Urinary prevalence, metabolite detection rates, temporal patterns and evaluation of suitable LC-MS/MS targets to document synthetic cannabinoid intake in US military urine specimens

A new application of the switchable hydrophilicity solvent-based homogenous liquid-liquid microextraction to analyze synthetic cannabinoids in plasma by LC-MS/MS

Synthetic cannabinoids are still a growing trend among drug users and consist of a group of hundreds of highly potent compounds. To investigate the use of such substances, sample preparation of biological matrices is a crucial step prior to instrumental analysis. Although different efficient extraction techniques have been proposed for that aim, they usually do not fit eco-friendly guidelines that have been gaining popularity in recent years, such as Green Analytical Toxicology. This work uses describes for the first time the use of switchable hydrophilicity solvent-based homogenous liquid-liquid microextraction (SHS-HLLME) for synthetic cannabinoids. This is a green technique that replaces highly toxic organic reagents for switchable hydrophilicity solvents (SHS), substances that can be either water-miscible or immiscible depending on their protonation. Thus, by simply adjusting the pH of the system, these SHS can be used as extraction solvents. A full optimization study including type of SHS, volume of protonated SHS, volume of NaOH, salting-out effect, and extraction time was performed. The optimized procedure consisted of precipitating the proteins of 300 µL of plasma with 300 µL of acetonitrile followed by centrifugation; evaporation of the organic solvent under N2 stream; addition of 500 µL of the protonated DPA, DPA-HCl (6 M) (1:1, v/v); addition of 500 µL of NaOH (10 M); and finally centrifugation and evaporation. Validation results showed determination coefficients ≥ 0.99 for the 0.1-10 ng/mL linear range; 0.01-0.08 ng/mL as limit of detection; 0.1 ng/mL as limit of quantitation; accuracy and imprecision were within acceptable ranges; matrix effect, recovery, and process efficiency ranged from -55.6 to 185.9%, 36-56.7%, and 18.5-148.4%, respectively. The SHS-HLLME herein described was fully optimized providing satisfactory recoveries of 31 synthetic cannabinoids at low concentrations requiring only 300 µL of plasma. In addition, the validation results showed that the technique is a reliable eco-friendly alternative for clinical and toxicological analysis.

Phase I-metabolism studies of the synthetic cannabinoids PX-1 and PX-2 using three different in vitro models

PURPOSE

Synthetic cannabinoids (SCs), highly metabolized substances, are rarely found unmodified in urine samples. Urine screening relies on SC metabolite detection, requiring metabolism knowledge. Metabolism data can be acquired via in vitro assays, e.g., human hepatocytes, pooled human liver microsomes (pHLM), cytochrome P450 isoforms and a fungal model; or in vivo by screening, e.g., authentic human samples or rat urine. This work describes the comprehensive study of PX-1 and PX-2 in vitro metabolism using three in vitro models. 5F-APP-PICA (PX-1) and 5F-APP-PINACA (PX-2) were studied as they share structural similarity with AM-2201, THJ-2201 and 5F-AB-PINACA, the metabolism of which was described in the literature.

METHODS

For SC incubation, pHLM, cytochrome P450 isoenzymes and the fungal model Cunninghamella elegans LENDNER (C. elegans) were used. PX-1 and PX-2 in vitro metabolites were revealed comprehensively by liquid chromatography-high-resolution mass spectrometry measurements.

RESULTS

In total, 30 metabolites for PX 1 and 15 for PX-2 were detected. The main metabolites for PX-1 and PX-2 were the amide hydrolyzed metabolites, along with an indole monohydroxylated (for PX-1) and a defluorinated pentyl-monohydroxylated metabolite (for PX-2).

CONCLUSIONS

CYP isoforms along with fungal incubation results were in good agreement to those obtained with pHLM incubation. CYP2E1 was responsible for many of the metabolic pathways; particularly for PX-1. This study shows that all three in vitro assays are suitable for predicting metabolic pathways of synthetic cannabinoids. To establish completeness of the PX-1 and PX-2 metabolic pathways, it is not only recommended but also necessary to use different assays.

