CP47,497-C8 and JWH073, commonly found in 'Spice' herbal blends, are potent and efficacious CB(1) cannabinoid receptor agonists

Delineating the molecular mechanisms of hippocampal neurotoxicity induced by chronic administration of synthetic cannabinoid AB-FUBINACA in mice

Chronic use of synthetic cannabinoids (SCs) has been associated with cognitive and behavioural deficits and an increased risk of neuropsychiatric disorders. The underlying molecular and cellular mechanisms of the neurotoxic effects of long-term use of SCs have not been well investigated in the literature. Herein, we evaluated the in vivo effects of chronic administration of AB-FUBINACA on the hippocampus in mice. Our results revealed that the administration of AB-FUBINACA induced a significant impairment in recognition memory associated with histopathological changes in the hippocampus. These findings were found to be correlated with increased level of oxidative stress, neuroinflammation, and apoptosis markers, and reduced expression of brain-derived neurotrophic factor (BDNF), which plays an essential role in modulating synaptic plasticity integral for promoting learning and memory in the hippocampus. Additionally, we showed that AB-FUBINACA significantly decreased the expression of NR1, an important functional subunit of glutamate/NMDA receptors and closely implicated in the development of toxic psychosis. These findings shed light on the long-term neurotoxic effects of SCs on hippocampus and the underlying mechanisms of these effects. This study provided new targets for possible medical interventions to improve the treatment guidelines for SCs addiction.

CB1 Receptor Negative Allosteric Modulators as a Potential Tool to Reverse Cannabinoid Toxicity

While the opioid crisis has justifiably occupied news headlines, emergency rooms are seeing many thousands of visits for another cause: cannabinoid toxicity. This is partly due to the spread of cheap and extremely potent synthetic cannabinoids that can cause serious neurological and cardiovascular complications-and deaths-every year. While an opioid overdose can be reversed by naloxone, there is no analogous treatment for cannabis toxicity. Without an antidote, doctors rely on sedatives, with their own risks, or 'waiting it out' to treat these patients. We have shown that the canonical synthetic 'designer' cannabinoids are highly potent CB1 receptor agonists and, as a result, competitive antagonists may struggle to rapidly reverse an overdose due to synthetic cannabinoids. Negative allosteric modulators (NAMs) have the potential to attenuate the effects of synthetic cannabinoids without having to directly compete for binding. We tested a group of CB1 NAMs for their ability to reverse the effects of the canonical synthetic designer cannabinoid JWH018 in vitro in a neuronal model of endogenous cannabinoid signaling and also in vivo. We tested ABD1085, RTICBM189, and PSNCBAM1 in autaptic hippocampal neurons that endogenously express a retrograde CB1-dependent circuit that inhibits neurotransmission. We found that all of these compounds blocked/reversed JWH018, though some proved more potent than others. We then tested whether these compounds could block the effects of JWH018 in vivo, using a test of nociception in mice. We found that only two of these compounds-RTICBM189 and PSNCBAM1-blocked JWH018 when applied in advance. The in vitro potency of a compound did not predict its in vivo potency. PSNCBAM1 proved to be the more potent of the compounds and also reversed the effects of JWH018 when applied afterward, a condition that more closely mimics an overdose situation. Lastly, we found that PSNCBAM1 did not elicit withdrawal after chronic JWH018 treatment. In summary, CB1 NAMs can, in principle, reverse the effects of the canonical synthetic designer cannabinoid JWH018 both in vitro and in vivo, without inducing withdrawal. These findings suggest a novel pharmacological approach to at last provide a tool to counter cannabinoid toxicity.

CB 1 Cannabinoid Receptor Agonists Induce Acute Respiratory Depression in Awake Mice

Recreational use of synthetic cannabinoid agonists (i.e., "Spice" compounds) that target the Cannabinoid Type 1 receptor (CB 1 ) can cause respiratory depression in humans. However, Δ 9 -tetrahydrocannabinol (THC), the major psychoactive phytocannabinoid in cannabis, is not traditionally thought to interact with CNS control of respiration, based largely upon sparse labeling of CB1 receptors in the medulla and few reports of clinically significant respiratory depression following cannabis overdose. The respiratory effects of CB 1 agonists have rarely been studied in vivo , suggesting that additional inquiry is required to reconcile the conflict between conventional wisdom and human data. Here we used whole body plethysmography to examine the respiratory effects of the synthetic high efficacy CB 1 agonist CP55,940, and the low efficacy CB 1 agonist Δ 9 -tetrahydrocannabinol in male and female mice. CP55,940 and THC, administered systemically, both robustly suppressed minute ventilation. Both cannabinoids also produced sizable reductions in tidal volume, decreasing both peak inspiratory and expiratory flow - measures of respiratory effort. Similarly, both drugs reduced respiratory frequency, decreasing both inspiratory and expiratory time while markedly increasing expiratory pause, and to a lesser extent, inspiratory pause. Respiratory suppressive effects occurred at lower doses in females than in males, and at many of the same doses shown to produce cardinal behavioral signs of CB 1 activation. We next used RNAscope in situ hybridization to localize CB 1 mRNA to glutamatergic neurons in the medullary pre-Bötzinger Complex, a critical nucleus in controlling respiration. Our results show that, contrary to previous conventional wisdom, CB 1 mRNA is expressed in glutamatergic neurons in a brain region essential for breathing and CB 1 agonists can cause significant respiratory depression.

Psychosexual dysfunction in male patients with cannabis dependence and synthetic cannabinoid dependence

OBJECTIVE

There are contradicting reports regarding the relationship between cannabis use and male sexual functions with almost no data about synthetic cannabinoids (SC) and its effect on male sexual functions. This study investigates psychological concerns related to male sexual functions among cannabis and SC users. The research aims to assess different sexual functions and aspects of sexual psychopathology in cannabis and SCs dependent men compared to controls.

METHOD

Thirty male patients with cannabis dependence, thirty male patients with SCs dependence and thirty matched controls from the outpatient clinic of Kasr Al Ainy hospital, Egypt, were assessed using Structured Clinical Interview for DSM-IV TR Axis I Disorders (SCID-I), International Index of Erectile Function (IIEF), and Sexuality scale.

RESULTS

The means of IIEF questionnaire in the cannabis and SC group were significant lower than the means of the control group (P < .001) except the orgasmic function in cannabis group (P = .052). In the SCs group, sexual depression was higher and preoccupation lower than the cannabis (P < .020; P < .003, respectively) and control groups (P < .001; P < .001, respectively). The duration and dose of intake of cannabis and SCs correlated significant with sexual esteem, sexual preoccupation and all domains of IIEF.

CONCLUSION

Cannabis and SC dependence were associated with lower erectile function, sexual desire, intercourse satisfaction and overall satisfaction, and lower orgasmic functions in the SC group than controls. Both groups showed higher sexual depression, lower sexual esteem and sexual preoccupation than controls. SC has a higher negative impact on male sexual functions and psychopathology than cannabis.

