Pharmacokinetics and pharmacodynamics of the synthetic cannabinoid, 5F-MDMB-PICA, in male rats.

5F-MDMB-PICA is a popular synthetic cannabinoid associated with analytically confirmed intoxications. In vitro studies show 5F-MDMB-PICA is a potent cannabinoid-1 receptor (CB1) agonist, but little information is available about in vivo pharmacokinetics and pharmacodynamics. To this end, the present study had three aims: 1) to develop a validated method for detection of 5F-MDMB-PICA and its metabolites in rat plasma, 2) to utilize the method for investigating pharmacokinetics of 5F-MDMB-PICA in rats, and 3) to relate 5F-MDMB-PICA pharmacokinetics to pharmacodynamic effects. 5F-MDMB-PICA and its metabolites were quantified using liquid chromatography tandem mass spectrometry (LC-MS/MS) and method validation followed forensic standards. Male Sprague-Dawley rats bearing surgically implanted jugular catheters and subcutaneous (s.c.) temperature transponders received 5F-MDMB-PICA (50, 100, or 200 µg/kg, s.c.) or its vehicle. Blood samples were drawn at 15, 30, 60, 120, 240, and 480 min post-injection, and plasma was assayed using LC-MS/MS. At each blood draw, body temperature, and catalepsy scores were recorded. Maximum plasma concentrations (Cmax) of 5F-MDMB-PICA rose linearly with increasing dose (1.72-6.20 ng/mL), and plasma half-life (t1/2) ranged from 400 to 1000 min 5F-MDMB-PICA-3,3-dimethylbutanoic acid and 5OH-MDMB-PICA were the only metabolites detected, and plasma concentrations were much lower than the parent drug. 5F-MDMB-PICA induced robust hypothermia and catalepsy-like symptoms that were significantly correlated with concentrations of 5F-MDMB-PICA. Radioligand binding in rat brain membranes revealed 5F-MDMB-PICA displays high affinity for CB1 (IC50 = 2 nM) while metabolites do not. In summary, 5F-MDMB-PICA is a potent CB1 agonist in rats whose pharmacodynamic effects are related to circulating concentrations of the parent drug and not its metabolites.

Assessment of cognitive and psychomotor impairment, subjective effects, and blood THC concentrations following acute administration of oral and vaporized cannabis.

BACKGROUND: Cannabis legalization is expanding, but there are no established methods for detecting cannabis impairment. AIM: Characterize the acute impairing effects of oral and vaporized cannabis using various performance tests. METHODS: Participants (N = 20, 10 men/10 women) who were infrequent cannabis users ingested cannabis brownies (0, 10, and 25 mg Δ-9-tetrahydrocannabinol, THC) and inhaled vaporized cannabis (0, 5, and 20 mg THC) in six double-blind outpatient sessions. Cognitive/psychomotor impairment was assessed with a battery of computerized tasks sensitive to cannabis effects, a novel test (the DRiving Under the Influence of Drugs, DRUID®), and field sobriety tests. Blood THC concentrations and subjective drug effects were evaluated. RESULTS: Low oral/vaporized doses did not impair cognitive/psychomotor performance relative to placebo but produced positive subjective effects. High oral/vaporized doses impaired cognitive/psychomotor performance and increased positive and negative subjective effects. The DRUID® was the most sensitive test to cannabis impairment, as it detected significant differences between placebo and active doses within both routes of administration. Women displayed more impairment on the DRUID® than men at the high vaporized dose only. Field sobriety tests showed little sensitivity to cannabis-induced impairment. Blood THC concentrations were far lower after cannabis ingestion versus inhalation. After inhalation, blood THC concentrations typically returned to baseline well before pharmacodynamic effects subsided. CONCLUSIONS: Standard approaches for identifying impairment due to cannabis exposure (i.e. blood THC and field sobriety tests) have severe limitations. There is a need to identify novel biomarkers of cannabis exposure and/or behavioral tests like the DRUID® that can reliably and accurately detect cannabis impairment at the roadside and in the workplace.

Altered Signaling in CB1R-5-HT2AR Heteromers in Olfactory Neuroepithelium Cells of Schizophrenia Patients is Modulated by Cannabis Use.

