Single administration of a psychedelic [(R)-DOI] influences coping strategies to an escapable social stress.

Psychedelic compounds have potentially rapid, long-lasting anxiolytic, antidepressive and anti-inflammatory effects. We investigated whether the psychedelic compound (R)-2,5-dimethoxy-4-iodoamphetamine [(R)-DOI], a selective 5-HT2A receptor partial agonist, decreases stress-related behavior in male mice exposed to repeated social aggression. Additionally, we explored the likelihood that these behavioral changes are related to anti-inflammatory properties of [(R)-DOI]. Animals were subjected to the Stress Alternatives Model (SAM), an escapable social stress paradigm in which animals develop reactive coping strategies - remaining in the SAM arena (Stay) with a social aggressor, or dynamically initiated stress coping strategies that involve utilizing the escape holes (Escape) to avoid aggression. Mice expressing these behavioral phenotypes display behaviors like those in other social aggression models that separate animals into stress-vulnerable (as for Stay) or stress-resilient (as for Escape) groups, which have been shown to have distinct inflammatory responses to social stress. These results show that Stay animals have heightened cytokine gene expression, and both Stay and Escape mice exhibit plasma and neural concentrations of the inflammatory cytokine tumor necrosis factor-α (TNFα) compared to unstressed control mice. Additionally, these results suggest that a single administration of (R)-DOI to Stay animals in low doses, can increase stress coping strategies such as increasing attention to the escape route, promoting escape behavior, and reducing freezing during socially aggressive interaction in the SAM. Lower single doses of (R)-DOI, in addition to shifting behavior to suggest anxiolytic effects, also concomitantly reduce plasma and limbic brain levels of the inflammatory cytokine TNFα.

Estimulantes de tipo anfetamínico en estudiantes de medicina latinoamericanos: una revisión / Amphetamine-type stimulants in Latin American medicine students: a review

Introducción: el consumo de estimulantes de tipo anfetamínico (ETA) y sus derivados está cada vez más presente en los estudiantes universitarios y, en particular, en los programas de medicina. El objetivo principal de este estudio fue revisar la literatura sobre el uso de ETA y sus derivados en estudiantes de medicina latinoamericanos. Materiales y método: se realizó una revisión de la literatura disponible, utilizando las bases de datos PubMed, SciELO y LILACS. Se encontraron un total de 1.054 artículos, de los cuales 17 fueron seleccionados para esta revisión. Resultados: la revisión muestra, en general, una mayor frecuencia de uso de ETA en estudiantes de medicina de América Latina en comparación con la población general y estudiantes de otras carreras universitarias. También existe una tendencia a un mayor uso en hombres, de mayor nivel socioeconómico y en cursos posteriores del programa. La razón más informada para usar ETA fue aumentar el rendimiento académico. Como factor protector se destacaron los deportes, el tiempo en familia y la profesión de alguna creencia religiosa. De los artículos seleccionados, no se encontraron estudios sobre las consecuencias a largo plazo del uso de ETA en estudiantes de medicina. Discusión: en resumen, los estudiantes de medicina latinoamericanos tienen un alto consumo de ETA, por lo que es evidente la necesidad de nuevos estudios para mejorar la precisión estadística, determinar factores de riesgo específicos, estudiar las consecuencias a largo plazo y establecer políticas de prevención y tratamiento.

Introduction: the consumption of amphetamine-type stimulants (ATS) and their derivatives are increasingly present in university students and in particular in medical programs. The main objective of this study was to review the literature on the use of ATS and their derivatives in Latin American medical students. Materials and method: a review of the literature available was performed, using PubMed, SciELO, and LILACS databases. A total of 1054 articles were found, of which 17 were selected for this review. Results: the review generally shows a higher frequency of use of ATS in medical students of Latin America compared to the general population and students from other university degrees. There is also a tendency of a higher use in men, from higher socioeconomic status, and in later courses of the program. The most reported reason for using ATS was to increase the academic performance. As a protective factor, sports, family time and professing some religious belief stood out. Of the selected articles, no studies were found on the long-term consequences of the use of ATS in medical students. Discussion: in summary, Latin American medical students have a high consumption of ATS, and therefore there is an evident need for new studies to improve statistical precision, to determine specific risk factors, to study long-term consequences, and to stablish prevention policies and treatment.

