Deaths of individuals aged 16-24 years in the UK after using mephedrone

Effects of congeners of amphetamine on the human heart

Central stimulatory and hallucinogenic drugs of abuse like amphetamine and most congeners of amphetamine can have cardiac harmful effects. These cardiac side effects can lead to morbidities and death. In this paper, we review current knowledge on the direct and indirect effects of these amphetamine congeners on the mammalian heart-more specifically, the isolated human heart muscle preparation. In detail, we address the question of whether and how these drugs affect cardiac contractility and their mechanisms of action. Based on this information, further research areas are defined, and further research efforts are proposed.

A narrative review of the neuropharmacology of synthetic cathinones-Popular alternatives to classical drugs of abuse

OBJECTIVE

To review the literature on the neuropharmacology of synthetic cathinones.

METHODS

A comprehensive literature search was carried out across multiple databases (mainly PubMed, World Wide Web, and Google Scholar) using relevant keywords.

RESULTS

Cathinones exhibit a broad toxicological profile, mimicking the effects of a wide variety of 'classic drugs' such as 3,4-methylenedioxymethamphetamine (MDMA), methamphetamine and cocaine. Even small structural changes affect their interactions with key proteins. This article reviews existing knowledge of the mechanisms of action of cathinones at the molecular level, and key findings from research on their structure-activity relationship. The cathinones are also classified according to their chemical structure and neuropharmacological profiles.

CONCLUSIONS

Synthetic cathinones represent one of the most numerous and widespread groups among new psychoactive substances. Initially developed for therapeutic purposes, they quickly started to be used recreationally. With a rapidly increasing number of new agents entering the market, structure-activity relationship studies are valuable for assessing and predicting the addictive potential and toxicity of new and potential future substances. The neuropharmacological properties of synthetic cathinones are still not fully understood. A full elucidation of the role of some key proteins, including organic cation transporters, requires detailed studies.

Contribution of Drugs to Drowning in Scotland from 1996 to 2020

OBJECTIVE

Psychoactive substance use (including alcohol) can affect risk perception, leading to accidents and deaths. There is little detailed or up-to-date information on the role of drugs in drownings in the United Kingdom (UK). This Scottish case-study aimed to fill this knowledge gap.

METHODS

Anonymised data for individual drug-poisoning-related drowning registered from 1996 to 2020 were provided by the National Records of Scotland. Statistical analyses were performed for socio-demographics, ICD coding, cause of death, and substances implicated.

RESULTS

It has been reported that death registrations increased from 7 in 2017 to over 20 during 2019-20. These deaths (n=160) accounted for <1% of all drug-related poisoning deaths; this proportion rose to record levels (c.1.5%) during 2019-20. Most deaths (69%) involved males. The mean age was 39.8 (range 16-81, SD 15.0) years. The main drug classes implicated were: opiates/opioids (41%), benzodiazepines (31%), stimulants (19%), and antidepressants (14%). Moreover, 57% of benzodiazepines were 'designer' drugs.

CONCLUSION

Scottish drownings associated with drug consumption are increasing rapidly. It has been observed that central nervous system depressant drugs (e.g., opioids, benzodiazepines, alcohol) are often involved in drowning. 'Designer' benzodiazepines are a principal factor in increasing Scottish drug-related poisoning deaths; they may be partially responsible for increasing numbers of related drownings. Evidence-based strategies to further reduce the number of preventable drownings should include reference to the dangers of drugs.

Characteristics of fatal 'novel' synthetic opioid toxicity in Australia

BACKGROUND

Aims: To determine 1. The characteristics of all recorded cases of fatal drug poisoning involving novel synthetic opioids (NSOs) in Australia; 2. The toxicology of cases; and 3. The major autopsy findings.

METHODS

Review of all fatal poisonings related to NSOs in Australia 2000-2021 identified in the National Coronial Information System.

RESULTS

Thirty-one cases were identified, 96.8% due to unintentional drug toxicity. The mean age was 31.9 years and 87.1% were male. Only six were aged over forty. A history of substance use problems was documented in 80.6% and 58.1% had a history of injecting drug use. In 32.3% the final route of administration of a NSO was by non-injecting routes of administration. Ten NSOs were identified. Fentanyl analogues were present in 67.2%, most commonly furanylfenatyl (19.4%). Other NSO types were present in 39.7%, most commonly U-47700 (35.5%). Substances other than NSOs were present in 90.3%, most commonly benzodiazepines (67.7%) and other opioids (51.6%). A CNS depressant in addition to NSOs was present in 90.3%, and a new psychoactive substance other than a NSO in 25.8%. Pulmonary oedema was diagnosed in 82.6%, aspiration of vomitus in 30.4%, and acute bronchopneumonia in 17.4%.

CONCLUSIONS

Ten NSOs were identified. Case characteristics suggest a younger cohort whose profile is more typical of use of other NPS than of the established opioids. A large proportion used NSOs by non-injecting routes of administration.

Attempted suicide with intravenous methamphetamine and chemsex

BACKGROUND

Undiagnosed attention deficit and hyperactivity disorder (ADHD) is frequent in the substance abuse disorder population, and has an intense repercussion in the daily life of the patients. That condition increases the risk of substance abuse disorders and risk conducts derived from impulsivity. There are not yet studies linking ADHD and the new emergent phenomenon of chemsex, that is, the action of use the intravenous injection of substances in sex parties, with the objective of maximising the practising time and sexual experience. In these sessions, different types of drug are used, for example, synthetic cathinone or mephedrone, and may lead to diverse medical and psychiatric complications like psychosis, aggressiveness and suicide ideation.

CASE

We report the case of a 44-year-old man admitted into a psychiatric unit, presenting with 2^nd time suicidal high risk attempt using intravenous methamphetamine and a dissolvent acid in the context of a depressive episode, after practising chemsex sessions almost every weekend with psychoactive substances taken orally, intravenously and intrarectally. The patient also presented psychotic symptoms from the use of these drugs. When we interviewed the patient during his hospital stay, we observed that there were symptoms of a possible attention and hyperactivity deficit, which was confirmed by study with ASRS-V1.1 and WURS scales. After three weeks, the patient improved substantially as his depressive symptoms and autolytic ideation disappeared.

