The Pharmacologic and Clinical Effects of Illicit Synthetic Cannabinoids

Sex-specific behavioural, metabolic, and immunohistochemical changes after repeated administration of the synthetic cannabinoid AKB48 in mice

BACKGROUND AND PURPOSE

AKB48 is a synthetic cannabinoid illegally sold for its psychoactive cannabis-like effects that have been associated with acute intoxication and whose effects are poorly known.

EXPERIMENTAL APPROACH

Using a behavioural, neurochemical, and immunohistochemical approach, we investigated the pharmaco-toxicological effects, pharmacokinetics, and neuroplasticity at cannabinoid CB1 receptors in the cerebellum and cortex induced by repeated AKB48 administration in male and female mice.

KEY RESULTS

The effects of AKB48 varied significantly depending on sex and treatment duration. The first injection impaired sensorimotor responses and reduced body temperature, analgesia, and breath rate to a greater extent in females than in males; the second injection induced stronger effects in males while the third injection of AKB48 induced weaker responses in both sexes, suggesting emergence of tolerance. The CB1 receptor antagonist NESS-0327 prevented the effects induced by repeated AKB48, confirming a CB1 receptor-mediated action. Blood AKB48 levels were higher in females than in males and repeated administration caused a progressive rise of AKB48 levels in both sexes, suggesting an inhibitory effect on cytochrome activity. Finally, immunohistochemical analysis revealed higher expression of CB1 receptors in the cerebellum and cortex of females, and a rapid CB1 receptor down-regulation in cerebellar and cortical areas following repeated AKB48 injections, with neuroadaptation occurring generally more rapidly in females than in males.

CONCLUSION AND IMPLICATIONS

We have shown for the first time that AKB48 effects significantly vary with prolonged use and that sex affects the pharmacodynamic/pharmacokinetic responses to repeated administration, suggesting a sex-tailored approach in managing AKB48-induced intoxication.

Acute, chronic, and post-mortem toxicity: a review focused on three different classes of new psychoactive substances

PURPOSE

New psychoactive substances (NPS) are not controlled under the Single Convention on Narcotic Drugs of 1961 or the 1971 Convention, but they may pose a public health threat. Knowledge of the main properties and toxicological effects of these substances is lacking. According to the current Drugs Law (Law n. 11.343/2006), the Brazilian Surveillance Agency issues directives for forbidden substances in Brazil, and structural classes of synthetic cannabinoids, cathinones, and phenylethylamines are considered illicit drugs. Considering that data on these controlled substances are scattered, the main objective of this work was to collect and organize data to generate relevant information on the toxicological properties of NPS.

METHODS

We carried out a literature review collecting information on the acute, chronic, and post-mortem toxicity of these classes of NSP. We searched info in five scientific databases considering works from 2017 to 2021 and performed a statistical evaluation of the data.

RESULTS

Results have shown a general lack of studies in this field given that many NPS have not had their toxicity evaluated. We observed a significant difference in the volume of data concerning acute and chronic/post-mortem toxicity. Moreover, studies on the adverse effects of polydrug use are scarce.

CONCLUSIONS

More in-depth information about the main threats involving NPS use are needed.

The Impact of Psychedelic Drugs on Anxiety and Depression in Advanced Cancer or other Life-threatening Disease: A Systematic Review With Meta-analysis

OBJECTIVES

Life-threatening cancer or other diseases can induce anxiety and depressive symptoms. We performed a systematic review with meta-analyses of randomized controlled trials assessing patients with cancer or other life-threatening diseases using validated anxiety and depression scales.

METHODS

PubMed was searched up to November 15, 2022 and citations were applied to prespecified inclusion criteria. Disease rating scales for anxiety or depression included the State-Trait Anxiety Inventory (STAI) (STAI Trait [STAI-T], STAI-State [STAI-S]), Beck Depression Inventory (BDI), Hospital Anxiety and Depression Scale (HADS) (HADS-Anxiety [HADS-A]; HADS-Depression [HADS-D]), Profile of Mood States (POMS), and the Hamilton Rating Scale for Depression (HAM-D or GRID-HAM-D-17). Safety outcomes included assessments of blood pressure and heart rate.

RESULTS

Five trials, predominantly in cancer patients, had data assessing anxiety and depressive symptoms. These trials found promising results for psychedelics versus placebo in several anxiety and depression scales but increases in blood pressure and heart rate also occurred. There were some concerns of risk of bias because it is difficult to truly randomize a psychedelic trial and there was a high percentage of patients in the trials who had used psychedelics in the past. There was high heterogeneity for all analyses that we could not explain.

CONCLUSIONS

Although the results are promising, future trials are needed to assess the optimal psychedelic, dose, number of sessions required, and how psychedelic naïve patients would respond both psychologically and hemodynamically before this therapy can be considered for widescale clinical use.

Structural confirmation of synthetic cannabinoids in seized electronic cigarette oil: A combined mass spectrometric and computational study

RATIONALE

Synthetic cannabinoids are some of the most used and abused new psychoactive substances, because they can produce a stronger intense pleasure than natural cannabis. Most of the new synthetic cannabinoids are structurally similar to existing synthetic cannabinoids and can be obtained by modifying partial structures of the latter without changing their effects. Therefore, the derivatization rules and common fragmentation patterns of synthetic cannabinoids could be used for rapid screening and structural identification of them.