A collection of cannabinoid-related negative findings from autaptic hippocampal neurons

Autaptic hippocampal neurons are an architecturally simple model of neurotransmission that express several forms of cannabinoid signaling. Over the past twenty years this model has proven valuable for studies ranging from enzymatic control of endocannabinoid production and breakdown, to CB1 receptor structure/function, to CB2 signaling, understanding 'spice' (synthetic cannabinoid) pharmacology, and more. However, while studying cannabinoid signaling in these neurons, we have occasionally encountered what one might call 'interesting negatives', valid and informative findings in the context of our experimental design that, given the nature of scientific publishing, may not otherwise find their way into the scientific literature. In autaptic hippocampal neurons we have found that: (1) The fatty acid binding protein (FABP) blocker SBFI-26 does not alter CB1-mediated neuroplasticity. (2) 1-AG signals poorly relative to 2-AG in autaptic neurons. (3) Indomethacin is not a CB1 PAM in autaptic neurons. (4) The CB1-associated protein SGIP1a is not necessary for CB1 desensitization. We are presenting these negative or perplexing findings in the hope that they will prove beneficial to other laboratories and elicit fruitful discussions regarding their relevance and significance.

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.

Cannabimimetic effects of abused indazole-carboxamide synthetic cannabinoid receptor agonists AB-PINACA, 5F-AB-PINACA and 5F-ADB-PINACA in mice: Tolerance, dependence and withdrawal

BACKGROUND

Chronic abuse of synthetic cannabinoid receptor agonists (SCRAs), known as "K2″ or "Spice", threatens public health and safety. Recently, SCRAs of the indazole-carboxamide structural class have become more prevalent. Preclinical studies investigating the tolerance and dependence potentially involved in chronic SCRA abuse is limited. The present study determined the in vivo effects of chronic exposure to indazole-carboxamide SCRAs, AB-PINACA, 5F-AB-PINACA and 5F-ADB-PINACA compared to the first-generation SCRA, JWH-018.

METHODS

Adult male C57Bl/6 mice were used for dose-effect determinations of hypothermic effects. Adult male NIH Swiss mice were used in biotelemetry studies to assess tolerance to hypothermic effects following repeated SCRA administration over 5 consecutive days, and to determine the role of Phase I drug metabolism via acute CYP450 inhibition in the presence of 1-ABT, a nonspecific CYP450 inhibitor. SCRA dependence was determined in adult male NIH Swiss mice via assessment of rimonabant-precipitated observable sign of withdrawal (i.e., front paw tremors).

RESULTS

All SCRAs elicited dose-dependent hypothermia mediated through cannabinoid CB1 receptors (CB1Rs). 1-ABT increased duration of hypothermia for all SCRAs tested, and increased the magnitude of hypothermia for all SCRAs except 5F-ADB-PINACA. Upon repeated administration, tolerance to hypothermic effects of AB-PINACA, 5F-AB-PINACA and 5F-ADB-PINACA was much less than that of JWH-018. Similarly, rimonabant-precipitated front paw tremors were much less frequent in mice treated with 5F-AB-PINACA and 5F-ADB-PINACA than in mice treated with JWH-018.

CONCLUSIONS

These findings suggest a decreased potential for tolerance and withdrawal among indazole-carboxamide SCRAs, and may imply structural class-dependent profiles of in vivo effects among SCRAs.

Synthetic cannabinoid JWH-073 alters both acute behavior and in vivo/vitro electrophysiological responses in mice

JWH-073 is a synthetic cannabinoid (SCB) that is illegally marketed within an "herbal blend", causing psychoactive effects more intense than those produced by Cannabis. Users report that JWH-073 causes less harmful effects than other SCBs, misrepresenting it as a "safe JWH-018 alternative", which in turn prompts its recreational use. The present study is aimed to investigate the in vivo pharmacological activity on physiological and neurobehavioral parameters in male CD-1 mice after acute 1 mg/kg JWH-073 administration. To this aim we investigate its effect on sensorimotor (visual, acoustic, and tactile), motor (spontaneous motor activity and catalepsy), and memory functions (novel object recognition; NOR) in mice coupling behavioral and EEG data. Moreover, to clarify how memory function is affected by JWH-073, we performed in vitro electrophysiological studies in hippocampal preparations using a Long-Term Potentiation (LTP) stimulation paradigm. We demonstrated that acute administration of JWH-073 transiently decreased motor activity for up to 25 min and visual sensorimotor responses for up to 105 min, with the highest effects at 25 min (~48 and ~38%, respectively), while the memory function was altered up to 24 h (~33%) in treated-mice as compared to the vehicle. EEG in the somatosensory cortex showed a maximal decrease of α (~23%) and γ (~26%) bands at 15 min, β (~26%) band at 25 min, a maximal increase of θ (~14%) band at 25 min and δ (~35%) band at 2 h, and a significant decrease of θ (~18%), α (~26%), and β (~10%) bands during 24 h. On the other hand, EEG in the hippocampus showed a significant decrease of all bands from 10 min to 2 h, with the maximal effect at 30 min for θ (~34%) and γ (~26%) bands and 2 h for α (~36%), β (~29%), and δ (~15%) bands. Notably, the δ band significant increase both at 5 min (~12%) and 24 h (~19%). Moreover, in vitro results support cognitive function impairment (~60% of decrease) by interfering with hippocampal synaptic transmission and LTP generation. Our results suggest that JWH-073 deeply alters brain electrical responsiveness with minor behavioral symptoms. Thus, it poses a subtle threat to consumers who mistakenly consider it safer than other SCBs.

Cannabinoid Receptor Type 1 Regulates Drug Reward Behavior via Glutamate Decarboxylase 67 Transcription

Interaction of cannabinoid receptor type 1 (CB1) and GABAergic neuronal activity is involved in drug abuse-related behavior. However, its role in drug-dependent Pavlovian conditioning is not well understood. In this study, we aimed to evaluate the effects of a CB1 agonist, JWH-210, on the development of conditioned place preference (CPP)-induced by methamphetamine (METH). Pretreatment with a synthetic cannabinoid, JWH-210 (CB1 agonist), increased METH-induced CPP score and METH-induced dopamine release in acute striatal slices. Interestingly, CB1 was expressed in glutamate decarboxylase 67 (GAD67) positive cells, and overexpression of CB1 increased GAD67 expression, while CB1 knockdown reduced GAD67 expression in vivo and in vitro. GAD67 is known as an enzyme involved in the synthesis of GABA. CB1 knockdown in the mice striatum increased METH-induced CPP. When GAD67 decreased in the mice striatum, mRNA level of CB1 did not change, suggesting that CB1 can regulate GAD67 expression. GAD67 knockdown in the mouse striatum augmented apomorphine (dopamine receptor D2 agonist)–induced climbing behavior and METH-induced CPP score. Moreover, in the human brain, mRNA level of GAD67 was found to be decreased in drug users. Therefore, we suggest that CB1 potentiates METH-induced CPP through inhibitory GABAergic regulation of dopaminergic neuronal activity.