The Spicy Story of Cannabimimetic Indoles

The Sterling Research Group identified pravadoline as an aminoalkylindole (AAI) non-steroidal anti-inflammatory pain reliever. As drug design progressed, the ability of AAI analogs to block prostaglandin synthesis diminished, and antinociceptive activity was found to result from action at the CB1 cannabinoid receptor, a G-protein-coupled receptor (GPCR) abundant in the brain. Several laboratories applied computational chemistry methods to ultimately conclude that AAI and cannabinoid ligands could overlap within a common binding pocket but that WIN55212-2 primarily utilized steric interactions via aromatic stacking, whereas cannabinoid ligands required some electrostatic interactions, particularly involving the CB1 helix-3 lysine. The Huffman laboratory identified strategies to establish CB2 receptor selectivity among cannabimimetic indoles to avoid their CB1-related adverse effects, thereby stimulating preclinical studies to explore their use as anti-hyperalgesic and anti-allodynic pharmacotherapies. Some AAI analogs activate novel GPCRs referred to as "Alkyl Indole" receptors, and some AAI analogs act at the colchicine-binding site on microtubules. The AAI compounds having the greatest potency to interact with the CB1 receptor have found their way into the market as "Spice" or "K2". The sale of these alleged "herbal products" evades FDA consumer protections for proper labeling and safety as a medicine, as well as DEA scheduling as compounds having no currently accepted medical use and a high potential for abuse. The distribution to the public of potent alkyl indole synthetic cannabimimetic chemicals without regard for consumer safety contrasts with the adherence to regulatory requirements for demonstration of safety that are routinely observed by ethical pharmaceutical companies that market medicines.

Determination of synthetic cannabinoids in randomly urine samples collected from probationers in Turkey

Synthetic cannabinoids are a significant public health and safety problem that complicates drug tests with their ever-changing structures in our country and worldwide. The fact that most synthetic cannabinoids cannot be detected in biological samples by routine drug of abuse screening tests also causes an increase in the use of these substances in return. In this study, 500 urine samples of randomly selected probationers, analyzed with an enzymatic immunoassay test at Ege University Institute of Drug Addiction, Toxicology and Pharmaceutical Sciences (BATI) and tested negative, were then selected for retrospective analysis. Synthetic cannabinoids and their metabolites were quantitatively scanned in the collected urine samples via the liquid-liquid extraction method with the LC-MS/MS. Of the 500 studied urine samples, 108 (21.6%) were positive for 20 synthetic cannabinoids and their metabolites. The two most detected synthetic cannabinoids were 5F-NPB-22 (58%) and (S)-AB-FUBINACA (36%), and their mean concentrations were 72.94 ± 47.51 ng/mL and 5.84 ± 14.7 ng/mL, respectively. These results were also compared with national statistics from the general population. It resulted that immunoassay screening tests used in this study were insufficient, and urine samples should be studied in clinical and forensic cases with a validated chromatographic method.

In vitro metabolic profiling of synthetic cannabinoids by pooled human liver microsomes, cytochrome P450 isoenzymes, and Cunninghamella elegans and their detection in urine samples

