Acute Effects of the Novel Psychoactive Drug 2C-B on Emotions

Tusi: a new ketamine concoction complicating the drug landscape

A drug concoction called tusi has emerged in Latin America and in Europe and is now beginning to acquire popularity in the United States. "Tusi" is a phonetic translation of "2C," a series of psychedelic phenethylamines. The concoction is also sometimes referred to as "pink cocaine" as it typically comes in the form of pink powder. However, despite its name, the concoction rarely contains 2C series drugs. Multiple drug checking studies have found that the majority of tusi samples contain ketamine, often combined with 3,4-methylenedioxymethamphetamine (MDMA), methamphetamine, cocaine, opioids, and/or new psychoactive substances. The tusi phenomenon complicates the drug landscape because it has the potential to confuse both people who use it and researchers alike. People using may think the drug is 2C/2C-B, and they may also be unaware that the concoction tends to consist of ketamine and a wide variety of other drugs. Unintentional exposure to its contents can lead to increased risk of adverse effects. The tusi phenomenon also has the potential to complicate drug research as unknown exposure to drugs like ketamine and MDMA will lead to underreporting of use. A combination of self-report and toxicological testing may be needed to inform the most accurate estimates of use. Both researchers and people at risk for use need to be informed about this new concoction. Drug researchers need to be cognizant about the way they query use, and people at risk for using need to be educated about the possible contents of tusi and associated dangers.

Acute behavioral and Neurochemical Effects of Novel N-Benzyl-2-Phenylethylamine Derivatives in Adult Zebrafish

Hallucinogenic drugs potently affect brain and behavior and have also recently emerged as potentially promising agents in pharmacotherapy. Complementing laboratory rodents, the zebrafish (Danio rerio) is a powerful animal model organism for screening neuroactive drugs, including hallucinogens. Here, we test a battery of ten novel N-benzyl-2-phenylethylamine (NBPEA) derivatives with the 2,4- and 3,4-dimethoxy substitutions in the phenethylamine moiety and the -OCH₃, -OCF₃, -F, -Cl, and -Br substitutions in the ortho position of the phenyl ring of the N-benzyl moiety, assessing their acute behavioral and neurochemical effects in the adult zebrafish. Overall, substitutions in the Overall, substitutions in the N-benzyl moiety modulate locomotion, and substitutions in the phenethylamine moiety alter zebrafish anxiety-like behavior, also affecting the brain serotonin and/or dopamine turnover. The 24H-NBOMe(F) and 34H-NBOMe(F) treatment also reduced zebrafish despair-like behavior. Computational analyses of zebrafish behavioral data by artificial intelligence identified several distinct clusters for these agents, including anxiogenic/hypolocomotor (24H-NBF, 24H-NBOMe, and 34H-NBF), behaviorally inert (34H-NBBr, 34H-NBCl, and 34H-NBOMe), anxiogenic/hallucinogenic-like (24H-NBBr, 24H-NBCl, and 24H-NBOMe(F)), and anxiolytic/hallucinogenic-like (34H-NBOMe(F)) drugs. Our computational analyses also revealed phenotypic similarity of the behavioral activity of some NBPEAs to that of selected conventional serotonergic and antiglutamatergic hallucinogens. In silico functional molecular activity modeling further supported the overlap of the drug targets for NBPEAs tested here and the conventional serotonergic and antiglutamatergic hallucinogens. Overall, these findings suggest potent neuroactive properties of several novel synthetic NBPEAs, detected in a sensitive in vivo vertebrate model system, the zebrafish, raising the possibility of their potential clinical use and abuse.

Acute Pharmacological Effects and Oral Fluid Concentrations of the Synthetic Cannabinoids JWH-122 and JWH-210 in Humans After Self-Administration: An Observational Study