Self-administration of inhaled delta-9-tetrahydrocannabinol and synthetic cannabinoids in non-human primates

Cannabis and synthetic cannabinoids are abused in spite of possible adverse health consequences. The current study investigated the reinforcing effects of an ecologically relevant mode of administration (inhalation) of delta-9-tetrahydrocannabinol (THC), the primary psychoactive component of cannabis, and three synthetic cannabinoids detected in synthetic cannabinoid products (JWH-018, JWH-073, and HU-210) in non-human primates (NHPs). Male and female (N = 4 each) rhesus macaques were trained to inhale warm air via a metal stem to receive a candy reinforcer, an alcohol aerosol vehicle was then paired with the candy. Dose-dependent responding for inhaled aerosols of THC (2.0-16.0 μg/kg/inhalation), JWH-018 (0.2-1.6 μg/kg/inhalation), JWH-073 (2.0-8.0 μg/kg/inhalation), and HU-210 (1.0-8.0 μg/kg/inhalation) was established using a fixed-ratio five schedule of reinforcement and compared to vehicle (alcohol) self-administration. Dose-dependent responding for inhaled heroin (25.0-100.0 μg/kg/inhalation), a known reinforcer in NHPs, was also established. Responding approximated vehicle levels for many drug doses tested, but at least half of the monkeys responded for ≥ one dose of each cannabinoid and heroin above vehicle, with the exception of THC. Drug deliveries calculated as percent vehicle followed a prototypical inverted-U shaped dose-response curve for cannabinoids and heroin except for THC and JWH-018 (in males). Grouped data according to sex demonstrated that peak percent of vehicle reinforcers earned for THC was greater in males than females, whereas peak percent of vehicle reinforcers earned for JWH-018, HU-210, and heroin were greater in females than males. These findings indicate minimal reinforcing effects of CB1 receptor agonists when self-administered by NHPs via aerosol inhalation. (PsycInfo Database Record (c) 2021 APA, all rights reserved).

Cannabinoid Receptor Modulation of Neurogenesis: ST14A Striatal Neural Progenitor Cells as a Simplified In Vitro Model

The endocannabinoid system (ECS) is involved in the modulation of several basic biological processes, having widespread roles in neurodevelopment, neuromodulation, immune response, energy homeostasis and reproduction. In the adult central nervous system (CNS) the ECS mainly modulates neurotransmitter release, however, a substantial body of evidence has revealed a central role in regulating neurogenesis in developing and adult CNS, also under pathological conditions. Due to the complexity of investigating ECS functions in neural progenitors in vivo, we tested the suitability of the ST14A striatal neural progenitor cell line as a simplified in vitro model to dissect the role and the mechanisms of ECS-regulated neurogenesis, as well as to perform ECS-targeted pharmacological approaches. We report that ST14A cells express various ECS components, supporting the presence of an active ECS. While CB1 and CB2 receptor blockade did not affect ST14A cell number, exogenous administration of the endocannabinoid 2-AG and the synthetic CB2 agonist JWH133 increased ST14A cell proliferation. Phospholipase C (PLC), but not PI3K pharmacological blockade negatively modulated CB2-induced ST14A cell proliferation, suggesting that a PLC pathway is involved in the steps downstream to CB2 activation. On the basis of our results, we propose ST14A neural progenitor cells as a useful in vitro model for studying ECS modulation of neurogenesis, also in prospective in vivo pharmacological studies.

Highly sensitive screening and analytical characterization of synthetic cannabinoids in nine different herbal mixtures

The popularity of new psychoactive substances among drug users has become a public health concern worldwide. Among them, synthetic cannabinoids (SCs) represent the largest, most diversified and fastest growing group. Commonly known as 'synthetic marijuana' as an alternative to cannabis, these synthetic compounds are easily accessible via the internet and are sold as 'herbal incenses' under different brand names with no information about the chemical composition. In the present work, we aim to integrate gas chromatography-tandem mass spectrometry (GC-MS) and nuclear magnetic resonance (NMR) data as useful strategy for the identification and confirmation of synthetic cannabinoids present in nine seized herbal incenses. The analysis of all samples allowed the initial identification of 9 SCs, namely 5 napthoylindoles (JWH-018, JWH-073, JWH-122, JWH-210, MAM-2201), APINACA, XLR-11 and CP47,497-C8 and its enantiomer. JWH-018 was the most frequently detected synthetic compound (8 of 9 samples), while APINACA and XLR-11 were only identified in one herbal product. Other non-cannabinoid drugs, including oleamide, vitamin E and vitamin E acetate, have also been detected. Oleamide and vitamin E are two adulterants, frequently added to herbal products to mask the active ingredients or added as preservatives. However, to our knowledge, no analytical data about vitamin E acetate was reported in herbal products, being the first time that this compound is identified on this type of samples. The integration data obtained from the used analytical technologies proved to be useful, allowing the preliminary identification of the different SCs in the mixture. Furthermore, the examination of mass spectral fragment ions, as well as the results of both 1D and 2D NMR experiments, enabled the identification and confirmation of the molecular structure of SCs.

QSAR Model for Predicting the Cannabinoid Receptor 1 Binding Affinity and Dependence Potential of Synthetic Cannabinoids

In recent years, there have been frequent reports on the adverse effects of synthetic cannabinoid (SC) abuse. SCs cause psychoactive effects, similar to those caused by marijuana, by binding and activating cannabinoid receptor 1 (CB1R) in the central nervous system. The aim of this study was to establish a reliable quantitative structure–activity relationship (QSAR) model to correlate the structures and physicochemical properties of various SCs with their CB1R-binding affinities. We prepared tetrahydrocannabinol (THC) and 14 SCs and their derivatives (naphthoylindoles, naphthoylnaphthalenes, benzoylindoles, and cyclohexylphenols) and determined their binding affinity to CB1R, which is known as a dependence-related target. We calculated the molecular descriptors for dataset compounds using an R/CDK (R package integrated with CDK, version 3.5.0) toolkit to build QSAR regression models. These models were established, and statistical evaluations were performed using the mlr and plsr packages in R software. The most reliable QSAR model was obtained from the partial least squares regression method via Y-randomization test and external validation. This model can be applied in vivo to predict the addictive properties of illicit new SCs. Using a limited number of dataset compounds and our own experimental activity data, we built a QSAR model for SCs with good predictability. This QSAR modeling approach provides a novel strategy for establishing an efficient tool to predict the abuse potential of various SCs and to control their illicit use.

Biased agonism at the cannabinoid receptors - Evidence from synthetic cannabinoid receptor agonists

The type 1 and type 2 cannabinoid receptors are G protein-coupled receptors implicated in a variety of physiological processes and diseases. Synthetic cannabinoid receptor agonists (SCRAs) were originally developed to explore the therapeutic benefits of cannabinoid receptor activation, although more recently, these compounds have been diverted to the recreational drug market and are increasingly associated with incidences of toxicity. A prominent concept in contemporary pharmacology is functional selectivity or biased agonism, which describes the ability of ligands to elicit differential activation of signalling pathways through stabilisation of distinct receptor conformations. Biased agonists may maximise drug effectiveness by reducing on-target adverse effects if they are mediated by signalling pathways distinct from those that drive the therapeutic effects. For the cannabinoid receptors, it remains unclear as to which signalling pathways mediate desirable and adverse effects. However, given their structural diversity and potential to induce a plethora of signalling effects, SCRAs provide the most promising prospect for detecting and studying bias at the cannabinoid receptors. This review summarises the emerging evidence of SCRA bias at the cannabinoid receptors.

Review of the Endocannabinoid System

The endocannabinoid system (ECS) is a widespread neuromodulatory network involved in the developing central nervous system as well as playing a major role in tuning many cognitive and physiological processes. The ECS is composed of endogenous cannabinoids, cannabinoid receptors, and the enzymes responsible for the synthesis and degradation of endocannabinoids. In addition to its endogenous roles, cannabinoid receptors are the primary target of Δ⁹-tetrahydrocannabinol, the intoxicating component of cannabis. In this review, we summarize our current understanding of the ECS. We start with a description of ECS components and their role in synaptic plasticity and neurodevelopment, and then discuss how phytocannabinoids and other exogenous compounds may perturb the ECS, emphasizing examples relevant to psychosis.