DISCUSSION

Look for "hidden" symptoms in substance abuse disorder patients. It is important not to delay important diagnostic tests and to prevent complications. Psychiatric and medical conditions related to chemsex have been reported in several European cities, and recently in Spain where it is an emergent phenomenon and a problem concerning medical and political institutions. The suicide attempt with metamphetamine and acid taken intravenously in the case we report, depressive and psychotic symptoms, addiction, suicide attempts and medical complications are described.

Effects of synthetic cathinone naphyrone in the conditioned place preference test - evidence of its addictive potential

Naphyrone, also known as NRG-1, is a novel psychoactive substance (NPS), a cathinone with stimulatory properties available on the grey/illicit drug market for almost a decade. It is structurally related to infamously known powerful stimulants with the pyrovalerone structure, such as alpha-pyrrolidinovalerophenone (α-PVP) or methylenedioxypyrovalerone (MDPV) that are labeled as a cheap replacement for cocaine and other stimulants. Despite the known addictive potential of α-PVP and MDPV, there are no studies directly evaluating naphyrone's addictive potential e.g., in conditioned place preference (CPP) test or using self-administration. Therefore, our study was designed to evaluate the addictive potential in a CPP test in male Wistar rats and compare its effect to another powerful stimulant with a high addictive potential - methamphetamine. Naphyrone increased time spent in the drug-paired compartment with 5 and 20mg/kg s.c. being significant and 10mg/kg s.c. reaching the threshold (p = 0.07); the effect was comparable to that of methamphetamine 1.5mg/kg s.c. The lowest dose, naphyrone 1mg/kg s.c., had no effect on CPP. Interestingly, no dose response effect was detected. Based on these data, we are able to conclude that naphyrone has an addictive potential and may possess a significant risk to users.

New Psychoactive Substances and Suicidality: A Systematic Review of the Current Literature

Background and Objectives: Over the past twenty years a large number of new psychoactive substances (NPS) have entered and modified the recreational drug scene. Their intake has been associated with health-related risks, especially so for vulnerable populations such as people with severe mental illness, who might be at higher risk of suicidality or self-injurious behavior. This paper aims at providing an overview of NPS abuse and the effects on mental health and suicidality issues, by performing a literature review of the current related knowledge, thereby identifying those substances that, more than others, are linked to suicidal behaviors. Materials and Methods: A comprehensive and updated overview of the literature regarding suicidality and NPS categories has been undertaken. An electronic search was performed, including all papers published up to March 2021, using the following keywords “NPS” OR “new psychoactive substances” OR “novel psychoactive substances” OR “synthetic cannabinoids” OR “phenethylamines” OR “synthetic cathinones” OR “tryptamines” OR “piperazines” OR “new synthetic opioids” OR “designer benzodiazepines” AND (“suicide” OR “suicidality”) NOT review NOT animal on the PubMed, Cochrane Library, and Web of Science online databases. Results: Suicidality and self-injurious behavior appear to be frequently associated with some NPS such as cathinones, synthetic cannabinoids, and new synthetic opioids. The results are organized according to the substances recorded. Conclusion: The growing use of NPS has become a significant clinical issue, causing increasing concern and challenges for clinicians working in both mental health and emergency departments. Thus, considering the associations between NPS and suicidality or self-injurious behaviors, areas where suicide-prevention efforts and strategies might be focused are the early detection, monitoring, and restriction of NPS.

Post-mortem distribution of mephedrone and its metabolites in body fluids and organ tissues of an intoxication case

New psychoactive substances (NPS) are substances that continue to appear on the drug market to bypass controlled substance legislation. Mephedrone or 4-methylmethcathinone is becoming the most popular new psychoactive substance among youth as a recreational drug. The present study describes the optimization and validation of a sensitive method that combined clean up procedure and LC-MS/MS technique designed to simultaneously determine the presence of Mephedrone and its two metabolites (normephedrone as active metabolite and dyhidromephedrone) in post-mortem specimens (body fluids and organ tissues). To date, this is the first determination of Mephedrone metabolites in post-mortem specimens. The validated method was applied to a fatal Mephedrone intoxication case. The distribution of the three analytes in different post-mortem matrices was presented. The toxicological results of the studied case are discussed, along with autopsy, histopathological evidence and crime-scene information. The toxicological results presented in the study provide new data relative to mephedrone and the distribution of its metabolites in post-mortem specimens. In our opinion, the metabolite concentration database must be developed because the metabolites may be linked to toxicity. The pattern of parent drug and its metabolites can be helpful in the interpretation of fatal cases involving mephedrone, which will contribute to the currently limited knowledge about mephedrone and metabolites concentrations.

Outcomes associated with scheduling or up-scheduling controlled substances

BACKGROUND

Many nations place drugs into various "schedules" according to their risk of abuse and/or recognized medical value that vary in terms of their restrictions. To mitigate diversion or abuse, drugs sometimes get rescheduled or are scheduled for the first time. Until now, there have not been efforts to integrate lessons from across the range of such past events.

METHODS AND DATA

We searched for peer-reviewed evaluations of instances of (re-)scheduling drugs in the United States after 1969 and a comparably large set of instances from other countries. Those 109 articles were supplemented by 30 others found in other ways but not meeting those search criteria (e.g., because the information on rescheduling was a minor part of a more general article).

FINDINGS

Findings are reported for many outcomes and with diverse measures over different timelines, making standardization of outcomes difficult. For more than half of the events for which quantitative outcomes were reported, there were declines in use-related measures by at least 40 percent. It is common for there to be reports of increases in indicators pertaining to other substances, sometimes more dangerous but sometimes less dangerous; overall, substitution appears to occur, but be partial.

CONCLUSION

Scheduling and up-scheduling can - though does not always - have substantial effects on a range of outcomes. Substitution to other substances is a possibility and so should be anticipated.

Attempted Suicide with Intravenous Methamphetamine and Chemsex

BACKGROUND

Undiagnosed attention deficit and hyperactivity disorder (ADHD) is frequent in the substance abuse disorder population, and has an intense repercussion in the daily life of the patients. That condition increases the risk of substance abuse disorders and risk conducts derived from impulsivity. There are not yet studies linking ADHD and the new emergent phenomenon of chemsex, that is, the action of use the intravenous injection of substances in sex parties, with the objective of maximising the practising time and sexual experience. In these sessions, different types of drug are used, for example, synthetic cathinone or mephedrone, and may lead to diverse medical and psychiatric complications like psychosis, aggressiveness and suicide ideation.