METHODS

The derivatization rules of synthetic cannabinoids are summarized, and the common fragmentation pattern of synthetic cannabinoids including three typical cleavage pathways was explored and extended in this work based on combined mass spectrometry (MS) and density functional theory studies. Five synthetic cannabinoids in electronic cigarette oil from a drug case were separated and characterized using gas chromatography with MS and liquid chromatography coupled to high-resolution quadrupole Orbitrap MS.

RESULTS

The structures of five synthetic cannabinoids in seized electronic cigarette oil were deduced from electron impact ion source (EI) MS and high-resolution electrospray ionization (ESI) MSⁿ data, along with the derivatization rules and common fragmentation pattern of synthetic cannabinoids. The proposed structures of these synthetic cannabinoids were further verified via reference substances. Computational study showed that selective cleavage of these compounds was mainly controlled by spin population in EI-MS, but a tunneling effect arose from proton transfer in ESI-MSⁿ detection, which has been rarely reported in previous works.

CONCLUSIONS

Our results showed that EI-MS was suitable for identifying synthetic cannabinoids with aromatic ketone structure, which could also be extended to adamantane linked group. Nevertheless, synthetic cannabinoids with carbamoyl linked group were better characterized by high-resolution ESI-MSⁿ compared to EI-MS. This study demonstrated a method with promising potential for rapid and reliable screening of synthetic cannabinoids in mixtures with enhanced detection throughput and operation simplicity.

Methyl (S)-2-(1-7 (5-fluoropentyl)-1H-indole-3-carboxamido)-3,3-dimethylbutanoate (5F-MDMB-PICA) intoxication in a child with identification of two new metabolites (ultra-high-performance liquid chromatography-tandem mass spectrometry)

PURPOSE

Methyl (S)-2-(1-7 (5-fluoropentyl)-1H-indole-3-carboxamido)-3,3-dimethylbutanoate (5F-MDMA-PICA) intoxication in 1.5-year-old child was presented, together with diagnostic parameters discussion and 5F-MDMB-PICA determination in biological material. Furthermore, 5F-MDMB-PICA metabolites were identified in a urine sample as markers of exposure in situation when a parent compound is not present in specimens.

METHODS

Drugs and metabolites were extracted from serum and urine with ethyl acetate both under alkaline (pH 9) and acidic (pH 3) conditions. Hair, after decontamination and pulverization, were incubated with methanol (16 h, 60 °C). The analysis was carried out using ultra-high-performance liquid chromatography-tandem mass spectrometry. For the identification of 5F-MDMB-PICA metabolites, an urine sample was precipitated with cold acetonitrile. Analysis was performed using ultra-high-performance liquid chromatograph with quadrupole time-of-flight mass spectrometer.

RESULTS

5F-MDMB-PICA was determined only in serum sample at concentration of 298 ng/mL. After 1 year, when analysis was repeated, concentration of synthetic cannabinoid in the same sample was only 17.6 ng/mL which revealed high instability of 5F-MDMB-PICA in serum sample. Eight 5F-MDMB-PICA metabolites were identified in urine sample, including two potentially new ones with m/z 391.18964 and m/z 275.14016.

CONCLUSIONS

Toxicological analysis confirmed a 1.5-year-old boy intoxication with 5F-MDMB-PICA. Besides the parent drug, metabolites of 5F-MDMB-PICA were identified, including two potentially new ones, together with possible metabolic reactions which they resulted from. Metabolites determination could serve as a marker of 5F-MDMB-PICA exposure when no parent drug is present in biological material.

Rapid biosensor development using plant hormone receptors as reprogrammable scaffolds

A general method to generate biosensors for user-defined molecules could provide detection tools for a wide range of biological applications. Here, we describe an approach for the rapid engineering of biosensors using PYR1 (Pyrabactin Resistance 1), a plant abscisic acid (ABA) receptor with a malleable ligand-binding pocket and a requirement for ligand-induced heterodimerization, which facilitates the construction of sense-response functions. We applied this platform to evolve 21 sensors with nanomolar to micromolar sensitivities for a range of small molecules, including structurally diverse natural and synthetic cannabinoids and several organophosphates. X-ray crystallography analysis revealed the mechanistic basis for new ligand recognition by an evolved cannabinoid receptor. We demonstrate that PYR1-derived receptors are readily ported to various ligand-responsive outputs, including enzyme-linked immunosorbent assay (ELISA)-like assays, luminescence by protein-fragment complementation and transcriptional circuits, all with picomolar to nanomolar sensitivity. PYR1 provides a scaffold for rapidly evolving new biosensors for diverse sense-response applications.

Strukturelle Gehirnveränderungen und Läsionen durch den Konsum illegaler Drogen und Psychedelika

Drogen können sowohl die Funktion wie auch die Struktur des Gehirns verändern. Gelegentlicher oder regelmäßiger Drogenkonsum ist in der Bevölkerung weit verbreitet. Daher ist die Kenntnis möglicher Nebenwirkungen und charakteristischer Bildbefunde bei Untersuchungen des Gehirns für den klinischen Alltag wichtig. Dieser Artikel beschreibt die für die am weitesten verbreiteten Substanzen typischen Komplikationen und morphologisch-radiologischen Veränderungen. Zu den möglichen Pathomechnismen gehören neurotoxische Effekte, die zu Leukenzephalopathie oder Hirnatrophie führen können, und vaskuläre Komplikationen wie Vasokonstriktion, Vaskulitis oder Hypertonus, durch die es zu intrazerebralen Blutungen oder Infarkten kommen kann. Da die klinische Präsentation oft unspezifisch ist, und die betroffenen Patienten ihren Drogenkonsum häufig verschweigen, ist das Erkennen typischer Bildbefunde essentiell für eine zuverlässige Diagnosestellung und zielgerichtete Therapie.

