Serological response to SARS-CoV-2 vaccination in patients with inflammatory rheumatic disease treated with disease modifying anti-rheumatic drugs: A cohort study and a meta-analysis.

INTRODUCTION: Vaccination is considered as a cornerstone of the management of COVID-19 pandemic. However, while vaccines provide a robust protection in immunocompetent individuals, the immunogenicity in patients with inflammatory rheumatic diseases (IRD) is not well established. METHODS: A monocentric observational study evaluated the immunogenicity of a two-dose regimen vaccine in adult patients with IRD (n=123) treated with targeted or biological therapies. Serum IgG antibody levels against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) spike proteins were measured after the second vaccination. In addition, a search for observational studies performed in IRD under biologic or targeted therapies up to September 31, 2021 (PROSPERO registration number: CRD42021259410) was undertaken in publication databases, preprint servers, and grey literature sources. Studies that reported sample size, study date, location, and seroprevalence estimate were included. A meta-analysis was conducted to identify demographic differences in the prevalence of SARS-CoV-2 antibodies. RESULTS: Of 123 patients (median age 66 IQR 57-75), 69.9% have seroconverted after vaccination. Seroconverted patients were older than non-seroconverted ones in our cohort. Rituximab was associated with a significantly low antibody response. Besides, we identified 20 seroprevalence studies in addition to our cohort including 4423 participants in 11 countries. Meta-analysis confirmed a negative impact of rituximab on seroconversion rate and suggested a less substantial effect of abatacept, leflunomide and methotrexate. CONCLUSION: Rituximab impairs serological response to SARS-CoV-2 vaccines in patients with IRD. This work suggests also a negative impact of abatacept, methotrexate or leflunomide especially when associated to biological therapy.

Zonisamide attenuates the severity of levodopa-induced dyskinesia via modulation of the striatal serotonergic system in a rat model of Parkinson's disease.

Glutamate, GABA, acetylcholine, dopamine, and serotonin interact with each other to regulate the flow of neural information in the striatum. Serotonin type 1A receptor (5HT1A) is primarily expressed on glutamatergic nerve terminals, and 5HT1B is expressed on GABAergic medium spiny neurons (MSNs). Zonisamide (ZNS) reportedly improves the off period without worsening levodopa-induced dyskinesia (LID) in patients with advanced Parkinson's disease. In this study, LID model rats were prepared by administrating levodopa to unilaterally 6-OHDA-lesioned rats. We analyzed changes in serotonergic neurotransmission of LID model rats to elucidate the relationship between LID and the serotonergic system and pathomechanism of the anti-dyskinetic effects of ZNS. Abnormal involuntary movements (AIMs) were most severe in intermittently levodopa-treated rats but milder in rats intermittently medicated with levodopa and ZNS. Continuously levodopa-infused rats or intermittently ZNS-injected rats did not develop AIMs, and no differences in the expression of brain-derived neurotrophic factor, 5-HT transporter, 5HT1A, and 5HT1B mRNA between the lesioned striatum and normal side were observed. Expression of 5HT1B mRNA was elevated in the lesioned striatum of intermittently levodopa-treated rats, but this elevation was normalized by concomitant use of ZNS. The severity of AIMs was correlated with the ratio of 5HT1B to 5HT1A mRNA expression in the lesioned striatum, indicating that the anti-LID effect of ZNS is based on inhibition via 5HT1B receptors to direct pathway MSNs sensitized by intermittent levodopa treatment. Selectively acting serotonergic drugs, especially those that lower the 5HT1B to 5HT1A ratio, are promising new therapeutic agents to attenuate LID development.

Serotonergic antidepressants and hospitalization for bleeding in patients supported with a continuous flow left ventricular assist device.