Synthetic cannabinoids (SCs) are a group of new psychoactive drugs used recreationally with potential health risks. They are monitored by the EU Early Warning System since 2010 due to severe adverse effects on consumers. JWH-122 and JWH-210 are naphthoylindole SCs and potent cannabinoid receptor CB1 and CB2 agonists. Information about the effects of SCs usually is available from intoxication cases and surveys, and few studies on humans after controlled administration or observational/naturalistic studies using standardized measures of cardiovascular and subjective effects are available. The aim of this study was to evaluate the acute pharmacological effects of JWH-122 and JWH-210 recreational consumption in a 4 h observational study and assess their disposition in oral fluid (OF). Sixteen volunteers self-administered 1 mg dose of JWH-122 (n = 8) or 2.25 mg mean dose of JWH-210 (range 2–3 mg, n = 8) by inhalation (smoking). Physiological parameters including blood pressure (systolic and diastolic), heart rate (HR), and cutaneous temperature were measured. A set of visual analog scales, the 49-item short-form version of the Addiction Research Center Inventory (ARCI), and the Evaluation of the Subjective Effects of Substances with Abuse Potential (VESSPA-SSE) were used for the evaluation of subjective effects. OF was collected at baseline and at 10, 20, and 40 min and 1, 2, 3, and 4 h after self-administration. Statistically significant increases in systolic blood pressure (SBP), diastolic blood pressure (DBP), and HR were observed after JWH-122 self-administration but not after JWH-210 self-administration. JWH-210 self-administration produced significant changes in subjective drug effects, similar to those induced by THC (intensity, high, good effects, and hunger). The subjective effects following JWH-122 consumption were minimal. The maximal effects were mostly observed 20 min after intake. JWH-122 and JWH 210 OF concentration reached a peak 20 min after administration and could not be detected after 3 h. The results demonstrated a different pattern of effects of these two SCs. Due to the limitations of our observational study, further research with a larger sample and controlled studies are needed to better define the acute pharmacological effect and health risk profile of JWH-122 and JWH-210.

Self-reported Subjective Effects of Analytically Confirmed New Psychoactive Substances Consumed by e-Psychonauts: Protocol for a Longitudinal Study Using a New Internet-Based Methodology

Background

During the last few years, the continuous emergence of new psychoactive substances (NPS) has become an important public health challenge. The use of NPS has been rising in two different ways: buying and consuming NPS knowingly and the presence of NPS in traditional drugs as adulterants. The rise of NPS use is increasing the number of different substances in the market to an extent impossible to study with current scientific methodologies. This has caused a remarkable absence of necessary information about newer drug effects on people who use drugs, mental health professionals, and policy makers. Current scientific methodologies have failed to provide enough data in the timeframe when critical decisions must be made, being not only too slow but also too square. Last but not least, they dramatically lack the high resolution of phenomenological details.

Objective

This study aims to characterize a population of e-psychonauts and the subjective effects of the NPS they used during the study period using a new, internet-based, fast, and inexpensive methodology. This will allow bridging an evidence gap between online surveys, which do not provide substance confirmation, and clinical trials, which are too slow and expensive to keep up with the new substances appearing every week.

Methods

To cover this purpose, we designed a highly personalized, observational longitudinal study methodology. Participants will be recruited from online communities of people who use NPS, and they will be followed online by means of a continuous objective and qualitative evaluation lasting for at least 1 year. In addition, participants will send samples of the substances they intend to use during that period, so they can be analyzed and matched with the effects they report on the questionnaires.

Results

The research protocol was approved by the Institutional Review Board of the Hospital del Mar Research Institute on December 11, 2018. Data collection started in August 2019 and was still ongoing when the protocol was submitted (September 2020). The first data collection period of the study ended in October 2020. Data analysis began in November 2020, and it is still ongoing. The authors expect to submit the first results for publication by the end of 2021. A preliminary analysis was conducted when the manuscript was submitted and was reviewed after it was accepted in February 2021.

Conclusions

It is possible to conduct an institutional review board–approved study using this new methodology and collect the expected data. However, the meaning and usefulness of these data are still unknown.

International Registered Report Identifier (IRRID)

DERR1-10.2196/24433

Beyond ecstasy: Alternative entactogens to 3,4-methylenedioxymethamphetamine with potential applications in psychotherapy

The last two decades have seen a revival of interest in the entactogen 3,4-methylenedioxy-N-methylamphetamine (MDMA) as an adjunct to psychotherapy, particularly for the treatment of post-traumatic stress disorder. While clinical results are highly promising, and MDMA is expected to be approved as a treatment in the near future, it is currently the only compound in its class of action that is being actively investigated as a medicine. This lack of alternatives to MDMA may prove detrimental to patients who do not respond well to the particular mechanism of action of MDMA or whose treatment calls for a modification of MDMA's effects. For instance, patients with existing cardiovascular conditions or with a prolonged history of stimulant drug use may not fit into the current model of MDMA-assisted psychotherapy, and could benefit from alternative drugs. This review examines the existing literature on a host of entactogenic drugs, which may prove to be useful alternatives in the future, paying particularly close attention to any neurotoxic risks, neuropharmacological mechanism of action and entactogenic commonalities with MDMA. The substances examined derive from the 1,3-benzodioxole, cathinone, benzofuran, aminoindane, indole and amphetamine classes. Several compounds from these classes are identified as potential alternatives to MDMA.