The Chronic Oral Administration of Clobenzorex or Amphetamine Decreases Motor Behavior and Induces Glial Activation in the Striatum Without Dopaminergic Degeneration.

Described as amphetamine-like due to their structural and stimulant similarities, clobenzorex is one of the five most-commonly used drugs in Mexico for the treatment of obesity. Various studies have shown that amphetamines induce dopaminergic neurotoxicity and neuroinflammation in the striatum, symptoms which are associated with motor damage. For this reason, the present study aimed to evaluate the effect of chronic clobenzorex administration on motor behaviors, TH immunoreactivity, gliosis, and the neurodegenerative process in the striatum and substantia nigra pars compacta (SNpc). The present research was conducted on three experimental groups of male Wistar rats: the vehicle group, the amphetamine group (2 mg/kg), and the clobenzorex group (30 mg/kg). All groups were subject to oral administration every 24 h for 31 days. Motor activity and motor coordination were evaluated in the open field test and the beam walking test, respectively. The animals were euthanized after the last day of treatment to enable the extraction of their brains for the evaluation of tyrosine hydroxylase (TH) levels, the immunoreactivity of the glial cells, and the neurodegeneration of both the striatum and SNpc via amino-cupric-silver stain. The results obtained show that amphetamine and clobenzorex administration decrease motor activity and motor coordination in the beam walking test and cause increased gliosis in the striatum, while no significant changes were observed in terms of immunoreactivity to TH and neurodegeneration in both the striatum and SNpc. These results suggest that the chronic administration of clobenzorex may decrease motor function in a manner similar to amphetamine, via the neuroadaptive and non-neurotoxic changes caused to the striatum under this administration scheme.

Medication Use in the Management of Comorbidities Among Individuals With Autism Spectrum Disorder From a Large Nationwide Insurance Database.

Importance: Although there is no pharmacological treatment for autism spectrum disorder (ASD) itself, behavioral and pharmacological therapies have been used to address its symptoms and common comorbidities. A better understanding of the medications used to manage comorbid conditions in this growing population is critical; however, most previous efforts have been limited in size, duration, and lack of broad representation. Objective: To use a nationally representative database to uncover trends in the prevalence of co-occurring conditions and medication use in the management of symptoms and comorbidities over time among US individuals with ASD. Design, Setting, and Participants: This retrospective, population-based cohort study mined a nationwide, managed health plan claims database containing more than 86 million unique members. Data from January 1, 2014, to December 31, 2019, were used to analyze prescription frequency and diagnoses of comorbidities. A total of 26 722 individuals with ASD who had been prescribed at least 1 of 24 medications most commonly prescribed to treat ASD symptoms or comorbidities during the 6-year study period were included in the analysis. Exposures: Diagnosis codes for ASD based on International Classification of Diseases, Ninth Revision, and International Statistical Classification of Diseases and Related Health Problems, Tenth Revision. Main Outcomes and Measures: Quantitative estimates of prescription frequency for the 24 most commonly prescribed medications among the study cohort and the most common comorbidities associated with each medication in this population. Results: Among the 26 722 individuals with ASD included in the analysis (77.7% male; mean [SD] age, 14.45 [9.40] years), polypharmacy was common, ranging from 28.6% to 31.5%. Individuals' prescription regimens changed frequently within medication classes, rather than between classes. The prescription frequency of a specific medication varied considerably, depending on the coexisting diagnosis of a given comorbidity. Of the 24 medications assessed, 15 were associated with at least a 15% prevalence of a mood disorder, and 11 were associated with at least a 15% prevalence of attention-deficit/hyperactivity disorder. For patients taking antipsychotics, the 2 most common comorbidities were combined type attention-deficit/hyperactivity disorder (11.6%-17.8%) and anxiety disorder (13.1%-30.1%). Conclusions and Relevance: This study demonstrated considerable variability and transiency in the use of prescription medications by US clinicians to manage symptoms and comorbidities associated with ASD. These findings support the importance of early and ongoing surveillance of patients with ASD and co-occurring conditions and offer clinicians insight on the targeted therapies most commonly used to manage co-occurring conditions. Future research and policy efforts are critical to assess the extent to which pharmacological management of comorbidities affects quality of life and functioning in patients with ASD while continuing to optimize clinical guidelines, to ensure effective care for this growing population.