BACKGROUND: Continuous flow left ventricular assist devices (CF -LVAD) improve survival in patients with advanced heart failure, but confer risk of bleeding complications. Serotonergic antidepressants (SA) are commonly used in heart failure patients receiving LVADs, but their inhibitory effect on platelet function may contribute to bleeding risk. METHODS: We performed a retrospective analysis of LVAD patients at our institution from 2016 -2019 comparing patients treated with SA after LVAD to those without SA. Demographic and clinical variables related to bleeding were collected on discharge from index hospitalization for CF-LVAD implantation and on admission for any bleeding event. The primary endpoint was incidence of bleeding requiring hospitalization after discharge. Secondary endpoints included overall number of admissions for bleeding, time to first hospitalization for a bleeding event, and incidence rate of hospitalizations for bleeding per patient year. RESULTS: 100 patients met inclusion criteria for the study. A total of 5 patients without a history of SA use and 31 patients who were prescribed SA after CF -LVAD implant were readmitted for a bleeding event after initial implant hospitalization (15% vs 46%, p = 0.004). Bleeding rate per person year (0.3 vs 0.61, p = 0.01) were significantly less in patients without SA use. Age-adjusted multivariable analysis found SA use to be associated with a hospitalization for bleeding (HR 2.3, 95% CI 0.99 -5.4). The higher incidence of hospitalization for bleeding was driven by non-gastrointestinal anatomical sites (6% vs 28%, p = 0.02) with a HR 7.7 (95% CI 0.96 -62). CONCLUSIONS: SA treatment after CF-LVAD implantation was associated with an increased risk for bleeding complications requiring hospitalization, particularly non-gastrointestinal bleeding.

Concomitant drugs associated with increased mortality for MDMA users reported in a drug safety surveillance database.

3,4-Methylenedioxymethamphetamine (MDMA) is currently being evaluated by the Food and Drug Administration (FDA) for the treatment of post-traumatic stress disorder (PTSD). If MDMA is FDA-approved it will be important to understand what medications may pose a risk of drug-drug interactions. The goal of this study was to evaluate the risks due to MDMA ingestion alone or in combination with other common medications and drugs of abuse using the FDA drug safety surveillance data. To date, nearly one thousand reports of MDMA use have been reported to the FDA. The majority of these reports include covariates such as co-ingested substances and demographic parameters. Univariate and multivariate logistic regression was employed to uncover the contributing factors to the reported risk of death among MDMA users. Several drug classes (MDMA metabolites or analogs, anesthetics, muscle relaxants, amphetamines and stimulants, benzodiazepines, ethanol, opioids), four antidepressants (bupropion, sertraline, venlafaxine and citalopram) and olanzapine demonstrated increased odds ratios for the reported risk of death. Future drug-drug interaction clinical trials should evaluate if any of the other drug-drug interactions described in our results actually pose a risk of morbidity or mortality in controlled medical settings.

Serotonin research: Crossing scales and boundaries.

Nearly 100 years after the discovery of serotonin, its role remains elusive. Modulation of serotonin transmission is considered in numerous central nervous system (CNS) diseases including depression, anxiety, schizophrenia, obsessive-compulsive disorders, addiction, Parkinson's disease, and Alzheimer's disease. The therapeutic strategies based on serotonin systems have evolved thanks to better identification of the involvement of serotonin in various diseases, the better use of animal models, a better understanding of the molecular environment of serotonin receptors, and ultimately the better understanding of the interaction of serotonin neurotransmission with other biological systems. Some 5-HT receptors are still the object of numerous investigations including 5-HT1A, 5-HT2A, and 5-HT6 receptor subtypes. It is noteworthy that the direction of research is moving towards a simultaneous action at multiple targets either through different 5-HT targets or the consideration of both 5-HT and other targets to achieve better therapeutic responses.

Therapeutic advances in Dravet syndrome: a targeted literature review.