IL-8, MSPa, MIF, FGF-9, ANG-2 and AgRP collection were identified for the diagnosis of colorectal cancer based on the support vector machine model

Colorectal cancer (CRC) is one of the most common cancer, and the early detection of CRC is essential to improve the survival rate of patients. To identify diagnostic markers for colorectal cancer (CRC) by screening differentially expressed proteins (DEPs) in CRC. The DEPs were initially obtained from 12 CRC samples and 12 healthy control samples, and verification analysis was performed in another 34 CRC samples and 34 normal controls. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment with DEPs was analyzed by the R package clusterProfiler (Version 3.2.11), and the DEP-associated protein-protein interaction (PPI) network was created from the STRING database. Additionally, Support Vector Machine (SVM) model prediction and survival analyses were conducted on the key DEPs. Preliminary screening and functional analysis showed that the DEPs mainly overrepresented in pathways such as cytokine-cytokine receptor interaction, chemokine signaling pathway, Rap1, Ras, and MAPK signaling pathways. The key DEPs, including AgRP, ANG-2, Dtk, EOT3, FGF-4, FGF-9, HCC-4, IL-16, IL-8, MIF, MSPa, TECK, TPO, TRAIL R3, and VEGF-D, were used to construct a custom chip. The drug-gene interaction network suggested that TPO was a key drug target. ROC curve showed the SVM diagnostic model with the DEPs IL-8, MSPa, MIF, FGF-9, ANG-2, and AgRP had better diagnostic performance with an AUC of 0.933. Survival analysis showed the expression of FGF9, TPO, TRAIL R3, Dtk, TECK and FGF4 were associated with prognosis. This study revealed the important serum proteins in the pathogenesis of CRC, which might serve as useful and noninvasive predictors for the diagnosis of CRC.

Acute Pharmacological Effects and Oral Fluid Biomarkers of the Synthetic Cannabinoid UR-144 and THC in Recreational Users

Synthetic cannabinoids (SCs) are one of the most frequent classes of new psychoactive substances monitored by the EU Early Warning System and World Health Organization. UR-144 is a SC with a relative low affinity for the CB1 receptor with respect to that for the CB2 receptor. As with other cannabinoid receptor agonists, it has been monitored by the EU Early Warning System since 2012 for severe adverse effects on consumers. Since data for UR-144 human pharmacology are very limited, an observational study was carried out to evaluate its acute pharmacological effects following its administration using a cannabis joint as term of comparison. Disposition of UR-144 and delta-9-tetrahydrocannibinol (THC) was investigated in oral fluid. Sixteen volunteers smoked a joint prepared with tobacco and 1 or 1.5 mg dose of UR-144 (n = 8) or cannabis flowering tops containing 10 or 20 mg THC (n = 8). Physiological variables including systolic and diastolic blood pressure, heart rate and cutaneous temperature were measured. A set of Visual Analog Scales (VAS), the Addiction Research Centre Inventory (ARCI)-49-item short form version and the Evaluation of the Subjective Effects of Substances with Abuse Potential (VESSPA-SSE) were administered to evaluate subjective effects. Oral fluid was collected at baseline, 10, 20, 40 min and 1, 2, 3 and 4 h after smoking, for UR-144 or THC concentration monitoring. Results showed significant statistical increases in both systolic and diastolic blood pressure and heart rate after both UR-144 and cannabis smoking. Both substances produced an increase in VAS related to stimulant-like and high effects, but scores were significantly higher after cannabis administration. No hallucinogenic effects were observed. Maximal oral fluid UR-144 and THC concentrations appeared at 20 and 10 min after smoking, respectively. The presence of UR-144 in oral fluid constitutes a non-invasive biomarker of SC consumption. The results of this observational study provide valuable preliminary data of the pharmacological effects of UR-144, showing a similar profile of cardiovascular effects in comparison with THC but lower intensity of subjective effects. Our results have to be confirmed by research in a larger sample to extensively clarify pharmacological effects and the health risk profile of UR-144.