Synthetic Cannabinoid-Related Deaths in England, 2012-2019

Aim: To identify drug-related death trends associated with synthetic cannabinoid receptor agonists (SCRAs) reported to the National Programme on Substance Abuse Deaths (NPSAD) from England. Design: Case reports from NPSAD (England) where a SCRA was detected in post-mortem tissue(s) and/or implicated in the death were extracted, analyzed, and compared against non-SCRA-related deaths that occurred over the same time period (2012-2019). Findings: One hundred sixty-five death SCRA-related reports were extracted, with 18 different SCRAs detected. Following the first death in 2012, a subsequent sharp increase in reporting is evident. Acute SCRA use was the underlying cause of death in the majority of cases (75.8%) with cardiorespiratory complications the most frequently cited underlying physiological cause (13.4%). SCRA users were predominantly found dead (68.6%), with a large proportion of those witnessed becoming unresponsive described as suddenly collapsing (81.6%). Psychoactive polydrug use was detected in 90.3% of cases, with alcohol the most commonly co-detected (50.3%), followed by opioids (42.2%), benzodiazepines/Z-drugs (32.1%), stimulants (32.1%, [28.5% cocaine]), and cannabis (24.8%). Compared to all non-SCRA-related NPSAD deaths occurring over the same time period, SCRA-related decedents were more predominantly male (90.3% vs. 72.0%; p<0.01), and lived in more deprived areas (p<0.01). While a comparatively significant proportion of decedents were homeless (19.4% vs. 4.1%), living in a hostel (13.3% vs. 2.3%) or in prison (4.9% vs. 0.2%) at time of death (all p<0.01), the greatest majority of SCRA-related decedents were living in private residential accommodations (57.6%). Conclusions: This is the largest dataset regarding SCRA-related mortalities reported to date. Reporting of SCRA-related deaths in England have increased considerably, with polydrug use a specific concern. Lack of effective deterrents to SCRA use under current UK legislation, compounded by limited knowledge regarding the physiological impacts of SCRA consumption and their interaction with other co-administered substances are contributory factors to the occurrence of SCRA-related mortalities in an increasingly deprived demographic.

Does cannabis testing in the military drive synthetic cannabinoid use? Self-reported use motivations among justice-involved veterans

BACKGROUND

Though synthetic cannabinoid receptor agonists (SCRAs) were controlled after being introduced as a 'legal high,' SCRAs likely remain appealing to individuals subject to routine drug screens as not all testing programs consistently include SCRAs. Military populations have been linked to SCRAs due to the unconfirmed supposition that testing protocols led many to substitute SCRAs for cannabis. This study aimed to explore SCRA use prevalence, correlates, and use motivations among veterans, with a particular focus on whether United States military personnel substituted SCRAs for cannabis to subvert testing protocols.

METHODS

All veterans appearing in one of eight civilian criminal courts in three U.S. states were invited to answer questionnaire items related to military service, court functionality, and substance use. Of the 579 veterans eligible, 54.9% chose to participate, yielding a cross-sectional sample of 318 veterans charged with a criminal offense by civilian authorities.

RESULTS

Sixty-five (21.3%) justice-involved veterans reported lifetime SCRA use. Use while within the military was reported by 15.0% of veterans enlisting after 2008. Only eight (12.3%) reported SCRAs were used as a substitute for cannabis. Boredom (36.9%), experimentation (27.7%), and social aspects of SCRA use (32.3%) were more commonly reported motives. Logistic regression models indicated that use of cannabis (aPR=2.06, p<.05), hallucinogens (aPR=2.50, p<.01), and SCRAs (aPR=2.49, p<.05) while in the military were risk factors for SCRA use after leaving the military, whereas older age at time of military exist was a protective factor (aPR=.87, p<.01) CONCLUSIONS: Drug testing programs within the military do not appear to have the unintended consequence of routing individuals to more risky drugs; however, SCRAs appear to have been an underappreciated problem within the military. Further, use extends beyond the military with many only initiating use after discharge, suggesting SCRA use may jeopardize the health of veterans post-service.