Synthetic cannabinoid receptor agonists-induced recurrent seizure in elderly patient

Abuse of synthetic cannabinoid receptor agonists (SCRAs) has been associated with young individuals. The abuse of SCRAs is very rare in elderly people, but a few cases highlight the SCRAs-induced side effects. These substances lead to a variety of clinical and psychiatric symptoms including seizures. Here we report recurrent seizures after SCRA abuse by an elderly patient.

Regional trends in suspected synthetic cannabinoid exposure from January 2016 to September 2019 in the United States

BACKGROUND

The unpredictable physiologic and pharmacologic effects of synthetic cannabinoids (SCs) are continuously changing as the chemical structure of SCs evolve to avoid classification as a Schedule I drug under the Controlled Substances Act in the U.S. This results in unpredictable pharmacologic effects and subsequent sequelae. Little is known about national or regional trends of SC clusters. The objective of this study is to investigate trends in SC exposure using emergency department (ED) syndromic data.

METHODS

We analyzed ED syndromic data to detect quarterly trends from January 2016 through September 2019 for SC-related exposures within 59 jurisdictions in 47 states by U.S. region. Pearson chi-square tests detected quarter-to-quarter changes and Joinpoint regression assessed trends over time.

RESULTS

From January 2016 to September 2019, 21,714 of 303.5 million ED visits involved suspected SC exposures. Nationally, SC-related exposures decreased by 1.9 % (p = .04) on average per quarter, yet exposures increased in the Midwest by 6.3 % (p = .002) and in the Northeast by 3.2 % (p = .03) on average per quarter, and decreased on average per quarter by 7.7% (p ≤ .001) in the Southeast and 11.4 % in the West (p ≤ .001). Known SC exposures that may align with clusters were identified in quarter-to-quarter monitoring.

CONCLUSIONS

Only a small proportion of ED visits were related to suspected SC exposure. Although we did identify a small decrease in national SC exposures, there was wide variation by region. Additional efforts are needed to understand variation and to develop prevention and response strategies.

Case Report: Synthetic Cannabinoid Deaths in State of Florida Prisoners

Between March 2017 and November 2018, 54 prisoner fatal overdose cases submitted to the University of Florida Forensic Toxicology Laboratory involved synthetic cannabinoids including 5F-ADB, FUB-AMB, 5F-AMB, MDMB-FUBINACA and AB-CHMINACA. Analysis of blood and urine samples was performed at NMS Labs (Horsham, PA) by liquid chromatography/tandem mass spectrometry screening, confirmatory and quantitative methods validated according to Scientific Working Group for Forensic Toxicology guidelines. This work highlights the importance of effective communication between toxicologists and medical examiners/coroners, and the value of public-private partnerships to provide coverage while laboratories work to update instrumentation and validate their own new methods to keep up with the challenges of emerging substances.

Identification of synthetic cannabinoids that were seized, consumed, or associated with deaths in Kuwait in 2018 using GC-MS and LC-MS-MS analysis

Synthetic cannabinoids are gaining much popularity worldwide. Although the death rate associated with their use is rising, these drugs are the largest and fastest growing class of novel psychoactive substances. Despite increased concerns regarding adverse effects stemming from the use of synthetic cannabinoids, there is no published data on the subject for the Gulf region or Kuwait, specifically. The current study investigates the diversity of synthetic cannabinoids in Kuwait in 2018. In total, 434 cases from the Narcotics and Psychotropic Laboratory, 70 cases from the Toxicology Laboratory, and six cases from the Forensic Medicine Department were reviewed and analyzed. Numerous synthetic cannabinoid types were identified using GC-MS and LC-MS-MS. The majority of synthetic cannabinoids were members of the indazole-3-carboxamide or indole-3-carboxamide families. Members from the indazole-3-carboxamide family identified in Kuwait were 5F-ADB, FUB-AMB, ADB-FUBINACA, AB-FUBINACA, 5F-ADB-PINACA, 5F-AKB-48, 5Cl-AKB-48, MDMB-FUBINACA, 5F-AB-PINACA, APINACA, and AB-PINACA whereas MDMB-CHMICA, 5F-MDMB-PICA, ADB-BICA, and MMB-CHMICA belonged to the indole-3-carboxamide family. In addition, members of other families were identified, including CBL2201 and UR-144, which belonged to indole-3-carboxylate and cyclopropylindole families, respectively. The most common synthetic cannabinoids were 5F-ADB, FUB-AMB, and 5Cl-AKB-48. Various mixes of two, three, or four types of synthetic cannabinoids were identified, and mixtures of synthetic cannabinoids with other illicit drugs were also present. Our findings show that in Kuwait, the most common mix of synthetic cannabinoids is FUB-AMB with 5F-ADB. These two types were mixed, either together or individually, with methamphetamine, tramadol, heroin, ^Δ9THC, and ketamine. Most importantly, our results reveal the synthetic cannabinoid types that were associated with six reported deaths.

Convulsant Effects of Abused Synthetic Cannabinoids JWH-018 and 5F-AB-PINACA Are Mediated by Agonist Actions at CB1 Receptors in Mice

Convulsant effects of abused synthetic cannabinoid (SCB) drugs have been reported in humans and laboratory animals, but the mechanism of these effects is not known. We compared convulsant effects of partial CB1R agonist ∆9-tetrahydrocannabinol (THC), full CB1R agonist SCBs JWH-018 and 5F-AB-PINACA, and classic chemical convulsant pentylenetetrazol (PTZ) using an observational rating scale in mice. THC did not elicit convulsions, but both SCBs did so as effectively as and more potently than PTZ. SCB-elicited convulsions were attenuated by the CB1R antagonist rimonabant or by THC, or by dose regimens of THC and JWH-018, which downregulate and desensitize CB1Rs. None of these treatments altered the convulsant effects of PTZ, although diazepam attenuated PTZ-elicited convulsions without altering SCB-induced convulsant effects. Repeated administration of a subthreshold dose of PTZ kindled convulsant effects, but this was not observed with the SCBs, and no cross-kindling was observed. Repeated administration of the SCBs resulted in tolerance to convulsant effects, but no cross-tolerance to PTZ was observed. Inhibition on Phase I metabolism via nonselective inhibition of CYP450s with 1-aminobenzotriazole potentiated the hypothermic effects of the SCBs and protected against the convulsant effects of JWH-018, but not those of 5F-AB-PINACA or PTZ. Incubation of human liver microsomes with the SCBs showed that JWH-018 is eliminated via oxidation, whereas 5F-AB-PINACA is not. These studies suggest that SCB-elicited convulsions are mediated by high intrinsic efficacy at CB1Rs and that benzodiazepines may not be effective treatments. Finally, drug metabolism may dramatically modulate the convulsant effects of some, but not all, SCBs.

Novel behavioral assays of spontaneous and precipitated THC withdrawal in mice

BACKGROUND

A subset of cannabis users develop some degree of Cannabis Use Disorder (CUD). Although behavioral therapy has some success in treating CUD, many users relapse, often citing altered sleep, mood, and irritability. Preclinical animal tests of cannabinoid withdrawal focus primarily on somatic-related behaviors precipitated by a cannabinoid receptor antagonist. The goal of the present study was to develop novel cannabinoid withdrawal assays that are either antagonist-precipitated or spontaneously induced by abstinence.