Acute Pharmacological Effects of Oral and Intranasal Mephedrone: An Observational Study in Humans

Mephedrone (4-methylmethcathinone) is a synthetic cathinone with psychostimulant properties which remains one of the most popular new psychoactive substances (NPS). It is frequently used orally and/or intranasally. To date, no studies have evaluated the acute effects and pharmacokinetics after self-administration of mephedrone orally (ingestion) and intranasally (insufflation) in naturalistic conditions. An observational study was conducted to assess and compare the acute pharmacological effects, as well as the oral fluid (saliva) concentrations of mephedrone self-administered orally and intranasally. Ten healthy experienced drug users (4 females and 6 males) self-administered a single dose of mephedrone, orally (n = 5, 100–200 mg; mean 150 mg) or intranasally (n = 5, 50–100 mg, mean 70 mg). Vital signs (blood pressure, heart rate, and cutaneous temperature) were measured at baseline (0), 1, 2, and 4 h after self-administration. Each participant completed subjective effects questionnaires: A set of Visual Analogue Scales (VAS), the 49-item Addiction Research Centre Inventory (ARCI), and Evaluation of the Subjective Effects of Substances with Abuse Potential (VESSPA-SSE) at baseline, 1, 2, and 4 h after self-administration. Oral fluid and urine were collected during 4 h. Both routes of mephedrone self-administration enhanced ratings of euphoria and well-being effects and increased cardiovascular effects in humans. Although it was at times assessed that the oral route produced greater and larger effects than the intranasal one, concentrations of mephedrone in oral fluid and also the total amount of mephedrone and metabolites in urine showed that concentrations of mephedrone are considerably higher when self-administered intranasally in comparison to orally. Controlled clinical trials are needed to confirm our observational results.

Disposition of Phytocannabinoids, Their Acidic Precursors and Their Metabolites in Biological Matrices of Healthy Individuals Treated with Vaporized Medical Cannabis

Inhalation by vaporization is a useful application mode for medical cannabis. In this study, we present the disposition of Δ9-tetrahydrocannabinol (THC), cannabidiol (CBD), their acidic precursors, and their metabolites in serum, oral fluid, and urine together with the acute pharmacological effects in 14 healthy individuals treated with vaporized medical cannabis. THC and CBD peaked firstly in serum and then in oral fluid, with higher concentrations in the first biological matrices and consequent higher area under the curve AUCs. Acidic precursors Δ-9-tetrahydrocannabinolic acid A (THCA) and cannabidiolic acid (CBDA) showed a similar time course profile but lower concentrations due to the fact that vaporization partly decarboxylated these compounds. All THC and CBD metabolites showed a later onset with respect to the parent compounds in the absorption phase and a slower decrease to baseline. In agreement with serum kinetics, THC-COOH-GLUC and 7-COOH-CBD were the significantly most excreted THC and CBD metabolites. The administration of vaporized medical cannabis induced prototypical effects associated with the administration of cannabis or THC in humans, with a kinetic trend overlapping that of parent compounds and metabolites in serum. The pharmacokinetics of cannabinoids, their precursors, and their metabolites in biological fluids of individuals treated with vaporized medical cannabis preparations showed a high interindividual variability as in the case of oral medical cannabis decoction and oil. Inhaled medical cannabis was absorbed into the organism earlier than decoction and oil. Cannabinoids reached higher systemic concentrations, also due to the fact that the acid precursors decarboxylated to parent cannabinoids at high temperatures, and consequently, the physiological and subjective effects occurred earlier and resulted with higher intensity. No serious adverse effects were observed.

Sex and Gender Differences in the Effects of Novel Psychoactive Substances

Sex and gender deeply affect the subjective effects and pharmaco-toxicological responses to drugs. Men are more likely than women to use almost all types of illicit drugs and to present to emergency departments for serious or fatal intoxications. However, women are just as likely as men to develop substance use disorders, and may be more susceptible to craving and relapse. Clinical and preclinical studies have shown important differences between males and females after administration of “classic” drugs of abuse (e.g., Δ9-tetrahydrocannabinol (THC), morphine, cocaine). This scenario has become enormously complicated in the last decade with the overbearing appearance of the new psychoactive substances (NPS) that have emerged as alternatives to regulated drugs. To date, more than 900 NPS have been identified, and can be catalogued in different pharmacological categories including synthetic cannabinoids, synthetic stimulants (cathinones and amphetamine-like), hallucinogenic phenethylamines, synthetic opioids (fentanyls and non-fentanyls), new benzodiazepines and dissociative anesthetics (i.e., methoxetamine and phencyclidine-derivatives). This work collects the little knowledge reached so far on the effects of NPS in male and female animal and human subjects, highlighting how much sex and gender differences in the effects of NPS has yet to be studied and understood.

The Clinical Toxicology of 4-Bromo-2,5-dimethoxyphenethylamine (2C-B): The Severity of Poisoning After Exposure to Low to Moderate and High Doses

STUDY OBJECTIVE

We studied the severity of poisoning after exposure to low to moderate and high doses of 4-bromo-2,5-dimethoxyphenethylamine (2C-B).