How Frequent Is Switching From an Initial Stimulant Family to the Alternative One in the Clinical Setting?: A Pilot Study of 49 Consecutively Referred Medication-Naive Adults With Attention-Deficit/Hyperactivity Disorder.

PURPOSE/BACKGROUND: This study aimed to evaluate the frequency of needing to switch the initial treatment of a stimulant to the alternative family in newly referred, medication-naive adults with attention-deficit/hyperactivity disorder (ADHD) initiating treatment with stimulants. METHODS/PROCEDURES: Subjects were 49 unmedicated adults (18-45 years old) with Diagnostic and Statistical Manual of Disorders (Fifth Edition) ADHD who initiated treatment with a stimulant. Before the clinical assessment with an expert clinician, participants completed the Adult Self-Report, Behavior Rating Inventory of Executive Function-Adult Version, Emotional Dysregulation Subscale of the Barkley Current Behavior Scale-Self-report, and Mind Wandering Questionnaire. The rate of switching was examined using information from the electronic medical record for up to three clinical follow-up visits. Comparisons were made between those who did and did not need to switch on baseline demographic and clinical characteristics. FINDINGS/RESULTS: Sixty-seven percent of ADHD patients were initially prescribed a methylphenidate product, and 33%, an amphetamine product. Forty-one percent of ADHD patients needed to switch from their initially prescribed stimulant family within 90 days of initiating treatment because of poor tolerability. Whereas the rate of switching was significantly higher in those initially prescribed methylphenidate, the rate of patients who required changes in formulation (long- to short-acting and vice versa) or additional antianxiety or antidepressant treatment ("strugglers") was higher in those taking amphetamine. Switchers were more impaired on the Adult Self-Report Intrusive scale, whereas nonswitchers were more impaired on the Behavior Rating Inventory of Executive Function Inhibit and Task Monitor scales. However, these findings were small and of unclear clinical significance. IMPLICATIONS/CONCLUSIONS: Forty-one percent of medication-naive adults with ADHD initiating stimulant treatment required a switch from the initially prescribed stimulant family to the alternative one because of poor tolerability. Switching could not be adequately predicted by baseline demographic or clinical characteristics. These findings call for improved efforts to help identify predictors of response to stimulant treatment in adults with ADHD to avoid unnecessary delays in identifying a safe and effective treatment for these patients.

Joint effects of alcohol and stimulant use disorders on self-reported sexually transmitted infections in a prospective study of Cambodian female entertainment and sex workers.

Female entertainment and sex workers (FESW) have high rates of alcohol and amphetamine-type stimulant (ATS) use, increasing risk for HIV/sexually transmitted infections (STI), and other negative outcomes. A prospective cohort of 1,198 FESW in a HIV/ATS use prevention intervention in Cambodia was assessed for alcohol and stimulant use disorders (AUD and SUD) using the Alcohol and Substance Use Involvement (ASSIST) scale. STI history was measured by self-report at baseline and at quarterly follow-up visits. Participants were asked if they had been diagnosed with an STI by a medical provider in the past 3 months. Marginal structural models were used to estimate joint effects of AUD and SUD on recent STI. At baseline, one-in-four screened AUD positive and 7% screened positive for SUD. At 18-months, 26% reported ≥1 recent STI. Accounting for time-varying and other known confounders, the adjusted odds ratio (AOR) for recent STI associated with AUD alone and SUD alone were 2.8 (95% CI:1.5-5.1) and 3.5 (95% CI:1.1-11.3), respectively. The AOR for joint effects of AUD and SUD was 5.7 (95% CI:2.2-15.2). AUD and SUD are independently and jointly associated with greater odds of STI among Cambodian FESW. Further research is critical for understanding how AUD and SUD potentiate biological and behavioural pathways that influence STI acquisition and to inform HIV risk-reduction interventions in FESW.

