“Spice” and “K2” Herbal Highs: A Case Series and Systematic Review of the Clinical Effects and Biopsychosocial Implications of Synthetic Cannabinoid Use in Humans

CB1 cannabinoid receptor stimulation during adolescence impairs the maturation of GABA function in the adult rat prefrontal cortex

Converging epidemiological studies indicate that cannabis abuse during adolescence increases the risk of developing psychosis and prefrontal cortex (PFC)-dependent cognitive impairments later in life. However, the mechanisms underlying the adolescent susceptibility to chronic cannabis exposure are poorly understood. Given that the psychoactive constituent of cannabis binds to the CB1 cannabinoid receptor, the present study was designed to determine the impact of a CB1 receptor agonist (WIN) during specific windows of adolescence on the functional maturation of the rat PFC. By means of local field potential recordings and ventral hippocampal stimulation in vivo, we found that a history of WIN exposure during early (postnatal days - P35-40) or mid-(P40-45) adolescence, but not in late adolescence (P50-55) or adulthood (P75-80), is sufficient to yield a state of frequency-dependent prefrontal disinhibition in adulthood comparable to that seen in the juvenile PFC. Remarkably, this prefrontal disinhibition could be normalized following a single acute local infusion of the GABA-Aα1 positive allosteric modulator Indiplon, suggesting that adolescent exposure to WIN causes a functional downregulation of GABAergic transmission in the PFC. Accordingly, in vitro recordings from adult rats exposed to WIN during adolescence demonstrate that local prefrontal GABAergic transmission onto layer V pyramidal neurons is markedly reduced to the level seen in the P30-35 PFC. Together, these results indicate that early and mid-adolescence constitute a critical period during which repeated CB1 receptor stimulation is sufficient to elicit an enduring state of PFC network disinhibition resulting from a developmental impairment of local prefrontal GABAergic transmission.

A review of clinical manifestations in adolescent and young adults after use of synthetic cannabinoids

PURPOSE

The purpose of this review is to heighten the awareness of the increased use and risks of synthetic cannabinoids (SCs) and associated clinical manifestations among adolescents and young adults.

CONCLUSIONS

Reviewed case studies suggest that the use of SCs have unpredictable negative psychological and physiological effects. Predominant manifestations reported were anxiety, agitation, paranoia, hallucinations, tachycardia, nausea and vomiting, and diaphoresis.

PRACTICE IMPLICATIONS

Nurses provide the most direct and supportive care to patients who present for medical treatment after the use of SCs. Knowledge of clinical manifestations can facilitate supportive management of patients suspected of SCs use.

Synthetic Cannabinoids: Pharmacology, Behavioral Effects, and Abuse Potential

Cannabis has been used throughout the world for centuries. The psychoactive effects of cannabis are largely attributable to Δ⁹-tetrahydrocannabinol (Δ⁹-THC), the prototypical cannabinoid that occurs naturally in the plant. More recently, chemically- and pharmacologically-distinct synthetic cannabinoids (SCBs) have emerged as drugs of abuse. As compared to Δ⁹-THC, the distinct structures of these compounds allow them to avoid legal restrictions (at least initially) and detection in standard drug screens. This has contributed to the popularity of SCBs among drug users who seek to avoid positive drug screens. Importantly, the distinct structures of the SCBs also typically result in increased affinity for and efficacy at cannabinoid CB1 receptors, which are thought to be responsible for the psychoactive effects of Δ⁹-THC and its analogues. Accordingly, it seems likely that these more powerful cannabimimetic effects could result in increased adverse reactions and toxicities not elicited by Δ⁹-THC in cannabis. Animal models useful for the study of emerging SCBs include the cannabinoid tetrad, drug discrimination, and assays of tolerance, dependence, and withdrawal. However, these in vivo procedures have not been particularly informative with regards to drug efficacy, where the majority of SCB effects are comparable to those of Δ⁹-THC. In contrast, essentially all in vitro measures of drug efficacy confirm Δ⁹-THC as a relatively weak CB1 partial agonist, while the majority of the SCBs detected in commercial preparations are full agonists at the CB1 receptor. As use of these emerging SCBs continues to rise, there is an urgent need to better understand the pharmacology and toxicology of these novel compounds.

A survey of synthetic cannabinoid consumption by current cannabis users

BACKGROUND

Despite growing concern about the increased rates of synthetic cannabinoid (SC) use and their effects, only limited data are available that addresses these issues. This study assessed the extent of SC product use and reported effects among a cohort of adult marijuana and tobacco users.