METHODS

Patients for whom the Dutch Poisons Information Centre was consulted for 2C-B exposure from 2016 to 2018 were included in a prospective cohort study. Data were collected through telephone interviews with the physician or patient. Patients were categorized according to the reported 2C-B dose: low to moderate (up to 20 mg), high (greater than 20 mg), or unknown. Presence of 2C-B was analyzed in leftover drug and biological samples with liquid/gas chromatography-mass spectrometry. The severity of poisoning was graded with the Poisoning Severity Score.

RESULTS

We included 59 patients, of whom 32 could be followed up. Low to moderate 2C-B doses were reported by 9 patients (28%), high doses by 17 (53%), and unknown doses by 6 (19%). Poisoning was moderate in the majority of patients in both the low- to moderate-dose and high-dose groups. Frequently reported symptoms included mydriasis, agitation or aggression, hallucinations, confusion, anxiety, hypertension, and tachycardia. The presence of 2C-B was confirmed in 5 patients in urine (n=3) or drug samples (n=4).

CONCLUSION

In this study, most 2C-B poisonings resulted in moderate toxicity even at high reported doses up to 192 mg. No severe cases were observed. The clinical course was usually short-lived (up to 24 hours) and typically involved hallucinations in addition to mild somatic effects.

Designer drugs: mechanism of action and adverse effects

Psychoactive substances with chemical structures or pharmacological profiles that are similar to traditional drugs of abuse continue to emerge on the recreational drug market. Internet vendors may at least temporarily sell these so-called designer drugs without adhering to legal statutes or facing legal consequences. Overall, the mechanism of action and adverse effects of designer drugs are similar to traditional drugs of abuse. Stimulants, such as amphetamines and cathinones, primarily interact with monoamine transporters and mostly induce sympathomimetic adverse effects. Agonism at μ-opioid receptors and γ-aminobutyric acid-A (GABA_A) or GABA_B receptors mediates the pharmacological effects of sedatives, which may induce cardiorespiratory depression. Dissociative designer drugs primarily act as N-methyl-d-aspartate receptor antagonists and pose similar health risks as the medically approved dissociative anesthetic ketamine. The cannabinoid type 1 (CB₁) receptor is thought to drive the psychoactive effects of synthetic cannabinoids, which are associated with a less desirable effect profile and more severe adverse effects compared with cannabis. Serotonergic 5-hydroxytryptamine-2A (5-HT_2A) receptors mediate alterations of perception and cognition that are induced by serotonergic psychedelics. Because of their novelty, designer drugs may remain undetected by routine drug screening, thus hampering evaluations of adverse effects. Intoxication reports suggest that several designer drugs are used concurrently, posing a high risk for severe adverse effects and even death.

Acute Effects of 2C-E in Humans: An Observational Study

2,5-Dimethoxy-4-ethylphenethylamine (2C-E) is psychedelic phenylethylamine, with a chemical structure similar to mescaline, used as new psychoactive substance (NPS). It inhibits norepinephrine and serotonin uptake and, more relevant, acts as a partial agonist of the serotonin 2A (5-HT_{2 A}), 2B (5-HT_{2 B}), and (5-HT_{2 C}) receptors. Consumers have reported that 2C-E induces mild-moderate psychedelic effects, but its pharmacology in humans, including pharmacological effects and pharmacokinetics, have not yet studied. To assess the acute effects of 2C-E on physiological and subjective effects and evaluate its pharmacokinetics, an observational study was carried-out. Ten recreational users of psychedelics self-administered a single oral dose of 2C-E (6.5, 8, 10, 15, or 25 mg). Blood pressure and heart rate were evaluated at baseline, 2, 4, and 6 h post-administration. Three rating scales were administered to evaluate subjective effects: a set of Visual Analog Scales (VAS), the 49-item short form version of the Addiction Research Centre Inventory (ARCI), and the Evaluation of the Subjective Effects of Substances with Abuse Potential (VESSPA-SSE) at baseline, 2, 4, and 6 h after self-administration. To assess 2C-E concentrations oral fluid (saliva) was collected during 6 h. 2C-E induced primarily alterations in perceptions, hallucinations, and euphoric-mood. Saliva maximal concentrations were achieved 2 h after self-administration. Administration of oral 2C-E at recreational doses produces a group of psychedelic-like effects such to 2C-B and other serotonin-acting drugs.

A qualitative descriptive analysis of effects of psychedelic phenethylamines and tryptamines

OBJECTIVE

The number of novel psychedelic phenethylamines and tryptamines has continued to increase, but little academic research has focused on the effects of these substances. We sought to determine and compare the subjective effects of various substances.