Analysis of 4-fluoroamphetamine in cerumen after controlled oral application.

Cerumen was found to be a promising alternative specimen for the detection of drugs. In a pilot study, drugs of abuse were identified at a higher detection rate and a longer detection window in cerumen than in urine. In this study, cerumen from subjects was analyzed after they ingested the designer stimulant 4-fluoroamphetamine (4-FA) in a controlled manner. METHODS: Twelve subjects ingested placebo and 100 mg of 4-FA. Five of them were also given 150 mg of 4-FA in 150 mL Royal Club bitter lemon drink at least after 7 days. Cerumen was sampled using cotton swabs at baseline, 1 h after the ingestion of the drug and at the end of the study day (12 h). After extraction with ethyl acetate followed by solid-phase extraction, the extracts were analyzed using liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). RESULTS AND DISCUSSION: In the cerumen of all 12 subjects, 4-FA was detected 12 h after its ingestion; in most subjects, cerumen was detected after 1 h of ingestion, ranging from 0.06 to 13.90 (median 1.52) ng per swab. The detection of 4-FA in cerumen sampled 7 days or more after the first dose suggested a long detection window of cerumen. CONCLUSIONS: Cerumen can be successfully used to detect a single drug ingestion even immediately after the ingestion when a sufficient amount of cerumen is used.

Transdermal Delivery of the Free Base of 3-Fluoroamphetamine: In Vitro Skin Permeation and Irritation Potential.

This work aimed to continue our effort in establishing the feasibility of 3-fluoroamphetamine (also known as PAL-353) to be a transdermal drug candidate by studying the delivery of the base form through the human cadaver skin in lieu of the previously investigated salt form, and for the first time using an EPIDERM™-reconstructed human epidermal model to predict the skin irritation potential of PAL-353, in support of development for a matrix-type transdermal delivery system. Passive and enhanced (with chemical permeation enhancers) transdermal delivery were investigated via in vitro permeation studies that were performed on Franz diffusion cells with dermatomed human cadaver skin. After 24 h, PAL-353 free base revealed high passive permeation of 417.49 ± 30.12, 1577.68 ± 165.41, and 4295.16 ± 264.36 µg/cm2, with applied formulation concentrations of 5.5 (F1), 20 (F2), and 40 (F3) mg/mL, respectively. Oleyl alcohol produced an approximately threefold steady-state flux enhancement at 5% or 10% w/w but may not be needed as the free base alone provided therapeutically relevant permeation. Further, it was predicted that therapeutically relevant delivery would be unlikely to cause skin irritation using the EPIDERM™-reconstructed human epidermal model. In conclusion, the present study further supported the development of PAL-353 transdermal delivery systems.

Pharmaceutical Creep: U.S. Military Power and the Global and Transnational Mobility of Psychopharmaceuticals.

In 2006, the United States Department of Defense developed for the first time official criteria for the use of psychopharmaceuticals "in theater"-in the physical and tactical spaces of military operations including active combat. Based on fieldwork with Army soldiers and veterans, this article explores the transnational and global dimensions of military psychopharmaceutical use in the post-9/11 wars. I consider the spatial, material, and symbolic dimensions of what I call "pharmaceutical creep"-the slow drift of psychopharmaceuticals from the civilian world into theater and into the military corporate body. While pharmaceutical creep is managed by the U.S. military as a problem of gatekeeping and of supply and provisioning, medications can appear as the solution to recruitment and performance problems once in theater. Drawing on soldiers' accounts of medication use, I illuminate the possibilities, but also the frictions, that arise when routine psychopharmaceuticals are remade into technologies of global counterinsurgency.

Prevalence of Non-medical Amphetamine Use Among Men with Diagnosed HIV Infection Who Have Sex with Men in the United States, 2015-2016.

