem blood and vitreous humor samples confirms the previous reports of 4-CMC instability in biological material. Authors suggest that the biological material should be stored frozen until analyses are carried out as soon as possible after collection of the material.

Cathinone Use Disorder in the Context of Slam Practice: New Pharmacological and Clinical Challenges

BACKGROUND

"Slam" has emerged since 2008 as a new international phenomenon among men who have sex with men (MSM); it consists of the intravenous injection of drugs before or during planned sexual activity. The practice of slam is associated with the use of psychostimulants, including synthetic cathinones.

METHODS

All spontaneous notifications (Nots) of slam practice reported between January 2012 and October 2019 at the Nantes addictovigilance center in France were collected and analyzed. The purpose of this work was to analyze cases of slam to characterize cathinone use disorder according to the diagnostic criteria of the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5) and to further our knowledge of slam practice based on data on drug use, risk taking and harmful consequences.

RESULTS

We collected 39 slam Nots. The severity of cathinone use disorder was mild, moderate and severe for 18%, 12%, and 58% of the patients, respectively. "Much time spent using cathinone" was the diagnostic criterion most often cited (82%).

CONCLUSIONS

To the best of our knowledge, our study is the first to evaluate the presence of a cathinone use disorder. Cathinone use disorder seems particularly important in this population of users, and negative consequences of slam practice appear quickly.

4-Fluoromethylphenidate: Fatal Intoxication Involving a Previously Unreported Novel Psychoactive Substance in the USA

The (±)-threo-4-fluoromethylphenidate (4F-MPH) is a fluorinated analog of the prescription central nervous system stimulant medication, methylphenidate. This novel psychoactive substance was first detected in drug paraphernalia at the Miami-Dade County Medical Examiner Department Toxicology Laboratory in 2016 but was not detected in a biological specimen until 2018. Limited literature is available on 4F-MPH, with predominate literature being published out of Europe, and no known toxicities reported in the USA. Post-mortem specimens were screened using both gas chromatography mass spectrometry and liquid chromatography ion trap mass spectrometry (LC–Ion Trap-MSn). In addition, a validated method for the quantification of 4F-MPH was developed using liquid chromatography–tandem mass spectrometry (LC–MS-MS), with a linear range of 0.01–0.500 mg/L and acceptable validation criteria including precision, bias, carry-over, linearity and endogenous/exogenous interferences. In addition to the detection of 4F-MPH, 3-methoxy-PCP, amphetamine, methamphetamine, 6-monoacetylmorphine, morphine, codeine and tetrahydrocannabinol were also identified in the decedent. A single source of blood was collected (femoral vein) and quantified in all blood tubes used for collection, with concentrations varying from 0.012 to 0.05 mg/L. Additional specimens available for screening included gastric contents and urine. An additional peak having the same targeted ions and transitions as 4F-MPH was identified in both the LC–Ion Trap-MSn screening procedure and the LC–MS-MS quantitative procedure. This peak suggests the presence of a structural isomer, possibly (±)-erythro-4-fluoromethylphenidate, which cannot be confirmed due to there being no available certified reference material. This case report presents the first time that 4F-MPH was detected in a decedent, as well as the first time 4F-MPH has been listed in the official cause of death of a decedent in Florida.

Evidence of 2 Populations of Mephedrone Abusers by Hair Testing. Application to 4 Forensic Expertises

Background

New psychoactive substances are conquering the drug scene. Among these substances, cathinone derivatives have been observed since late in the years 2000. At that time, there was evidence of increasing use of the synthetic cathinone mephedrone, particularly amongst clubbers. Although the emergent drugs have an aura of safety, there is an increasing amount of experiences on their secondary effects. Mephedrone is known to induce psychosis.

Method

Given the potential negative effects of mephedrone, the laboratory was asked to test for the drug in hair, a cumulative matrix that can document single, occasional or repetitive abuse of xenobiotics. Mephedrone was tested in hair by GC/MS, using a standard procedure developed for stimulants such as amphetamine or ecstasy.

Results

In the head hair of 24 positive abusers, mephedrone was identified in the range 0.1 to 87 ng/mg, clearly determining 2 populations, one with co-administration of ecstasy and a second without ecstasy. In the first population, mephedrone concentrations were 0.1 to 5 ng/mg; in the second population, mephedrone concentrations were 3 to 87 ng/mg. These findings should help in the understanding the addiction of subjects. In 4 separate forensic cases, mephedrone was identified in hair of abusers, including a rape case (0.54 ng/mg), a fatal car crash (0.38 ng/mg), a fatal drowning (1.21 ng/mg), and a fatal overdose (6.99 ng/mg).