Reports of Adverse Events Associated with Use of Novel Psychoactive Substances, 2017-2020: A Review

An important role of modern forensic and clinical toxicologists is to monitor the adverse events of novel psychoactive substances (NPS). Following a prior review from 2013 to 2016, this critical literature review analyzes and evaluates published case reports for NPS from January 2017 through December 2020. The primary objective of this study is to assist in the assessment and interpretation of these cases as well as provide references for confirmation methods. Chemistry, pharmacology, adverse events and user profiles (e.g., polypharmacy) for NPS are provided including case history, clinical symptoms, autopsy findings and analytical results. Literature reviews were performed in PubMed and Google Scholar for publications using search terms such as NPS specific names, general terms (e.g., ‘designer drugs’ and ‘novel psychoactive substances’), drug classes (e.g., ‘designer stimulants’) and outcome-based terms (e.g., ‘overdose’ and ‘death’). Government and website drug surveillance databases and abstracts published by professional forensic science organizations were also searched. Toxicological data and detailed case information were extracted, tabulated, analyzed and organized by drug category. Case reports included overdose fatalities (378 cases), clinical treatment and hospitalization (771 cases) and driving under the influence of drugs (170 cases) for a total of 1,319 cases providing details of adverse events associated with NPS. Confirmed adverse events with associated toxidromes of more than 60 NPS were reported including synthetic cannabinoid, NPS stimulant, NPS hallucinogen, NPS benzodiazepine and NPS opioid cases. Fifty of these NPS were reported for the first time in January 2017 through December 2020 as compared to the previous 4 years surveyed. This study provides insight and context of case findings described in the literature and in digital government surveillance databases and websites during a recent 4-year period. This review will increase the awareness of adverse events associated with NPS use to better characterize international emerging drug threats.

Electrochemiluminescence sensors and forensic investigations: a viable technique for drug detection?

Novel psychoactive substances (NPS) are today considered one of the major ticking public health time bombs in regard to drug abuse. The inability to identify these substances with current screening methods, sees their distribution remain uninterrupted and contributes to the high death rates amongst users. To tackle this problem, it is vital that new robust screening methods are developed, addressing the limitation of those currently in place, namely colour subjectivity and lack of compatibility with the complex matrices these substances may be found within. To this avail, electrochemical methods have been assessed. These low cost and extremely portable sensors have been successfully applied for the direct detection of a broad range of compounds of interest in a range of matrices including, herbal material, commercial drinks and biological fluids (serum, saliva, sweat and urine). With their high versatility, gifted through a significant degree of flexibility in regard to electrode material a range of sensors have to date been reported. In this review the various electrochemical sensors developed to date for NPS detection will be compared and contrasted, with a special focus upon those utilising electrochemiluminescence (ECL) technology.

Substance-Induced Psychoses: An Updated Literature Review

Background: On the current psychopharmacological panorama, the variety of substances able to provoke an episode of acute psychosis is rapidly increasing. Such psychotic episodes are classified according to the major category of symptoms: positive, negative, or cognitive psychotic episodes. On one hand, the abuse of methamphetamines, cannabis, and cocaine plays a big role in increasing the incidence of episodes resembling a psychotic disorder. On the other hand, the progress in terms of pharmacodynamics knowledge has led to the synthesis of new drugs, such as cannabinoids and cathinone's, which have rapidly entered into the common pool of abusers' habits. Regarding these newly synthesized substances of abuse, further clinical studies are needed to understand their psychogenic properties. The topic of this review is complicated due to the frequent abuse of psychotomimetic drugs by patients affected by psychotic disorders, a fact that makes it extremely difficult to distinguish between an induced psychosis and a re-exacerbation of a previously diagnosed disorder. Methods: The present narrative review summarizes results from clinical studies, thus investigating the psychotogenic properties of abused substances and the psychotic symptoms they can give rise to. It also discusses the association between substance abuse and psychosis, especially with regards to the differential diagnosis between a primary vs. a substance-induced psychotic disorder. Findings: Our findings support the theory that psychosis due to substance abuse is commonly observed in clinical practice. The propensity to develop psychosis seems to be a function of the severity of use and addiction. Of note, from a phenomenological point of view, it is possible to identify some elements that may help clinicians involved in differential diagnoses between primary and substance-induced psychoses. There remains a striking paucity of information on the outcomes, treatments, and best practices of substance-induced psychotic episodes.

Inherent Dangers of Using Non-US Food and Drug Administration-Approved Substances of Abuse

Use of US Food and Drug Administration-approved substances of abuse has innate risks due to pharmacologic and pharmacokinetic properties of the medications, but the risk when using nonapproved drug products is much greater. Unbeknownst to the user, the dose of active ingredients in substances of abuse can vary substantially between different products because of manufacturing practices or improper storage. Even naturally occurring substances of abuse can have extensive dosage variability because of effects of the growing season and conditions, or differences in harvesting, storage, or manufacture of the finished products. Many illicit substances are adulterated, to make up for intentional underdosing or to enhance the effect of the intended active ingredient. These adulterants can be dangerous and produce direct cardiovascular, neurologic, hematologic, or dermatologic reactions or obscure adverse effects. Finally, an illicit substance can be contaminated or substituted for another one during its manufacture, leading to differences in adverse events, adverse event severity, or the drug interaction profile. Substances can be contaminated with microbes that induce infections or heavy metals that can damage organs or cause cancer. This milieu of undisclosed substances can also induce drug interactions. For reasons that are discussed, individuals who use substances of abuse are at increased risk of morbidity or mortality if they develop coronavirus disease 2019. Health professionals who treat patients with acute, urgent events associated with substances of abuse, or those treating the chronic manifestations of addiction, need to appreciate the complex and variable composition of substances of abuse and their potential health effects.