CASE

We report the case of a 44-year-old man admitted into a psychiatric unit, presenting with 2nd time suicidal high risk attempt using intravenous methamphetamine and a dissolvent acid in the context of a depressive episode, after practising chemsex sessions almost every weekend with psychoactive substances taken orally, intravenously and intrarectally. The patient also presented psychotic symptoms from the use of these drugs. When we interviewed the patient during his hospital stay, we observed that there were symptoms of a possible attention and hyperactivity deficit, which was confirmed by study with ASRS-V1.1 and WURS scales. After three weeks, the patient improved substantially as his depressive symptoms and autolytic ideation disappeared.

DISCUSSION

Look for "hidden" symptoms in substance abuse disorder patients. It is important not to delay important diagnostic tests and to prevent complications. Psychiatric and medical conditions related to chemsex have been reported in several European cities, and recently in Spain where it is an emergent phenomenon and a problem concerning medical and political institutions. The suicide attempt with metamphetamine and acid taken intravenously in the case we report, depressive and psychotic symptoms, addiction, suicide attempts and medical complications are described.

The rise of new psychoactive substances and psychiatric implications: A wide-ranging, multifaceted challenge that needs far-reaching common legislative strategies

The ever-growing number of novel psychoactive substances (NPS) that have been surfacing globally, as well as related changes in drug abuse trends, undoubtedly constitute a difficult and multifaceted challenge for psychiatry. The intake and abuse of such substances has been linked to a risk of psychopathological disturbances, which stem from imbalances of a range of neurotransmitter pathways and receptors. Through an analysis of relevant research articles and reviews (particularly those outlining NPS neurological and cerebral mechanisms of action and psychopathological consequences arising from NPS abuse; research papers more closely focused on chemical/pharmacological aspects have been ruled out), through a systematic analysis of Pubmed, Medline, PsycLIT and EMBASE literature, as well as data released by health care institutions and drug enforcement agencies (among which the World Health Organization, the United Nations Office on Drugs and Crime, the European Monitoring Centre for Drugs and Drug Addiction, Eurojust, the Novel Psychoactive Treatment UK Network, the Court of Justice of the European Union), the authors aimed to elaborate on the most relevant data relative to NPS-related psychiatric effects, focusing on the conceptual and definition-related complexities inherent to NPS, clinical management and motivations for NPS use; moreover, an effort has been made to highlight the possible measures in order to tackle the unremitting rise of such elusive and potentially harmful substances.

Mephedrone and MDMA: A comparative review

Mephedrone and MDMA are both constituents of party drugs, with mephedrone being relatively new compared to MDMA. This review compares current knowledge regarding the patterns of usage and neuropsychobiological effects of both mephedrone and MDMA. Both drugs share common psychoactive effects, the duration of which is significantly shorter with mephedrone use, attributing towards a pattern of binge use among users. Both drugs have also been associated with adverse health, psychiatric, and neurocognitive problems. Whilst there is extensive research into the psychobiological problems induced by MDMA, the evidence for mephedrone is comparatively limited. The adverse effect profile of mephedrone appears to be less severe than that of MDMA. Users often believe it to be safer, although both drugs have been associated with overdoses. The neurotoxic potential of mephedrone appears to be low, whereas MDMA can cause long-term damage to the serotonergic system, although this needs further investigation. The abuse liability of mephedrone is significantly greater than that of MDMA, raising concerns regarding the impact of lifetime usage on users. Given that mephedrone is relatively new, the effects of long-term exposure are yet to be documented. Future research focused on lifetime users may highlight more severe neuropsychobiological effects from the drug.

Mephedrone and Alcohol Interactions in Humans

Mephedrone (4-MMC, mephedrone) is a synthetic cathinone derivative included in the class of new psychoactive substances. It is commonly used simultaneously with alcohol (ethanol). The aim of the present study was to evaluate the interactions on subjective, cardiovascular and hormone effects and pharmacokinetics between mephedrone and alcohol in humans. Eleven male volunteers participated as outpatients in four experimental sessions in a double-blind, randomized, cross-over, and placebo-controlled clinical trial. Participants received a single oral dose of 200 mg of mephedrone plus 0.8 g/kg of alcohol (combination condition); 200 mg of mephedrone plus placebo alcohol (mephedrone condition); placebo mephedrone plus 0.8 g/kg of ethanol (alcohol condition); and placebo mephedrone plus placebo alcohol (placebo condition). Outcome variables included physiological (blood pressure, heart rate, temperature, and pupil diameter), psychomotor (Maddox wing), subjective (visual analogue scales, Addiction Research Center Inventory 49 item short form, and Valoración de los Efectos Subjetivos de Sustancias con Potencial de Abuso questionnaire), and pharmacokinetic parameters (mephedrone and ethanol concentrations). The study was registered in ClinicalTrials.gov, number NCT02294266. The mephedrone and alcohol combination produced an increase in the cardiovascular effects of mephedrone and induced a more intense feeling of euphoria and well-being in comparison to the two drugs alone. Mephedrone reduced the sedative effects produced by alcohol. These results are similar to those obtained when other psychostimulants such as amphetamines and 3,4-methylenedioxymethamphetamine are combined simultaneously with alcohol. The abuse liability of mephedrone combined with alcohol is greater than that induced by mephedrone alone.

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.

The Bridge Between Classical and "Synthetic"/Chemical Psychoses: Towards a Clinical, Psychopathological, and Therapeutic Perspective

The critical spread and dissemination of novel psychoactive substances (NPS), particularly among the most vulnerable youngsters, may pose a further concern about the psychotic trajectories related to the intake of new synthetic drugs. The psychopathological pattern of the "new psychoses" appears to be extremely different from the classical presentation. Therefore, clinicians need more data on these new synthetic psychoses and recommendations on how to manage them. The present mini-review aims at deepening both the clinical, psychopathological features of synthetic/chemical NPS-induced psychoses and their therapeutic strategies, according to the different NPS classes implicated, by underlining the main differences with the "classical" psychoses. A comprehensive review was conducted using the PubMed/Medline database by combining the search strategy of free-text terms and exploding a range of MESH headings relating to the topics of novel psychoactive substances and synthetic/chemical psychoses as follows: {(Novel Psychoactive Substances[Title/Abstract]) AND Psychosis[Title/Abstract])} and for each NPS categories as well, focusing on synthetic cannabinoids and cathinones, without time and/or language restrictions. Finally, an overview of the main clinical and psychopathological features between classical versus NPS-induced chemical/synthetic psychoses is provided for clinicians working with dual disorders and addiction psychiatry. Further insight is given here on therapeutic strategies and practical guidelines for managing patients affected with synthetic/chemical NPS-induced psychoses.