METHODS

We conducted in-depth interviews with 39 adults (75.4% male and 87.2% White) who reported experience using psychedelic phenethylamines and/or tryptamines. Participants described the effects of compounds they have used. We examined the subjective drug effects in a qualitative descriptive manner.

RESULTS

Participants reported on the use of 36 compounds. The majority (64.1%) reported the use of 2C series drugs, with 2C-B use being most prevalent; 38.5% reported the use of NBOMe, and 25.6% reported the use of DOx. With regard to tryptamines, 46.2% reported use, and 4-AcO-DMT was the most prevalent drug used in this class. 2C-B was often described as being more favorable than other 2C series compounds with the effects described as being comparable with MDMA and LSD. NBOMe effects were generally described in an unfavorable manner, and the effects of DOx were often described as lasting too long (12-36 hr). The effects of 4-AcO-DMT were often described as mimicking psilocybin.

CONCLUSION

Knowing the effects of various compounds can inform education, prevention, and harm reduction efforts regarding the use of these drugs.

Aromatic Bromination Abolishes the Psychomotor Features and Pro-social Responses of MDMA ("Ecstasy") in Rats and Preserves Affinity for the Serotonin Transporter (SERT)

The entactogen MDMA (3,4-methylenedioxy-methamphetamine, “Ecstasy”) exerts its psychotropic effects acting primarily as a substrate of the serotonin transporter (SERT) to induce a non-exocytotic release of serotonin. Nevertheless, the roles of specific positions of the aromatic ring of MDMA associated with the modulation of typical entactogenic effects, using analogs derived from the MDMA template, are still not fully understood. Among many possibilities, aromatic halogenation of the phenylalkylamine moiety may favor distribution to the brain due to increased lipophilicity, and sometimes renders psychotropic substances of high affinity for their molecular targets and high potency in humans. In the present work, a new MDMA analog brominated at C(2) of the aromatic ring (2-Br-4,5-MDMA) has been synthesized and pharmacologically characterized in vitro and in vivo. First, binding competition experiments against the SERT-blocker citalopram were carried out in human platelets and compared with MDMA. Besides, its effects on platelet aggregation were performed in platelet enriched human plasma using collagen as aggregation inductor. Second, as platelets are considered an appropriate peripheral model for estimating central serotonin availability, the functional effects of 2-Br-4,5-MDMA and MDMA on ATP release during human platelet aggregation were evaluated. The results obtained showed that 2-Br-4,5-MDMA exhibits higher affinity for SERT than MDMA and fully abolishes both platelet aggregation and ATP release, resembling the pharmacological profile of citalopram. Subsequent in vivo evaluation in rats at three dose levels showed that 2-Br-4,5-MDMA lacks all key MDMA-like behavioral responses in rats, including hyperlocomotion, enhanced active avoidance conditioning responses and increased social interaction. Taken together, the results obtained are consistent with the notion that 2-Br-4,5-MDMA should not be expected to be an MDMA-like substrate of SERT, indicating that aromatic bromination at C(2) modulates the pharmacodynamic properties of the substrate MDMA, yielding a citalopram-like compound.

Dark Classics in Chemical Neuroscience: Mescaline

Archeological studies in the United States, Mexico, and Peru suggest that mescaline, as a cactus constituent, has been used for more than 6000 years. Although it is a widespread cactus alkaloid, it is present in high concentrations in few species, notably the North American peyote ( Lophophora williamsii) and the South American wachuma ( Trichocereus pachanoi, T. peruvianus, and T. bridgesii). Spanish 16th century chroniclers considered these cacti "diabolic", leading to their prohibition, but their use persisted to our days and has been spreading for the last 150 years. In the late 1800s, peyote attracted scientific attention; mescaline was isolated, and its role in the psychedelic effects of peyote tops or "mescal buttons" was demonstrated. Its structure was established by synthesis in 1929, and alternative routes were developed, providing larger amounts for pharmacological and biosynthetic research. Although its effects are attributed mainly to its action as a 5-HT_2A serotonin receptor agonist, mescaline binds in a similar concentration range to 5-HT_1A and α_2A receptors. It is largely excreted unchanged in human urine, and its metabolic products are apparently unrelated to its psychedelic properties. Its low potency is probably responsible for its relative neglect by recreational substance users, as the successful search for structure-activity relationships in the hallucinogen field focused largely on finding more potent analogues. Renewed interest in the possible therapeutic applications of psychedelic drugs may hopefully lead to novel insights regarding the commonalities and differences between the actions of individual classic hallucinogens.