Conclusion

Hair testing for new psychoactive substances appears as a good complement to standard urine analyses. This study confirms the increasing diffusion of new drugs among the forensic population of abusers.

Neurotoxicity Induced by Mephedrone: An up-to-date Review

Mephedrone is a β-ketoamphetamine belonging to the family of synthetic cathinones, an emerging class of designer drugs known for their hallucinogenic and psychostimulant properties as well as for their abuse potential. The aim of this review was to examine the emerging scientific literature on the possible mephedrone-induced neurotoxicity, yet not well defined due to the limited number of experimental studies, mainly carried on animal models. Relevant scientific articles were identified from international literature databases (Medline, Scopus, etc.) using the keywords: “Mephedrone”, “4-MMC,” “neurotoxicity,” “neuropharmacology”, “patents”, “monoamine transporters” and “neurochemical effects”. Of the 498 sources initially found, only 36 papers were suitable for the review. Neurotoxic effect of mephedrone on 5-HT and DA systems remains controversial. Although some studies in animal models reported no damage to DA nerve endings in the striatum and no significant changes in brain monoamine levels, some others suggested a rapid reduction in 5-HT and DA transporter function. Persistent serotonergic deficits were observed after binge like treatment in a warm environment and in both serotonergic and dopaminergic nerve endings at high ambient temperature. Oxidative stress cytotoxicity and an increase in frontal cortex lipid peroxidation were also reported. In vitro cytotoxic properties were also observed, suggesting that mephedrone may act as a reductant agent and can also determine changes in mitochondrial respiration. However, due to the differences in the design of the experiments, including temperature and animal model used, the results are difficult to compare. Further studies on toxicology and pharmacology of mephedrone are therefore necessary to establish an appropriate treatment for substance abuse and eventual consequences for public health.

Correlation between Blood and Oral Fluid Psychoactive Drug Concentrations and Cognitive Impairment in Driving under the Influence of Drugs

BACKGROUND

The effects of drugs on driving performance should be checked with drug concentration in the brain and at the same time with the evaluation of both the behavioural and neurophysiological effects. The best accessible indicator of this information is the concentration of the drug and/or metabolites in blood and, to a certain extent, oral fluid. We sought to review international studies on correlation between blood and oral fluid drug concentrations, neurological correlates and cognitive impairment in driving under the influence of drugs.

METHODS

Relevant scientific articles were identified from PubMed, Cochrane Central, Scopus, Web of Science, Science Direct, EMBASE up to April 2017.

RESULTS

Up to 2010, no epidemiological studies were available on this matter and International scientists suggested that even minimal amounts of parent drugs in blood and oral fluid could affect driving impairment. More recently, epidemiological data, systematic reviews and meta-analysis on drugged drivers allowed the suggestion of impairment concentration limits for the most common illicit drugs. These values were obtained comparing driving disability induced by psychotropic drugs with that of established blood alcohol limits. Differently from ethyl alcohol where both detection methods and concentration limits have been well established even with inhomogeneity of ranges within different countries, in case of drugs of abuse no official cut-offs have yet been established, nor any standardized analytical protocols.

CONCLUSION

Multiple aspects of driving performance can be differently affected by illicit drugs, and even if for few of them some dose/concentration dependent impairment has been reported, a wider knowledge on concentration/impairment relationship is still missing.

How Postmortem Redistribution of MDMA in Acute Alcohol-MDMA Combined-Use Rats Change under Effects of Alcohol

MDMA is often taken recreationally with alcohol as combined-use. The objective was to determine MDMA postmortem redistribution (PMR) and corresponding effects in combined-style under different storage conditions. Steps were 20%-mixture of alcohol-water for initial 4 weeks to Group-A&B and intragastric infusions of MDMA (150 mg/kg) to Group-A later; in the same time, drinking pure water to Group-C&D first and then MDMA-fed to Group-C. The sacrificed rats were kept under different conditions for 10-d, during which the body fluids and tissues were collected on 15 continuous time-points and then detected. The MDMA concentrations were quite different along with postmortem interval (PMI) went by; the area under concentration-PMI curve significantly increased with combined-alcohol in comparison to MDMA alone, while that significantly decreased by lowering preservation temperature, allied with corresponding humidity. Combined-alcohol could exacerbate PMR of MDMA, as concentrations of combined-use rats’ samples were quite higher than mono-MDMA ones under any conditions, while different for body fluids and tissues; meanwhile lowering storage temperature could alleviate effects of alcohol. The study implies that in case of combined-use, the changes of concentrations are probably effected by some combined component, especially when come to identification of toxic level or even death.