Schizophrenia (SCZ) has been associated with serotonergic and endocannabinoid systems dysregulation, but difficulty in obtaining in vivo neurological tissue has limited its exploration. We investigated CB1R-5-HT2AR heteromer expression and functionality via intracellular pERK and cAMP quantification in olfactory neuroepithelium (ON) cells of SCZ patients non-cannabis users (SCZ/nc), and evaluated whether cannabis modulated these parameters in patients using cannabis (SCZ/c). Results were compared vs healthy controls non-cannabis users (HC/nc) and healthy controls cannabis users (HC/c). Further, antipsychotic effects on heteromer signaling were tested in vitro in HC/nc and HC/c. Results indicated that heteromer expression was enhanced in both SCZ groups vs HC/nc. Additionally, pooling all 4 groups together, heteromer expression correlated with worse attentional performance and more neurological soft signs (NSS), indicating that these changes may be useful markers for neurocognitive impairment. Remarkably, the previously reported signaling properties of CB1R-5-HT2AR heteromers in ON cells were absent, specifically in SCZ/nc treated with clozapine. These findings were mimicked in cells from HC/nc exposed to clozapine, suggesting a major role of this antipsychotic in altering the quaternary structure of the CB1R-5-HT2AR heteromer in SCZ/nc patients. In contrast, cells from SCZ/c showed enhanced heteromer functionality similar to HC/c. Our data highlight a molecular marker of the interaction between antipsychotic medication and cannabis use in SCZ with relevance for future studies evaluating its association with specific neuropsychiatric alterations.

Lasting effects of repeated ∆9 -tetrahydrocannabinol vapour inhalation during adolescence in male and female rats.

BACKGROUND AND PURPOSE: Adolescents are regularly exposed to ∆9 -tetrahydrocannabinol (THC) via smoking and, more recently, vaping cannabis extracts. Growing legalization of cannabis for medical and recreational purposes, combined with decreasing perceptions of harm, makes it increasingly important to determine the consequences of frequent adolescent exposure for motivated behaviour and lasting tolerance in response to THC. EXPERIMENTAL APPROACHES: Male and female rats inhaled THC vapour, or that from the propylene glycol (PG) vehicle, twice daily for 30 min from postnatal day (PND) 35-39 and PND 42-46 using an e-cigarette system. Thermoregulatory responses to vapour inhalation were assessed by radio-telemetry during adolescence and from PND 86-94. Chow intake was assessed in adulthood. Blood samples were obtained from additional adolescent groups following initial THC inhalation and after 4 days of twice daily exposure. Additional groups exposed repeatedly to THC or PG during adolescence were evaluated for intravenous self-administration of oxycodone as adults. KEY RESULTS: Female, not male, adolescents developed tolerance to the hypothermic effects of THC inhalation in the first week of repeated exposure despite similar plasma THC levels. Each sex exhibited tolerance to THC hypothermia in adulthood after repeated adolescent THC. However, enhanced potency was found in females. Repeated THC male rats consumed more food than their PG-treated control group, without significant bodyweight differences. Adolescent THC did not alter oxycodone self-administration in either sex but increased fentanyl self-administration in females. CONCLUSIONS AND IMPLICATIONS: Repeated THC vapour inhalation in adolescent rats has lasting consequences observable in adulthood.

Identification of a thermal degradation product of CUMYL-PEGACLONE and its detection in biological samples.

The structural diversity of synthetic cannabinoids makes it a challenging task to have a comprehensive screening method for this class of drugs. The difficulty is increased by the fact that some synthetic cannabinoids undergo thermal decomposition during common routes of administration, such as smoking or vaping. CUMYL-PEGACLONE is a relatively new synthetic cannabinoid which has a structural variant from most other synthetic cannabinoids: a γ-carbolinone core. To investigate its thermal stability, CUMYL-PEGACLONE was heated in an oven at temperatures ranging from 200 to 350o C, and a major thermal degradation product, N-pentyl-γ-carbolinone, was subsequently identified. Unlike some other synthetic cannabinoids, the thermal degradation product of CUMYL-PEGACLONE is not one of its known metabolites, nor were any known metabolites detected during the thermal stability experiments. The degradation product was formed in significant amounts at temperatures above 250°C, and has been detected (along with CUMYL-PEGACLONE) in case samples, including post-mortem blood and urine, and residue found at a scene.

An act of balance: Interaction of central and peripheral chemosensitivity with inflammatory and anti-inflammatory factors in obstructive sleep apnoea.