Characteristics and circumstances of death related to new psychoactive stimulants and hallucinogens in Australia

BACKGROUND

New psychoactive stimulants and hallucinogens comprise a range of "designer drugs" that have risen to prominence in the 21^st century. The study aimed to: 1. Determine the characteristics, and circumstances of death, of all recorded cases of new psychoactive stimulant and hallucinogen-related death in Australia; 2. Determine the toxicology of such deaths; and 3. Determine the major organ pathology of cases.

METHODS

All cases in which new psychoactive stimulants were a mechanism contributory to death were retrieved from the National Coronial Information System (2000-2017). Information was collected on cause of death, demographics, drug use history, circumstances of death, toxicology and major organ pathology.

RESULTS

82 cases were identified. The mean age was 30.7yrs and 86.6% were male. Circumstances of death were: accidental drug toxicity (59.8%), traumatic accident (15.9%), suicide (12.2%) and natural disease (2.4%). The most common clinical presentation observed proximal to death was delirium (26.8%). Delirium was mostly frequently observed after phenethylamine consumption (72.2%). The most common cardiovascular diagnosis at autopsy was replacement fibrosis, indicative of previous ischemia (10.5%). New psychoactive stimulants and hallucinogens detected in toxicology were: cathinones (75.7%), phenethylamines (22.0%) and piperazines (6.1%). Other substances were present in 83.5% of cases, most commonly established controlled psychostimulants (58.2%).

CONCLUSIONS

Acute toxicity was the most common cause of death, but more than a third of deaths were due to trauma. Cathinones were the most commonly detected of the new psychoactive stimulants and hallucinogens. Delirium was the most frequently reported clinical sign proximal to death and was strongly associated with the phenethylamines.

The use of new psychoactive substances (NPS) in young people and their role in mental health care: a systematic review

Introduction: Over the past 10 years, a large number of New Psychoactive Substances (NPS) have entered the recreational drug scenario. NPS intake has been associated with health-related risks, and especially so for vulnerable populations such as the youngsters. Currently, most knowledge on the NPS health effects is learnt from both a range of users' reports, made available through the psychonauts' web fora, and from the few published, related toxicity, clinical observations.Areas covered: This paper aims at providing an overview of NPS effects on youngsters' mental health, whilst performing a systematic review of the current related knowledge.Expert opinion: NPS consumption poses serious health risks, due to both a range of unpredictable clinical pharmacological properties and the typical concomitant use of other psychoactive molecules; overall, this can lead to near misses and fatalities. In comparison with adults, the central nervous system of children/adolescents may be more vulnerable to the activity of these molecules, hence raising even further the levels of health-related concerns. More research is needed to provide evidence of both short- and long-term effects of NPS, related health risks, and their addiction potential.

Synthetic Cathinone Use Among Polysubstance Users: Indirect Indicator of Indiscriminate Drug Taking or Preferred Drug of Abuse?

A survey pertaining to synthetic cathinone (SC) use was completed by 499 polysubstance users enrolled in a residential recovery program in the Southeastern United States. Of the final sample, 28% reported ever SC use. SC-users, compared with nonusers, were more often younger (32.7 vs. 36.0, p = .001), White (93.4% vs. 80.8%, p = .001), and on probation/parole since 2010 (80.9% vs. 70.9%, p = .032). SC-users evidenced extensive drug histories and were less likely to be enrolled in an urban-based program, compared to a rural, Appalachian-based program (73.8% vs. 86.6%, p = .001). Use of synthetic cannabinoids (adjusted odds ratio [AOR] = 1.9, p = .044), kratom (AOR = 1.7, p = .045), and inhalants (AOR = 2.3, p = .001) were significantly associated with SC use. Approximately 23% of SC-users preferred SCs to amphetamines or cocaine; however, only 3.6% ranked SC as their most preferred drug. Past-year SC use declined to 6.6%. Among polysubstance users in this sample, SC use may be a potential indicator of versatile and indiscriminate drug-taking.

Phantom menace: novel psychoactive substances and the UK Armed Forces

Novel psychoactive substances (NPS) encompass a large group of synthesised compounds specifically designed to mimic traditional recreational drugs. Current UK Armed Forces compulsory drug testing does not screen for these substances, making them tempting to the small proportion of UK Armed Forces personnel who indulge in recreational drug use. The acute and chronic sequelae of NPS misuse are widely variable and associated with high morbidity. In this paper, we discuss NPS pharmacology and clinical presentation. We describe toxidromes and management of patients who have misused NPS.Finally, we reflect on the legal, ethical and military consequences of NPS misuse for both the service person misusing NPS and the Military Physician providing their care.

Mephedrone (4-Methylmethcathinone): Acute Behavioral Effects, Hyperthermic, and Pharmacokinetic Profile in Rats