Amphetamine use is higher among men who have sex with men (MSM) compared with other men, and is associated with sexual behavior linked to HIV transmission. No national estimates of amphetamine use among MSM with HIV have been published. We used data from the Medical Monitoring Project, a nationally representative sample of persons with diagnosed HIV, to describe patterns in amphetamine use in the past 12 months among MSM during 2015-2016 (N = 3796). Prevalence of amphetamine use in this population was 9.6% (95% CI 7.6, 11.6%) in the past 12 months. MSM who used amphetamines were more likely to have condomless sex with partners without HIV or of unknown serostatus (PR 1.87; 95% CI 1.62, 2.16) and less likely to be durably virally suppressed (PR 0.81; 95% CI 0.71, 0.91). Interventions to address amphetamine use and associated transmission risk behaviors among MSM living with HIV may decrease transmission.

Synthetic cathinones and their phenethylamine analogues produce distinct psychomotor and reward behavior in crayfish.

Synthetic cathinones share potent sympathomimetic properties with amphetamines due to their shared phenethylamine backbone. Despite recent work focused on understanding the behavioral effects of synthetic cathinones, a systematic comparison of neuropharmacology, behavior, and physiological effects with other stimulants, has remained elusive. In the present study, we explore the behavioral effects of cathinones in crayfish, a model system which combines a well characterized behavioral paradigm for addiction-like behaviors, a modularly organized nervous system, the lack of a formal blood-brain barrier, and experimental tractability. The objective of this study was to characterize the psychomotor and rewarding effects of methylated cathinones (methylone, mephedrone), and their non ß-ketone substituted amphetamine analogs (4-methylmethamphetamine, 4-MMA and 3,4-methylenedioxymethamphetamine MDMA) in crayfish. Our results suggest that these drugs produce psychostimulation, which sensitizes upon repeated drug administration. Furthermore, crayfish demonstrated a conditioned substrate preference for mephedrone and 4-MMA drug-pairings at a 10 µg/g dose, a preference which persisted even through a series of extinction trials. Our study indicates that synthetic cathinones and substituted amphetamine analogues produce distinct behavioral effects in an invertebrate system which consists of a relatively simple neuronal organization. The present findings provide an evolutionary context to our understanding about how drugs of abuse initiate reward at levels far beyond those specific to humans.

The pharmacokinetics of 3-fluoroamphetamine following delivery using clinically relevant routes of administration.

3-Fluoroamphetamine (also called PAL-353) is a synthetic amphetamine analog that has been investigated for cocaine use disorder (CUD), yet no studies have characterized its pharmacokinetics (PK). In the present study, we determined the PK of PAL-353 in male Sprague Dawley rats following intravenous bolus injection (5 mg/kg). Plasma samples were analyzed using a novel bioanalytical method that coupled liquid-liquid extraction and LC-MS/MS. The primary PK parameters determined by WinNonlin were a C0 (ng/mL) of 1412.09 ± 196.12 and a plasma half-life of 2.27 ± 0.67 h. As transdermal delivery may be an optimal approach to delivering PAL-353 for CUD, we assessed its PK profile following application of 50 mg of transdermal gel (10% w/w drug over 5 cm2). The 10% w/w gel resulted in a short lag time, sustained delivery, and a rapid clearance in plasma immediately after removal. The rodent PK data were verified by examining in vitro permeation through human epidermis mounted on Franz diffusion cells. An in vitro-in vivo correlation (IVIVC) analysis was performed using the Phoenix IVIVC toolkit to assess the predictive relationship between rodent and human skin absorption/permeation. The in vitro permeation study revealed a dose-proportional cumulative and steady-state flux with ~ 70% of drug permeated. The fraction absorbed in vivo and fraction permeated in vitro showed a linear relationship. In conclusion, we have characterized the PK profile of PAL-353, demonstrated that it has favorable PK properties for transdermal administration for CUD, and provided preliminary evidence of the capacity of rodent data to predict human skin flux.

Excretion of 4-fluoroamphetamine and three metabolites in urine after controlled oral ingestion.

