The novel psychoactive substance 3-methylmethcathinone (3-MMC or metaphedrone): A review

A dual-mode biosensor based on silica inverse opal photonic crystals modulated electrochemiluminescence and dye displacement colorimetry for the sensitive detection of synthetic cathinone in water environment

To address the challenges posed by signal capacity limitations and the reliance of sensing methods on single analytical information, this study developed an electrochemiluminescence (ECL) and colorimetric dual-mode sensing platform for the precise detection of 4-chloroethcathinone (4-CEC) in water environments. Firstly, the accurate alignment of the reflection wavelength of appropriately sized silica inverse opal photonic crystals (SIOPCs) with the ECL emission wavelength of luminescent metal-organic frameworks (PCN-224) has been achieved via diameter modulation. This innovative design, which cleverly utilized the band-edge effect, improved the luminous intensity of the ECL sensor, leading to a significant boost in analytical performance. Secondly, the establishment of a colorimetric detection method for confirming the presence of 4-CEC in samples through visual observation of color changes was achieved by employing an aptamer-based dye displacement reaction, utilizing differential binding affinities between the aptamer and both the sulforhodamine B (SRB) and 4-CEC. Under the optimal experimental conditions, the dual-mode sensor demonstrated ECL detection of limits (LOD) of 2.6 × 10-13 g/L and colorimetric LOD of 6.5 ng/L for 4-CEC. These findings highlighted the tremendous potential of developing streamlined and efficient dual-signal readout platforms using ECL aptamer sensors for the precise determination of other Synthetic cathinones (SCs) in water environments.

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.

In vitro metabolism of cathinone positional isomers: does sex matter?

Synthetic cathinones, one of the most prevalent categories of new psychoactive substances, have been posing a serious threat to public health. Methylmethcathinones (MMCs), notably 3-MMC, have seen an alarming increase in their use in the last decade. The metabolism and toxicology of a large majority of synthetic cathinones, including 3-MMC and 2-MMC, remain unknown. Traditionally, male-derived liver materials have been used as in vitro metabolic incubations to investigate the metabolism of xenobiotics, including MMCs. Therefore, little is known about the metabolism in female-derived in vitro models and the potential sex-specific differences in biotransformation. In this study, the metabolism of 2-MMC, 3-MMC, and 4-MMC was investigated using female rat and human liver microsomal incubations, as well as male rat and human liver microsomal incubations. A total of 25 phase I metabolites of MMCs were detected and tentatively identified using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Seven sex-specific metabolites were detected exclusively using pooled male rat liver microsomal incubations. In addition, the metabolites generated from the sex-dependent in vitro metabolic incubations that were present in both male and female rat liver microsomal incubations showed differences in relative abundance. Yet, neither sex-specific metabolites nor significant differences in relative abundance were observed from pooled human liver microsomal incubations. This is the first study to report the phase I metabolic pathways of MMCs using in vitro metabolic incubations for both male and female liver microsomes, and the relative abundance of the metabolites observed from each sex.

Drug behaviors, sexually transmitted infection prevention, and sexual consent during chemsex: insights generated in the Budd app after each chemsex session

Chemsex refers to the intentional use of drugs before or during sex in a specific context, typically involving prolonged sex sessions with multiple partners. Engaging in chemsex is associated with a wide range of health risks and related risk behaviors. We developed a mobile phone application ('Budd-app') to support and inform chemsex participants, reduce potential negative impacts associated with chemsex (e.g., physical, psychological and social health harms), and encourage more reasoned participation. During Budd's development process, 11 participants completed a survey after each chemsex session they attended. This data collection approach provided precise experiences on drug related behavior, prevention measures for sexually transmitted infection and sexual consent on 63 chemsex sessions. The mean duration of chemsex sessions was 17.5 h. Polydrug use was reported during 95% of chemsex sessions with an average of 3.5 agents per session. Unsafe dosing occurred at 49% of chemsex sessions, and 9/11 participants dosed unsafely at least once. Seven participants did not consistently take measures to prevent STI transmission. Nine had experienced peer pressure, both regarding drug use and sexual health. The same number reported sex without consent, not respecting others' boundaries as well as their own boundaries not being respected. Many participants experienced negative impact of their chemsex behavior during (7/9) and after (8/9) chemsex. Through participants' behavior assessment during multiple chemsex sessions, 'within-person' variability can be clarified. This clarification provides valuable insights in personal, emotional and contextual vulnerabilities. These insights can direct an individualized care and support trajectory aimed at addressing those vulnerabilities.