METHODS

C57BL/6 J mice were repeatedly administered the phytocannabinoid Δ⁹-tetrahydrocannabinol (THC; 1, 10 or 50 mg/kg, s.c.), the synthetic cannabinoid receptor agonist JWH-018 (1 mg/kg, s.c.), or vehicle (1:1:18 parts ethanol:Kolliphor EL:saline, s.c.) for 6 days. Withdrawal was precipitated with the cannabinoid receptor inverse agonist rimonabant (3 mg/kg, i.p.) or elicited via abstinence (i.e., spontaneous withdrawal), and putative stress-related behavior was scored. Classic somatic signs of cannabinoid withdrawal were also quantified.

RESULTS

Precipitated THC withdrawal significantly increased plasma corticosterone. Precipitated withdrawal from either THC or JWH-018 suppressed marble burying, increased struggling in the tail suspension test, and elicited somatic withdrawal behaviors. The monoacylglycerol lipase inhibitor JZL184 attenuated somatic precipitated withdrawal but had no effect on marble burying or struggling. Spontaneous THC or JWH-018 withdrawal-induced paw tremors, head twitches, and struggled in the tail suspension test after 24-48 h abstinence. JZL184 or THC attenuated these spontaneous withdrawal-induced behaviors.

CONCLUSION

Outcomes from tail suspension and marble burying tests reveal that THC withdrawal is multifaceted, eliciting and suppressing behaviors in these tests, in addition to inducing well-documented somatic signs of withdrawal.

Methodology for controlled administration of smoked synthetic cannabinoids JWH-018 and JWH-073

Synthetic cannabinoids (SCs) are a significant public health concern given their widespread use and severe effects associated with intoxication. However, there is a paucity of controlled human studies investigating the behavioral and physiological effects and pharmacokinetics of these compounds. Designing a reliable method to administer consistent, concentration-dependent synthetic cannabinoids is an integral component of controlled study of these compounds. Further, optimizing methods to assess the parent compounds and metabolites in plasma is critical in order to be able to establish their pharmacokinetics after administration. To develop a reliable method to administer smokable, concentration-dependent SCs, cigarettes were prepared with plant matter adulterated with increasing concentrations of the first generation cannabinoids found in SC products, JWH-018 and JWH-073. Cigarettes were assessed 1-6 months after preparation using ultra-high-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) to determine compound stability over time and concentration consistency throughout the cigarettes. Optimal conditions to detect metabolites in human plasma as a function of storage temperature (-4 °C to -80 °C) and time (24 h - 1 month) were also determined. Analyses verified that the method utilized to develop SC cigarettes yielded consistent, concentration-dependent products within 25% of the expected concentrations. JWH-018, JWH-073 and metabolites in spiked plasma were stable under the time and temperature conditions; concentrations were within ±20% of target values. These studies provide techniques and methods to conduct controlled investigations of the dose-dependent effects of first generation SCs to begin understanding risks associated with use. This article is part of the Special Issue entitled 'Designer Drugs and Legal Highs.'

Disruption of hippocampal synaptic transmission and long-term potentiation by psychoactive synthetic cannabinoid 'Spice' compounds: comparison with Δ9 -tetrahydrocannabinol

There has been a marked increase in the availability of synthetic drugs designed to mimic the effects of marijuana. These cannabimimetic drugs, sold illicitly as 'Spice' and related products, are associated with serious medical complications in some users. In vitro studies suggest that synthetic cannabinoids in these preparations are potent agonists at central cannabinoid CB1 receptors (CB1Rs), but few investigations have delineated their cellular effects, particularly in comparison with the psychoactive component of marijuana, Δ9 -tetrahydrocannabinol (Δ9 -THC). We compared the ability of three widely abused synthetic cannabinoids and Δ9 -THC to alter glutamate release and long-term potentiation in the mouse hippocampus. JWH-018 was the most potent inhibitor of hippocampal synaptic transmission (EC50 ~15 nM), whereas its fluoropentyl derivative, AM2201, inhibited synaptic transmission with slightly lower potency (EC50 ~60 nM). The newer synthetic cannabinoid, XLR-11, displayed much lower potency (EC50 ~900 nM) that was similar to Δ9 -THC (EC50 ~700 nM). The effects of all compounds occurred via activation of CB1Rs, as demonstrated by reversal with the selective antagonist/inverse agonist AM251 or the neutral CB1R antagonist PIMSR1. Moreover, AM2201 was without effect in the hippocampus of transgenic mice lacking the CB1R. Hippocampal slices exposed to either synthetic cannabinoids or Δ9 -THC exhibited significantly impaired long-term potentiation (LTP). We find that, compared with Δ9 -THC, the first-generation cannabinoids found in Spice preparations display higher potency, whereas a recent synthetic cannabinoid is roughly equipotent with Δ9 -THC. The disruption of synaptic function by these synthetic cannabinoids is likely to lead to profound impairments in cognitive and behavioral function.

[Synthetic cannabinoids: A new addiction matrix]

Synthetic cannabinoids (SC) belong to the emergent market of new psychoactive substances, sold on the Internet or specialized shops. Since the 1970s, more than 160 new SC have invaded the drug market. These substances imitate the psychoactive effects of cannabis. Underestimated for too long, SC's market growth and consequences are no longer to be ignored, first of all in terms of public health. SC were first synthesized during researches on the endocannabinoid system. Though they are agonists of the cannabinoid receptors 1 and 2, as Δ9-tetrahydrocannabinol in cannabis, they can also have a really high affinity with these receptors, rising up their potency. Each country in the world has chosen various ways how to deal with SC: scheduling, blanket ban, regulation… In order to contour the legal system, producers regularly modify the chemical formulas of those substances and hand out an attracting packaging looking harmless. However, the content of those small packets is extremely unstable and unreliable, including harmful compounds to health. Reports show an increasing number of non-fatal intoxications but also fatalities. Consequences on the body are numerous but there have been also reports of mental health imbalance and appearances of addiction-linked clinical signs. This review of literature aims at establishing a picture on SC in order to raise awareness among professionals in the health field on this new addiction matrix.

Synthetic Cathinone and Cannabinoid Designer Drugs Pose a Major Risk for Public Health

As part of an increasing worldwide use of designer drugs, recent use of compounds containing cathinones and synthetic cannabinoids is especially prevalent. Here, we reviewed current literature on the prevalence, epidemiology, bio-behavioral effects, and detection of these compounds. Gender differences and clinical effects will also be examined. Chronic use of synthetic cathinone compounds can have major effects on the central nervous system and can induce acute psychosis, hypomania, paranoid ideation, and delusions, similar to the effects of other better-known amphetamine-type stimulants. Synthetic cannabinoid products have effects that are somewhat similar to those of natural cannabis but more potent and long-lasting than THC. Some of these compounds are potent and dangerous, having been linked to psychosis, mania, and suicidal ideation. Novel compounds are developed rapidly and new screening techniques are needed to detect them as well as a rigorous regulation and legislation reinforcement to prevent their distribution and use. Given the rapid increase in the use of synthetic cathinones and cannabinoid designer drugs, their potential for dependence and abuse, and harmful medical and psychiatric effects, there is a need for research and education in the areas of prevention and treatment.