METHODS

A brief telephone interview was conducted with individuals who had given permission to be contacted for future research while screening for a cannabis/nicotine dependence medication development study (NCT01204723).

RESULTS

Respondents (N = 42; 88% participation rate) were primarily young adults, male, racially diverse, and high school graduates. Nearly all currently smoked tobacco and cannabis, with 86% smoking cannabis on 5 or more days per week. Nearly all (91%) were familiar with SC products, half (50%) reported smoking SC products previously, and a substantial minority (24%) reported current use (i.e., past month). Despite a federal ban on 5 common SCs, which went into effect on March 1, 2011, a number of respondents reported continued SC product use. Common reasons reported for use included, but were not limited to, seeking a new "high" similar to that produced by marijuana and avoiding drug use detection via a positive urine screen. The primary side effects were trouble thinking clearly, headache, dry mouth, and anxiety. No significant differences were found between synthetic cannabinoid product users (ever or current) and nonusers by demographics or other characteristics.

CONCLUSIONS

Among current marijuana and tobacco users, SC product consumption was common and persisted despite a federal ban. The primary reasons for the use of SC-containing products seem to be to evade drug detection and to experience a marijuana-like high.

Fascination and Social Togetherness-Discussions about Spice Smoking on a Swedish Internet Forum

Spice is a smoking mixture containing synthetic cannabinoids with psychoactive effects similar to herbal cannabis. It is sold on the Internet and has become popular among young people. The purpose of the present study was to investigate experiences of intoxication induced by Spice, as described on a Swedish internet-based discussion forum. A systematic search yielded 40 reports, which were analyzed using phenomenological method. A total of 7 themes (composed of 27 categories) emerged from the analysis: 1. Spice use as social ritual; 2. Social secretiveness; 3. Intoxication remarks; 4. Well-being and elation; 5. Altered perception of reality; 6. Fears and coping; 7. Unpleasant physical effects. The results show that smoking was a social activity mostly carried out in small peer-groups, and that the substances induced strong intoxication with both positive and negative effects. Despite fears and unpleasant effects, the intoxication was often considered fascinating and rewarding.

Forensic investigation of K2, Spice, and "bath salt" commercial preparations: a three-year study of new designer drug products containing synthetic cannabinoid, stimulant, and hallucinogenic compounds

New designer drugs such as K2, Spice, and "bath salts" present a formidable challenge for law enforcement and public health officials. The following report summarizes a three-year study of 1320 law enforcement cases involving over 3000 products described as vegetable material, powders, capsules, tablets, blotter paper, or drug paraphernalia. All items were seized in Arkansas from January 2010 through December 2012 and submitted to the Arkansas State Crime Laboratory for analysis. The geographical distribution of these seizures co-localized in areas with higher population, colleges, and universities. Validated forensic testing procedures confirmed the presence of 26 synthetic cannabinoids, 12 designer stimulants, and 5 hallucinogenic-like drugs regulated by the Synthetic Drug Prevention Act of 2012 and other state statutes. Analysis of paraphernalia suggests that these drugs are commonly used concomitantly with other drugs of abuse including marijuana, MDMA, and methamphetamine. Exact designer drug compositions were unpredictable and often formulated with multiple agents, but overall, the synthetic cannabinoids were significantly more prevalent than all the other designer drugs detected. The synthetic cannabinoids JWH-018, AM2201, JWH-122, JWH-210, and XLR11 were most commonly detected in green vegetable material and powder products. The designer stimulants methylenedioxypyrovalerone (MDPV), 3,4-methylenedioxy-N-methylcathinone (methylone), and α-methylamino-valerophenone (pentedrone) were commonly detected in tablets, capsules, and powders. Hallucinogenic drugs were rarely detected, but generally found on blotter paper products. Emerging designer drug products remain a significant problem and continued surveillance is needed to protect public health.

Distinct pharmacology and metabolism of K2 synthetic cannabinoids compared to Δ(9)-THC: mechanism underlying greater toxicity?

