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Concept: Mephedrone


The drug 4-methylmethcathinone (4-MMC; aka, mephedrone, MMCAT, “plant food”, “bath salts”) is a recent addition to the list of popular recreational psychomotor-stimulant compounds. Relatively little information about this drug is available in the scientific literature, but popular media reports have driven recent drug control actions in the UK and several US States. Online user reports of subjective similarity to 3,4-methylenedioxymethamphetamine (MDMA, “Ecstasy”) prompted the current investigation of the thermoregulatory and locomotor effects of 4-MMC. Male Wistar and Sprague-Dawley rats were monitored after subcutaneous administration of 4-MMC (1-10 mg/kg ) using an implantable radiotelemetry system under conditions of low (23°C) and high (27°C) ambient temperature. A reliable reduction of body temperature was produced by 4-MMC in Wistar rats at 23°C or 27°C with only minimal effect in Sprague-Dawley rats. Increased locomotor activity was observed after 4-MMC administration in both strains with significantly more activity produced in the Sprague-Dawley strain. The 10 mg/kg s.c. dose evoked greater increase in extracellular serotonin, compared with dopamine, in the nucleus accumbens. Follow-up studies confirmed that the degree of locomotor stimulation produced by 10 mg/kg 4-MMC was nearly identical to that produced by 1 mg/kg d-methamphetamine in each strain. Furthermore, hypothermia produced by the serotonin 1(A/7) receptor agonist 8-hydroxy-N,N-dipropyl-2-aminotetralin (8-OH-DPAT) was similar in each strain. These results show that the cathinone analog 4-MMC exhibits thermoregulatory and locomotor properties that are distinct from those established for methamphetamine or MDMA in prior work, despite recent evidence of neuropharmacological similarity with MDMA.

Concepts: Serotonin, Agonist, Dopamine, Amphetamine, Methamphetamine, MDMA, Designer drug, Mephedrone


Novel psychoactive drugs, such as amphetamine-, cathinone-, benzofury- and tryptamine derivatives, gained high popularity on the global drug market in the last years. These drugs are sold via the Internet as for example “research chemicals”, “room odorizers” or “lawn fertilizers” by different online suppliers. They are also known as “Legal Highs”, among them, cathinone derivatives play an important role. Well known substituted cathinone derivatives are mephedrone, brephedrone and flephedrone. Since a couple of weeks, a chlorine substituted methcathinone derivative, namely clephedrone (4-chloromethcathinone), is commercially available via the Internet from The goal of this study was to confirm identity of this substance, which was done successfully by GC-MS and NMR. Since all cathinone derivatives are chiral, it was found out, whether the purchased sample was present as a racemic mixture. For this purpose, methods for enantioseparation by GC and CE were developed and applied successfully. In case of CE a chiral selector was added, whereas chiral separation with GC-MS was done indirectly, after derivatization of clephedrone with trifluoroacetyl-l-prolyl chloride.

Concepts: Drug, Drugs, Opioid, Psychoactive drug, Recreational drug use, Psychedelic drug, Mephedrone, Substituted cathinone


Mephedrone (4-methylmethcathinone (4-MMC)) (MEPH) is a new psychoactive substance (NPS) of the synthetic cathinone class. MEPH has a chiral center and exists as two enantiomers (R-,S-MEPH), yet stereospecific effects of MEPH have not been extensively investigated in preclinical assays. Because significant behavioral and neurochemical differences can exist between enantiomers, probing effects of stereochemistry on biological activity enables separation of adverse and therapeutic effects. Our prior work showed that R-MEPH, relative to S-MEPH, produced greater locomotor activation, place preference and facilitation of brain reward thresholds in rodents. The present study sought to determine if MEPH enantiomers display stereospecific reward and reinforcement in rat self-administration assays. In Experiment 1, rats were trained to self-administer racemic MEPH (0.50 mg/kg/inf), and dose substitution effects of R-MEPH (0.50 mg/kg/inf) and S-MEPH (0.25, 0.50, 2.00 mg/kg/inf) were examined. In Experiment 2, separate rats were trained to self-administer R-MEPH (0.25, 0.50, 2.00 mg/kg/inf) or S-MEPH (0.25, 0.50, 2.00 mg/kg/inf) and were thereafter evaluated under progressive-ratio access conditions. Within this cohort, 50-kHz ultrasonic vocalizations (USVs) were recorded to measure potential differences in subjective positive affect associated with MEPH enantiomer self-administration. We identified enantiomer- and dose-dependent effects on infusions earned during self-administration following acquisition of racemic MEPH, with greatest infusions under low-effort, fixed-ratio 1 access conditions from low-dose S-MEPH self-administration. When taxed with progressive-ratio access conditions, rats trained to self-administer R-MEPH showed higher breakpoints than those of rats trained to self-administer S-MEPH. Additionally, R-MEPH elicited greatest rates of 50-kHz USVs compared to S-MEPH. Taken together, these data suggest that the R-enantiomer of MEPH is primarily responsible for the rewarding, reinforcing, and motivational properties of racemic MEPH, which increases our understanding of stereospecific preferences pertaining to MEPH abuse.