Monoamine Transporter and Receptor Interaction Profiles in Vitro Predict Reported Human Doses of Novel Psychoactive Stimulants and Psychedelics

BACKGROUND

Pharmacological profiles of new psychoactive substances can be established rapidly in vitro and provide information on potential psychoactive effects in humans. The present study investigated whether specific in vitro monoamine transporter and receptor interactions can predict effective psychoactive doses in humans.

METHODS

We correlated previously assessed in vitro data of stimulants and psychedelics with human doses that are reported on the Internet and in books.

RESULTS

For stimulants, dopamine and norepinephrine transporter inhibition potency was positively correlated with human doses, whereas serotonin transporter inhibition potency was inversely correlated with human doses. Serotonin 5-hydroxytryptamine-2A (5-HT2A) and 5-HT2C receptor affinity was significantly correlated with psychedelic doses, but 5-HT1A receptor affinity and 5-HT2A and 5-HT2B receptor activation potency were not.

CONCLUSIONS

The rapid assessment of in vitro pharmacological profiles of new psychoactive substances can help to predict psychoactive doses and effects in humans and facilitate the appropriate scheduling of new psychoactive substances.

Acute Pharmacological Effects of 2C-B in Humans: An Observational Study

2,5-dimethoxy-4-bromophenethylamine (2C-B) is a psychedelic phenylethylamine derivative, structurally similar to mescaline. It is a serotonin 5-hydroxytryptamine-2A (5-HT_2A), 5-hydroxytryptamine-2B (5-HT_2B), and 5-hydroxytryptamine-2C (5-HT_2C) receptor partial agonist used recreationally as a new psychoactive substance. It has been reported that 2C-B induces mild psychedelic effects, although its acute pharmacological effects and pharmacokinetics have not yet been fully studied in humans. An observational study was conducted to assess the acute subjective and physiological effects, as well as pharmacokinetics of 2C-B. Sixteen healthy, experienced drug users self-administered an oral dose of 2C-B (10, 15, or 20 mg). Vital signs (blood pressure and heart rate) were measured at baseline 1, 2, 3, 4, and 6 hours (h). Each participant completed subjective effects using three rating scales: the visual analog scale (VAS), the Addiction Research Centre Inventory (ARCI), and the Evaluation of the Subjective Effects of Substances with Abuse Potential (VESSPA-SSE) at baseline, 2–3 and 6 h after self-administration (maximum effects along 6 h), and the Hallucinogenic Rating Scale (maximum effects along 6 h). Oral fluid (saliva) was collected to assess 2C-B and cortisol concentrations during 24 h. Acute administration of 2C-B increased blood pressure and heart rate. Scores of scales related to euphoria increased (high, liking, and stimulated), and changes in perceptions (distances, colors, shapes, and lights) and different body feelings/surrounding were produced. Mild hallucinating effects were described in five subjects. Maximum concentrations of 2C-B and cortisol were reached at 1 and 3 h after self-administration, respectively. Oral 2C-B at recreational doses induces a constellation of psychedelic/psychostimulant-like effects similar to those associated with serotonin-acting drugs.

Monoamine receptor interaction profiles of 4-thio-substituted phenethylamines (2C-T drugs)

BACKGROUND

4-Thio-substituted phenethylamines (2C-T drugs) are potent psychedelics with poorly defined pharmacological properties. Because of their psychedelic effects, 2C-T drugs are sometimes sold as new psychoactive substances (NPSs). The aim of the present study was to characterize the monoamine receptor and transporter interaction profiles of a series of 2C-T drugs.

METHODS

We determined the binding affinities of 2C-T drugs at monoamine receptors and transporters in human cells that were transfected with the respective receptors or transporters. We also investigated the functional activation of serotonergic 5-hydroxytryptamine 2A (5-HT_2A) and 5-HT_2B receptors, activation of human trace amine-associated receptor 1 (TAAR₁), and inhibition of monoamine uptake transporters.

RESULTS

2C-T drugs had high affinity for 5-HT_2A and 5-HT_2C receptors (1-54 nM and 40-350 nM, respectively). With activation potencies of 1-53 nM and 44-370 nM, the drugs were potent 5-HT_2A receptor and 5-HT_2B receptor, respectively, partial agonists. An exception to this were the benzylthiophenethylamines, which did not potently activate the 5-HT_2B receptor (EC₅₀ > 3000 nM). Furthermore, the compounds bound to serotonergic 5-HT_1A and adrenergic receptors. The compounds had high affinity for the rat TAAR₁ (5-68 nM) and interacted with the mouse but not human TAAR₁. The 2C-T drugs did not potently interact with monoamine transporters (K_i > 4000 nM).