OBJECTIVES: Central and peripheral chemosensitivity i.e. ventilatory response to CO2 and O2 are thought to be decisive for ventilatory control instability in obstructive sleep apnoea (OSA). Obesity is associated with chronic low level inflammation. Whether body mass related inflammatory and anti-inflammatory factors influencing peripheral and central chemosensitivity differentially is unclear. METHODS: Ventilatory response to hypercapnic-hyperoxic and hypercapnic-hypoxic gas mixtures in patients with OSA (n = 46) and healthy individuals (n = 45) was measured. C-reactive protein (CRP), leptin, adiponectin, and endocannabinoids 2-arachidonoylglycerol (2-AG) and anandamide (AEA) were measured in blood samples. RESULTS: Mediation analysis revealed that association of chemoresponse to CO2 with apnoea hypopnea index (AHI) was fully mediated by body mass index (BMI). Regression analysis showed that CRP and leptin levels explained ˜25% and ˜15% of the variance in central CO2 response, while 2-AG explained ˜42% of the variance in peripheral response to hypoxia. CONCLUSION: Inflammatory and anti-inflammatory factors could explain differential alterations in peripheral and central ventilatory chemoresponse in patients with OSA.

Preclinical evaluation of [18 F]MA3: a CB2 receptor agonist radiotracer for PET.

BACKGROUND AND PURPOSE: Non-invasive in vivo imaging of cannabinoid CB2 receptors using PET is pursued to study neuroinflammation. The purpose of this study is to evaluate the in vivo binding specificity of [18 F]MA3, a CB2 receptor agonist, in a rat model with local overexpression of human (h) CB2 receptors. METHODS: [18 F]MA3 was produced with good radiochemical yield and radiochemical purity. The radiotracer was evaluated in rats with local overexpression of hCB2 receptors and in a healthy non-human primate using PET. KEY RESULTS: Ex vivo autoradiography demonstrated CB2 -specific binding of [18 F]MA3 in rat hCB2 receptor vector injected striatum. In a PET study, increased tracer binding in the hCB2 receptor vector-injected striatum compared to the contralateral control vector-injected striatum was observed. Binding in hCB2 receptor vector-injected striatum was blocked with a structurally non-related CB2 receptor inverse agonist, and a displacement study confirmed the reversibility of tracer binding. This study identified the utility of mutated inactive vector model for evaluation of CB2 receptor agonist PET tracers. [18 F]MA3 PET scans in the non-human primate showed good uptake and fast washout from brain, but no CB2 receptor-specific binding was observed. CONCLUSION AND IMPLICATIONS: Evaluation of [18 F]MA3 in a rat model with local overexpression of hCB2 receptors showed CB2 receptor-specific and reversible tracer binding. [18 F]MA3 showed good brain uptake and subsequent washout in a healthy non-human primate, but no specific binding was observed. Further clinical evaluation of [18 F]MA3 in patients with neuroinflammation is warranted. LINKED ARTICLES: This article is part of a themed section on 8th European Workshop on Cannabinoid Research. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.10/issuetoc.

Plasma anandamide concentrations are lower in children with autism spectrum disorder.

Background: Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by restricted, stereotyped behaviors and impairments in social communication. Although the underlying biological mechanisms of ASD remain poorly understood, recent preclinical research has implicated the endogenous cannabinoid (or endocannabinoid), anandamide, as a significant neuromodulator in rodent models of ASD. Despite this promising preclinical evidence, no clinical studies to date have tested whether endocannabinoids are dysregulated in individuals with ASD. Here, we addressed this critical gap in knowledge by optimizing liquid chromatography-tandem mass spectrometry methodology to quantitatively analyze anandamide concentrations in banked blood samples collected from a cohort of children with and without ASD (N = 112). Findings: Anandamide concentrations significantly differentiated ASD cases (N = 59) from controls (N = 53), such that children with lower anandamide concentrations were more likely to have ASD (p = 0.041). In keeping with this notion, anandamide concentrations were also significantly lower in ASD compared to control children (p = 0.034). Conclusions: These findings are the first empirical human data to translate preclinical rodent findings to confirm a link between plasma anandamide concentrations in children with ASD. Although preliminary, these data suggest that impaired anandamide signaling may be involved in the pathophysiology of ASD.

Human Toxicity Caused by Indole and Indazole Carboxylate Synthetic Cannabinoid Receptor Agonists: From Horizon Scanning to Notification.