Pharmacological and Toxicological Effects of Synthetic Cannabinoids and Their Metabolites

Commercial preparations containing synthetic cannabinoids (SCBs) are rapidly emerging as drugs of abuse. Although often assumed to be "safe" and "legal" alternatives to cannabis, reports indicate that SCBs induce toxicity not often associated with the primary psychoactive component of marijuana, Δ9-tetrahydrocannabinol (Δ9-THC). This chapter will summarize the evidence that use of SCBs poses greater health risks relative to marijuana and suggest that distinct pharmacological properties and metabolism of SCBs relative to Δ9-THC may contribute to this increased toxicity. Studies reviewed will indicate that in contrast to partial agonist properties of Δ9-THC typically observed in vitro, SCBs act as full CB1 and CB2 receptor agonists both in cellular assays and animal studies. Furthermore, unlike Δ9-THC metabolism, several SCB metabolites retain high affinity for and exhibit a range of intrinsic activities at CB1 and CB2 receptors. Finally, the potential for SCBs to cause adverse drug-drug interactions with other drugs of abuse, as well as with common therapeutic agents, will be discussed. Collectively, the evidence provided in this chapter indicates that SCBs should not be considered safe and legal alternatives to marijuana. Instead, the enhanced toxicity of SCBs relative to marijuana, perhaps resulting from the combined actions of a complex mixture of different SCBs present and their active metabolites that retain high affinity for CB1 and CB2 receptors, highlights the inherent danger that may accompany use of these substances.

Stratification of Cannabinoid 1 Receptor (CB1R) Agonist Efficacy: Manipulation of CB1R Density through Use of Transgenic Mice Reveals Congruence between In Vivo and In Vitro Assays

Synthetic cannabinoids (SCs) are an emerging class of abused drugs that differ from each other and the phytocannabinoid ∆⁹-tetrahydrocannabinol (THC) in their safety and cannabinoid-1 receptor (CB₁R) pharmacology. As efficacy represents a critical parameter to understanding drug action, the present study investigated this metric by assessing in vivo and in vitro actions of THC, two well-characterized SCs (WIN55,212-2 and CP55,940), and three abused SCs (JWH-073, CP47,497, and A-834,735-D) in CB₁ (+/+), (+/-), and (-/-) mice. All drugs produced maximal cannabimimetic in vivo effects (catalepsy, hypothermia, antinociception) in CB₁ (+/+) mice, but these actions were essentially eliminated in CB₁ (-/-) mice, indicating a CB₁R mechanism of action. CB₁R efficacy was inferred by comparing potencies between CB₁ (+/+) and (+/-) mice [+/+ ED₅₀ /+/- ED₅₀], the latter of which has a 50% reduction of CB₁Rs (i.e., decreased receptor reserve). Notably, CB₁ (+/-) mice displayed profound rightward and downward shifts in the antinociception and hypothermia dose-response curves of low-efficacy compared with high-efficacy cannabinoids. In vitro efficacy, quantified using agonist-stimulated [³⁵S]GTPγS binding in spinal cord tissue, significantly correlated with the relative efficacies of antinociception (r = 0.87) and hypothermia (r = 0.94) in CB₁ (+/-) mice relative to CB₁ (+/+) mice. Conversely, drug potencies for cataleptic effects did not differ between these genotypes and did not correlate with the in vitro efficacy measure. These results suggest that evaluation of antinociception and hypothermia in CB₁ transgenic mice offers a useful in vivo approach to determine CB₁R selectivity and efficacy of emerging SCs, which shows strong congruence with in vitro efficacy.

Synthetic cannabinoid JWH-018 and its halogenated derivatives JWH-018-Cl and JWH-018-Br impair Novel Object Recognition in mice: Behavioral, electrophysiological and neurochemical evidence

It is well known that an impairment of learning and memory function is one of the major physiological effects caused by natural or synthetic cannabinoid consumption in rodents, nonhuman primates and in humans. JWH-018 and its halogenated derivatives (JWH-018-Cl and JWH-018-Br) are synthetic CB1/CB2 cannabinoid agonists, illegally marketed as "Spice" and "herbal blend" for their Cannabis-like psychoactive effects. In the present study the effects of acute exposure to JWH-018, JWH-018-Cl, JWH-018-Br (JWH-018-R compounds) and Δ(9)-THC (for comparison) on Novel Object Recognition test (NOR) has been investigated in mice. Moreover, to better characterize the effects of JWH-018-R compounds on memory function, in vitro electrophysiological and neurochemical studies in hippocampal preparations have been performed. JWH-018, JWH-018-Cl and JWH-018-Br dose-dependently impaired both short- and long-memory retention in mice (respectively 2 and 24 h after training session). Their effects resulted more potent respect to that evoked by Δ(9)-THC. Moreover, in vitro studies showed as JWH-018-R compounds negatively affected electrically evoked synaptic transmission, LTP and aminoacid (glutamate and GABA) release in hippocampal slices. Behavioral, electrophysiological and neurochemical effects were fully prevented by CB1 receptor antagonist AM251 pretreatment, suggesting a CB1 receptor involvement. These data support the hypothesis that synthetic JWH-018-R compounds, as Δ(9)-THC, impair cognitive function in mice by interfering with hippocampal synaptic transmission and memory mechanisms. This data outline the danger that the use and/or abuse of these synthetic cannabinoids may represent for the cognitive process in human consumer.

Pharmacological characterization of repeated administration of the first generation abused synthetic cannabinoid CP47,497

A series of in vivo and in vitro assays were conducted to characterize the pharmacological effects of the first generation abused synthetic cannabinoid CP47,497, a racemic bicyclic cannabinoid that is similar in structure to the potent, high-efficacy synthetic cannabinoid CP55,940. CP47,497 was less efficacious than CP55,940 in activating G-proteins and dose-dependently produced common CB1 receptor-dependent pharmacological effects (i.e. catalepsy, hypothermia, antinociception, and hypolocomotion). CP47,497 also substituted for Δ9-tetrahydrocannabinol (THC) in the mouse drug discrimination, indicating that both drugs elicited a similar interceptive stimulus. The pharmacological effects of CP47,497 underwent tolerance following repeated administration and showed cross-tolerance following repeated THC administration, further suggesting a common cannabimimetic mechanism of action. Finally, the CB1 receptor antagonist rimonabant precipitated similar magnitudes of somatic withdrawal responses in mice treated repeatedly with THC or CP47,497. Taken together, these data verify the acute cannabimimetic effects of CP47,497, and indicate tolerance and dependence following repeated administration. The assays used here provide a straightforward approach to characterize the emerging next generation of abused synthetic cannabinoids.

Adverse Effects of Synthetic Cannabinoids: Management of Acute Toxicity and Withdrawal

Although several chemical structural classes of synthetic cannabinoids (SCs) were recently classified as Schedule I substances, rates of use and cases of serious toxic effects remain high. While case reports and media bring attention to severe SC toxicity, daily SC use resulting in dependence and withdrawal is a significant concern that is often overlooked when discussing the risks of these drugs. There is a rich literature on evidence-based approaches to treating substance use disorders associated with most abused drugs, yet little has been published regarding how to best treat symptoms related to SC dependence given its recency as an emerging clinically significant issue. This review provides a background of the pharmacology of SCs, recent findings of adverse effects associated with both acute intoxication and withdrawal as a consequence of daily use, and treatment approaches that have been implemented to address these issues, with an emphasis on pharmacotherapies for managing detoxification. In order to determine prevalence of use in cannabis smokers, a population at high risk for SC use, we obtained data on demographics of SC users, frequency of use, and adverse effects over a 3.5-year period (2012-2015) in the New York City metropolitan area, a region with a recent history of high SC use. While controlled studies on the physiological and behavioral effects of SCs are lacking, it is clear that risks associated with using these drugs pertain not only to the unpredictable and severe nature of acute intoxication but also to the effects of long-term, chronic use. Recent reports in the literature parallel findings from our survey, indicating that there is a subset of people who use SCs daily. Although withdrawal has not been systematically characterized and effective treatments have yet to be elucidated, some symptom relief has been reported with benzodiazepines and the atypical antipsychotic, quetiapine. Given the continued use and abuse of SCs, empirical studies characterizing (1) SCs acute effects, (2) withdrawal upon cessation of use, and (3) effective treatment strategies for SC use disorder are urgently needed.