INTRODUCTION: Dravet syndrome (DS), a prototypic developmental and genetic epileptic encephalopathy (DEE), is characterized by an early onset of treatment-refractory seizures, together with impairments in motor control, behavior, and cognition. Even with multiple conventional anti-epileptic drugs, seizures remain poorly controlled, and there has been a considerable unmet need for effective and tolerable treatments. AREAS COVERED: This targeted literature review aims to highlight recent changes to the therapeutic landscape for DS by summarizing the most up-to-date, evidence-based research, including pivotal data from the clinical development of stiripentol, cannabidiol, and fenfluramine, which are important milestones for DS treatment, together with the latest findings of other pharmacotherapies in development. In phase III, double-blind, placebo-controlled randomized controlled trials stiripentol, cannabidiol, and fenfluramine have shown clinically relevant reductions in convulsive seizure frequency, and are generally well tolerated. Stiripentol was associated with responder rates (greater than 50% reduction in convulsive seizure frequency) of 67%-71%, when added to valproic acid and clobazam; cannabidiol was associated with responder rates of 43%-49% (48%-63% in conjunction with clobazam), and fenfluramine of 54%-68% across studies. Therapies in development include soticlestat, ataluren, verapamil, and clemizole, with strategies to treat the underlying cause of DS, including gene therapy and antisense oligonucleotides beginning to emerge from preclinical studies. EXPERT OPINION: Despite the challenges of drug development in rare diseases, this is an exciting time for the treatment of DS, with the promise of new efficacious and well-tolerated therapies, which may pave the way for treatment advances in other DEEs.

Modulation of the Paracrine Kynurenic System in Bone as a New Regulator of Osteoblastogenesis and Bone Mineral Status in an Animal Model of Chronic Kidney Disease Treated with LP533401.

An increase in the peripheral synthesis of serotonin and kynurenine, observed during the chronic kidney disease (CKD) course, is negatively associated with bone health. Serotonin and kynurenine are connected by the common precursor, tryptophan. LP533401 is an inhibitor of peripheral serotonin synthesis. This study aimed to establish if the inhibition of serotonin synthesis by LP533401 may affect the kynurenine pathway activity in bone tissue and its potential consequence with regard to osteogenesis and bone mineral status. Nephrectomized rats were treated with LP533401 at a dose of 30 and 100 mg/kg daily for eight weeks. Tryptophan and kynurenine concentrations were determined, and tryptophan 2,3-dioxygenase (TDO) expression was assessed. We discovered the presence of a TDO-dependent, paracrine kynurenic system in the bone of rats with CKD. Its modulation during LP533401 treatment was associated with impaired bone mineral status. Changes in TDO expression affecting the kynurenine pathway activity were related to the imbalance between peripheral serotonin and 25-hydroxyvitamin D. There were also close associations between the expression of genes participating in osteoblastogenesis and activation of the kynurenine pathway in the bones of LP53301-treated rats. Our results represent the next step in studying the role of tryptophan metabolites in renal osteodystrophy.

Use of the French healthcare insurance database to estimate the prevalence of exposure to potential drug-drug interactions.

PURPOSE: Drug-drug interactions (DDIs) require monitoring in an aging population with increasing polypharmacy exposure. We aimed to estimate the prevalence of exposure to potential DDIs using the French healthcare insurance system database, for six DDIs with various clinical relevance: angiotensin II receptor blockers or angiotensin-converting enzyme inhibitors and nonsteroidal anti-inflammatory drugs (ARBs-ACEIs + NSAIDs), antiplatelet agents and NSAIDs (AAP + NSAIDs), serotonergic drugs and tramadol (SD + T), statins and macrolides (S + M), oral anticoagulant and NSAIDs (OAC + NSAIDs), and colchicine and macrolides (C + M). METHODS: We used exhaustive healthcare data from a 1/97th random sample of the population covered by the French health insurance system (EGB) between 2006 and 2016. Exposure to a DDI was defined as overlapping exposure to two interacting drugs. The prevalence of exposure was estimated by year. RESULTS: Prevalence of exposure in 2016 was estimated at 3.7% for ARBs-ACEIs + NSAIDs, 1.5% for AAP + NSAIDs, 0.76% for SD + T, 0.36% for S + M, 0.24% for AOC + NSAIDs, and 0.02% for C + M. In 26% to 58% of episodes of exposure, the two interacting drugs were prescribed by the same physician and dispensed by the same pharmacy the same day. Between 2006 and 2016, the yearly prevalence was increasing for SD + T and for DDIs involving NSAIDs, and it was decreasing for those involving macrolides. CONCLUSION: Exposures to potential DDIs in France are not uncommon with a high proportion resulting from a co-prescription by the same physician. Monitoring the prevalence of exposure to DDIs is needed to implement prevention measures. Administrative data enable this surveillance in large and representative cohorts.