BACKGROUND: The emergence of novel psychoactive substances (NPS), particularly synthetic cannabinoid receptor agonists (SCRA), has involved hundreds of potentially harmful chemicals in a highly dynamic international market challenging users', clinicians', and regulators' understanding of what circulating substances are causing harm. We describe a toxicovigilance system for NPS that predicted the UK emergence and identified the clinical toxicity caused by novel indole and indazole carboxylate SCRA. METHODS: To assist early accurate identification, we synthesized 5 examples of commercially unavailable indole and indazole carboxylate SCRA (FUB-NPB-22, 5F-NPB-22, 5F-SDB-005, FUB-PB-22, NM-2201). We analyzed plasma and urine samples from 160 patients presenting to emergency departments with severe toxicity after suspected NPS use during 2015 to 2016 for these and other NPS using data-independent LC-MS/MS. RESULTS: We successfully synthesized 5 carboxylate SCRAs using established synthetic and analytical chemistry methodologies. We identified at least 1 SCRA in samples from 49 patients, including an indole or indazole carboxylate SCRA in 17 (35%), specifically 5F-PB-22 (14%), FUB PB-22 (6%), BB-22 (2%), 5F NPB-22 (20%), FUB NPB-22 (2%), and 5F-SDB-005 (4%). In these 17 patients, there was analytical evidence of other substances in 16. Clinical features included agitation and aggression (82%), reduced consciousness (76%), acidosis (47%), hallucinations and paranoid features (41%), tachycardia (35%), hypertension (29%), raised creatine kinase (24%), and seizures (12%). CONCLUSIONS: This toxicovigilance system predicted the emergence of misuse of indole and indazole carboxylate SCRA, documented associated clinical harms, and notified relevant agencies. Toxicity appears consistent with other SCRA, including mental state disturbances and reduced consciousness.

Effects of tetrahydrocannabinol on glucose uptake in the rat brain.

Δ9-Tetrahydrocannabinol (THC) is the psychoactive component of the plant Cannabis sativa and acts as a partial agonist at cannabinoid type 1 and type 2 receptors in the brain. The goal of this study was to assess the effect of THC on the cerebral glucose uptake in the rat brain. 21 male Sprague Dawley rats (12-13 w) were examined and received five different doses of THC ranging from 0.01 to 1 mg/kg. For data acquisition a Focus 120 small animal PET scanner was used and 24.1-28.0 MBq of [18F]-fluoro-2-deoxy-d-glucose were injected. The data were acquired for 70 min and arterial blood samples were collected throughout the scan. THC, THC-OH and THC-COOH were determined at 55 min p.i. Nine volumes of interest were defined, and the cerebral glucose uptake was calculated for each brain region. Low blood THC levels of < 1 ng/ml (injected dose: ≤ 0.01 mg/kg) corresponded to an increased glucose uptake (6-30 %), particularly in the hypothalamus (p = 0.007), while blood THC levels > 10 ng/ml (injected dose: ≥ 0.05 mg/kg) coincided with a decreased glucose uptake (-2 to -22 %), especially in the cerebellar cortex (p = 0.008). The effective concentration in this region was estimated 2.4 ng/ml. This glucose PET study showed that stimulation of CB1 receptors by THC affects the glucose uptake in the rat brain, whereby the effect of THC is regionally different and dependent on dose - an effect that may be of relevance in behavioural studies.

Acute Toxicity Associated with Use of 5F-Derivations of Synthetic Cannabinoid Receptor Agonists with Analytical Confirmation.

INTRODUCTION: Synthetic Cannabinoid Receptor Agonists (SCRAs) are the largest group of new psychoactive substances reported to the European Warning System and the United Nations Office on Drugs and Crime to date. The heterogeneous nature and speed of diversification of these compounds make it challenging to accurately characterise and predict harms of these compounds in pre-clinical studies, ahead of their appearance. CASE REPORT: We report the case of a 19-year-old female who purchased three products from a headshop: two new psychoactive substances (sachets of "cannabis tea" and "mushroom tea") as well as two LSD blotters. After the "cannabis tea" was smoked and the two LSD blotters and "mushroom tea" were ingested, the patient became tachycardic (HR 128), developed seizures, agitation, visual hallucinations as well as suspected serotonergic toxicity (sustained ankle clonus 20-30 beats) 1-2 hours after use. She was treated with 1 mg of intravenous midazolam. Symptoms/signs resolved within 13 hours. No further supportive care was required. Plasma, blood, and urine samples confirmed the presence of two SCRAs: 5FAKB-48 and 5F-PB-22. The patient also reported therapeutic use of both fluoxetine and citalopram for depression. DISCUSSION: To the best of our knowledge, this is the first case report of non-fatal intoxication with 5F-AKB-48 with analytical confirmation and exposure times. It also highlights the difficulties in understanding the pattern of toxicity of certain SCRAs in the context of psychotropic medications/co-morbid mental illness.