A novel screening method for 64 new psychoactive substances and 5 amphetamines in blood by LC-MS/MS and application to real cases

Identification and quantification of new psychoactive substances (NPS), both in biological and non-biological samples, represent a hard challenge for forensic toxicologists. NPS are increasingly emerging on illegal drug market. Many cases of co-consumption of NPS and other substances have also been reported. Hence, the development of analytical methods aiming at the detection of a broad-spectrum of compounds (NPS and "traditional" drugs) could be helpful. In this paper, a fully validated screening method in blood for the simultaneous detection of 69 substances, including 64 NPS (28 synthetic cannabinoids, 19 synthetic cathinones, 5 phenethylamines, 3 indanes, 2 piperazines, 2 tryptamines, 2 phencyclidine, methoxetamine, ketamine and its metabolite) and 5 amphetamines (amphetamine, methamphetamine, MDMA, MDA, 3,4-methylenedioxy-N-ethylamphetamine - MDEA-) by a dynamic multiple reaction monitoring analysis through liquid chromatography - tandem mass spectrometry (LC-MS/MS) is described. This method is very fast, easy to perform and cheap as it only requires the deproteinization of 200μL of blood sample with acetonitrile. The chromatographic separation is achieved with a C18 column. The analysis is very sensitive, with limits of quantification ranging from 0.1 to 0.5ng/mL. The method is linear from 1 to 100ng/mL and the coefficient of determination (R(2)) was always above 0.9900. Precision and accuracy were acceptable at any quality control level and recovery efficiency range was 72-110%. Matrix effects did not negatively affect the analytical sensitivity. This method was successfully applied to three real cases, allowing identification and quantification of: mephedrone and methamphetamine (post-mortem); ketamine, MDMA and MDA (post-mortem); AB-FUBINACA (ante-mortem).

Synthetic cathinone pharmacokinetics, analytical methods, and toxicological findings from human performance and postmortem cases

Synthetic cathinones are commonly abused novel psychoactive substances (NPS). We present a comprehensive systematic review addressing in vitro and in vivo synthetic cathinone pharmacokinetics, analytical methods for detection and quantification in biological matrices, and toxicological findings from human performance and postmortem toxicology cases. Few preclinical administration studies examined synthetic cathinone pharmacokinetic profiles (absorption, distribution, metabolism, and excretion), and only one investigated metabolite pharmacokinetics. Synthetic cathinone metabolic profiling studies, primarily with human liver microsomes, elucidated metabolite structures and identified suitable biomarkers to extend detection windows beyond those provided by parent compounds. Generally, cathinone derivatives underwent ketone reduction, carbonylation of the pyrrolidine ring, and oxidative reactions, with phase II metabolites also detected. Reliable analytical methods are necessary for cathinone identification in biological matrices to document intake and link adverse events to specific compounds and concentrations. NPS analytical methods are constrained in their ability to detect new emerging synthetic cathinones due to limited commercially available reference standards and continuous development of new analogs. Immunoassay screening methods are especially affected, but also gas-chromatography and liquid-chromatography mass spectrometry confirmation methods. Non-targeted high-resolution-mass spectrometry screening methods are advantageous, as they allow for retrospective data analysis and easier addition of new synthetic cathinones to existing methods. Lack of controlled administration studies in humans complicate interpretation of synthetic cathinones in biological matrices, as dosing information is typically unknown. Furthermore, antemortem and postmortem concentrations often overlap and the presence of other psychoactive substances are typically found in combination with cathinones derivatives, further confounding result interpretation.

A study to model the post-mortem stability of 4-MMC, MDMA and BZP in putrefying remains

There is currently limited data available on the stabilities of the three stimulants 4-methylmethcathinone (4-MMC), 3,4-methylenedioxymethamphetamine (MDMA) and N-benzylpiperazine (BZP) in a putrefying matrix. A Gas Chromatography Mass Spectrometry (GC-MS) method to determine the concentration of the three drugs in putrefying porcine liver over a three month period was developed and validated. Both 4-MMC and BZP were found to be unstable, becoming undetectable and having an average recovery of 52% respectively after one month at ambient room temperature (20°C). MDMA was found to be moderately stable, with an average recovery of 74% after three months at room temperature. This study indicated that the putrefaction process could have a significant impact on concentrations of 4-MMC and BZP in post-mortem cases involving putrefied remains.