Mephedrone (MEPH) is a synthetic cathinone derivative with effects that mimic MDMA and/or cocaine. Our study in male Wistar rats provides detailed investigations of MEPH's and its primary metabolite nor-mephedrone's (nor-MEPH) pharmacokinetics and bio-distribution to four different substrates (serum, brain, lungs, and liver), as well as comparative analysis of their effects on locomotion [open field test (OFT)] and sensorimotor gating [prepulse inhibition of acoustic startle reaction (PPI ASR)]. Furthermore, in order to mimic the crowded condition where MEPH is typically taken (e.g., clubs), the acute effect of MEPH on thermoregulation in singly- and group-housed rats was evaluated. Pharmacokinetics of MEPH and nor-MEPH after MEPH (5 mg/kg, sc.) were analyzed over 8 h using liquid chromatography with mass spectrometry. MEPH (2.5, 5, or 20 mg/kg, sc.) and nor-MEPH (5 mg/kg, sc.) were administered 5 or 40 min before the behavioral testing in the OFT and PPI ASR; locomotion and its spatial distribution, ASR, habituation and PPI itself were quantified. The effect of MEPH on rectal temperature was measured after 5 and 20 mg/kg, sc. Both MEPH and nor-MEPH were detected in all substrates, with the highest levels detected in lungs. Mean brain: serum ratios were 1:1.19 (MEPH) and 1:1.91 (nor-MEPH), maximum concentrations were observed at 30 min; at 2 and 4 h after administration, nor-MEPH concentrations were higher compared to the parent drug. While neither of the drugs disrupted PPI, both increased locomotion and affected its spatial distribution. The effects of MEPH were dose dependent, rapid, and short-lasting, and the intensity of locomotor stimulant effects was comparable between MEPH and nor-MEPH. Despite the disappearance of behavioral effects within 40 min after administration, MEPH induced rectal temperature elevations that persisted for 3 h even in singly housed rats. To conclude, we observed a robust, short-lasting, and most likely synergistic stimulatory effect of both drugs which corresponded to brain pharmacokinetics. The dissociation between the duration of behavioral and hyperthermic effects is indicative of the possible contribution of nor-MEPH or other biologically active metabolites. This temporal dissociation may be related to the risk of prolonged somatic toxicity when stimulatory effects are no longer present.

Fatal Poisonings Associated with New Psychoactive Substances

This chapter describes how new psychoactive substances (NPS) have been involved in fatal intoxications from 2010 and onwards. It summarizes the circumstances, antemortem symptoms, and adverse effects that have led to death after ingestion of one or more NPS and tabulates concentrations, and postmortem findings from these intoxications.Consumption of NPS exerts health problems and unknown risks for the users. Data on toxicity of many NPS are scarce or nonexistent and long-term toxicity and risks are still largely unknown. In addition, purity and composition of products containing NPS are often inconsistent or not known, which places users at high risk as evidenced by hospital emergency admissions and deaths.The most serious threat to drug users are the synthetic opioids that with strong central nervous depressant effects have caused numerous accidental deaths spread over the entire globe. The synthetic cannabinoids seem to be the most unpredictable with no clear toxidrome and unknown or poorly understood mechanisms of toxicity, but with adverse effects pointing toward the cardiovascular system. The toxidromes commonly encountered after ingestion of cathinones and phenethylamines are of sympathomimetic and hallucinogenic character, which includes risk of developing a serotonin syndrome, excited delirium, and life-threatening cardiovascular effects. In comparison to their conventional "parent" drug, i.e., heroin, cannabis, and amphetamine, most NPS appear to exhibit more severe adverse effects. The deaths attributed to NPS have dramatically increased in the last years. In our opinion, this is because of the shift from synthetic cannabinoids and cathinones to the even more toxic and dangerously potent fentanyl analogues.

Examination of Synthetic Cannabinoid and Cathinone Use among a Drug-Using Offender Sample, 2013-2015

Use of novel psychoactive substances (NPS) such as synthetic cannabinoids (e.g., "Spice," "Serenity") and cathinones (e.g., "bath salts") has proliferated in recent years; however, there is a gap in research examining prevalence among offender samples. This study examined demographics, drug use, mental health characteristics, and criminal histories of NPS users compared to non-NPS users within an offender sample entering drug treatment. Using logistic regression analysis, combined 2013-2015 assessment data were examined (N = 8,791). NPS users offended more often (x̄ = 10.3), were more likely to have experienced homelessness (12.2%), and to have lived in a metro area (59.0%). NPS users reported significantly more past-year drug use, including substances not readily detected by standard urine analysis (e.g., hallucinogens, alcohol, and inhalants). Individuals with higher anxiety symptom counts (OR = 1.07; p < .001) and those who reported drinking to intoxication (OR = 1.30; p < .001) had an increased likelihood of NPS use. Older individuals (OR = 0.95; p < .001) and those who began using drugs at an older age (OR = 0.95; p < .001) were less likely to report NPS use. NPS use may be a marker of more severe using patterns in an offender sample. Future investigation should focus on NPS use as a possible method for bypassing drug testing measures.

The Novel Psychoactive Substances in the UK Project: empirical and conceptual review work to produce research recommendations

Background

Although illegal drug use has largely been declining in the UK over the past decade, this period has witnessed the emergence of a range of novel psychoactive substances (NPS) (‘legal highs’). These are new, mostly synthetic, substances that mimic the effects of existing drugs). Despite there being many causes for concern in relation to NPS, there has been little prior study of the burden associated with their use in public health terms. Clarity is lacking on research priorities in this rapidly developing literature.

Objectives

To inform the development of public health intervention research on NPS by reviewing existing data on their use, associated problems and potential responses to such problems.

Design

A scoping review and narrative synthesis of selected bodies of evidence was undertaken to summarise and evaluate what is known about NPS use and the related harms of, and responses to, such use. Relevant literature was identified from electronic databases (covering January 2006 to June 2016 inclusive), Google (Google Inc., Mountain View, CA, USA), relevant websites and online drug forums and by contacting experts. Articles were included if they were primary studies, secondary studies involving the analysis and interpretation of primary research or discussion papers. A conceptual framework postulating an evidence-informed public health approach to NPS use in the UK was developed through a pragmatic literature review, the iterative development of concepts and finalisation in light of the results from the empirical review work. The process also involved feedback from various stakeholders. Research recommendations were developed from both strands of work.

Results

A total of 995 articles were included in the scoping review, the majority of which related to individual-level health-related adverse effects attributable to NPS use. The prevalence of lifetime NPS use varied widely between (e.g. with higher prevalence in young males) and within population subgroups. The most commonly reported adverse effects were psychiatric/other neurological, cardiovascular, renal and gastrointestinal manifestations, and there is limited evidence available on responses. In these and other respects, available evidence is at an early stage of development. Initial evidence challenges the view that NPS should be treated differently from other illicit drugs. The conceptual framework indicated that much of the evidence that would be useful to inform public health responses does not yet exist. We propose a systems-based prevention approach that develops existing responses, is multilevel and life course informed in character, and emphasises commonalities between NPS and other legal and illegal drug use. We make 20 recommendations for research, including nine key recommendations.

Limitations

Scoping reviews do not interrogate evidence in depth, and the disjunction between the scoping review and the conceptual framework findings is worthy of careful attention.

