Deployment and validation of the CLL treatment infection model adjoined to an EHR system.

Research algorithms are seldom externally validated or integrated into clinical practice, leaving unknown challenges in deployment. In such efforts, one needs to address challenges related to data harmonization, the performance of an algorithm in unforeseen missingness, automation and monitoring of predictions, and legal frameworks. We here describe the deployment of a high-dimensional data-driven decision support model into an EHR and derive practical guidelines informed by this deployment that includes the necessary processes, stakeholders and design requirements for a successful deployment. For this, we describe our deployment of the chronic lymphocytic leukemia (CLL) treatment infection model (CLL-TIM) as a stand-alone platform adjoined to an EPIC-based Danish Electronic Health Record (EHR), with the presentation of personalized predictions in a clinical context. CLL-TIM is an 84-variable data-driven prognostic model utilizing 7-year medical patient records and predicts the 2-year risk composite outcome of infection and/or treatment post-CLL diagnosis. As an independent validation cohort for this deployment, we used a retrospective population-based cohort of patients diagnosed with CLL from 2018 onwards (n = 1480). Unexpectedly high levels of missingness for key CLL-TIM variables were exhibited upon deployment. High dimensionality, with the handling of missingness, and predictive confidence were critical design elements that enabled trustworthy predictions and thus serves as a priority for prognostic models seeking deployment in new EHRs. Our setup for deployment, including automation and monitoring into EHR that meets Medical Device Regulations, may be used as step-by-step guidelines for others aiming at designing and deploying research algorithms into clinical practice.

I Didn't Want the Psychotic Thing to Get Out to Anyone at All: Adolescents with Early Onset Psychosis Managing Stigma.

The impact of stigmatisation on adults with mental illnesses has been thoroughly demonstrated. However, little is known about experiences of stigmatisation among adolescents with mental illness. Through semi-structured interviews with 34 Danish adolescents (14-19 years) diagnosed with psychosis, this study explores adolescents' experiences of psychosis stigma. On the basis of phenomenological analysis, we find that stigmatisation is widely experienced, and psychosis is generally regarded as more stigmatising than co-morbid mental illnesses. The participants engage in different strategies to manage possible stigma, especially strategies of (non-)disclosure. Disclosure is experienced as both therapeutic and normative, but also bears the risk of stigmatisation, and is therefore associated with numerous considerations. Being understood when disclosing is central to the participants, and lack of understanding from others is a continuous challenge. Nevertheless, participants experience benefits when feeling understood by people they confide in and can to a degree create the grounds for this through centralising aspects of their experiences of psychosis and mental illness. We argue that disclosure is both a stigma management strategy and a normative imperative, and that being understood or not is a challenge transcending stigma definitions.Clinical trial registration: Danish Health and Medicines Authority: 2612-4168. The Ethics Committee of Capital Region: H-3-2009-123. ClinicalTrials.gov: NCT01119014. Danish Data Protection Agency: 2009-41-3991.

Structural insights into GABAA receptor potentiation by Quaalude.

Methaqualone, a quinazolinone marketed commercially as Quaalude, is a central nervous system depressant that was used clinically as a sedative-hypnotic, then became a notorious recreational drug in the 1960s-80s. Due to its high abuse potential, medical use of methaqualone was eventually prohibited, yet it persists as a globally abused substance. Methaqualone principally targets GABAA receptors, which are the major inhibitory neurotransmitter-gated ion channels in the brain. The restricted status and limited accessibility of methaqualone have contributed to its pharmacology being understudied. Here, we use cryo-EM to localize the GABAA receptor binding sites of methaqualone and its more potent derivative, PPTQ, to the same intersubunit transmembrane sites targeted by the general anesthetics propofol and etomidate. Both methaqualone and PPTQ insert more deeply into subunit interfaces than the previously-characterized modulators. Binding of quinazolinones to this site results in widening of the extracellular half of the ion-conducting pore, following a trend among positive allosteric modulators in destabilizing the hydrophobic activation gate in the pore as a mechanism for receptor potentiation. These insights shed light on the underexplored pharmacology of quinazolinones and further elucidate the molecular mechanisms of allosteric GABAA receptor modulation through transmembrane binding sites.