Concepts: Therapeutic effect, Stereochemistry, Enantiomer, Motivation, Preference, Reward system, Reinforcement, Mephedrone


Methamphetamine and mephedrone are designer drugs with high abuse liability and they share extensive similarities in their chemical structures and neuropharmacological effects. However, these drugs differ in one significant regard: methamphetamine elicits dopamine neurotoxicity and mephedrone does not. From a structural perspective, mephedrone has a β-keto group and a 4-methyl ring addition, both of which are lacking in methamphetamine. Our previous studies found that methcathinone, which contains only the β-keto substituent, is neurotoxic, while 4-methylmethamphetamine, which contains only the 4-methyl ring substituent, elicits minimal neurotoxicity. In the present study, it was hypothesized that the varying neurotoxic potential associated with these compounds is mediated by the drug-releasable pool of dopamine, which may be accessed by methamphetamine more readily than mephedrone, methcathinone, and 4-methylmethamphetamine. To test this hypothesis, L-DOPA and pargyline, compounds known to increase both the releasable pool of dopamine and methamphetamine neurotoxicity, were combined with mephedrone, 4-methylmethamphetamine and methcathinone. Methamphetamine was also tested because of its ability to increase releasable dopamine. All three regimens significantly enhanced striatal neurotoxicity and glial reactivity for 4-methylmethamphetamine. Methcathinone neurotoxicity and glial reactivity were enhanced only by L-DOPA. Mephedrone remained non-neurotoxic when combined with either L-DOPA or pargyline. Body temperature effects of each designer drug were not altered by the combined treatments. These results support the conclusion that the neurotoxicity of 4-methylmethamphetamine, methcathinone and methamphetamine may be differentially regulated by the drug-releasable pool of dopamine due to β-keto and 4-methyl substituents, but that mephedrone remains non-neurotoxic despite large increases in this pool of dopamine.

Concepts: Drugs, Amphetamine, Methamphetamine, Neurotoxicity, The Conclusion, Designer drug, Mephedrone, Methcathinone


Although the synthetic cathinone 4-methylmethcathinone (4-MMC, mephedrone) has been a subject of intensive research investigation, the pharmacological mechanisms involved in its interoceptive stimulus effects have yet to be fully characterized.

Concepts: Cathinones, Mephedrone, Methcathinone, Substituted cathinone


Background Mephedrone (4-methylmethcathinone, 4-MMC), a ring-substituted synthetic cathinone derivative has become established as a permanent illicit drug in the dynamic new psychoactive substances (NPS) scene. Objective This review summarizes current knowledge on mephedrone concentrations in biological samples from cases of acute intoxications (fatal and non-fatal), pharmacokinetics studies, wastewater and anonymous pooled urine analysis in order to provide an overview of the reliable scientific knowledge on toxicokinetics of mephedrone in humans. Method The PubMed® database complemented with Google Scholar® was systematically searched to find published cases of mephedrone intoxications. The searches were done using the keyword “mephedrone OR 4-methylmethcathinone” in association to each of the following strategies: i) “intoxication OR poisoning”; ii) “(blood OR serum OR plasma”) OR “urine” OR (“saliva OR oral fluid”) OR “hair”; iii) “forensic toxicology samples”; iv) “wastewater OR sewage OR pooled urine” and v) “toxicity OR death OR fatal”. Results Since 2010, a total of 97 fatal cases and 57 non-fatal intoxication cases were identified that presented mephedrone concentrations in human biological matrices attributed directly or indirectly to mephedrone. Typical subjects involved were young male with concomitant use of other drugs (psychostimulants, cannabis, alcohol and other depressants). Mephedrone mean blood concentration from fatal cases was 2,663 ng/mL (range 51-22,000 ng/mL), from non-fatal cases was 166 ng/mL (range, 13-412 ng/mL), that resulted in a similar range from data found in controlled studies with no acute toxicity associated (135 ng/mL, range 52-218 ng/mL). Forensic epidemiology studies based on wastewater and anonymous pooled urine analysis point towards similar variations in use (nightclub scene) to those self-reported in surveys and questioners. Conclusion Mephedrone blood concentrations in cases of fatal intoxications were higher than in non-fatal cases. In both cases, great variability in mephedrone concentration potentially attributable to interindividual differences in pharmacokinetics-pharmacodynamics and poly-drug use complicates the interpretation of the forensic toxicological analysis.