As synthetic cannabinoids are extensively metabolized, there is an urgent need for data on which metabolites can be used for successful urine screening. This study examines the in vitro metabolism of EG-018 and its 5F-analogue EG-2201 by means of comparing three different in vitro models: pooled human liver microsomes, cytochrome P450 isoenzymes, and a fungal approach utilizing the filamentous fungus Cunninghamella elegans LENDNER, which is known for its ability to mimic human biotransformation of xenobiotics. In addition, this study includes the screening of two authentic urine samples from individuals with proven EG-018 consumption, for the evaluation of in vitro-in vivo extrapolations made in the study. Incubation with pooled human liver microsomes yielded 15 metabolites of EG-018 belonging to six different metabolite subgroups, and 21 metabolites of EG-2201 belonging to seven different metabolite subgroups, respectively. Incubation with cytochrome P450 isoenzymes incubation yielded a further three EG-018 and five EG-2201 metabolites. With reference to their summed metabolite peak abundancies, the isoenzymes CYP2C9, CYP2C19, CYP2D6, CYP3A4, and CYP3A5 were shown to contribute most to the microsomal metabolism of EG-018 and EG-2201. CYP2B6 was shown to make the lowest contribution, by far. As the phase I metabolism of both synthetic cannabinoids was shown to be distributed over a substantial number of different cytochrome P450 isoenzymes, it was concluded that it is likely to not be significantly affected by co-consumption of other drugs. Although fungal incubation with Cunninghamella elegans yielded an additional three EG-018 and four EG-2201 metabolites not observed after microsomal incubation, metabolites generated by Cunninghamella elegans were in good correlation with those generated by microsomal incubations. The fungal model demonstrated its ability to be an independent in vitro model in synthetic cannabinoid metabolism research. The three tested in vitro models enable sufficient predictive in vitro-in vivo extrapolations, comparable to those obtained from hepatocyte incubation published in the literature. In addition, with regard to the screening of authentic urine samples and comparison with the literature, one monohydroxylated EG-018 metabolite and two monohydroxylated EG-2201 metabolites can be recommended as urinary targets, on the basis of the tested in vitro models. Graphical abstract.

Distribution of Synthetic Cannabinoids JWH-210, RCS-4 and Δ 9-Tetrahydrocannabinol After Intravenous Administration to Pigs

Background:

Synthetic cannabinoids (SCs) have become an increasing issue in forensic toxicology. Controlled human studies evaluating pharmacokinetic data of SCs are lacking and only few animal studies have been published. Thus, an interpretation of analytical results found in intoxicated or poisoned individuals is difficult. Therefore, the distribution of two selected SCs, namely 4-ethylnaphthalen-1-yl-(1-pentylindol-3-yl)methanone (JWH-210) and 2-(4-methoxyphenyl)-1-(1-pentyl-indol-3-yl)methanone (RCS-4) as well as ∆9-tetrahydrocannabinol (THC) as reference were examined in pigs.

Methods:

Pigs (n = 6 per drug) received a single intravenous 200 µg/kg BW dose of JWH-210, RCS-4, or THC. Six hours after administration, the animals were exsanguinated and relevant organs, important body fluids such as bile, and tissues such as muscle and adipose tissue, as well as the bradytrophic specimens dura and vitreous humor were collected. After hydrolysis and solid phase extraction, analysis was performed by LC-MS/MS. To overcome matrix effects of the LC-MS/MS analysis, a standard addition method was applied for quantification.

Results:

The parent compounds could be detected in every analyzed specimen with the exception of THC that was not present in dura and vitreous humor. Moderate concentrations were present in brain, the site of biological effect. Metabolite concentrations were highest in tissues involved in metabolism and/or elimination.

Conclusions:

Besides kidneys and lungs routinely analyzed in postmortem toxicology, brain, adipose, and muscle tissue could serve as alternative sources, particularly if other specimens are not available. Bile fluid is the most appropriate specimen for SCs and THC metabolites detection.

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

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

Intoxication from the novel synthetic cannabinoids AB-PINACA and ADB-PINACA: A case series and review of the literature