Maternal Exposure and Neonatal Effects of Drugs of Abuse

The public health crisis of pregnant women being exposed to drugs of abuse and of its impact on their unborn children continues to grow at an alarming rate globally. The state of pregnancy is unique, with physiological changes that can lead to changes in the way drugs are handled by the body in both pharmacokinetics and response. These changes place the pregnant woman, fetus, and newborn infant at risk, as many of these drugs can cross the placenta and into breast milk. The substances most commonly linked to harmful effects include alcohol, tobacco, cannabis, stimulants, and opioids. The pharmacological and toxicological changes caused by in utero exposure or breastfeeding exposure are difficult to study, and the full extent of the mechanisms involved are not fully understood. However, these changes can significantly affect the risks of substance abuse and influence optimal treatment of pregnant women with a substance use disorder. In addition, newborns who were exposed to drugs of abuse in utero can experience withdrawal syndromes. Pharmacological management in infants is used to guide and treat withdrawal symptoms, with the goal being to improve the infant's sleep, eating, and comfort. Several barriers may prevent pregnant women from seeking help for substance use, including stigma and interactions with the legal system. Understanding changes in pharmacology, including pharmacokinetic changes that happen during pregnancy, is essential for anticipating the extent of maternal exposure and neonatal adverse effects.

Near-Fatal Spice Intoxication of a Toddler

Synthetic cannabinoids are a heterogenous group of novel, legally regulated psychoactive substances that can result in broad, multisystemic, dangerous effects. Despite growing literature regarding synthetic cannabinoid toxicity, little is known about the extent of these effects in young children. Caregivers of drug-endangered children may not provide an accurate history of exposure when children present with symptoms of intoxication, and lack of swift detection on routine urine drug screens may further obscure and delay the diagnosis. Clinical recognition carries forensic relevance that may support interventions to aid in protecting vulnerable children. We describe a case of near-fatal child maltreatment due to supervisory neglect resulting from ingestion of an increasingly common synthetic cannabinoid. Furthermore, we highlight clinical findings that should increase a physician's index of suspicion for synthetic cannabinoid toxicity, even in the absence of a history of exposure.

'Synthetic cannabis': A dangerous misnomer

The term 'synthetic cannabis' has been widely used in public discourse to refer to a group of cannabinoid receptor agonists. In this paper we detail the characteristics of these drugs, and present the case that the term is a misnomer. We describe the pharmacodynamics of these drugs, their epidemiology, mechanisms of action, physiological effects and how these differ substantially from delta-9-tetrahydrocannabinol (THC). We argue that not only is the term a misnomer, but it is one with negative clinical and public health implications. Rather, the substances referred to as 'synthetic cannabis' in public discourse should instead be referred to consistently as synthetic cannabinoid receptor agonists (SCRAs), a drug class distinct from plant-derived cannabinoids. SCRAs have greater potency and efficacy, and psychostimulant-like properties. While such terminology may be used in the scientific community, it is not widely used amongst the media, general public, people who use these drugs or may potentially do so. A new terminology has the potential to reduce the confusion and harms that result from the misnomer 'synthetic cannabis'. The constant evolution of this distinct drug class necessitates a range of distinct policy responses relating to terminology, harm reduction, epidemiology, treatment, and legal status.

Drug-related medical hospital admissions during and after a period of head shop expansion

BACKGROUND

New psychoactive substance (NPS) use can negatively impact health and may result in drug-related hospital admissions (DRHAs). Irish youth reported very high rates of NPS use by international standards, the most common being synthetic cannabinoids and cathinones. There was a rapid expansion in specialist shops, called head shops, selling NPS in 2010. Government responded to public protests about head shops by enacting legislation in May and August 2010 to end this trade. Many academics argued that such actions would prove futile. We sought to determine if changes in head shop activity coincided with changes in DRHA.

METHODS

The national database on admissions to general hospitals hospital in-patient enquiry was examined focusing on young adults admitted from 2008 to 2012, and all emergency admissions with an International Classification of Diseases-10 diagnosis of mental disorder related to any drug (F11-F19) were identified. Joinpoint regression analysis was utilized to explore for the presence of trend changes in DRHA.

RESULTS

Joinpoint regression analysis identified a significant downward trend change which occurred in June 2010 (95% CI February 2010 to January 2011). DRHA increased by 0.5% (95% CI 0.1-0.9) per month prior to this and then fell by 2.6% (95% CI -1.4 to -3.8) per month over the next 16 months.

CONCLUSIONS

Cessation of NPS sale by head shops coincided with a reversal in the upward trend of emergency hospital admissions related to drugs. Although correlation does not confirm causation, legislation which successfully curtails the commercial sale of NPS may result in reduced hospitalizations.

Pharmacology and adverse effects of new psychoactive substances: synthetic cannabinoid receptor agonists

Over the last decade, new psychoactive substances (NPS) have continuously been the focus of the international society since their emergence on the illicit drug market. NPS can be classified into six groups including; synthetic cannabinoid receptor agonists (SCRAs), stimulants, opioids, dissociatives, sedatives/hypnotics, and classic hallucinogens with psychoactive effects. These are sold as "herbal incense," "bath salts," "legal highs," and "research chemicals". They can be synthesized easily with slight changes in the chemical moieties of known psychoactive substances. NPS are sold worldwide via on- and off-line markets without proper scientific evaluation regarding their safety or harmfulness. Abuse of NPS poses a serious public health issue, and systematic studies on their adverse effects are lacking. Therefore, it would be meaningful to collect currently available data in order to understand NPS and to establish viable solutions to cope with the various health issues related to them. In this article, we reviewed the general pharmacological characteristics, recent findings, and adverse effects of representative NPS; SCRAs. SCRAs are known as the most commonly abused NPS. Most SCRAs, cannabinoid receptor 1 and cannabinoid receptor 2 agonists, are often associated with severe toxicities, including cardiotoxicity, immunotoxicity, and even death, unlike natural cannabinoid Δ⁹-Tetrahydrocannabinol.