Effect of the glucagon-like peptide-1 (GLP-1) receptor agonist semaglutide on alcohol consumption in alcohol-preferring male vervet monkeys.

RATIONALE: Glucagon-like peptide-1 (GLP-1) receptor agonists reduce alcohol consumption in rodents and non-human primates. Semaglutide is a new long-acting GLP-1 receptor agonist, widely used in the clinic against type 2 diabetes and obesity. It is also reported to reduce alcohol intake in rodents. OBJECTIVES: This study investigates the possible inhibitory effect of semaglutide on alcohol intake in alcohol-preferring African green monkeys. METHODS: We performed a vehicle-controlled study on male monkeys that had demonstrated a preference for alcohol. In the monkeys selected for voluntary alcohol drinking, alcohol consumption was measured for ten days at baseline (Monday to Friday for two weeks). During this period, the monkeys had access to alcohol 4 h per day and free access to water 24 h per day. After two weeks of baseline measurements, the monkeys were randomized to semaglutide or vehicle. Each group consisted of ten monkeys, and the two groups were balanced with respect to baseline alcohol intake. Following the baseline period, the monkeys were treated with escalating doses of semaglutide (up to 0.05 mg/kg) or vehicle subcutaneously twice weekly for two weeks during which period alcohol was not available. After uptitration, the monkeys had access to alcohol 4 h daily for 20 days (Monday to Friday for 4 weeks), and alcohol consumption was measured. During this alcohol exposure period, treatment with semaglutide (0.05 mg/kg twice weekly) or vehicle continued for three weeks followed by a one-week washout period. RESULTS: Compared to the vehicle, semaglutide significantly reduced alcohol intake. There were no signs of emetic events or changes in water intake. CONCLUSIONS: These data demonstrate for the first time the potent effect of semaglutide in reducing voluntary alcohol intake in non-human primates and further substantiate the need for clinical trials investigating the effect of semaglutide in patients with alcohol-use disorder.

Psychopharmacological treatment in patients planned for hip or knee replacement.

Psychopharmacological treatment may be an independent risk factor for increased length of stay and readmission after hip and knee replacement. Thus, temporary perioperative discontinuation may be beneficial. However, little is known regarding the treatments, and not all are feasible to discontinue. Therefore, the aim of this study was to describe the treatments in terms of type, dose, duration, indication and initiating physician to assess the feasibility of temporary perioperative discontinuation. We included 482 patients planned for hip or knee replacement in psychopharmacological treatment for psychiatric disorders from 2021 to 2023 at five orthopaedic departments in Denmark. Most patients were treated with antidepressants (89%); most frequently, either selective serotonin reuptake inhibitors (SSRIs; 48%) or serotonin-norepinephrine reuptake inhibitors (SNRIs; 21%). The majority received monotherapy (70%); most frequently, an SSRI (36%) or an SNRI (12%). Most antidepressants were initiated by general practitioners (71%), and the treatments had lasted for more than a year (87%). The doses of SSRIs/SNRIs were moderate, and the most frequent indication for antidepressants was depression (77%). These results imply that temporary perioperative SSRI/SNRI discontinuation may be feasible in hip and knee replacement patients and support a future randomized controlled trial investigating the potential benefits of temporary discontinuation.

Discovery and Structure-Activity Relationships of 2,5-Dimethoxyphenylpiperidines as Selective Serotonin 5-HT2A Receptor Agonists.

Classical psychedelics such as psilocybin, lysergic acid diethylamide (LSD), and N,N-dimethyltryptamine (DMT) are showing promising results in clinical trials for a range of psychiatric indications, including depression, anxiety, and substance abuse disorder. These compounds are characterized by broad pharmacological activity profiles, and while the acute mind-altering effects can be ascribed to their shared agonist activity at the serotonin 2A receptor (5-HT2AR), their apparent persistent therapeutic effects are yet to be decidedly linked to activity at this receptor. We report herein the discovery of 2,5-dimethoxyphenylpiperidines as a novel class of selective 5-HT2AR agonists and detail the structure-activity investigations leading to the identification of LPH-5 [analogue (S)-11] as a selective 5-HT2AR agonist with desirable drug-like properties.