Synthetic cannabinoids (SC), are a novel class of designer drugs which emerged as a drug of abuse in the late 2000's. We report a case series of 6 patients who may have smoked a synthetic cannabinoid product in a remote wilderness setting. They presented with varying degrees of altered mental status, agitation, and seizures. Two were confirmed to have AB-PINACA, ADB-PINACA and their respective pentanoic acid metabolites in biological specimens via liquid chromatography time-of-flight mass spectrometry (LC-TOF/MS). Both compounds had DEA Schedule I classification at the time of case presentation, and 22 SCs are currently temporary or permanent DEA Schedule I. More than 150 SCs are known to date, and new compounds are appearing at a rapid rate on darknet and surface web e-commerce websites, marketed as "research chemicals" or "legal highs." The scale and rapidity of SC evolution make legal control and analytical detection difficult. Nontargeted testing with liquid chromatography high resolution mass spectrometry (LC-HRMS), examining both parent compounds and metabolites, is the ideal method for novel SC identification and confirmation. Due to full agonism at the cannabinoid receptors CB1 and CB2, clinical effects are more severe than marijuana, which is a partial cannabinoid receptor agonist. They include agitated delirium, lethargy and coma, seizures, tachycardia, hypertension, and hallucinations, among other findings. Treatment is primarily symptomatic and aimed at airway protection and control of agitation and seizures. SCs do not appear to be abating anytime soon and require the cooperation of law enforcement, analytical scientists, and clinicians to adequately control. This article is part of the Special Issue entitled 'Designer Drugs and Legal Highs.'

Acute and residual effects in adolescent rats resulting from exposure to the novel synthetic cannabinoids AB-PINACA and AB-FUBINACA

Synthetic cannabinoids (SCs) have rapidly proliferated as recreational drugs, and may present a substantial health risk to vulnerable populations. However, information on possible effects of long-term use is sparse. This study compared acute and residual effects of the popular indazole carboxamide SC compounds AB-PINACA and AB-FUBINACA in adolescent rats with ∆⁹-tetrahydrocannabinol (THC) and control treatments. Albino Wistar rats were injected (i.p.) with AB-PINACA or AB-FUBINACA every second day (beginning post-natal day (PND) 31), first at a low dose (0.2 mg/kg on 6 days) followed by a higher dose (1 mg/kg on a further 6 days). THC-treated rats received equivalent doses of 6 × 1 mg/kg and 6 × 5 mg/kg. During drug treatment, THC, AB-PINACA, and AB-FUBINACA decreased locomotor activity at high and low doses, increased anxiety-like behaviours and audible vocalisations, and reduced weight gain. Two weeks after dosing was completed, all cannabinoid pre-treated rats exhibited object recognition memory deficits. These were notably more severe in rats pre-treated with AB-FUBINACA. However, social interaction was reduced in the THC pre-treated group only. Six weeks post-dosing, plasma levels of cytokines interleukin (IL)-1α and IL-12 were reduced by AB-FUBINACA pre-treatment, while cerebellar endocannabinoids were reduced by THC and AB-PINACA pre-treatment. The acute effects of AB-PINACA and AB-FUBINACA were broadly similar to those of THC, suggesting that acute SC toxicity in humans may be modulated by dose factors, including inadvertent overdose and product contamination. However, some lasting residual effects of these different cannabinoid receptor agonists were subtly different, hinting at recruitment of different mechanisms of neuroadaptation.

Clinical Interpretation of Urine Drug Tests: What Clinicians Need to Know About Urine Drug Screens

Urine drug testing is frequently used in clinical, employment, educational, and legal settings and misinterpretation of test results can result in significant adverse consequences for the individual who is being tested. Advances in drug testing technology combined with a rise in the number of novel misused substances present challenges to clinicians to appropriately interpret urine drug test results. Authors searched PubMed and Google Scholar to identify published literature written in English between 1946 and 2016, using urine drug test, screen, false-positive, false-negative, abuse, and individual drugs of abuse as key words. Cited references were also used to identify the relevant literature. In this report, we review technical information related to detection methods of urine drug tests that are commonly used and provide an overview of false-positive/false-negative data for commonly misused substances in the following categories: cannabinoids, central nervous system (CNS) depressants, CNS stimulants, hallucinogens, designer drugs, and herbal drugs of abuse. We also present brief discussions of alcohol and tricyclic antidepressants as related to urine drug tests, for completeness. The goal of this review was to provide a useful tool for clinicians when interpreting urine drug test results and making appropriate clinical decisions on the basis of the information presented.