Each year, synthetic drugs are occurring in high numbers in the illicit drug market. But data on their pharmacology and toxicology are scarcely available. Therefore, a pilot study was performed to evaluate excretion of 4-fluoroamphetamine (4FA) in humans and identify metabolites in urine. Twelve subjects ingested 100 mg and five 150 mg 4-FA in a bitter lemon drink. Urine samples were scheduled at baseline and 4 times during the following 12 h and analyzed by liquid chromatography-mass spectrometry (LC-MSMS). Concentrations of 4-FA were in the range of 0.7-38 mg/l which is in accordance with the data in previously reported cases. A marked decrease of creatinine excretion in the first two samples was noted. The creatinine normalized concentrations show a maximum 4 h after ingestion in accordance with serum pharmacokinetics. Three products of two metabolic pathways were identified in very low concentrations, two diastereomers of 4-fluorophenylpropanolamine and one ring hydroxylated 4-FA that was conjugated to a large extent. The concentration-time courses paralleled those of 4-FA. The study results show the range of 4-FA concentrations to be expected in urine after oral ingestion of typical dosages and show two pathways of 4-FA metabolism.

Concomitant Use of Quinolones and Stimulants and the Risk of Adverse Cardiovascular Symptoms: A Retrospective Cohort Study.

OBJECTIVE: To examine whether concomitant use of quinolones and stimulants increases the risk of cardiac events in adults. STUDY DESIGN: A retrospective cohort study of privately insured adults using MarketScan® claims data from 2008 to 2015. PATIENTS: Stimulant (methylphenidate or mixed amphetamine salts) users (18-65 yrs old) with continuous health plan enrollment for the 6 months (baseline) prior to the first dispensation (index date) of oral quinolones or comparators (amoxicillin ± clavulanate or azithromycin). OUTCOMES DEFINITION: (1) Cardiac symptoms (palpitation, tachycardia, or syncope); (2) cardiac arrhythmias (ventricular arrhythmias, paroxysmal ventricular tachycardia, or cardiac arrest). ANALYSIS: Baseline covariates adjustment was through inverse probability of treatment weighting. Adults were followed until the antimicrobial therapy ended. The hazard of cardiac events in stimulant-quinolones-exposed adults was compared to those who were treated with stimulant-comparator antibiotics using a weighted Cox regression model. Several sensitivity analyses were performed to challenge the results robustness. RESULTS: The study cohorts comprised 390,490 stimulants users who initiated either quinolone or amoxicillin, and 387,574 patients receiving stimulants who initiated quinolone or azithromycin. The unadjusted incidence rate for cardiac symptoms in stimulant-quinolones users was 471 cases/10,000 patient-years, and it was 244 cases/10,000 patient-years in patients exposed to stimulant-amoxicillin; whereas the unadjusted incidence rate for cardiac symptoms was 728 and 358 per 10,000 patient-years for stimulant-quinolones and stimulant-azithromycin cohorts, respectively. Compared to stimulant-amoxicillin use, the adjusted hazard ratio (HR) for cardiac symptoms with stimulant-quinolones use was 1.61 (95% confidence interval [CI], 1.30-1.98). The HR for cardiac symptoms for patient exposed to stimulant-quinolones was 1.69 (95% CI, 1.32-2.13) when compared to stimulant-azithromycin. The sensitivity analysis findings were consistent with the primary analysis. A few patients across the study comparison groups developed cardiac arrhythmias. CONCLUSION: Concomitant use of stimulants and quinolone was associated with an increased hazard of cardiac symptoms in comparison to concomitant use of stimulants and amoxicillin or azithromycin, but there was no apparent difference in cardiac arrhythmias.

Intra-Nasally Administered Oligopeptide Lunasin Acts as a Possible Anti-Psychotic Agent in Mice Models.