Liraglutide 3.0 mg once daily for the treatment of overweight and obesity in patients hospitalised at a forensic psychiatric department: A 26-week open-label feasibility study.

INTRODUCTION: Overweight and obesity constitute a major concern among patients treated at forensic psychiatric departments. The present clinical feasibility study aimed at investigating the extent to which glucagon-like peptide 1 receptor agonist (GLP-1RA) treatment with once-daily liraglutide 3.0 mg could be a feasible pharmacological treatment of these conditions in patients with schizophrenia spectrum disorders hospitalised in forensic psychiatry. METHODS: The 26-week, open-label feasibility study included participants aged 18-65 years diagnosed with a severe mental illness and hospitalised at a forensic psychiatric department. At the time of inclusion, all participants fulfilled the indication for using liraglutide as a treatment for overweight and obesity. Participants' baseline examinations were followed by a 26-week treatment period with liraglutide injection once daily according to a fixed uptitration schedule of liraglutide, with a target dose of 3.0 mg. Each participant attended seven visits to evaluate the efficacy and adverse events. The primary endpoint was the number of "completers", with adherence defined as >80% injections obtained in the period, weeks 12-26. Determining whether liraglutide is a feasible treatment was pre-defined to a minimum of 75% completers. RESULTS: Twenty-four participants were included in the study. Sex, male = 19 (79.2%). Mean age: 42.3 [25th and 75th percentiles: 39.1; 48.4] years; body mass index (BMI): 35.7 [31.7; 37.5] kg/m2; glycated haemoglobin (HbA1c): 37 [35; 39] mmol/mol. Eleven out of 24 participants (46%) completed the study. For the completers, the median net body weight loss after 26 weeks of participation was -11.4 kg [-15.4; -5.9]. The net difference in HbA1C and BMI was -2.0 mmol/mol [-4; -1] and -3.6 kg/m2 [-4.7; -1.8], respectively. The weight change and reduction in HbA1c and BMI were all statistically significant from baseline. CONCLUSION: The study did not confirm our hypothesis that liraglutide is a feasible treatment for a minimum of 75% of the patients initiating treatment with liraglutide while hospitalised in a forensic psychiatric department. The high dropout rate may be due to the non-naturalistic setting of the clinical trial. For the proportion of patients compliant with the medication, liraglutide 3.0 mg was an efficient treatment for overweight.

Late effects following breast cancer treatment.

Improved survival after breast cancer treatment comes at a cost in the form of increased risk of late effects. A number of these are summarised in this review. The late effects can be divided in 1) late effects after locoregional treatment, e.g., lymphoedema, impaired shoulder movement, and pain; 2) consequences of systemic treatment, e.g. polyneuropathy, problems related to premature menopause, and increased risk of cardio-vascular disease; and 3) general late effects, commonly seen across all cancer types, including fatigue, insomnia, and cognitive impairment. There is a need for more knowledge about risk factors, prognoses, and the most effective treatments.

Patients' views on usefulness and effects of a risk communication tool for cardiovascular disease: a qualitative analysis.

BACKGROUND: Failing to comprehend risk communication might contribute to poor treatment adherence. Using hypertension as a case, we investigated how a risk communication tool for patients with an elevated risk of cardiovascular disease was perceived. METHODS: As part of a large project featuring a randomised controlled trial in a general practice setting in the Region of Southern Denmark, we conducted a semi-structured individual interview study. The study included patients with hypertension who had used an intervention comprising a visual and dynamic cardiovascular risk communication tool, along with receiving recurring emails providing advice on a healthy lifestyle. The analyses were based on Malterud's Systematic Text Condensation. RESULTS: This article focuses solely on the results of the interview study, which comprised a total of 9 conducted and analysed interviews. The IT setup had a major impact on adherence to the intervention. A positive impact was found when the IT setup was perceived as easy to use and accessible, while a negative impact was noted when it malfunctioned. The intervention increased patients' self-reported insight into risk of cardiovascular disease. Patients reported the intervention and their risk of cardiovascular disease to become less important to them when they had more severe comorbidities. The involved health professional was very important for treatment adherence when communicating risk visually. Patients expressed trust in their general practitioners, and the general practitioners' attitudes toward the intervention affected patients' perceptions of its usefulness. While the informants reported an increased awareness of their risk of cardiovascular disease, none of them felt more concerned. CONCLUSIONS: Patients reported an increase in their perceived insight into the risk of cardiovascular disease but not an increased concern. Our findings align with previous studies emphasizing the importance of patients' motivation as well as risk perception for adherence. General practitioners have an important role when implementing new tools for patients.