Concepts: Drug, Toxicology, Toxicity, Poison, Psychoactive drug, Recreational drug use, Depressant, Mephedrone


Synthetic cathinones, 4-methylmethcathinone (4-MMC) and 3,4-methylenedioxypyrovalerone (MDPV), serve as a substrate or blocker at monoaminergic transporters, respectively, and produce locomotor stimulant effects in rodents. The present study investigated in rats the effects of repeated exposure to 4-MMC, MDPV, or mixtures of the two on the induction of locomotor sensitization and expression of cross-sensitization to cocaine.

Concepts: Present, Magnesium sulfate, Cathinones, Mephedrone, Methcathinone, Euphoriants, Substituted cathinone


Flephedrone (4-fluoromethcathinone, 4-FMC) was analysed using (1)H, (13)C, (15)N HMBC, and (19)F observe spectroscopy, gas chromatography-flame ionisation detection (GC-FID), and electrospray ionisation-mass spectrometry (ESI-MS). Analysis of four 4-FMC samples (from a Bristol nightclub in 2013) showed that they all contained benzocaine as the cutting agent present in different amounts from 5 to 12%. Using these methods, we successfully differentiated between flephedrone regioisomers and mephedrone in an analytical method validated for flephedrone as a substituted cathinone. The data show that these now illegal cathinone-derived stimulants (highs) are now being cut; users cannot be certain of the purity of the drug they are taking. Furthermore, there are risks from the pharmaceutically active cutting agents themselves.

Concepts: Spectroscopy, Mass spectrometry, Cathinones, Mephedrone, Substituted cathinone, Flephedrone, Substituted amphetamine


In recent years there has been a large increase in the use of substituted cathinones such as mephedrone (4-methylmethcathinone, 4-MMC), a psychostimulant drug that shows a strong resemblance to methamphetamine (METH). Unlike METH, which can produce clear long-term effects, the effects of 4-MMC have so far remained elusive. We employ manganese-enhanced magnetic resonance imaging (MEMRI), a highly sensitive method for detecting changes in NEURONAL ACTIVATION: , to investigate the effects of METH and 4-MMC on the brain.

Concepts: Brain, Magnetic resonance imaging, Methamphetamine, Cathinones, Designer drug, Mephedrone, Methcathinone, Substituted cathinone


Background. 3-Methylmethcathinone (3-MMC) is a synthetic cathinone stimulant structurally related to the new psychoactive substance (NPS) mephedrone (4-methylmethcathinone, 4-MMC). We describe a case series of analytically confirmed intoxications involving 3-MMC presented to emergency departments in Sweden and included in the STRIDA project. Study design. Observational case series of consecutive patients with self-reported or suspected use of NPS presenting to hospitals in Sweden between August 2012 and March 2014. Methods. NPS analysis was performed by a liquid chromatography-mass spectrometry (MS)/MS method that is updated with new substances as they appear. Data on clinical features were collected during Poisons Information Centre consultations and retrieved from medical records. Results. 3-MMC was detected in 50 (6.4%) of the 786 cases included in the STRIDA project during the 20-month study period, with the peak occurring in August 2013. The age range of patients testing positive for 3-MMC was 17-49 years (median 24) and 76% of them were men. The 3-MMC concentration in serum ranged between 0.002 and 1.49 μg/mL (median, 0.091) and between 0.007 and 290 μg/mL (median, 3.05) in urine. Co-exposure to other NPS and/or traditional drugs was very common, and 3-MMC mono-intoxication was found in only 4 (8%) cases. The most frequent clinical features were tachycardia (48% of cases) and agitation (42%). Other features included a reduced level of consciousness (32%), dilated pupils (24%), hallucinations (20%), diaphoresis (12%), seizures (8%), and hyperthermia (6%). Most patients (60%) needed hospital care for only 1 day but in 8% for 3 days or longer. Conclusion. The majority of patients with analytically confirmed 3-MMC exposure had sympathomimetic features similar to those associated with mephedrone intoxication. However, the high incidence of co-exposure to other drugs makes the clinical interpretation difficult. Nevertheless, 3-MMC was associated with a high admittance rate to intensive care (30%), and detected in two cases with a fatal outcome, suggesting that 3-MMC is a harmful drug.

Concepts: Hospital, Drug, Drugs, Case, Psychoactive drug, Cocaine, Recreational drug use, Mephedrone