Post-Mortem Toxicology: A Systematic Review of Death Cases Involving Synthetic Cannabinoid Receptor Agonists

BACKGROUND

Synthetic cannabinoid receptor agonists (SCRAs) have become the largest group of new psychoactive substances monitored by the European Union Early Warning System. Despite the wide diffusion on the market, data regarding effects, toxicities, and mechanisms as well as toxic/lethal doses are still scarce.

METHODS

A comprehensive literature search for articles published up to January 2019 was performed in multiple electronic databases. Only cases of death in which toxicological analyses revealed the presence of SCRAs in blood or urine and at least an external examination was performed, including those occurred in emergency departments, were included.

RESULTS

Of 380 studies identified, 354 were excluded, while 8 additional manuscripts were included through the screening of relevant references cited in the selected articles. A total number of 34 manuscripts (8 case series and 26 case reports) were included.

CONCLUSIONS

Typical toxic ranges for SCRAs have not been so far identified, and the results of toxicological analyses should be interpreted with caution. In death cases involving SCRAs, a thorough post-mortem examination is a prerequisite to assess the role of the substance use in the deceased and to identify a probable mechanism of death. Even after a comprehensive analysis of clinical, circumstantial, toxicological, and autoptic data, the cause and manner of death remain unclear in some cases.

New psychoactive substances: a review and updates

New psychoactive substances (NPS) are a heterogeneous group of substances. They are associated with a number of health and social harms on an individual and societal level. NPS toxicity and dependence syndromes are recognised in primary care, emergency departments, psychiatric inpatient and community care settings. One pragmatic classification system is to divide NPS into one of four groups: synthetic stimulants, synthetic cannabinoids, synthetic hallucinogens and synthetic depressants (which include synthetic opioids and benzodiazepines). We review these four classes of NPS, including their chemical structures, mechanism of action, modes of use, intended intoxicant effects, and their associated physical and mental health harms. The current challenges faced by laboratory testing for NPS are also explored, in the context of the diverse range of NPS currently available, rate of production and emergence of new substances, the different formulations, and methods of acquisition and distribution.

Clinical value of analytical testing in patients presenting with new psychoactive substances intoxication

New psychoactive substances (NPS) have emerged worldwide in recent years, posing a threat to public health and a challenge to drug policy. NPS are usually derivatives or analogues of classical recreational drugs designed to imitate their effects while circumventing regulations. This article provides an overview of benefits and limitations of analytical screening in managing patients presenting with acute NPS toxicity. NPS typically cannot be analytically identified with the usual immunoassay tests. To detect NPS using an immunoassay, antibodies specifically binding to the new structures would have to be developed, which is complicated by the rapid change of the NPS market. Activity-based assays could circumvent this problem since no prior knowledge on the substance structure is necessary. However, classical recreational drugs activating the same receptors could lead to false positive results. Liquid or gas chromatography coupled with mass spectrometry is a valuable NPS analysis tool, but its costs (e.g. equipment), run time (results usually within hours vs minutes in case of immunoasssays) and the need for specialized personnel hinder its use in clinical setting, while factors such as lack of reference standards can pose further limitations. Although supportive measures are sufficient in most cases for adequate patient management, the detection and identification of NPS can contribute significantly to public health and safety in cases of e.g. cluster intoxications and outbreaks, and to the investigation of these novel compounds' properties. However, this requires not only availability of the necessary equipment and personnel, but also collaboration between clinicians, authorities and laboratories.

Pharmacological and Behavioral Effects of the Synthetic Cannabinoid AKB48 in Rats

AKB48 is a designer drug belonging to the indazole synthetic cannabinoids class, illegally sold as herbal blend, incense, or research chemicals for their psychoactive cannabis-like effects. In the present study, we investigated the in vivo pharmacological and behavioral effects of AKB48 in male rats and measured the pharmacodynamic effects of AKB48 and simultaneously determined its plasma pharmacokinetic. AKB48 at low doses preferentially stimulated dopamine release in the nucleus accumbens shell (0.25 mg/kg) and impaired visual sensorimotor responses (0.3 mg/kg) without affecting acoustic and tactile reflexes, which are reduced only to the highest dose tested (3 mg/kg). Increasing doses (0.5 mg/kg) of AKB48 impaired place preference and induced hypolocomotion in rats. At the highest dose (3 mg/kg), AKB48 induced hypothermia, analgesia, and catalepsy; inhibited the startle/pre-pulse inhibition test; and caused cardiorespiratory changes characterized by bradycardia and mild bradipnea and SpO2 reduction. All behavioral and neurochemical effects were fully prevented by the selective CB₁ receptor antagonist/inverse agonist AM251. AKB48 plasma concentrations rose linearly with increasing dose and were correlated with changes in the somatosensory, hypothermic, analgesic, and cataleptic responses in rats. For the first time, this study shows the pharmacological and behavioral effects of AKB48 in rats, correlating them to the plasma levels of the synthetic cannabinoid.

Chemical Compound Studied in This Article: AKB48 (PubChem CID: 57404063); AM251 (PubChem CID: 2125).