Clinical Effects of Synthetic Cannabinoid Receptor Agonists Compared with Marijuana in Emergency Department Patients with Acute Drug Overdose.

INTRODUCTION: Synthetic cannabinoid receptor agonists (SCRAs) are heterogeneous compounds originally intended as probes of the endogenous cannabinoid system or as potential therapeutic agents. We assessed the clinical toxicity associated with recent SCRA use in a large cohort of drug overdose patients. METHODS: This subgroup analysis of a large (n = 3739) drug overdose cohort study involved consecutive ED patients at two urban teaching hospitals collected between 2009 and 2013. Clinical characteristics of patients with the exposure to SCRAs (SRCA subgroup) were compared with those from patients who smoked traditional cannabinoids (marijuana subgroup). Data included demographics, exposure details, vital signs, mental status, and basic chemistries gathered as part of routine clinical care. Study outcomes included altered mental status and cardiotoxicity. RESULTS: Eighty-seven patients reported exposure to any cannabinoid, of whom 17 reported SCRAs (17 cases, 70 controls, mean age 38.9 years, 77 % males, 31 % Hispanic). There were no significant differences between SRCA and marijuana with respect to demographics (age, gender, and race/ethnicity), exposure history (suicidality, misuse, and intent), vital signs, or serum chemistries. Mental status varied between SRCA and marijuana, with agitation significantly more likely in SCRA subgroup (OR = 3.8, CI = 1.2-11.9). Cardiotoxicity was more pronounced in the SCRA subgroup with dysrhythmia significantly more likely (OR = 9.2, CI = 1.0-108). CONCLUSIONS: In the first clinical study comparing the adverse effects of SCRA overdose vs. marijuana controls in an ED population, we found that SCRA overdoses had significantly pronounced neurotoxicity and cardiotoxicity compared with marijuana.

Clinical toxicity following analytically confirmed use of the synthetic cannabinoid receptor agonist MDMB-CHMICA. A report from the Identification Of Novel psychoActive substances (IONA) study.

CONTEXT: Recreational use of Synthetic Cannabinoid Receptors Agonists (SCRAs) has become increasingly common in many countries and may cause severe toxic effects. OBJECTIVE: To describe the clinical features of toxicity in seven men after analytically confirmed exposure to MDMB-CHMICA, a recently described indole-based SCRA. MATERIALS AND METHODS: Clinical information and biological samples (blood, urine) were collected from patients with severe toxicity after suspected use of novel psychoactive substances. Samples were analyzed by data-independent liquid chromatography-tandem mass spectrometry (LC-MS/MS). CASE REPORTS: All seven cases were men who presented to hospitals in England between July and October 2015; six reported smoking "legal high" products. In all cases, MDMB-CHMICA was identified in blood samples taken on admission to hospital. Other substances were identified in four cases (methadone 1, methiopropamine 1, other SCRAs 2). Clinical features in all seven cases and in the three exposed to MDMB-CHIMICA alone included acidosis (7/7 and 3/3) which was respiratory (3/7 and 3/3), metabolic (3/7 and 0/3) or mixed (1/7, 0/3), reduced level of consciousness (6/7 and 3/3), mydriasis (5/7 and 3/3), tachycardia (5/7 and 2/3), bradycardia (2/7 and 1/3), tonic-clonic convulsions (2/7 and 1/3) and agitation (3/7 and 1/3). Recovery occurred within 24 h in all cases except one male also exposed to methiopropamine. CONCLUSIONS: Analytically confirmed exposure to MDMB-CHMICA was associated with acidosis (often of respiratory origin), reduced level of consciousness, mydriasis, heart rate disturbances and convulsions.