Conclusions

Key research recommendations build on those that have previously been made and offer more evidence-based justification and detail, as previous recommendations have not yet been acted on. The case for decision-making on commissioning new research based on these recommendations is both strong and urgent.

Future work

The validity of recommendations generated through this project could be enhanced via further work with research commissioners, policy-makers, researchers and the public.

Study registration

The systematic review element of this study is registered as PROSPERO CRD42016026415.

Funding

The National Institute for Health Research Public Health Research programme.

A matter of life and death: substance-caused and substance-related fatalities in Ibiza in 2015

OBJECTIVES AND METHODS

In the framework of the EU-funded project "EU-Madness," we collected and analysed all the reports of fatalities directly or indirectly related to substances of abuse registered in Ibiza from January to September 2015, in order to analyse the characteristics of the sample, the identified substances, and the nature of deaths associated with their consumption.

RESULTS

A significant increase of substance-caused deaths with respect to the previous 4 years has been highlighted. Most of the subjects were young males, more than half were not Spanish. Males prevailed also amongst the victims of traffic accidents and suicides. The most commonly involved substances included MDMA, alcohol, cocaine, THC, opiates and prescription drugs.

CONCLUSIONS

Although the use of NPS is rapidly increasing in Europe, according to the results from our sample, alcohol and well-known stimulants (MDMA and cocaine) are still the substances of abuse mainly involved in the cases of substance-caused and substance-related fatalities. The significant increase of fatalities in Ibiza in the last 5 years is an issue that must be taken into account and should be better investigated, as other theories besides NPS-increased diffusion should be proposed, and therefore, targeted prevention strategies should be designed.

4,4'-Dimethylaminorex ("4,4'-DMAR"; "Serotoni") misuse: A Web-based study

BACKGROUND

4,4'-DMAR (4,4'-dimethylaminorex; "Serotoni") is a potent stimulant drug that has recently been associated with a number of fatalities in Europe. Over the last few years, online communities have emerged as important resources for disseminating levels of technical knowledge on novel psychoactive substances.

OBJECTIVE

Analysing the information provided by the fora communities on 4,4'-DMAR use, additionally critical reviewing the available evidence-based literature on this topic.

METHODS

Different website drug fora were identified. A critical review of the existing evidence-based literature was undertaken. Individuation and analysis of qualitative data from the identified website fora were performed.

RESULTS

The combined search results identified six website fora from which a range of qualitative data on recurring themes was collected. These themes included routes of administration and doses; desired effects; adverse effects; comparison with other drugs; association with other drugs; medications self-administered to reverse 4,4'-DMAR action; overall impression; and provision of harm-reduction advice.

CONCLUSIONS

Although being characterized by a number of methodological limitations, the social networks' Web monitoring approach (netnography) may be helpful to better understand some of the clinical and psychopharmacological issues pertaining to a range of novel psychoactive substances, including 4,4'-DMAR, for which only extremely little, if any, scientific knowledge is available.

1-cyclohexyl-x-methoxybenzene derivatives, novel psychoactive substances seized on the internet market. Synthesis and in vivo pharmacological studies in mice

INTRODUCTION

Among novel psychoactive substances notified to EMCDDA and Europol were 1-cyclohexyl-x-methoxybenzene stereoisomers (ortho, meta, and para). These substances share some structural characteristics with phencyclidine and tramadol. Nowadays, no information on the pharmacological and toxicological effects evoked by 1-cyclohexyl-x-methoxybenzene are reported. The aim of this study was to investigate the effect evoked by each one stereoisomer on visual stimulation, body temperature, acute thermal pain, and motor activity in mice.

METHODS

Mice were evaluated in behavioral tests carried out in a consecutive manner according to the following time scheme: observation of visual placing response, measures of core body temperature, determination of acute thermal pain, and stimulated motor activity.

RESULTS

All three stereoisomers dose-dependent inhibit visual placing response (rank order: meta > ortho > para), induce hyperthermia at lower and hypothermia at higher doses (meta > ortho > para) and cause analgesia to thermal stimuli (para > meta = ortho), while they do not alter motor activity.

CONCLUSIONS

For the first time, this study demonstrates that systemic administration of 1-cyclohexyl-x-methoxybenzene compounds markedly inhibit visual response, promote analgesia, and induce core temperature alterations in mice. This data, although obtained in animal model, suggest their possible hazard for human health (i.e., hyperthermia and sensorimotor alterations). In particular, these novel psychoactive substances may have a negative impact in many daily activities, greatly increasing the risk factors for workplace accidents and traffic injuries.

Atypical binding at dopamine and serotonin transporters contribute to the discriminative stimulus effects of mephedrone

Mephedrone (4-methylmethcathinone), a constituent of the recreational substances known as "bath salts", is a synthetic cathinone that can produce auditory and visual hallucinations, as well as problematic cardiovascular effects. This study compared the discriminative stimulus effects of mephedrone (0.32-10 mg/kg) with other prototypical drugs of abuse: cocaine (0.56-32 mg/kg), d-amphetamine (0.18-3.2 mg/kg), ketamine (1.8-18 mg/kg), phencyclidine (PCP, 1-5.6 mg/kg), heroin (1-10 mg/kg), 2,5-dimethoxy-4-iodoamphetamine (R-DOI, 0.1-1 mg/kg), Δ⁹-tetrahydrocannabinol (Δ^9-THC 0.56-5.6 mg/kg), 3,4-methylenedioxyamphetamine (MDA, 0.32-5.6 mg/kg), methylphenidate (1-10 mg/kg), and 3,4-methylenedioxypyrovalerone (MDPV, 0.56-5.6 mg/kg). The discriminative stimulus effects of mephedrone were also assessed after administration of the sigma receptor antagonist rimcazole (0.32-10 mg/kg), the relatively selective norepinephrine transporter (NET) inhibitor desipramine (1.8-18 mg/kg), and the selective serotonin transporter (SERT) inhibitor fluoxetine (1-18 mg/kg). Initially, rats were trained to discriminate an intraperitoneal injection of mephedrone (3.2 mg/kg) from saline under a fixed-ratio 20 schedule of food presentation. Following training, cumulative doses of mephedrone and the other drugs were administered to test for substitution (80% drug-lever responding). Of the drugs tested, including those that were tested in combination with mephedrone (i.e., rimcazole, desipramine, and fluoxetine), only cocaine fully substituted for mephedrone without substantially decreasing response rate. In addition, the three drugs administered in combination with mephedrone shifted the cumulative dose-effect curves leftward (percent drug-lever responding) and down (response rate), although fluoxetine did so in a dose-dependent manner ranging from antagonism to potentiation. In summary, the discriminative stimulus effects of mephedrone were most similar to those for the central nervous system (CNS) stimulant, cocaine, and SERT and DAT activity were necessary for these effects.