Background and Objectives: Previously we have shown that synthetic lunasin, a 43 amino acid residue-containing peptide, after its central (intracisternal) administration in mice demonstrated antagonism against dopaminergic drug behavioural effects, indicating a putative antipsychotic/anti-schizophrenic profile of lunasin. The aims of the present studies were: to test whether lunasin would show an influence on the dopaminergic system after intranasal administration, and to examine the effect(s) of lunasin on serotonin and glutamatergic systems, which could play an essential role in antipsychotic action. Materials and Methods: Lunasin was administered intra-nasally at doses 0.1 and 1 nmol/mouse in ICR mice (n = 7-8) and tested in an open field on hyperlocomotion caused by amphetamine; serotonin 5-HT 2A/2C receptor agonist 1-(2,5-dimethoxy-4-iodophenyl)- 2-aminopropane (DOI); and glutamate NMDA receptor antagonist phencyclidine. Following behavioural testing, the contents of neurotransmitters and their metabolites in brain hemispheres (n = 6-8) were assessed by ultra-high-performance liquid chromatography-time of flight mas-spectrometry (UHPLC-TOF-MS) method. Also, lunasin binding to serotonin receptors was assessed. Results: Lunasin intra-nasally fully normalized hyper-locomotion and brain monoamine levels in amphetamine- and DOI-treated mice brains. Phencyclidine behavioural effects were not influenced. In vitro receptor binding data demonstrated a low affinity of lunasin (at µM concentrations) compared with DOI (nM concentrations) for the 5-HT2A and 5-HT2C receptors. Conclusions: These results demonstrated, for the first time, that the intranasal administration of oligopeptide lunasin normalized mice behaviour and brain monoamine levels in experimental psychosis mice models. Its neuro-regulatory effects indicated a usefulness of this peptide molecule for the design of novel psychotropic agents.

The adrenergic receptor antagonist carvedilol interacts with serotonin 2A receptors both in vitro and in vivo.

There is increasing support for the potential clinical use of compounds that interact with serotonin 2A (5-HT2A) receptors. It is therefore of interest to discover novel compounds that interact with 5-HT2A receptors. In the present study, we used computational chemistry to identify critical ligand structural features of 5-HT2A receptor binding and function. Query of compound databases using those ligand features revealed the adrenergic receptor antagonist carvedilol as a high priority match. As carvedilol is used clinically for cardiovascular diseases, we conducted experiments to assess whether it has any interactions with 5-HT2A receptors. In vitro experiments demonstrated that carvedilol has high nanomolar affinity for 5-HT2A receptors. In vivo experiments demonstrated that carvedilol increases the ethanol-induced loss of the righting reflex and suppresses operant responding in mice, and that these effects are attenuated by pretreatment with the selective 5-HT2A receptor antagonist M100907. Moreover, carvedilol did not induce the head-twitch response in mice, suggesting a lack of psychedelic effects. However, carvedilol did not activate canonical 5-HT2A receptor signaling pathways and antagonized serotonin-mediated signaling. It also reduced the head-twitch response induced by 2,5-Dimethoxy-4-iodoamphetamine, suggesting potential in vivo antagonism, allosteric modulation, or functional bias. These data suggest that carvedilol has functionally relevant interactions with 5-HT2A receptors, providing a novel mechanism of action for a clinically used compound. However, our findings do not clearly delineate the precise mechanism of action of carvedilol at 5-HT2A receptors, and additional experiments are needed to elucidate the role of 5-HT2A receptors in the behavioral and clinical effects of carvedilol.

Pharmacokinetic properties of 4-fluoroamphetamine in serum and oral fluid after oral ingestion.

INTRODUCTION: Each year, synthetic drugs occur in high numbers on the illicit drug market. But data on their pharmacology and toxicology are scarce. Therefore, a controlled study was performed to evaluate pharmacokinetic parameters of 4-fluoroamphetamine (4-FA) in humans and to compare it with effects. METHODS: Twelve subjects ingested 100 mg and five subjects also received 150 mg 4-FA in a bitter lemon drink. Blood and oral fluid samples were taken during the following 12 hours and analyzed for 4-FA and traces of amphetamine as impurity by liquid chromatography-tandem mass spectrometry (LC-MS/MS). RESULTS: For 12 hours after ingestion, the concentration-time course of 4-FA was similar to that of amphetamine with maximal concentrations appearing in serum after about 2 hours (in median 195 ng/mL after the 100 mg dose, range 155-316 ng/mL). The elimination half-life was approximately 8-9 hours and shorter than that of amphetamine but it exhibited a marked variation (5.5-16.8 hours). In oral fluid, 4-FA could also be detected for 12 hours and concentrations were higher than in serum. During the first 3 hours after ingestion concentrations were higher, most probably due to oral contamination. Serum concentrations in forensic cases were in the range of those observed in the present study suggesting dosages in recreational use in the range of those tested here. CONCLUSIONS: The pharmacokinetic properties of 4-FA are similar to that of amphetamine including a marked variation in elimination. However, recreational dosages may already exhibit prominent adverse effects and may even have life-threatening consequences.