Virtual reality-assisted cognitive behavioral therapy for patients with alcohol use disorder: a randomized feasibility study.

Introduction: Cognitive behavioral therapy (CBT) is an evidence-based treatment for alcohol use disorder (AUD). Exposure to high-risk situations in virtual reality (VR) has been suggested to have a potential therapeutical benefit, but no previous study has combined VR and CBT for AUD. We aimed to investigate the feasibility of using VR-simulated high-risk environments in CBT-based treatment of AUD. Methods: We randomized ten treatment-seeking AUD-diagnosed individuals to three sessions of conventional CBT or VR-assisted CBT performed at two outpatient clinics in Denmark. In each session, patients randomized to VR-CBT were exposed to VR-simulations from a restaurant to induce authentic thoughts, emotions, physiological reactions, and craving for CBT purposes. The primary outcome measure was feasibility: Drop-out rate, psychological reactions, and simulator sickness. Secondary outcomes were assessment of preliminary short-term changes in alcohol consumption and craving from baseline to one-week and one-month follow-up. In addition, the study was conducted for training in operationalization of VR equipment, treatment manuals, and research questionnaires. Results: The majority of patients completed all study visits (90%). VR induced authentic high-risk related thoughts, emotions, and physiological reactions that were considered relevant for CBT by patients and therapists. Four of five patients randomized to VR-CBT experienced cravings during VR simulations, and most of these patients (3/5) experienced mild simulator sickness during VR exposure. The preliminary data showed that patients receiving VR-CBT had more reduction in alcohol consumption than patients receiving conventional CBT at one week- (median 94% vs. 72%) and one-month follow-up (median 98% vs. 55%). Similar results were found regarding changes in cravings. Conclusion: We demonstrated VR-CBT to be a feasible intervention for patients with AUD which supports continued investigations in a larger randomized clinical trial evaluating the efficacy of VR-CBT. Clinical trial registration: https://www.clinicaltrials.gov/study/NCT04990765?cond=addiction%20CRAVR&rank=2, identifier NCT05042180.

Prognostic utility of Fibrosis-4 Index for risk of subsequent liver and cardiovascular events, and all-cause mortality in individuals with obesity and/or type 2 diabetes: a longitudinal cohort study.