Novel Psychoactive Substances-Recent Progress on Neuropharmacological Mechanisms of Action for Selected Drugs

A feature of human culture is that we can learn to consume chemical compounds, derived from natural plants or synthetic fabrication, for their psychoactive effects. These drugs change the mental state and/or the behavioral performance of an individual and can be instrumentalized for various purposes. After the emergence of a novel psychoactive substance (NPS) and a period of experimental consumption, personal and medical benefits and harm potential of the NPS can be estimated on evidence base. This may lead to a legal classification of the NPS, which may range from limited medical use, controlled availability up to a complete ban of the drug form publically accepted use. With these measures, however, a drug does not disappear, but frequently continues to be used, which eventually allows an even better estimate of the drug's properties. Thus, only in rare cases, there is a final verdict that is no more questioned. Instead, the view on a drug can change from tolerable to harmful but may also involve the new establishment of a desired medical application to a previously harmful drug. Here, we provide a summary review on a number of NPS for which the neuropharmacological evaluation has made important progress in recent years. They include mitragynine ("Kratom"), synthetic cannabinoids (e.g., "Spice"), dimethyltryptamine and novel serotonergic hallucinogens, the cathinones mephedrone and methylone, ketamine and novel dissociative drugs, γ-hydroxybutyrate, γ-butyrolactone, and 1,4-butanediol. This review shows not only emerging harm potentials but also some potential medical applications.

Clinical Pharmacology of the Synthetic Cathinone Mephedrone

4-Methyl-N-methylcathinone (mephedrone) is a popular new psychoactive substance (NPS) that is structurally related to the parent compound cathinone, the β-keto analogue of amphetamine. Mephedrone appeared on the street drug market as a substitute for 3,4-methylenedioxy-N-methylamphetamine (MDMA, ecstasy) and was subsequently banned due to the potential health risks associated with its use. Nevertheless, mephedrone continues to be widely consumed among specific populations, with unique patterns of misuse. To date, most information about the biological effects of mephedrone comes from user experiences, epidemiological data, clinical cases, toxicological findings, and animal studies, whilst there are very few data regarding its human pharmacodynamics and pharmacokinetics. This chapter reviews the available published data on patterns of mephedrone use, its acute and chronic effects, and its pharmacokinetic properties. More human research is needed to elucidate the safety, toxicity, and addiction potential of mephedrone and related NPS.

NPS: Medical Consequences Associated with Their Intake

Over the last decade, the 'traditional' drug scene has been supplemented - but not replaced - by the emergence of a range of novel psychoactive substances (NPS), which are either newly created or existing drugs, including medications, now being used in novel ways. By the end of 2014, in excess of 500 NPS had been reported by a large number of countries in the world. Most recent data show, however, that synthetic cathinones, synthetic cannabinoids, and psychedelics/phenethylamines account for the largest number of NPS.The present chapter aims at providing an overview of the clinical and pharmacological issues relating to these most popular NPS categories. Given the vast range of medical and psychopathological issues associated with the molecules here described, it is crucial for health professionals to be aware of the effects and toxicity of NPS. A general overview of the acute management of NPS adverse events is provided as well, although further studies are required to identify a range of evidence-based, index molecule-focused, treatment strategies. The rapid pace of change in the NPS online market constitutes a major challenge to the provision of current and reliable scientific knowledge on these substances.

Phase I metabolites of mephedrone display biological activity as substrates at monoamine transporters

BACKGROUND AND PURPOSE

4-Methyl-N-methylcathinone (mephedrone) is a synthetic stimulant that acts as a substrate-type releaser at transporters for dopamine (DAT), noradrenaline (NET) and 5-HT (SERT). Upon systemic administration, mephedrone is metabolized to several phase I compounds: the N-demethylated metabolite, 4-methylcathinone (nor-mephedrone); the ring-hydroxylated metabolite, 4-hydroxytolylmephedrone (4-OH-mephedrone); and the reduced keto-metabolite, dihydromephedrone.

EXPERIMENTAL APPROACH

We used in vitro assays to compare the effects of mephedrone and synthetically prepared metabolites on transporter-mediated uptake and release in HEK293 cells expressing human monoamine transporters and in rat brain synaptosomes. In vivo microdialysis was employed to examine the effects of i.v. metabolite injection (1 and 3 mg·kg(-1) ) on extracellular dopamine and 5-HT levels in rat nucleus accumbens.

KEY RESULTS

In cells expressing transporters, mephedrone and its metabolites inhibited uptake, although dihydromephedrone was weak overall. In cells and synaptosomes, nor-mephedrone and 4-OH-mephedrone served as transportable substrates, inducing release via monoamine transporters. When administered to rats, mephedrone and nor-mephedrone produced elevations in extracellular dopamine and 5-HT, whereas 4-OH-mephedrone did not. Mephedrone and nor-mephedrone, but not 4-OH-mephedrone, induced locomotor activity.

CONCLUSIONS AND IMPLICATIONS

Our results demonstrate that phase I metabolites of mephedrone are transporter substrates (i.e. releasers) at DAT, NET and SERT, but dihydromephedrone is weak in this regard. When administered in vivo, nor-mephedrone increases extracellular dopamine and 5-HT in the brain whereas 4-OH-mephedrone does not, suggesting the latter metabolite does not penetrate the blood-brain barrier. Future studies should examine the pharmacokinetics of nor-mephedrone to determine its possible contribution to the in vivo effects produced by mephedrone.

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.