CONCLUSION

The receptor binding profile of 2C-T drugs predicts psychedelic effects that are mediated by potent 5-HT₂ receptor interactions. This article is part of the Special Issue entitled 'Designer Drugs and Legal Highs.'

The Novel Psychoactive Substances in the UK Project: empirical and conceptual review work to produce research recommendations

Background

Although illegal drug use has largely been declining in the UK over the past decade, this period has witnessed the emergence of a range of novel psychoactive substances (NPS) (‘legal highs’). These are new, mostly synthetic, substances that mimic the effects of existing drugs). Despite there being many causes for concern in relation to NPS, there has been little prior study of the burden associated with their use in public health terms. Clarity is lacking on research priorities in this rapidly developing literature.

Objectives

To inform the development of public health intervention research on NPS by reviewing existing data on their use, associated problems and potential responses to such problems.

Design

A scoping review and narrative synthesis of selected bodies of evidence was undertaken to summarise and evaluate what is known about NPS use and the related harms of, and responses to, such use. Relevant literature was identified from electronic databases (covering January 2006 to June 2016 inclusive), Google (Google Inc., Mountain View, CA, USA), relevant websites and online drug forums and by contacting experts. Articles were included if they were primary studies, secondary studies involving the analysis and interpretation of primary research or discussion papers. A conceptual framework postulating an evidence-informed public health approach to NPS use in the UK was developed through a pragmatic literature review, the iterative development of concepts and finalisation in light of the results from the empirical review work. The process also involved feedback from various stakeholders. Research recommendations were developed from both strands of work.

Results

A total of 995 articles were included in the scoping review, the majority of which related to individual-level health-related adverse effects attributable to NPS use. The prevalence of lifetime NPS use varied widely between (e.g. with higher prevalence in young males) and within population subgroups. The most commonly reported adverse effects were psychiatric/other neurological, cardiovascular, renal and gastrointestinal manifestations, and there is limited evidence available on responses. In these and other respects, available evidence is at an early stage of development. Initial evidence challenges the view that NPS should be treated differently from other illicit drugs. The conceptual framework indicated that much of the evidence that would be useful to inform public health responses does not yet exist. We propose a systems-based prevention approach that develops existing responses, is multilevel and life course informed in character, and emphasises commonalities between NPS and other legal and illegal drug use. We make 20 recommendations for research, including nine key recommendations.

Limitations

Scoping reviews do not interrogate evidence in depth, and the disjunction between the scoping review and the conceptual framework findings is worthy of careful attention.

Conclusions

Key research recommendations build on those that have previously been made and offer more evidence-based justification and detail, as previous recommendations have not yet been acted on. The case for decision-making on commissioning new research based on these recommendations is both strong and urgent.

Future work

The validity of recommendations generated through this project could be enhanced via further work with research commissioners, policy-makers, researchers and the public.

Study registration

The systematic review element of this study is registered as PROSPERO CRD42016026415.

Funding

The National Institute for Health Research Public Health Research programme.

Human Pharmacology of Mephedrone in Comparison with MDMA

Mephedrone (4-methylmethcathinone) is a novel psychoactive substance popular among drug users because it displays similar effects to MDMA (3,4-methylenedioxymethamphetamine, ecstasy). Mephedrone consumption has been associated with undesirable effects and fatal intoxications. At present, there is no research available on its pharmacological effects in humans under controlled and experimental administration. This study aims to evaluate the clinical pharmacology of mephedrone and its relative abuse liability compared with MDMA. Twelve male volunteers participated in a randomized, double-blind, crossover, and placebo-controlled trial. The single oral dose conditions were: mephedrone 200 mg, MDMA 100 mg, and placebo. Outcome variables included physiological, subjective, and psychomotor effects, and pharmacokinetic parameters. The protocol was registered in ClinicalTrials.gov (NCT02232789). Mephedrone produced a significant increase in systolic and diastolic blood pressure, heart rate, and pupillary diameter. It elicited stimulant-like effects, euphoria, and well-being, and induced mild changes in perceptions with similar ratings to those observed after MDMA administration although effects peaked earlier and were shorter in duration. Maximal plasma concentration values for mephedrone and MDMA peaked at 1.25 h and 2.00 h, respectively. The elimination half-life for mephedrone was 2.15 h and 7.89 h for MDMA. In a similar manner to MDMA, mephedrone exhibits high abuse liability. Its earlier onset and shorter duration of effects, probably related to its short elimination half-life, could explain a more compulsive pattern of use as described by the users.