Background: The Fibrosis-4 Index (FIB-4) is used as a non-invasive tool for the presence of advanced liver fibrosis in metabolic dysfunction-associated steatotic liver disease and type 2 diabetes. However, evidence for an association between FIB-4 and risk of mortality and/or liver-related clinical outcomes is limited. The aim of this study was to investigate the association between FIB-4 and subsequent liver events, cardiovascular events, and all-cause mortality in individuals with obesity and/or type 2 diabetes examined in routine general practice. Methods: This was a longitudinal cohort study in which eligible adults had obesity and/or type 2 diabetes and ≥1 FIB-4 score calculable from UK Clinical Practice Research Datalink GOLD after 1 January 2001. No alcohol-related disorders and/or chronic liver diseases (except non-alcoholic fatty liver disease) and/or no prescriptions of drugs inducing liver disease were permitted. Individuals were followed until time of first event, 10 years, or 1 January 2020. Analyses were conducted using Aalen-Johansen cumulative incidence functions and Cox proportional hazards models. Findings: Among 44,481 included individuals (mean age 58·8 years; 54% female), there were 979 liver, 6002 cardiovascular, and 8971 mortality events during the 10 years of follow-up. At 10 years, the cumulative incidence of liver events in the high (>2·67), indeterminate (1·30-2·67), and low (<1·30) baseline FIB-4 risk groups were 15%, 3%, and 1%, respectively. Age- and sex-adjusted hazard ratios (HRs) for liver events were elevated in high (16·46; 95% confidence interval [CI] 13·65-19·85) and indeterminate (2·45; 95% CI 2·07-2·90) versus low FIB-4 risk groups. Similar results were found for cardiovascular events and all-cause mortality. Among 20,433 individuals with ≥2 FIB-4 measurements, increase/decrease in FIB-4 12 months after baseline was directly associated with risk of liver events: compared with individuals with low baseline FIB-4 and no change in FIB-4 (reference), the adjusted HR (95% CI) for those with high baseline FIB-4 was 24·27 (16·98-34·68) with a one-unit FIB-4 increase, and 10·90 (7·90-15·05) with a one-unit decrease. Interpretation: In addition to its value as a diagnostic tool, FIB-4 has clinical utility as a prognostic biomarker. Sequential measurement provides a pragmatic, tractable monitoring biomarker that refines risk assessment for liver events, cardiovascular events, and mortality. Funding: Novo Nordisk A/S.

Real-world study of the concomitant use of biphasic insulin aspart 30/70 with GLP-1 receptor agonist versus first-generation basal insulin with GLP-1 receptor agonist in type 2 diabetes.

AIMS: Combining insulin with a glucagon-like peptide-1 receptor agonist (GLP-1RA) to treat type 2 diabetes (T2D) is common. While many studies have investigated concomitant therapy with basal insulin+GLP-1RA, few have reported on premixed insulin+GLP-1RA. We aimed to address this gap using data from the Clinical Practice Research Datalink Aurum database in England. METHODS: This retrospective cohort study with propensity score matching assessed glycaemic levels and other clinical outcomes in people with T2D, comparing biphasic insulin aspart 30/70 (BIAsp 30) + GLP-1RA with basal insulin (insulin detemir/glargine U100) + GLP-1RA (from 2006 to 2021). RESULTS: In total, 4770 eligible people were identified; 1511 had a BIAsp 30 + GLP-1RA regimen and were propensity score-matched to an equal number receiving basal+GLP-1RA. There was no significant difference in glycated haemoglobin (HbA1c) reduction between cohorts at 6 months (p = 0.15), with a decrease of -1.07 (95% CI: -1.16; -0.98) %-points (-11.7 mmol/mol [95% CI: -12.7; -10.7]) in the BIAsp 30 + GLP-1RA cohort, versus -0.97 (95% CI: -1.07; -0.88) %-points (-10.6 mmol/mol [95% CI: -11.7; -9.6]) in the basal+GLP-1RA cohort. Body mass index (BMI) decreased by -0.35 kg/m2 (95% CI: -0.52;-0.18) at 6 months with BIAsp 30 + GLP-1RA, versus -0.72 kg/m2 (95% CI: -0.90;-0.54) with basal+GLP-1RA (p = 0.003). BMI was influenced by the initiation sequence of GLP-1RA in relation to insulin (p < 0.0001). Hypoglycaemia rates were low and not significantly different between cohorts. CONCLUSIONS: Combining BIAsp 30 + GLP-1RA provides glycaemic control with no significant difference to that of propensity score-matched people receiving basal insulin+GLP-1RA, with no increase in hypoglycaemia risk or weight gain.

Efficacy and safety of semaglutide 2.4 mg according to antidepressant use at baseline: A post hoc subgroup analysis.