Effects of acute metaphedrone exposure on the development, behaviour, and DNA integrity of zebrafish (Danio rerio)

The presence of new psychoactive substances (NPS), like metaphedrone (3-MMC), in aquatic environments raises concern about the potential negative effects on ichthyofauna. Therefore, the aim of this study was to evaluate the potential effects of 3-MMC on zebrafish embryonic development, behaviour, and DNA integrity. For that, embryos were exposed during 96 h post-fertilization to 3-MMC (0.1, 1, 10, and 100 µg/L). Overall, an increase in the eye area of zebrafish larvae was observed for the concentrations of 1 μg/L (increase of 24%) and 100 μg/L (increase of 25%) in comparison with the control group. Genetic damage was noted at the highest concentration (100 µg/L) with an increase of DNA damage (increase of 48%) and hyperactivity and disorganised swimming pattern characterised by an increase in speed (increase of 49%), total distance moved (increase of 53%), and absolute turn angle (increase of 48%) of zebrafish larvae. These findings pointed that, at environmental low levels, 3-MMC harmful effects are not expected to occur during critical development life stages of fish.

Effects of 3-methylmethcathinone on conditioned place preference and anxiety-like behavior: Comparison with methamphetamine

3-Methylmethcathinone (3-MMC), a drug belonging to synthetic cathinones family, raised public attention due to its harmful health effects and abuse potential. Although it has similar properties to other cathinone derivatives, the behavioral effects of 3-MMC remain largely unknown. In the present research, we evaluated the rewarding effect of 3-MMC using conditioned place preference (CPP) paradigm and its effect on anxiety-like behavior using elevated plus maze (EPM) and compared with methamphetamine (METH). Then, we performed a whole-brain c-Fos mapping to identify the specific brain regions in response to 3-MMC exposure and explored the changes of synaptic transmission in nucleus accumbens (NAc) using patch-clamp recording after chronic 3-MMC and METH exposure. 3-MMC induced CPP at higher doses of 3 or 10 mg/kg in rats and acute exposure of 3 mg/kg 3-MMC to rats produced anxiolytic-like effect, while anxiety-like behavior was increased after 7 days of injection with 3-MMC. Whole-brain immunostaining revealed increased c-Fos expression in anterior cingulate cortex (ACC), NAc and ventral tegmental area (VTA) after chronic 3-MMC injection compared with saline, which was similar to METH. Especially, 3-MMC induced more neural activation of VTA compared with METH. Finally, we found that amplitude of spontaneous inhibitory postsynaptic currents (sIPSCs) in NAc was decreased after chronic 3-MMC injection, while frequency of sIPSCs and spontaneous excitatory postsynaptic currents (sEPSCs) were not affected. Taken together, our results revealed the addictive potential of 3-MMC and its effect on anxiety-like behavior, which warn the risks of 3-MMC abuse and justify the control of synthetic cathinones. And 3-MMC selectively inhibit inhibitory but not excitatory transmission onto neurons in NAc, which may contribute to its effects.

Fatal Rectal Injection of 3-MMC in a Sexual Context. Toxicological Investigations Including Metabolites Identification Using LC-HRMS

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.

3-Methylmethcathinone (3-MMC) Poisonings: Acute Clinical Toxicity and Time Trend Between 2013 and 2021 in the Netherlands

STUDY OBJECTIVE

The synthetic cathinone 3-methylmethcathinone (3-MMC, or metaphedrone) has recently gained popularity. We studied the numbers of 3-MMC poisonings over time and the clinical effects following poisonings with 3-MMC.

METHODS

We performed a retrospective study on the numbers of self-reported 3-MMC poisonings to the Dutch Poisons Information Center (DPIC) from 2013 to June 2021. For poisonings reporting 3-MMC only, the symptoms were extracted and the Poisoning Severity Score (PSS) was determined. From 2016 to June 2019, a prospective cohort study on poisonings reporting only 3-MMC was performed, in which details on the clinical courses were collected through telephone interviews.

RESULTS

From 2013 to June 2021, the DPIC was consulted on 184 3-MMC poisonings. The number of poisonings increased from 1 in 2013 to 70 in the first half of 2021. In 84 poisonings with only 3-MMC (46%), sympathomimetic symptoms were commonly reported, including tachycardia (n=29, 35%), hypertension (n=17, 20%), and agitation (n=16, 19%). The initial PSS was usually minor (n=37, 44%) to moderate (n=39, 46%). Five patients (6%) experienced severe effects, including 3 patients experienced severe hypertension (systolic blood pressure >180 mmHg; n=3) and nonfatal cardiac arrest (n=1). Sympathomimetic symptoms (n=8) were also reported in the prospective cohort study. The percentage of moderate poisonings increased (n=6, 75%), and 1 (13%) severe poisoning was observed. Analytical confirmation of 3-MMC exposure was performed in 2 cases.