Characteristics and circumstances of synthetic cannabinoid-related death

Introduction: Synthetic cannabinoids are an emerging clinical and public health concern. The current study aimed to determine: (1) The characteristics and circumstances of death of all recorded cases of synthetic cannabinoid-related sudden or unnatural death in Australia, (2) The toxicology of cases and (3) Their major organ pathology.Methods: Retrospective study of all cases in Australia in which synthetic cannabinoid use was a mechanism contributory to death (n  =  55) 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: The mean age was 37.2 years and 91.1% were male. Causes of death comprised of accidental toxicity (38.2%), accidental toxicity/cardiovascular disease (9.1%), natural disease (20.0%), suicide (10.9%) and traumatic accident (10.9%). The most common clinical presentation proximal to death was sudden collapse (25.5%). Cardiovascular disease was prominent: severe atherosclerosis (20.0%), myocardial replacement fibrosis (18.0%), cardiomegaly (12.0%). The most frequent synthetic cannabinoids were the indazolecarboxemides (61.8%), most commonly AB-CHMINACA (38.2%). The most frequent other substances were alcohol (34.5%) and Δ⁹-THC (23.6%).Conclusions: AB-CHMINACA was the most commonly seen synthetic cannabinoid. There was a high representation of relatively older decedents and of older males in particular. While acute toxicity was the most common cause of death, cardiovascular disease was prominent.

Effects of unconventional recreational drug use in pregnancy

Recreational drug toxicity is a rapidly evolving aspect in clinical practice. The prevalence of recreational drug abuse in the past decade has achieved an epidemic scale due to invention of new agents and ease of accessibility to the abused drugs. "Unconventional recreational drugs" is the term that includes new psychoactive drugs and medications diverted for recreational goals. Misuse of unconventional recreational drugs during pregnancy can affect both the pregnant woman and the fetus. However, the problems are usually unrecognized and overlooked by healthcare professionals. In this articles, obstetric complications, teratogenicity and neonatal abstinence syndrome from exposure during pregnancy to synthetic cannabinoids, synthetic cathinones, tramadol, kratom, olanzapine, quetiapine, ketamine and ketamine are reviewed. The main purpose is to create awareness about maternal, fetal and neonatal effects of these unconventional recreational drugs, so healthcare professionals will have improved vigilance for these under-recognized issues.

Receptor Binding Affinities of Synthetic Cannabinoids Determined by Non-Isotopic Receptor Binding Assay

A major predictor of the efficacy of natural or synthetic cannabinoids is their binding affinity to the cannabinoid type I receptor (CB₁) in the central nervous system, as the main psychological effects of cannabinoids are achieved via binding to this receptor. Conventionally, receptor binding assays have been performed using isotopes, which are inconvenient owing to the effects of radioactivity. In the present study, the binding affinities of five cannabinoids for purified CB₁ were measured using a surface plasmon resonance (SPR) technique as a putative non-isotopic receptor binding assay. Results were compared with those of a radio-isotope-labeled receptor binding assay. The representative natural cannabinoid Δ⁹-tetrahydrocannabinol and four synthetic cannabinoids, JWH-015, JWH-210, RCS-4, and JWH-250, were assessed using both the SPR biosensor assay and the conventional isotopic receptor binding assay. The binding affinities of the test substances to CB₁ were determined to be (from highest to lowest) 9.52 × 10^-13 M (JWH-210), 6.54 × 10^-12 M (JWH-250), 1.56 × 10^-11 M (Δ⁹-tetrahydrocannabinol), 2.75 × 10^-11 M (RCS-4), and 6.80 ×10^-11 M (JWH-015) using the non-isotopic method. Using the conventional isotopic receptor binding assay, the same order of affinities was observed. In conclusion, our results support the use of kinetic analysis via SPR in place of the isotopic receptor binding assay. To replace the receptor binding affinity assay with SPR techniques in routine assays, further studies for method validation will be needed in the future.

Cannabinoids: from pot to lab

Cannabis is becoming increasingly present in our society. In recent years, the line between the natural (cannabis) and the synthetic (synthetic cannabinoids), the recreational (cannabis) and the medical (pharmaceutical cannabinoids and medical cannabis) has been crossed. In this paper we review some of the novel aspects of cannabis and cannabinoids in relation to their legal situation, changes in their composition and forms of cannabis use, the concept of medical cannabis, and synthetic cannabinoids as new psychoactive substances (NPS). We have also analyzed serious adverse reactions and intoxications associated with the use of synthetic cannabinoids, as well as the latest developments in the research of pharmaceutical cannabinoids.

New and Emerging Illicit Psychoactive Substances

Several novel psychoactive substances have emerged in recent years. Users are typically young men who use other substances. In the category of stimulants, cathinones ("bath salts") have predominated and can lead to agitation, psychosis, hyperthermia, and death. Synthetic cannabinoids ("spice") are more potent than marijuana and can lead to agitation, psychosis, seizures, and death. There are no rapid tests to identify these substances and general treatment includes benzodiazepines for agitation and supportive therapy. Many Synthetic opioids are potent analogues of fentanyl and carry a high risk of overdose. In addition, there are several designer benzodiazepines that have emerged.