Severe Psychosis, Drug Dependence, and Hepatitis C Related to Slamming Mephedrone

Background. Synthetic cathinones (SCs), also known as “bath salts,” are β-ketone amphetamine compounds derived from cathinone, a psychoactive substance found in Catha edulis. Mephedrone is the most representative SC. Slamming is the term used for the intravenous injection of these substances in the context of chemsex parties, in order to enhance sex experiences. Using IV mephedrone may lead to diverse medical and psychiatric complications like psychosis, aggressive behavior, and suicide ideation. Case. We report the case of a 25-year-old man admitted into a psychiatric unit, presenting with psychotic symptoms after slamming mephedrone almost every weekend for the last 4 months. He presents paranoid delusions, intense anxiety, and visual and kinesthetic hallucinations. He also shows intense craving, compulsive drug use, general malaise, and weakness. After four weeks of admission and antipsychotic treatment, delusions completely disappear. The patient is reinfected with hepatitis C. Discussion. Psychiatric and medical conditions related to chemsex and slamming have been reported in several European cities, but not in Spain. Psychotic symptoms have been associated with mephedrone and other SCs' consumption, with the IV route being prone to produce more severe symptomatology and addictive conducts. In the case we report, paranoid psychosis, addiction, and medical complications are described.

Neuropharmacology of New Psychoactive Substances (NPS): Focus on the Rewarding and Reinforcing Properties of Cannabimimetics and Amphetamine-Like Stimulants

New psychoactive substances (NPS) are a heterogeneous and rapidly evolving class of molecules available on the global illicit drug market (e.g smart shops, internet, “dark net”) as a substitute for controlled substances. The use of NPS, mainly consumed along with other drugs of abuse and/or alcohol, has resulted in a significantly growing number of mortality and emergency admissions for overdoses, as reported by several poison centers from all over the world. The fact that the number of NPS have more than doubled over the last 10 years, is a critical challenge to governments, the scientific community, and civil society [EMCDDA (European Drug Report), 2014; UNODC, 2014b; Trends and developments]. The chemical structure (phenethylamines, piperazines, cathinones, tryptamines, synthetic cannabinoids) of NPS and their pharmacological and clinical effects (hallucinogenic, anesthetic, dissociative, depressant) help classify them into different categories. In the recent past, 50% of newly identified NPS have been classified as synthetic cannabinoids followed by new phenethylamines (17%) (UNODC, 2014b). Besides peripheral toxicological effects, many NPS seem to have addictive properties. Behavioral, neurochemical, and electrophysiological evidence can help in detecting them. This manuscript will review existing literature about the addictive and rewarding properties of the most popular NPS classes: cannabimimetics (JWH, HU, CP series) and amphetamine-like stimulants (amphetamine, methamphetamine, methcathinone, and MDMA analogs). Moreover, the review will include recent data from our lab which links JWH-018, a CB1 and CB2 agonist more potent than Δ⁹-THC, to other cannabinoids with known abuse potential, and to other classes of abused drugs that increase dopamine signaling in the Nucleus Accumbens (NAc) shell. Thus the neurochemical mechanisms that produce the rewarding properties of JWH-018, which most likely contributes to the greater incidence of dependence associated with “Spice” use, will be described (De Luca et al., 2015a). Considering the growing evidence of a widespread use of NPS, this review will be useful to understand the new trends in the field of drug reward and drug addiction by revealing the rewarding properties of NPS, and will be helpful to gather reliable data regarding the abuse potential of these compounds.

Novel psychoactive substances: the pharmacology of stimulants and hallucinogens

There are increasing levels of concern relating to the rapidly evolving novel psychoactive substances/NPS and web markets' scenarios. The paper aims at providing an overview of the clinical pharmacological issues related to some of the most popular NPS categories, e.g. stimulants and hallucinogens. NPS intake is typically associated with the imbalance of a complex range of neurotransmitter pathways/receptors, namely: dopamine; cannabinoid/CB1; and 5-HT2A. The intake is almost invariably undetectable with standard screening tests. Hence, it may frequently occur that the acute management of NPS misusers will need to focus on decreasing levels of both self/outward-directed aggression and agitation. Benzodiazepines may be considered as first line treatment. Alternatively, propofol and/or antipsychotics can be administered. Focus will be as well on treatment of possible rhabdomyolysis and hyperthermia. Indeed, future studies should inform better tailored management/treatment strategies.

The effects and risks associated to mephedrone and methylone in humans: A review of the preliminary evidences

New psychoactive substances have drastically modified the world drug scene. An increasingly popular class comprises synthetic or substituted cathinones (legal highs, research chemicals, bath salts). Among the most common psychoactive constituents of bath salts are mephedrone and methylone. Recent reports on the abuse of novel synthetic cathinone derivatives call attention to the serious physical and psychological risks resulting from their consumption, thereby emphasizing the growing use of these drugs might constitute an important public health issue. In this paper, we will review the available data regarding the use and effects of mephedrone and methylone in humans in order to highlight their impact on public health. To reach this objective, a literature search was performed on two representative databases (Pubmed, Google Scholar), the Erowid Center website (a US non-profit educational organization that provides information about psychoactive plants and chemicals), and various governmental websites. The terms used for the database search were "mephedrone", "methylone", "new psychoactive substances", "synthetic cathinones", "substituted cathinones", "substance abuse", "substance use disorder", "adverse effects", "fatalities". The literature search was limited to years 2005-2015 and led to the identification of 71 potentially relevant articles. To date, the actual prevalence rates of their use remains difficult to estimate. Important health-related issues have emerged in relation to the somatic, psychiatric, and addictive consequences of their use. The potential chronic health effects of their prolonged use remain to date unknown (e.g., reproductive toxicity, genotoxicity and carcinogenic potential). Treatment for patients with prolonged exposure to synthetic cathinones should ideally include a drug management plan coupled with psychotherapy taking place in a structured program of care.

Novel psychoactive substances of interest for psychiatry

Novel psychoactive substances include synthetic cannabinoids, cathinone derivatives, psychedelic phenethylamines, novel stimulants, synthetic opioids, tryptamine derivatives, phencyclidine-like dissociatives, piperazines, GABA-A/B receptor agonists, a range of prescribed medications, psychoactive plants/herbs, and a large series of performance and image enhancing drugs. Users are typically attracted by these substances due to their intense psychoactive effects and likely lack of detection in routine drug screenings. This paper aims at providing psychiatrists with updated knowledge of the clinical pharmacology and psychopathological consequences of the use of these substances. Indeed, these drugs act on a range of neurotransmitter pathways/receptors whose imbalance has been associated with psychopathological conditions, including dopamine, cannabinoid CB1, GABA-A/B, 5-HT2A, glutamate, and k opioid receptors. An overall approach in terms of clinical management is briefly discussed.