K2 or Spice products are emerging drugs of abuse that contain synthetic cannabinoids (SCBs). Although assumed by many teens and first time drug users to be a "safe" and "legal" alternative to marijuana, many recent reports indicate that SCBs present in K2 produce toxicity not associated with the primary psychoactive component of marijuana, ∆(9)-tetrahydrocannabinol (Δ(9)-THC). This mini-review will summarize recent evidence that use of K2 products poses greater health risks relative to marijuana, and suggest that distinct pharmacological properties and metabolism of SCBs relative to Δ(9)-THC may contribute to the observed toxicity. Studies reviewed will indicate that in contrast to partial agonist properties of Δ(9)-THC typically observed in vitro, SCBs in K2 products act as full cannabinoid receptor type 1 (CB1R) and type 2 (CB2R) agonists in both cellular assays and animal studies. Furthermore, unlike Δ(9)-THC metabolism, several SCB metabolites retain high affinity for, and exhibit a range of intrinsic activities at, CB1 and CB2Rs. Finally, several reports indicate that although quasi-legal SCBs initially evaded detection and legal consequences, these presumed "advantages" have been limited by new legislation and development of product and human testing capabilities. Collectively, evidence reported in this mini-review suggests that K2 products are neither safe nor legal alternatives to marijuana. Instead, enhanced toxicity of K2 products 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 CB2Rs, highlights the inherent danger that may accompany use of these substances.

Toxicological findings of synthetic cannabinoids in recreational users

In recent years, several synthetic cannabinoid compounds have become popular recreational drugs of abuse because of their psychoactive properties. This paper presents toxicological findings of synthetic cannabinoids in whole blood from some cases of severe intoxication including quantitative data from recreational users and a fatal intoxication. Samples were analyzed by liquid chromatography-tandem mass spectrometry in a scheduled multiple reaction mode after a basic liquid extraction. Twenty-nine synthetic cannabinoids were included in the method. In our data set of ~3000 cases, 28% were found positive for one or more synthetic cannabinoid(s). The most common finding was AM-2201. Most of the analytes had median concentrations of <0.5 ng/g in agreement with other published data. The emerging drugs MAM-2201 (n = 151) and UR-144 (n = 181) had mean (median) concentrations of 1.04 (0.37) and 1.26 (0.34), respectively. The toxicity of the synthetic cannabinoids seems to be worse than that of natural cannabis, probably owing to the higher potency and perhaps also to the presence of several different cannabinoids in the smoked incense and the difficulties of proper dosing. The acute toxic effects may under certain circumstances contribute to death.

Substituted cathinone products: a new trend in "bath salts" and other designer stimulant drug use

There is a growing concern about the availability of a new generation of "designer drug" stimulants that are marketed as "bath salts" and other household products. The products are not true bath salts and contain substituted cathinone stimulant substances, such as methylenedioxypyrovalerone (MDPV) and mephedrone. Calls to the American Association of Poison Control Centers regarding "bath salts" consumption began in 2010 and have continued since that time. Few reports of systematic epidemiologic surveillance or definitive clinical effects of toxicity specifically associated with "bath salts" consumption have been reported in the medical literature. The current narrative review describes the growing trend of designer substituted cathinone use, pharmacology, clinical effects, and recent regulatory changes. It is hoped that a greater understanding of the clinical effects and use patterns will help inform policy and practice.

Cannabinoids in disguise: Δ9-tetrahydrocannabinol-like effects of tetramethylcyclopropyl ketone indoles

Synthetic indole-derived cannabinoids have become commonly used recreational drugs and continue to be abused despite their adverse consequences. As compounds that were identified early in the epidemic (e.g., naphthoylindoles) have become legally banned, new compounds have appeared on the drug market. Two tetramethylcyclopropyl ketone indoles, UR-144 [(1-pentyl-1H-indol-3-yl)-(2,2,3,3-tetramethylcyclopropyl)methanone] and XLR-11 [(1-(5-fluoropentyl)-1H-indol-3-yl)-(2,2,3,3-tetramethylcyclopropyl)methanone], recently have been identified in confiscated products. These compounds are structurally related to a series of CB2-selective compounds explored by Abbott Labs. The purpose of the present study was to evaluate the extent to which UR-144 and XLR-11 shared cannabinoid effects with Δ9-tetrahydrocannabinol (Δ9-THC). Indices of in vitro and in vivo activity at cannabinoid receptors were assessed. Similar to other psychoactive cannabinoid agonists, XLR-11 and UR-144 showed low nanomolar (<30) affinity for CB1 and CB2 receptors, activated these receptors as full agonists, and produced dose-dependent effects that were blocked by rimonabant in mice, including antinociception, hypothermia, catalepsy and suppression of locomotor activity. The potency of both compounds was several-fold greater than Δ9-THC. XLR-11 and UR-144 also substituted for Δ9-THC in a Δ9-THC discrimination procedure in mice, effects that were attenuated by rimonabant. Analysis of urine from mice treated with the compounds revealed that both were extensively metabolized, with predominant urinary excretion as glucuronide conjugates. Together, these results demonstrate that UR-144 and XLR-11 share a pharmacological profile of in vitro and in vivo effects with Δ9-THC and other abused indole-derived cannabinoids and would be predicted to produce Δ9-THC-like subjective effects in humans.