Finding order in chemical chaos - Continuing characterization of synthetic cannabinoid receptor agonists

Diversion of synthetic cannabinoids from the lab to drugs of abuse has become increasingly prevalent in recent years. Moreover, as earlier synthetic cannabinoids were banned, manufacturers introduced a new supply of novel compounds to serve as replacements. Hence, the chemical diversity of synthetic cannabinoid analogs has also rapidly increased. The present study examined 8 new synthetic cannabinoids: AM-1220, AM-2232, AM-2233, AM-679, EAM-2201, JWH-210, JHW-251, and MAM-2201. Each compound was assessed for binding affinity and functional activation of CB₁ and CB₂ receptors, and pharmacological equivalence with Δ⁹-tetrahydrocannabinol (THC) in THC drug discrimination. All compounds bound to and activated CB₁ and CB₂ receptors, although efficacy at the CB₂ receptor was reduced compared to that for the CB₁ receptor. Similarly, all compounds stimulated [³⁵S]GTPγS binding through the CB₁ receptor, and all compounds except AM-1220 and AM-2233 stimulated [³⁵S]GTPγS binding through the CB₂ receptor. Furthermore, these compounds, along with CP55,940, substituted for THC in THC drug discrimination. Rank order of potency in drug discrimination was correlated with CB₁ receptor binding affinity. Together, these results suggest that all test compounds share the THC-like subjective effects of marijuana. Interestingly, the most potent compounds in CB₁ binding in the present study were also the compounds that have been found recently in the U.S., MAM-2201, EAM-2201, JWH-210, AM-2233, and AM-1220. These results indicate that the evolution of the synthetic cannabinoid drug market may be focused toward compounds with increased potency. This article is part of the Special Issue entitled 'Designer Drugs and Legal Highs.'

Novel Psychoactive Substances and Trends of Abuse

The purpose of this paper is to review the most common and quickest growing classes of novel, or new, psychoactive substances. Abuse of novel psychoactive substances continues to increase, resulting in subsequent increases in hospitalizations. Furthermore, the chemical structures are ever-changing and substances are increasing in potency. Reviewing the chemistry behind these agents will facilitate a better understanding of the toxicity associated with them and allow for successful identification of and management in the critical care unit. Being familiar with the most common psychoactive substances and trends of abuse, as well as the challenges health care providers face when managing intoxication, is essential to the overall understanding and care of these critically ill patients.

Delirium and High Creatine Kinase and Myoglobin Levels Related to Synthetic Cannabinoid Withdrawal

Synthetic cannabinoids (SCs) are included in a group of drugs called new psychoactive substances. Effects of SCs on the central nervous system are similar to other cannabinoids, but 2-100 times more potent than marijuana. Thus, addiction and withdrawal symptoms are more severe than natural cannabinoids. Withdrawal symptoms of SCs were reported in the literature previously. But there is no report about SC withdrawal delirium and its treatment. Several studies reported that agonists of CB1 receptors play a role in GABA and glutamatergic neurotransmission, which is similar to the effects of alcohol on GABA and glutamatergic receptors. Previous studies on alcohol delirium cases suggested that elevated creatine kinase (CK) can be a marker of progress. This study reports delirium and high serum CK levels related to SC withdrawal and offers a treatment with benzodiazepine for them. We described two cases treated in our inpatient clinic about SC withdrawal with increase of serum CK level and other laboratory parameters. One of them demonstrated delirium symptoms and the other did not with early rapid treatment.

Psychostimulant Effect of the Synthetic Cannabinoid JWH-018 and AKB48: Behavioral, Neurochemical, and Dopamine Transporter Scan Imaging Studies in Mice

JWH-018 and AKB48 are two synthetic cannabinoids (SCBs) belonging to different structural classes and illegally marketed as incense, herbal preparations, or chemical supply for theirs psychoactive cannabis-like effects. Clinical reports from emergency room reported psychomotor agitation as one of the most frequent effects in people assuming SCBs. This study aimed to investigate the psychostimulant properties of JWH-018 and AKB48 in male CD-1 mice and to compare their behavioral and biochemical effects with those caused by cocaine and amphetamine. In vivo studies showed that JWH-018 and AKB48, as cocaine and amphetamine, facilitated spontaneous locomotion in mice. These effects were prevented by CB₁ receptor blockade and dopamine (DA) D_1/5 and D_2/3 receptors inhibition. SPECT-CT studies on dopamine transporter (DAT) revealed that, as cocaine and amphetamine, JWH-018 and AKB48 decreased the [¹²³I]-FP-CIT binding in the mouse striatum. Conversely, in vitro competition binding studies revealed that, unlike cocaine and amphetamine, JWH-018 and AKB48 did not bind to mouse or human DAT. Moreover, microdialysis studies showed that the systemic administration of JWH-018, AKB48, cocaine, and amphetamine stimulated DA release in the nucleus accumbens (NAc) shell of freely moving mice. Finally, unlike amphetamine and cocaine, JWH-018 and AKB48 did not induce any changes on spontaneous [³H]-DA efflux from murine striatal synaptosomes. The present results suggest that SCBs facilitate striatal DA release possibly with different mechanisms than cocaine and amphetamine. Furthermore, they demonstrate, for the first time, that JWH-018 and AKB48 induce a psychostimulant effect in mice possibly by increasing NAc DA release. These data, according to clinical reports, outline the potential psychostimulant action of SCBs highlighting their possible danger to human health.