OBJECTIVE: To explore the efficacy and safety of semaglutide 2.4 mg in people with overweight/obesity who were also being treated with antidepressants (ADs). METHODS: Across the Semaglutide Treatment Effect for People with obesity (STEP) 1-3 and 5 trials, adults with overweight/obesity and type 2 diabetes (STEP 2 only) were enrolled. People with severe major depressive disorder within 2 years prior to screening or with a patient health questionnaire-9 score ≥15 at screening were excluded. Participants were categorized into subgroups according to baseline AD status (on/off ADs) in this post hoc exploratory analysis of the STEP trials. RESULTS: Of 3683 participants randomized, 539 were on ADs at baseline. Mean body weight change from baseline to week 68 was greater for semaglutide versus placebo, regardless of baseline AD use. In STEP 1, for participants on ADs at baseline, mean change from baseline was -15.7% with semaglutide versus -0.2% with placebo and -14.7% versus -2.8% for those not on ADs at baseline. Similar patterns were seen in STEP 2, 3, and 5. The prevalence of adverse events (AEs) was generally similar between semaglutide and placebo in participants on ADs at baseline. CONCLUSIONS: In adults with overweight/obesity, semaglutide provided clinically meaningful weight loss regardless of baseline AD use, with an AE profile consistent with previous studies.

The Concise Guide to PHARMACOLOGY 2023/24: Ion channels.

The Concise Guide to PHARMACOLOGY 2023/24 is the sixth in this series of biennial publications. The Concise Guide provides concise overviews, mostly in tabular format, of the key properties of approximately 1800 drug targets, and over 6000 interactions with about 3900 ligands. There is an emphasis on selective pharmacology (where available), plus links to the open access knowledgebase source of drug targets and their ligands (https://www.guidetopharmacology.org/), which provides more detailed views of target and ligand properties. Although the Concise Guide constitutes almost 500 pages, the material presented is substantially reduced compared to information and links presented on the website. It provides a permanent, citable, point-in-time record that will survive database updates. The full contents of this section can be found at http://onlinelibrary.wiley.com/doi/10.1111/bph.16178. Ion channels are one of the six major pharmacological targets into which the Guide is divided, with the others being: G protein-coupled receptors, nuclear hormone receptors, catalytic receptors, enzymes and transporters. These are presented with nomenclature guidance and summary information on the best available pharmacological tools, alongside key references and suggestions for further reading. The landscape format of the Concise Guide is designed to facilitate comparison of related targets from material contemporary to mid-2023, and supersedes data presented in the 2021/22, 2019/20, 2017/18, 2015/16 and 2013/14 Concise Guides and previous Guides to Receptors and Channels. It is produced in close conjunction with the Nomenclature and Standards Committee of the International Union of Basic and Clinical Pharmacology (NC-IUPHAR), therefore, providing official IUPHAR classification and nomenclature for human drug targets, where appropriate.

Ligand selectivity hotspots in serotonin GPCRs.

Serotonin is a neurotransmitter regulating numerous physiological processes also modulated by drugs, for example, schizophrenia, depression, migraine, and obesity. However, these drugs typically have adverse effects caused by promiscuous binding across 12 serotonin and more than 20 homologous receptors. Recently, structures of the entire serotonin receptor family uncovered molecular ligand recognition. Here, we present a map of 19 'selectivity hotspots', that is, nonconserved binding site residues governing selectivity via favorable target interactions or repulsive 'off-target' contacts. Furthermore, we review functional rationale from observed ligand-binding affinities and mutagenesis effects. Unifying knowledge underlying specific probes and drugs is critical toward the functional characterization of different receptors and alleviation of adverse effects.

Vaginal CO2 laser therapy for genitourinary syndrome in breast cancer survivors-VagLaser study protocol: a randomized blinded, placebo-controlled trial.