Δ(9)-Tetrahydrocannabinol-like effects of novel synthetic cannabinoids in mice and rats

RATIONALE

Novel cannabinoid compounds continue to be marketed as "legal" marijuana substitutes, even though little is known about their molecular and behavioral effects.

OBJECTIVES

Six of these compounds (ADBICA, ADB-PINACA, THJ-2201, RCS-4, JWH-122, JWH-210) were tested for in vitro and in vivo cannabinoid-like effects to determine their abuse liability.

METHODS

Binding to and functional activity at CB1 cannabinoid receptors was tested. Locomotor activity in mice was tested to screen for behavioral activity and to identify behaviorally active dose ranges and times of peak effect. Discriminative stimulus effects of the six compounds were tested in rats trained to discriminate Δ(9)-tetrahydrocannabinol (Δ(9)-THC).

RESULTS

ADBICA, ADB-PINACA, THJ-2201, RCS-4, JWH-122, and JWH-210 showed high affinity binding at the CB1 receptor at nanomolar affinities (0.59 to 22.5 nM), and all acted as full agonists with nanomolar potencies (0.024 to 111 nM) when compared to the CB1 receptor full agonist CP 55940. All compounds depressed locomotor activity below 50 % of vehicle responding, with depressant effects lasting 1.5 to nearly 4 h. All compounds fully substituted (<80 % Δ(9)-THC-appropriate responding) for the discriminative stimulus effects of Δ(9)-THC. 3,4-Methylenedioxy-methamphetamine (MDMA) was tested as a negative control and did not substitute for Δ(9)-THC (11 % Δ(9)-THC-appropriate responding).

CONCLUSIONS

All six of the compounds acted at the CB1 receptor and produced behavioral effects common to abused cannabinoid compounds, which suggest that these compounds have substantial abuse liability common to controlled synthetic cannabinoid compounds.

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.

Differential physiological and behavioral cues observed in individuals smoking botanical marijuana versus synthetic cannabinoid drugs

CONTEXT

Synthetic cannabinoid use has increased in many states, and medicinal and/or recreational marijuana use has been legalized in some states. These changes present challenges to law enforcement drug recognition experts (DREs) who determine whether drivers are impaired by synthetic cannabinoids or marijuana, as well as to clinical toxicologists who care for patients with complications from synthetic cannabinoids and marijuana. Our goal was to compare what effects synthetic cannabinoids and marijuana had on performance and behavior, including driving impairment, by reviewing records generated by law enforcement DREs who evaluated motorists arrested for impaired driving.

METHODS

Data were from a retrospective, convenience sample of de-identified arrest reports from impaired drivers suspected of using synthetic cannabinoids (n = 100) or marijuana (n = 33). Inclusion criteria were arrested drivers who admitted to using either synthetic cannabinoids or marijuana, or who possessed either synthetic cannabinoids or marijuana; who also had a DRE evaluation at the scene; and whose blood screens were negative for alcohol and other drugs. Exclusion criteria were impaired drivers arrested with other intoxicants found in their drug or alcohol blood screens. Blood samples were analyzed for 20 popular synthetic cannabinoids by using liquid chromatography-tandem mass spectrometry. Delta-9-tetrahydrocannabinol (THC) and THC-COOH were quantified by gas chromatography-mass spectrometry. Statistical significance was determined by using Fisher's exact test or Student's t-test, where appropriate, to compare the frequency of characteristics of those in the synthetic cannabinoid group versus those in the marijuana group.

RESULTS

16 synthetic cannabinoid and 25 marijuana records met selection criteria; the drivers of these records were arrested for moving violations. Median age for the synthetic cannabinoid group (n = 16, 15 males) was 20 years (IQR 19-23 years). Median age for the marijuana group (n = 25, 21 males) was 20 years (IQR 19-24 years) (p = 0.46). In the synthetic cannabinoid group, 94% (15/16) admitted to using synthetic cannabinoids. In the marijuana group, 96% (24/25) admitted to using marijuana. Blood was available for testing in 96% (24/25) of the marijuana group; 21 of these 24 had quantitative levels of THC (mean + SD = 10.7 + 5 ng/mL) and THC-COOH (mean + SD = 57.8 + 3 ng/mL). Blood was available for testing in 63% (10/16) of the synthetic cannabinoid group, with 80% (8/10) of these positive for synthetic cannabinoids. Those in the synthetic cannabinoid group were more frequently confused (7/16 [44%] vs. 0/25 [0%], p ≤ 0.003) and disoriented (5/16 [31%] vs. 0/25 [0%], p ≤ 0.003), and more frequently had incoherent, slurred speech (10/16 [63%] vs. 3/25 [12%], p = 0.0014) and horizontal gaze nystagmus (8/16 [50%] vs. 3/25 [12%], p = 0.01) than those in the marijuana group.

CONCLUSION

Drivers under the influence of synthetic cannabinoids were more frequently impaired with confusion, disorientation, and incoherent, slurred speech than drivers under the influence of marijuana in this population evaluated by DREs.

Synthetic cannabinoids: the dangers of spicing it up

Cannabinoids are the most commonly used illegal substances in the world. Spice and K2 are synthetic cannabinoid (SC) products that contain a mixture of herbs and plant matter combined with synthetic compounds similar to tetrahydrocannabinol, the psychoactive component of cannabis. Because the effects of Spice and K2 are similar to cannabis, many users are smoking these products as legal substitutes despite package labeling that they are not designed for human consumption. These SC products appeal to users because they are easily accessible and not readily detected in standard urine drug screens. The active components in SC products are highly potent and poorly characterized. Use of these agents has been associated with serious psychological and physiological side effects. Because abuse of SC products has become a national public health issue, nurses should be aware of the effects of SC compounds and must take a lead role in educating patients about the dangers of their use.

Synthetic cannabinoids 2015: An update for pediatricians in clinical practice

Synthetic cannabinoids are a group of substances in the world of designer drugs that have become increasingly popular over the past few years. Synthetic cannabinoids are a chemically diverse group of compounds functionally similar to THC. Since first appearing on the world market a few years ago these compounds have evolved rapidly. Newer more potent analogues have been developed. Identifying youth who abuse these substances can be difficult. Newer forms of consumption have also evolved. These products are now manufactured in products that look like natural cannabis resin and in liquid cartridges used in electronic cigarettes. Synthetic cannabinoids appear to be associated with potentially dangerous health effects that are more severe than that of marijuana. Some synthetic cannabinoid compounds have been associated with serious physical consequences, such as, seizures, myocardial infarction and renal damage. In addition, psychoactive effects, such as aggression, confusion, anxiety and psychosis have also been reported. The diagnosis remains primarily clinical with toxicological confirmation difficult due to manufacturers constantly developing new analogues to avoid detection. Pediatricians are urged to familiarize themselves with these drugs and the typical presentations of patients who use them.