CONCLUSION

The number of 3-MMC poisonings reported to the DPIC has increased over time. Most poisonings with 3-MMC resulted in moderate toxicity and involved sympathomimetic effects, while severe effects were observed in 5 cases.

Central Effects of the Designer Drug Mephedrone in Mice—Basic Studies

Mephedrone belongs to the “party drugs” thanks to its psychostimulant effects, similar to the ones observed after amphetamines. Though mephedrone is used worldwide by humans and in laboratory animals, not all properties of this drug have been discovered yet. Therefore, the main aim of this study was to expand the knowledge about mephedrone’s activity in living organisms. A set of behavioral tests (i.e., measurement of the spontaneous locomotor activity, rotarod, chimney, elevated plus maze with its modification, novel object recognition, and pentylenetetrazol seizure tests) were carried out in male albino Swiss mice. Different dose ranges of mephedrone (0.05–5 mg/kg) were administered. We demonstrated that mephedrone at a dose of 5 mg/kg rapidly increased the spontaneous locomotor activity of the tested mice and its repeated administration led to the development of tolerance to these effects. Mephedrone showed the anxiolytic-like potential and improved spatial memory, but it did not affect recognition memory. Moreover, the drug seemed not to have any anticonvulsant or proconvulsant activity. In conclusion, mephedrone induces many central effects. It easily crosses the blood-brain barrier and peaks in the brain quickly after exposure. Our experiment on inducing a hyperlocomotion effect showed that mephedrone‘s effects are transient and lasted for a relatively short time.

Analytical Characterization of 3-MeO-PCP and 3-MMC in Seized Products and Biosamples: The Role of LC-HRAM-Orbitrap-MS and Solid Deposition GC-FTIR

Among the phencyclidine (PCP) and synthetic cathinone analogs present on the street market, 3-methoxyphencyclidine (3-MeO-PCP) is one of the most popular dissociative hallucinogen drugs, while 3-methylmethcathinone (3-MMC) is a commonly encountered psychostimulant. Numerous 3-MeO-PCP- and 3-MMC-related intoxication cases have been reported worldwide. Identification of the positional isomers of MeO-PCP and MMC families are particularly challenging for clinical and forensic laboratories; this is mostly due to their difficult chromatographic separation (particularly when using liquid chromatography–LC) and similar mass spectrometric behaviors. 3-MeO-PCP and 3-MMC were identified in two powders, detained by two subjects and seized by the police, by different analytical techniques, including liquid chromatography-high-resolution accurate-mass Orbitrap mass spectrometry (LC-HRAM-Orbitrap-MS), and solid deposition gas chromatography-Fourier transform infrared spectroscopy (sd-GC-FTIR). LC-HRAM-Orbitrap-MS allowed us to assign the elemental formulae C₁₈H₂₇NO (MeO-PCP) and C₁₁H₁₅NO (MMC) through accurate mass measurement of the two MH⁺ ions, and the comparison of experimental and calculated MH⁺ isotopic patterns. However, MH⁺ collision-induced product ions spectra were not conclusive in discriminating between the positional isomers [(3-MeO-PCP vs. 4-MeO-PCP) and (3-MMC vs. 4-MMC and 2-MMC)]. Likewise, sd-GC-FTIR easily allowed us to differentiate between the MeO-PCP and MMC positional isomers unambiguously, confirming the presence of 3-MeO-PCP and 3-MMC, due to the high-quality match factor of the experimental FTIR spectra against the target FTIR spectra of MeO-PCP and MMC isomers in a dedicated library. 3-MeO-PCP (in contrast to 3-MMC) was also detected in blood and urine samples of both subjects and analyzed in the context of routine forensic casework by LC-HRAM-Orbitrap-MS following a simple deproteinization step. In addition, this untargeted approach allowed us to detect dozens of phase I and phase II 3-MeO-PCP metabolites in all biological specimens. Analysis of the extracted samples by sd-GC-FTIR revealed the presence of 3-MeO-PCP, thus confirming the intake of such specific methoxy-PCP isomer in both cases. These results highlight the effectiveness of LC-HRAM-Orbitrap-MS and sd-GC-FTIR data in attaining full structural characterization of the psychoactive drugs, even in absence of reference standards, in both non-biological and biological specimens.

Interpol review of controlled substances 2016-2019

This review paper covers the forensic-relevant literature in controlled substances from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20Papers%202019.pdf.