Focus on cannabinoids and synthetic cannabinoids

The recent emergence of a multitude of synthetic cannabinoids (SCs) has generated a wealth of new information, suggesting the usefulness of state-of-the-art on lato sensu cannabinoids. By modulating a plurality of neurotransmission pathways, the endocannabinoid system is involved in many physiological processes that are increasingly explored. SCs desired and adverse effects are considered to be more intense than those observed with cannabis smoking, which is partly explained by the full agonist activity and higher affinity for cannabinoid receptors. Neurological and cardiovascular side effects observed after cannabinoid poisoning generally respond to conventional supportive care, but severe outcomes may occur in a minority of cases, mainly observed with SCs. The likelihood of severe abuse and addiction produced by SCs are of concern for the scientific community also interested in the potential therapeutic value of cannabinoids.

[INCREMENT]9-Tetrahydrocannabinol discriminative stimulus effects of AM2201 and related aminoalkylindole analogs in rats

The recent recreational use of synthetic cannabinoid ligands, collectively referred to as 'Spice', has raised concerns about their safety and possible differences in their biological effect(s) from marijuana/Δ-tetrahydrocannabinol (THC). AM2201, a highly efficacious, potent cannabinoid receptor 1 (CB1R) agonist, is a recently detected compound in 'Spice' preparations. Furthermore, structural analogs of AM2201 are now being found in 'Spice'. The present studies were conducted to investigate their Δ-THC-like effects using drug (Δ-THC) discrimination in rats. Results show that the tested compounds were potent cannabinergics that generalized to the response to Δ-THC, with AM2201 being most potent, exhibiting a 14-fold potency difference over Δ-THC. The other analogs were between 2.5-fold and 4-fold more potent than THC. Surmountable antagonism of AM2201 with the selective CB1R antagonist/inverse agonist rimonabant also established that the discrimination is CB1R dependent. Time-course data reveal that AM2201 likely peaks rapidly with an in-vivo functional half-life of only 60 min. The present data confirm and extend previous observations regarding Δ-THC-like effects of 'Spice' components.

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.

Oral fluid drug analysis in the age of new psychoactive substances

Oral fluid has become an important matrix for drugs of abuse analysis. These days the applicability is challenged by the fact that an increasing number of new psychoactive drugs are coming on the market. Synthetic cannabinoids and synthetic cathinones have been the main drug classes, but the diversity is increasing and other drugs like piperazines, phenethylamines, tryptamines, designer opioids and designer benzodiazepines are becoming more prevalent. Many of the substances are very potent, and low doses ingested will lead to low concentrations in biological media, including oral fluid. This review will highlight the phenomenon of new psychoactive substances and review methods for oral fluid drug testing analysis using on-site tests, immunoassays and chromatographic methods.

Emerging drugs of abuse: current perspectives on synthetic cannabinoids

New psychoactive drugs that have appeared over the last decade are typically dominated by cathinones and synthetic cannabinoids (SCs). SCs have been emerging as recreational drugs because they mimic the euphoria effect of cannabis while still being legal. Sprayed on natural herb mixtures, SCs have been primarily sold as "herbal smoking blends" or "herbal incense" under brand names like "Spice" or "K2". Currently, SCs pure compounds are available from websites for the combination with herbal materials or for the use in e-cigarettes. For the past 5 years, an ever increasing number of compounds, representative of different chemical classes, have been promoted and now represent a large assortment of new popular drugs of abuse, which are difficult to properly identify. Their legal status varies by country with many government institutions currently pushing for their control. The in vitro binding to CB1/CB2 receptors is usually well-known and considerable differences have been found in the CB1 versus CB2 selectivity and potency within the different SCs, with several structure-activity relations being evident. Desired effects by CB1 agonist users are relaxation/recreative, however, cardiovascular, gastrointestinal, or psychiatric/neurological side effects are commonly reported. At present there is no specific antidote existing if an overdose of designer drugs was to occur, and no curative treatment has been approved by health authorities. Management of acute toxic effects is mainly symptomatic and extrapolated from experience with cannabis.