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Hallucinations limit the widespread therapeutic use of psychedelics as rapid-acting antidepressants. Here we profiled the non-hallucinogenic lysergic acid diethylamide (LSD) analog 2-bromo-LSD (2-Br-LSD) at >33 aminergic G protein-coupled receptors (GPCRs). 2-Br-LSD shows partial agonism at several aminergic GPCRs, including 5-HT(2A) and does not induce the head-twitch response (HTR) in mice, supporting its classification as a non-hallucinogenic 5-HT(2A) partial agonist. Unlike LSD, 2-Br-LSD lacks 5-HT(2B) agonism, an effect linked to cardiac valvulopathy. Additionally, 2-Br-LSD produces weak 5-HT(2A) β-arrestin recruitment and internalization in vitro and does not induce tolerance in vivo after repeated administration. In cultured rat cortical neurons, 2-Br-LSD induces dendritogenesis and spinogenesis, and increases active coping behaviour in mice, an effect blocked by the 5-HT(2A)-selective antagonist volinaserin (M100,907). 2-Br-LSD also reverses the behavioral effects of chronic stress. Overall, 2-Br-LSD has an improved pharmacological profile compared to LSD and may have profound therapeutic value for mood disorders and other indications.

Seizures are a recognized and potentially serious complication of recreational drug use. This study examined a large international data set of presentations to Emergency Departments with acute recreational drug toxicity, the European Drug Emergencies Plus (Euro-DEN Plus) Network, to compare presentations with and without seizures and estimate incidence and associated drugs. Amongst 23,947 presentations between January 2014 and December 2017, there were 1013 (4.2%) with reported seizures. Clinical and demographic features were similar between individuals who had a seizure and those who did not, although rates of coma, cardiac arrest, intubation, intensive care admission, and death were significantly higher in those with seizures. There was a significant association between specific drugs and a higher seizure incidence, including fentanyl (odds ratio 2.63, 95% confidence interval 1.20-5.80), and synthetic cannabinoids (OR 2.90, 95% CI 2.19-3.84). Other drugs were associated with a lower seizure incidence, including heroin (OR 0.46, 95% CI 0.35-0.61), clonazepam (OR 0.22, 95% CI 0.06-0.91), and cannabis (OR 0.65, 95% CI 0.50-0.86). This substantiates observations that the synthetic cannabinoids as a group of novel psychoactive substances are clinically different in consequence of intoxication than cannabis, and that individuals who suffer a seizure in the context of recreational drug intoxication are likely to have worse outcomes overall. Utilising this information of what substances have a greater risk of seizures, could provide tailored harm reduction and education strategies to users to reduce the risk of seizures and their associated complications.

Background Chronic itch is the most common skin-related condition, associated with a high psychosocial and economic burden. In recent years, increasing evidence of sex differences in the perception, clinical presentation and treatment requirements of itch points towards potential benefits when using sex-adapted therapies. It is well-known that body composition, absorption, metabolism, elimination and adverse drug reactions (ADRs) differ between sexes, but only little is known about the impact of sex in the pharmacology of itch treatments, which could help to rationalise sex-adapted treatment strategies. Aim To evaluate and review sex effects in the pharmacokinetics and /-dynamics of drugs used to treat itch. Methods In this narrative review we performed a PubMed and MEDLINE (Ovid) search using the terms (itch OR pruritus) AND (gender OR sex) AND (drug OR medication OR pharmacokinetics OR pharmacodynamics). Additional searches were performed for the topical and systemic drugs recommended by the European Guideline on Chronic Pruritus. Results We found numerous reports with variable levels of evidence of sex effects with respect to the pharmacokinetics and/or pharmacodynamics of 14 drug classes used for the treatment of itch, including a total of 19 systemic and 3 topical drugs. Women seem to present higher plasma levels of several drugs used in itch treatment, including tri- and tetracyclic antidepressants (e.g. doxepin, amitriptyline, mirtazapine), serotonin reuptake inhibitors (e.g. paroxetine, sertraline, fluoxetine), immunosuppressive drugs (e.g. cyclosporine, mycophenolate mofetil), serotonin receptor antagonists (e.g. ondansetron) and betablockers (e.g. propranolol). Adverse drug reactions (ADRs) were generally more common in women. Being female was reported to be an independent risk factor for QTc-prolongation associated with antihistamines and tetracyclic antidepressants. Additionally, women seem to be more prone to sedative effects of antihistamines, and to suffer from a higher frequency as well as severity of side effects with systemic calcineurin inhibitors, opioid agonists, and opioid antagonists. Women were also sensitised more often to topically applied drugs. Of note, apart from only one experimental study with capsaicin, none of these reports were designed specifically to assess the effect of sex (and gender) in the treatment of itch. Discussion/conclusion Our review supports previous reports that sex is of importance in the pharmacokinetics and /-dynamics of several drugs used to treat itch although those drugs were mostly evaluated for non-itch indications. However, the results are limited by methodological limitations evident in most studies such as underrepresentation of women in clinical trials. This emphasises the need to study the impact of sex (and gender) in future itch trials to yield better outcomes and prevent ADRs in both sexes.

Lysergic acid diethylamide (LSD) is used recreationally and has been evaluated as an adjunct to psychotherapy to treat anxiety in patients with life-threatening illness. LSD is well-known to induce perceptual alterations, but unknown is whether LSD alters emotional processing in ways that can support psychotherapy. We investigated the acute effects of LSD on emotional processing using the Face Emotion Recognition Task (FERT) and Multifaceted Empathy Test (MET). The effects of LSD on social behavior were tested using the Social Value Orientation (SVO) test. Two similar placebo-controlled, double-blind, random-order, crossover studies were conducted using 100 μg LSD in 24 subjects and 200 μg LSD in 16 subjects. All of the subjects were healthy and mostly hallucinogen-naive 25- to 65-year-old volunteers (20 men, 20 women). LSD produced feelings of happiness, trust, closeness to others, enhanced explicit and implicit emotional empathy on the MET, and impaired the recognition of sad and fearful faces on the FERT. LSD enhanced the participants' desire to be with other people and increased their prosocial behavior on the SVO test. These effects of LSD on emotion processing and sociality may be useful for LSD-assisted psychotherapy.