Interpol review of toxicology 2016-2019

This review paper covers the forensic-relevant literature in toxicology from 2016 to 2019 as a part of the 19th Interpol International Forensic Science Managers Symposium. The review papers are also available at the Interpol website at: https://www.interpol.int/content/download/14458/file/Interpol%20Review%20.Papers%202019.pdf.

The Psychiatric Characteristics of People on a Mephedrone ("bath salts") Binge

Background: Despite solutions presented by the European Union and national regulations introduced by many countries, the problem of mephedrone (4-MMC) is growing. Objectives: The aim of this study was to investigate the effect of regular mephedrone intake with other psychoactive substances on the clinical picture of patients, including self-harms and suicide attempts. Methods: The study involved a group of 601 patients addicted to mephedrone who were admitted to a psychiatric hospital between 2010 and 2018 due to regular mephedrone intake. Results: There was a statistically significant relationship between sleep disorders and mephedrone combined with alcohol (p < .05) or cannabinols (p < .05). However, the highest number of statistically significant correlations was reported when mephedrone was combined with opioids. There was a growing year-on-year percentage of people who attempted suicide because of regular mephedrone intake (p < .001). The more psychoactive substances were combined with mephedrone, the greater the risk of attempted suicide (p < .01). 20% of the examined group were hospitalized several times. Among those hospitalized several times, significantly more people took more than one additional psychoactive substance (p < .01). Conclusions: The more psychoactive substances combined with mephedrone, the more clinical symptoms are associated with it.

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.

The new psychoactive substance 3-methylmethcathinone (3-MMC or metaphedrone) induces oxidative stress, apoptosis, and autophagy in primary rat hepatocytes at human-relevant concentrations

3-Methylmethcathinone (3-MMC or metaphedrone) has become one of the most popular recreational drugs worldwide after the ban of mephedrone, and was recently deemed responsible for several intoxications and deaths. This study aimed at assessing the hepatotoxicity of 3-MMC. For this purpose, Wistar rat hepatocytes were isolated by collagenase perfusion, cultured and exposed for 24 h at a concentration range varying from 31 nM to 10 mM 3-MMC. The modulatory effects of cytochrome P450 (CYP) inhibitors on 3-MMC hepatotoxicity were evaluated. 3-MMC-induced toxicity was perceived at the lysosome at lower concentrations (NOEC 312.5 µM), compared to mitochondria (NOEC 379.5 µM) and cytoplasmic membrane (NOEC 1.04 mM). Inhibition of CYP2D6 and CYP2E1 diminished 3-MMC cytotoxicity, yet for CYP2E1 inhibition this effect was only observed for concentrations up to 1.3 mM. A significant concentration-dependent increase of intracellular reactive species was observed from 10 μM 3-MMC on; a concentration-dependent decrease in antioxidant glutathione defences was also observed. At 10 μM, caspase-3, caspase-8, and caspase-9 activities were significantly elevated, corroborating the activation of both intrinsic and extrinsic apoptosis pathways. Nuclear morphology and formation of cytoplasmic acidic vacuoles suggest prevalence of necrosis and autophagy at concentrations higher than 10 μM. No significant alterations were observed in the mitochondrial membrane potential, but intracellular ATP significantly decreased at 100 μM. Our data point to a role of metabolism in the hepatotoxicity of 3-MMC, which seems to be triggered both by autophagic and apoptotic/necrotic mechanisms. This work is the first approach to better understand 3-MMC toxicology.

Dose-Response Pharmacological Study of Mephedrone and Its Metabolites: Pharmacokinetics, Serotoninergic Effects, and Impact of CYP2D6 Genetic Variation

Mephedrone (MEPH), the most widely consumed synthetic cathinone, has been associated with acute toxicity episodes. The aim of this report was to study its metabolic disposition and the impact of genetic variation of CYP2D6 on MEPH metabolism, in a dose range compatible with its recreational use. A randomized, crossover, phase I clinical trial was performed. Subjects received 50 and 100 mg (n = 3) and 150 and 200 mg (n = 6) of mephedrone and were genetically and phenotypically characterized for the CYP2D6 allelic variation. Our results showed a linear kinetics of mephedrone at the dose range assayed: plasma concentrations, cardiovascular and subjective effects, and blood serotonin concentrations all correlated in a dose-dependent manner. Mephedrone metabolic disposition is mediated by CYP2D6. Mephedrone pharmacology presented a linear dose-dependence within the range of doses tested. The metabolism of mephedrone by CYP2D6 implies that recreational users with no or low CYP2D6 functionality are exposed to unwanted acute toxicity episodes.