Sustained Activation of Postsynaptic 5-HT2A Receptors Gates Plasticity at Prefrontal Cortex Synapses.

The prefrontal cortex (PFC) plays a key role in many high-level cognitive processes. It is densely innervated by serotonergic neurons originating from the dorsal and median raphe nuclei, which profoundly influence PFC activity. Among the 5-HT receptors abundantly expressed in PFC, 5-HT2A receptors located in dendrites of layer V pyramidal neurons control neuronal excitability and mediate the psychotropic effects of psychedelic hallucinogens, but their impact on glutamatergic transmission and synaptic plasticity remains poorly characterized. Here, we show that a 20-min exposure of mouse PFC slices to serotonin or the 5-HT2A receptor agonist 2,5-dimethoxy-4-iodoamphetamine (DOI) produces a long-lasting depression of evoked AMPA excitatory postsynaptic currents in layer V pyramidal neurons. DOI-elicited long-term depression (LTD) of synaptic transmission is absent in slices from 5-HT2A receptor-deficient mice, is rescued by viral expression of 5-HT2A receptor in pyramidal neurons and occludes electrically induced long-term depression. Furthermore, 5-HT2A receptor activation promotes phosphorylation of GluA2 AMPA receptor subunit at Ser880 and AMPA receptor internalization, indicating common mechanisms with electrically induced LTD. These findings provide one of the first examples of LTD gating under the control of a G protein-coupled receptor that might lead to imbalanced synaptic plasticity and memory impairment following a nonphysiological elevation of extracellular serotonin.

4-Fluoramphetamine in the Netherlands: Text-mining and sentiment analysis of internet forums.

BACKGROUND: Users of new psychoactive substances including 4-fluoroamphetamine (4-FA/4-FMP) frequently share their experiences or opinions in online drug forums. We have tested the potential of computerised analysis of drug users' forum posts for monitoring and early detection of trends. Specifically, we tested whether changes in the volume of 4-FA related posts and sentiments expressed in those posts can be observed around the time 4-FA was increasingly reported by Dutch drug monitoring sources (2012-2017). METHODS: Opening posts from two popular Dutch internet-based drug discussion forums, written between January 1 st, 2012 and January 1 st, 2018 were scraped: Portions of the forum posts about 4-FA were collected. To contrast 4-FA findings against other categories of forum posts, we also collected posts on two other substances (ecstasy and cocaine) and posts not related to a specific substance. Sentiments expressed in these posts were inferred using text recognition software, and analysed for trends using linear mixed modelling. RESULTS: The number of 4-FA posts increased between 2012 and 2015: 76 posts in 2012, 138 in 2013, 322 in 2014, 323 in 2015, and decreased thereafter: 264 in 2016 and 135 in 2017; X2(5) = 271.8, p < .001. Over time, a decrease in positive sentiment towards 4-FA can be observed starting in 2015, compared to the period before 2015, coinciding with more news searches and reports on adverse events related to 4-FA use. Linear mixed modelling analysis confirmed a significantly higher sentiment score in 2015 compared to 2017 for 4-FA, B = 0.062; SE = 0.023; t(1252) = 2.70; p = 0.007, but not for posts on other substances. CONCLUSION: Changes in the volume and sentiments of forum posts coincided with news media exposure related to 4-FA and with trends observed by established drug monitoring sources. Hence, internet forum monitoring facilitates early discovery of trends in the popularity, prevalence and adverse events related to new psychoactive substances.