Native CB1 receptor affinity, intrinsic activity and accumbens shell dopamine stimulant properties of third generation SPICE/K2 cannabinoids: BB-22, 5F-PB-22, 5F-AKB-48 and STS-135

In order to investigate the in vivo dopamine (DA) stimulant properties of selected 3rd generation Spice/K2 cannabinoids, BB-22, 5F-PB-22, 5F-AKB-48 and STS-135, their in vitro affinity and agonist potency at native rat and mice CB1 receptors was studied. The compounds bind with high affinity to CB1 receptors in rat cerebral cortex homogenates and stimulate CB1-induced [(35)S]GTPγS binding with high potency and efficacy. BB-22 and 5F-PB-22 showed the lowest Ki of binding to CB1 receptors (0.11 and 0.13 nM), i.e., 30 and 26 times lower respectively than that of JWH-018 (3.38 nM), and a potency (EC50, 2.9 and 3.7 nM, respectively) and efficacy (Emax, 217% and 203%, respectively) as CB1 agonists higher than JWH-018 (EC50, 20.2 nM; Emax, 163%). 5F-AKB-48 and STS-135 had higher Ki for CB1 binding, higher EC50 and lower Emax as CB1 agonists than BB-22 and 5F-PB-22 but still comparatively more favourable than JWH-018. The agonist properties of all the compounds were abolished or drastically reduced by the CB1 antagonist/inverse agonist AM251 (0.1 μM). No activation of G-protein was observed in CB1-KO mice. BB-22 (0.003-0.01 mg/kg i.v.) increased dialysate DA in the accumbens shell but not in the core or in the medial prefrontal cortex, with a bell shaped dose-response curve and an effect at 0.01 mg/kg and a biphasic time-course. Systemic AM251 (1.0 mg/kg i.p.) completely prevented the stimulant effect of BB-22 on dialysate DA in the NAc shell. All the other compounds increased dialysate DA in the NAc shell at doses consistent with their in vitro affinity for CB1 receptors (5F-PB-22, 0.01 mg/kg; 5F-AKB-48, 0.1 mg/kg; STS-135, 0.15 mg/kg i.v.). 3rd generation cannabinoids can be even more potent and super-high CB1 receptor agonists compared to JWH-018. Future research will try to establish if these properties can explain the high toxicity and lethality associated with these compounds.

Δ9-Tetrahydrocannabinol-like discriminative stimulus effects of compounds commonly found in K2/Spice

A number of cannabinoid compounds are being sold in the form of incense as 'legal' alternatives to marijuana. The purpose of these experiments was to determine whether the most common of these compounds have discriminative stimulus effects similar to Δ-tetrahydrocannabinol (Δ-THC), the main active component in marijuana. Locomotor depressant effects of JWH-018, JWH-073, JWH-200, JWH-203, JWH-250, AM-2201, and CP 47,497-C8-homolog were tested in mice. The compounds were then tested for substitution in rats trained to discriminate Δ-THC (3 mg/kg, intraperitoneally). The time course of the peak dose of each compound was also tested. Each of the synthetic cannabinoids dose-dependently decreased locomotor activity for 1-2 h. Each of the compounds fully substituted for the discriminative stimulus effects of Δ-THC, mostly at doses that produced only marginal amounts of rate suppression. JWH-250 and CP 47,497-C8-homolog suppressed response rates at doses that fully substituted for Δ-THC. The time courses varied markedly between compounds. Most of the compounds had a shorter onset than Δ-THC, and the effects of three of the compounds lasted substantially longer (JWH-073, JWH-250, and CP 47,497-C8-homolog). Several of the most commonly used synthetic cannabinoids produce behavioral effects comparable with those of Δ-THC, which suggests that these compounds may share the psychoactive effects of marijuana responsible for abuse liability. The extremely long time course of the discriminative stimulus effects and adverse effects of CP 47,497-C8-homolog suggest that CP 47,497-C8-homolog may be associated with increased hazards among humans.

An animal model of female adolescent cannabinoid exposure elicits a long-lasting deficit in presynaptic long-term plasticity

Cannabis continues to be the most accessible and popular illicit recreational drug. Whereas current data link adolescence cannabinoid exposure to increased risk for dependence on other drugs, depression, anxiety disorders and psychosis, the mechanism(s) underlying these adverse effects remains controversial. Here we show in a mouse model of female adolescent cannabinoid exposure deficient endocannabinoid (eCB)-mediated signaling and presynaptic forms of long-term depression at adult central glutamatergic synapses in the prefrontal cortex. Increasing endocannabinoid levels by blockade of monoacylglycerol lipase, the primary enzyme responsible for degrading the endocannabinoid 2-arachidonoylglycerol (2-AG), with the specific inhibitor JZL 184 ameliorates eCB-LTD deficits. The observed deficit in cortical presynaptic signaling may represent a neural maladaptation underlying network instability and abnormal cognitive functioning. Our study suggests that adolescent cannabinoid exposure may permanently impair brain functions, including the brain's intrinsic ability to appropriately adapt to external influences.

Effects of acute and repeated dosing of the synthetic cannabinoid CP55,940 on intracranial self-stimulation in mice

BACKGROUND

Synthetic cannabinoids have emerged as a significant public health concern. To increase the knowledge of how these molecules interact on brain reward processes, we investigated the effects of CP55,940, a high efficacy synthetic CB1 receptor agonist, in a frequency-rate intracranial self-stimulation (ICSS) procedure.

METHODS

The impact of acute and repeated administration (seven days) of CP55,940 on operant responding for electrical brain stimulation of the medial forebrain bundle was investigated in C57BL/6J mice.

RESULTS

CP55,940 attenuated ICSS in a dose-related fashion (ED50 (95% C.L.)=0.15 (0.12-0.18)mg/kg). This effect was blocked by the CB1 receptor antagonist rimonabant. Tolerance developed quickly, though not completely, to the rate-decreasing effects of CP55,940 (0.3mg/kg). Abrupt discontinuation of drug did not alter baseline responding for up to seven days. Moreover, rimonabant (10mg/kg) challenge did not alter ICSS responding in mice treated repeatedly with CP55,940.

CONCLUSIONS

The finding that CP55,940 reduced ICSS in mice with no evidence of facilitation at any dose is consistent with synthetic cannabinoid effects on ICSS in rats. CP55,940-induced ICSS depression was mediated through a CB1 receptor mechanism. Additionally, tolerance and dependence following repeated CP55,940 administration were dissociable. Thus, CP55,940 does not produce reward-like effects in ICSS under these conditions.

Baths salts, spice, and related designer drugs: the science behind the headlines

The abuse of synthetic psychoactive substances known as "designer drugs," or "new psychoactive substances" (NPS), is increasing at an alarming rate. NPS are purchased as alternatives to traditional illicit drugs of abuse and are manufactured to circumvent laws regulating the sale and use of controlled substances. Synthetic cathinones (i.e., "bath salts") and synthetic cannabinoids (i.e., "spice") are two types of NPS that have received substantial media attention. Although low recreational doses of bath salts or spice compounds can produce desirable effects, high doses or chronic exposure often leads to dangerous medical consequences, including psychosis, violent behaviors, tachycardia, hyperthermia, and even death. Despite the popularity of NPS, there is a paucity of scientific data about these drugs. Here we provide a brief up-to-date review describing the mechanisms of action and neurobiological effects of synthetic cathinones and cannabinoids.