BACKGROUND: Vaginal CO2 laser therapy is a new treatment option for genitourinary syndrome of menopause. Its potential is particularly interesting in breast cancer survivors, where existing treatment options often are insufficient as hormonal treatment is problematic in these women. The objective of this study is to investigate the effectiveness of vaginal laser treatment for alleviation of genitourinary syndrome of menopause in breast cancer survivors treated with adjuvant endocrine therapy. The secondary objective is to explore the importance of repeated vaginal laser treatment and the long-term effects in this patient population. METHODS: VagLaser consist of three sub-studies; a dose response study, a randomized, participant blinded, placebo-controlled study and a follow-up study. All studies include breast cancer survivors in adjuvant endocrine therapy, and are conducted at the Department of Obstetrics and Gynecology, Randers Regional Hospital, Denmark. The first participant was recruited on 16th of February 2023. Primary outcome is vaginal dryness. Secondary subjective outcomes are vaginal pain, itching, soreness, urinary symptoms and sexual function. Secondary objective outcomes are change in vaginal histology (punch biopsy), change in vaginal and urine microbiota, and change in vaginal pH. DISCUSSION: More randomized controlled trials, with longer follow-up to explore the optimal treatment regimen and the number of repeat vaginal laser treatments for alleviation the symptoms of genitourinary syndrome of menopause in breast cancer survivors treated with endocrine adjuvant therapy, are needed. This study will be the first to investigate change in vaginal and urine microbiota during vaginal laser therapy in breast cancer survivors. TRIAL REGISTRATION: ClinicalTrials.gov: NCT06007027 (registered 22 August, 2023). PROTOCOL VERSION: Version 1, Date 13.11.2023.

Repeated low doses of psilocybin increase resilience to stress, lower compulsive actions, and strengthen cortical connections to the paraventricular thalamic nucleus in rats.

Psilocybin (a classic serotonergic psychedelic drug) has received appraisal for use in psychedelic-assisted therapy of several psychiatric disorders. A less explored topic concerns the use of repeated low doses of psychedelics, at a dose that is well below the psychedelic dose used in psychedelic-assisted therapy and often referred to as microdosing. Psilocybin microdose users frequently report increases in mental health, yet such reports are often highly biased and vulnerable to placebo effects. Here we establish and validate a psilocybin microdose-like regimen in rats with repeated low doses of psilocybin administration at a dose derived from occupancy at rat brain 5-HT2A receptors in vivo. The rats tolerated the repeated low doses of psilocybin well and did not manifest signs of anhedonia, anxiety, or altered locomotor activity. There were no deficits in pre-pulse inhibition of the startle reflex, nor did the treatment downregulate or desensitize the 5-HT2A receptors. However, the repeated low doses of psilocybin imparted resilience against the stress of multiple subcutaneous injections, and reduced the frequency of self-grooming, a proxy for human compulsive actions, while also increasing 5-HT7 receptor expression and synaptic density in the paraventricular nucleus of the thalamus. These results establish a well-validated regimen for further experiments probing the effects of repeated low doses of psilocybin. Results further substantiate anecdotal reports of the benefits of psilocybin microdosing as a therapeutic intervention, while pointing to a possible physiological mechanism.

In Vitro and In Vivo Evaluation of Pellotine: A Hypnotic Lophophora Alkaloid.

Quality of life is often reduced in patients with sleep-wake disorders. Insomnia is commonly treated with benzodiazepines, despite their well-known side effects. Pellotine (1), a Lophophora alkaloid, has been reported to have short-acting sleep-inducing properties in humans. In this study, we set out to evaluate various in vitro and in vivo properties of 1. We demonstrate that 1 undergoes slow metabolism; e.g. in mouse liver microsomes 65% remained, and in human liver microsomes virtually no metabolism was observed after 4 h. In mouse liver microsomes, two phase I metabolites were identified: 7-desmethylpellotine and pellotine-N-oxide. In mice, the two diastereomers of pellotine-O-glucuronide were additionally identified as phase II metabolites. Furthermore, we demonstrated by DESI-MSI that 1 readily enters the central nervous system of rodents. Furthermore, radioligand-displacement assays showed that 1 is selective for the serotonergic system and in particular the serotonin (5-HT)1D, 5-HT6, and 5-HT7 receptors, where it binds with affinities in the nanomolar range (117, 170, and 394 nM, respectively). Additionally, 1 was functionally characterized at 5-HT6 and 5-HT7, where it was found to be an agonist at the former (EC50 = 94 nM, Emax = 32%) and an inverse agonist at the latter (EC50 = 291 nM, Emax = -98.6). Finally, we demonstrated that 1 dose-dependently decreases locomotion in mice, inhibits REM sleep, and promotes sleep fragmentation. Thus, we suggest that pellotine itself, and not an active metabolite, is responsible for the hypnotic effects and that these effects are possibly mediated through modulation of serotonergic receptors.