Spicing things up: synthetic cannabinoids

RATIONALE

Recently, products containing synthetic cannabinoids, collectively referred to as Spice, are increasingly being used recreationally.

OBJECTIVES

The availability, acute subjective effects-including self-reports posted on Erowid-laboratory detection, addictive potential, and regulatory challenges of the Spice phenomenon are reviewed.

RESULTS

Spice is sold under the guise of potpourri or incense. Unlike delta-9-tetrahydrocannabinol, the synthetic cannabinoids present in Spice are high-potency, high-efficacy, cannabinoid receptor full agonists. Since standard urine toxicology does not test for the synthetic cannabinoids in Spice, it is often used by those who want to avoid detection of drug use. These compounds have not yet been subjected to rigorous testing in humans. Acute psychoactive effects include changes in mood, anxiety, perception, thinking, memory, and attention. Adverse effects include anxiety, agitation, panic, dysphoria, psychosis, and bizarre behavior. Psychosis outcomes associated with Spice provide additional data linking cannabinoids and psychosis. Adverse events necessitating intervention by Poison Control Centers, law enforcement, emergency responders, and hospitals are increasing. Despite statutes prohibiting the manufacture, distribution, and sale of Spice products, manufacturers are replacing banned compounds with newer synthetic cannabinoids that are not banned.

CONCLUSIONS

There is an urgent need for better research on the effects of synthetic cannabinoids to help clinicians manage adverse events and to better understand cannabinoid pharmacology in humans. The reported psychosis outcomes associated with synthetic cannabinoids contribute to the ongoing debate on the association between cannabinoids and psychosis. Finally, drug detection tests for synthetic cannabinoids need to become clinically available.

"Herbal incense": designer drug blends as cannabimimetics and their assessment by drug discrimination and other in vivo bioassays

Recently, synthetic cannabinoids originally designed for testing in the laboratory only have found use recreationally in designer herbal blends, originally called "Spice". The myriad of compounds found are for the most part potent full agonists of the cannabinoid receptor 1, producing effects similar to tetrahydrocannabinol (THC) and marijuana. Drug discrimination of these compounds offers a specific behavioral test that can help determine whether these new synthetic compounds share a similar "subjective high" with the effects of marijuana/THC. By utilization of drug discrimination and other behavioral techniques, a better understanding of these new "designer" cannabinoids may be reached to assist in treating both the acute and chronic effects of these drugs. The paper provides a brief exposé of modern cannabinoid research as a backdrop to the recreational use of designer herbal blend cannabimimetics.

Quadrupole-time-of-flight mass spectrometry screening for synthetic cannabinoids in herbal blends

'Legal highs' are novel substances which are intended to elicit a psychoactive response. They are sold from 'head shops', the internet and from street suppliers and may be possessed without legal restriction. Several months ago, a 19-year-old woman came searching for medical treatment as she had health problems caused by smoking legal highs. The substances were sold as herbal blends in plastic bags under four different labels. In this work, samples of these herbal blends have been analysed to investigate the presence of psychoactive substances without any reference standard being available at the laboratory. A screening strategy for a large number of synthetic and natural cannabinoids has been applied based on the use of ultra-high pressure liquid chromatography coupled to quadrupole-time of flight mass spectrometry (UHPLC-QTOF MS) under MS(E) mode. A customized home-made database containing literature-based exact masses for parent and product ions of around 200 synthetic and natural cannabinoids was compiled. The presence of the (de)protonated molecule measured at its accurate mass was evaluated in the samples. When a peak was detected, collision-induced dissociation fragments and characteristic isotopic ions were also evaluated and used for tentative identification. After this tentative identification, four synthetic cannabinoids (JWH-081, JWH-250, JWH-203 and JWH-019) were unequivocally confirmed by subsequent acquisition of reference standards. The presence in the herbal blends of these synthetic cannabinoids might explain the psychotic and catatonic symptoms observed in the patient, as JWH compounds could act as potent agonists of CB1 and CB2 receptors located in the Limbic System and Basal ganglia of the human brain.