Acute intoxication of four individuals following use of the synthetic cannabinoid MAB-CHMINACA.

CONTEXT: The largest group of new psychoactive substances (NPS) are synthetic cannabinoids (SC). Those that become controlled are immediately replaced by new uncontrolled substances. The recent resurgence of the NPS market in Poland resulted in a further amendment to the Drug Addiction Counteraction Act. This resulted in significant changes in the composition of "legal high" preparations, and consequently a large outbreak of intoxications with SC was reported in Poland at the beginning of July 2015. CASE DETAILS: This paper describes the circumstances of intoxication and toxicological findings in an acute intoxication of four individuals with MAB-CHMINACA. They each smoked tobacco mixed with powder from the package with the description "AM-2201". The adverse effects observed in the individuals included vomiting, seizures, limb twisting, muscle tremors, aggression, agitation, slurred speech, blood pressure spikes, wheezing, respiratory failure and losses of consciousness. Blood samples were analysed using liquid chromatography with mass spectrometry. Results from analysis performed on the blood samples showed the presence of MAB-CHMINACA, while AM-2201 was not found (LOD 0.09 ng/mL). The determined concentrations were 5.2, 1.3, 1.7 and 14.6 ng/mL, respectively. The analyses of the blood did not reveal any other substances (excluding medicines given in hospital). CONCLUSION: The presented cases show the health risks associated with MAB-CHMINACA use and confirm that "legal high" preparations do not always contain a substance represented on the package.

Analysis and clinical findings of cases positive for the novel synthetic cannabinoid receptor agonist MDMB-CHMICA.

CONTEXT: MDMB-CHMICA is a synthetic cannabinoid receptor agonist which has caused concern due to its presence in cases of adverse reaction and death. METHOD: 43 cases of suspected synthetic cannabinoid ingestion were identified from patients presenting at an Emergency Department and from post-mortem casework. These were subjected to liquid-liquid extraction using tertiary-butyl methyl ether and quantitatively analysed by Electrospray Ionisation Liquid Chromatography-tandem Mass Spectrometry. For positive samples, case and clinical details were sought and interrogated. RESULTS: 11 samples were found positive for MDMB-CHMICA. Concentrations found ranged from <1 to 22 ng/mL (mean: 6 ng/mL, median: 3 ng/mL). The age range was 15-44 years (mean: 26 years, median: 21 years), with the majority (82%) of positive results found in males. Clinical presentations included hypothermia, hypoglycaemia, syncope, recurrent vomiting, altered mental state and serotonin toxicity, with corresponding concentrations of MDMB-CHMICA as low as <1 ng/mL. Duration of hospitalisation ranged from 3 to 24 h (mean: 12 h, median: 8 h). DISCUSSION: The concentration range presented in this case series is indicative of MDMB-CHMICA having a high potency, as is known to be the case for other synthetic cannabinoid receptor agonists. The age range and gender representation were consistent with that reported for users of other drugs of this type. The clinical presentations observed were typical of synthetic cannabinoid receptor agonists and show the difficulties in identifying reactions potentially associated with drugs of this type. CONCLUSION: The range of MDMB-CHMICA concentrations in Emergency Department presentations (n = 9) and post-mortem cases (n = 2) was reported. No correlation between the concentration of this drug and clinical presentation or cause of death was reported in this sample. However, the potential for harm associated with low concentrations of MDMB-CHMICA and the symptoms of toxicity being non-specific were highlighted.

Evaluation of Δ(9) -tetrahydrocannabinol detection using DrugWipe5S(®) screening and oral fluid quantification after Quantisal™ collection for roadside drug detection via a controlled study with chronic cannabis users.