Driving under the influence of synthetic cannabinoids ("Spice"): a case series

Recreational use of synthetic cannabinoid receptor agonists-so-called "Spice" products-became very popular during the last few years. Several reports on clinical symptoms and poisonings were published. Unfortunately, most of these reports do not contain any analytical data on synthetic cannabinoids in body fluids, and no or only a limited number of cases were reported concerning driving under the influence (DUI) of this kind of drugs. In this article, several cases of DUI of synthetic cannabinoids (AM-2201, JWH-018, JWH-019, JWH-122, JWH-210, JWH-307, MAM-2201 (JWH-122 5-fluoropentyl derivative), and UR-144) are presented, focusing on analytical results and signs of impairment documented by the police or the physicians who had taken the blood sample from the suspects. Consumption of synthetic cannabinoids can lead to impairment similar to typical performance deficits caused by cannabis use which are not compatible with safe driving. These deficits include centrally sedating effects and impairment of fine motor skills necessary for keeping the vehicle on track. Police as well as forensic toxicologists and other groups should become familiar with the effects of synthetic cannabinoid use, and be aware of the fact that drug users may shift to these "legal" alternatives due to their nondetectability by commonly used drug screening tests based on antibodies. Sophisticated screening procedures covering the complete range of available compounds or their metabolites have to be developed for both blood/serum and urine testing.

Internet highs--seizures after consumption of synthetic cannabinoids purchased online

BACKGROUND

Since 2004, a new wave of synthetic cannabinoids (SCs) known as "Spice drugs" has come under scrutiny because of their suspected link to neurological and psychiatric sequelae. These "herbal incense" or "potpourri blends" have gained popularity as a result of being more potent than natural cannabinoids, are not detected with current screening tests, and are easily modified by manufacturers to bypass legal restrictions. Unfortunately, cases of withdrawal phenomena, nausea, hypertension, and psychosis are now being reported in the medical literature. In addition, after reports in lay media of seizures and coma attributed to the consumption of the drug, anecdotal reports have emerged of similar findings in the medical literature.

CASE DESCRIPTION

We report on a 48-year-old man who, after consuming the herbal blend, lost consciousness and suffered several episodes of seizures. Despite a complicated ICU stay, the patient recovered well with no subsequent neurological sequelae.

CONCLUSIONS

The authors interpreted the history and findings consistent with the consumption of a large amount of synthetic cannabinoids leading to new-onset seizures and coma. However, at the time of admission, the lack of routine laboratory testing and treatment options delayed the diagnosis and delivery of appropriate therapy.

Toxicological profiles of selected synthetic cannabinoids showing high binding affinities to the cannabinoid receptor subtype CB₁

Products containing synthetic cannabinoids are consumed as a surrogate for marihuana due to their non-detectability with commonly used drug tests and their strong cannabimimetic effects. Because data concerning their toxicological properties are scarce, the cytotoxic, genotoxic, immunomodulatory, and hormonal activities of four naphthoylindole compounds (JWH-018, JWH-073, JWH-122 and JWH-210) and of one benzoylindole (AM-694) were studied in human cell lines and primary cells; tetrahydrocannabinol was included as the classical non-endogenous cannabinoid receptor ligand. All compounds induced damage to the cell membranes of buccal (TR146) and breast (MCF-7) derived cells at concentrations of ≥75-100 μM. No cytotoxic responses were seen in other assays which reflect mitochondrial damage, protein synthesis, and lysosomal activities. JWH-073 and JWH-122 induced DNA migration in buccal and liver cells (HepG2) in single cell gel electrophoresis assays, while JWH-210 was only in the latter cell line active. No estrogenic activities were detected in bone marrow cells (U2-OS), but all compounds caused anti-estrogenic effects at levels between 2.1 and 23.0 μM. Furthermore, no impact on cytokine release (i.e., on IL-10, IL-6, IL-12/23p40 and TNFα levels) was seen in LPS-stimulated human PBMCs, except with JWH-210 and JWH-122 which caused a decrease of TNFα and IL-12/23p40. All toxic effects were observed with concentrations higher than those expected in body fluids of users. Since genotoxic effects are in general linear over a wide concentration range and the exposure levels may be higher in epithelial cells than [corrected] in serum, further experimental work is required to find out if DNA damage takes place in drug users.

New drugs of abuse: New threat?

There has been an increase in the abuse of synthetic drugs. This article explores the prevalence and legal issues regarding synthetic drugs (e.g., bath salts).