Oral fluid (OF) is potentially useful to detect driving under the influence of drugs because of its ease of sampling. While cannabis is the most prevalent drug in Europe, sensitivity issues for Δ(9) -tetrahydrocannabinol (THC) screening and problems during OF collection are observed. The ability of a recently improved OF screening device - the DrugWipe5S(®) , to detect recent THC use in chronic cannabis smokers, was studied. Ten subjects participated in a double-blind placebo-controlled study. The subjects smoked two subsequent doses of THC; 300 µg/kg and 150 µg/kg with a pause of 75 min using a Volcano vapourizer. DrugWipe5S(®) screening and OF collection using the Quantisal™ device were performed at baseline, 5 min after each administration and 80 min after the last inhalation. Blood samples were drawn simultaneously. The screening devices (n = 80) were evaluated visually after 8 min, while the corresponding OF and serum samples were analyzed respectively with ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) or gas chromatography-mass spectrometry (GC-MS). Neat OF THC concentrations ranged from 12 361 ng/g 5 min after smoking down to 34 ng/g 80 min later. Under placebo conditions, a median THC concentration of 8 ng/g OF (0-746 ng/g) and < 1 ng/ mL serum (0-7.8 ng/mL) was observed. The DrugWipe5S(®) was positive just after smoking (90%); however, sensitivity rapidly decreased within 1.5 h (50%). Sensitivity of DrugWipe5S(®) should be improved. As chronic cannabis users have high residual THC concentrations in their serum and OF, confirmation cut-offs should be set according to the aim of detecting recent drug use or establishing zero tolerance.

Impaired functional connectivity of brain reward circuitry in patients with schizophrenia and cannabis use disorder: Effects of cannabis and THC.

Cannabis use disorder (CUD) occurs in up to 42% of patients with schizophrenia and substantially worsens disease progression. The basis of CUD in schizophrenia is unclear and available treatments are rarely successful at limiting cannabis use. We have proposed that a dysregulated brain reward circuit (BRC) may underpin cannabis use in these patients. In the present pilot study, we used whole-brain seed-to-voxel resting state functional connectivity (rs-fc) to examine the BRC of patients with schizophrenia and CUD, and to explore the effects of smoked cannabis and orally administered delta-9-tetrahydrocannabinol (THC) on the BRC. 12 patients with schizophrenia and CUD and 12 control subjects each completed two fMRI resting scans, with patients administered either a 3.6% THC cannabis cigarette (n=6) or a 15 mg THC capsule (n=6) prior to their second scan. Results revealed significantly reduced connectivity at baseline in patients relative to controls, with most pronounced hypoconnectivity found between the nucleus accumbens and prefrontal cortical BRC regions (i.e., anterior prefrontal cortex, orbitofrontal cortex, and anterior cingulate cortex). Both cannabis and THC administration increased connectivity between these regions, in direct correlation with increases in plasma THC levels. This study is the first to investigate interregional connectivity of the BRC and the effects of cannabis and THC on this circuit in patients with schizophrenia and CUD. The findings from this pilot study support the use of rs-fc as a means of measuring the integrity of the BRC and the effects of pharmacologic agents acting on this circuit in patients with schizophrenia and CUD.

Quantification of anandamide and 2-arachidonoylglycerol plasma levels to examine potential influences of tetrahydrocannabinol application on the endocannabinoid system in humans.

The effects of tetrahydrocannabinol (THC) and endogenous cannabinoids (endocannabinoids, ECs) are both mediated by activation of the cannabinoid receptors CB1 and CB2. Exogenous activation of these receptors by THC could therefore alter EC levels. We tested this hypothesis in healthy volunteers (n = 25) who received a large intravenous dose of THC (0.10 mg/kg). Effects on the EC system were quantified by serial measurements of plasma ECs after THC administration. Eleven blood samples were drawn during the first 5 h after THC administration and two more samples after 24 and 48 h. THC, its metabolites THC-OH (biologically active) and THC-COOH (non-active), and the ECs anandamide and 2-arachidonoylglycerol (2-AG) were quantified by liquid chromatography-mass spectrometry. EC-plasma levels showed a biphasic response after THC injection reaching maximal values at 30 min. Anandamide increased slightly from 0.58 ± 0.21 ng/ml at baseline to 0.64 ± 0.24 ng/ml (p < 0.05) and 2-AG from 7.60 ± 4.30 ng/ml to 9.50 ± 5.90 ng/ml (p < 0.05). After reaching maximal concentrations, EC plasma levels decreased markedly to a nadir of 300 min after THC administration (to 0.32 ± 0.15 ng/ml for anandamide and to 5.50 ± 3.01 ng/ml for 2-AG, p < 0.05). EC plasma concentrations returned to near baseline levels until 48 h after the experiment. THC (0.76 ± 0.16 ng/ml) and THC-OH (0.36 ± 0.17 ng/ml) were still measurable at 24 h and remained detectible until 48 h after THC administration. Although the underlying mechanism is not clear, high doses of intravenous THC appear to influence endogenous cannabinoid concentrations and presumably EC-signalling.