Role of 5-HT receptors in neuropathic pain: potential therapeutic implications.

5-HT plays a crucial role in the progress and adjustment of pain both centrally and peripherally. The therapeutic action of the 5-HT receptors` agonist and antagonist in neuropathic pain have been widely reported in many studies. However, the specific roles of 5-HT subtype receptors have not been reviewed comprehensively. Therefore, we summarized the recent findings on multiple subtypes of 5-HT receptors in both central and peripheral nervous system in neuropathic pain, particularly, 5-HT1, 5-HT2, 5-HT3 and 5-HT7 receptors. In addition, 5-HT4, 5-HT5 and 5-HT6 receptors were also reviewed. Most of studies focused on the function of 5-HT subtype receptors in spinal level compared to brain areas. Based on these evidences, the pain process can be facilitated or inhibited that depending on the specific subtypes and the distribution of 5-HT receptors. Therefore, this review may provide potential therapeutic implications in treatment of neuropathic pain.

Opportunities for multiscale computational modelling of serotonergic drug effects in Alzheimer's disease.

Alzheimer's disease (AD) is an age-specific neurodegenerative disease that compromises cognitive functioning and impacts the quality of life of an individual. Pathologically, AD is characterised by abnormal accumulation of beta-amyloid (Aß) and hyperphosphorylated tau protein. Despite research advances over the last few decades, there is currently still no cure for AD. Although, medications are available to control some behavioural symptoms and slow the disease's progression, most prescribed medications are based on cholinesterase inhibitors. Over the last decade, there has been increased attention towards novel drugs, targeting alternative neurotransmitter pathways, particularly those targeting serotonergic (5-HT) system. In this review, we focused on 5-HT receptor (5-HTR) mediated signalling and drugs that target these receptors. These pathways regulate key proteins and kinases such as GSK-3 that are associated with abnormal levels of Aß and tau in AD. We then review computational studies related to 5-HT signalling pathways with the potential for providing deeper understanding of AD pathologies. In particular, we suggest that multiscale and multilevel modelling approaches could potentially provide new insights into AD mechanisms, and towards discovering novel 5-HTR based therapeutic targets.

Current and Future Therapies for Psoriasis with a Focus on Serotonergic Drugs.

Psoriasis is a chronic immune-mediated skin disease, with a pathogenesis resulting from a combination of genetic and environmental factors. The pathogenesis of psoriasis is driven by the interaction between innate and adaptive immune cells and keratinocytes, in a complex process mediated by cytokines and other signaling molecules. This leads to an inflammatory process with increased proliferation of epidermal cells, neo-angiogenesis, and infiltration of white cells in the skin, which cause the characteristic psoriasis plaques. Several studies have suggested that the neurotransmitter serotonin, a key mediator between the skin and the neuroendocrine system, also plays an important role in the pathogenesis of psoriasis. Psoriasis often needs long-term treatment, which can be a burden. Thus, the choice of the treatment is crucial to increase the patients' adherence and quality of life. This review addresses the currently available systemic and topical treatments for psoriasis, used by themselves or combined with phototherapy. It particularly focuses on the importance of advanced drug delivery systems as a way to increase the drug penetration and retention in the skin, while also enhancing its solubility and stability. Finally, we discuss the role of the serotonin system in psoriasis, and summarize what is known about the effects of antidepressants, in particular specific serotonin reuptake inhibitors, on the physical symptoms of this disease.

The serotonergic and alpha-1 adrenergic receptor modulator ACH-000029 ameliorates anxiety-like behavior in a post-traumatic stress disorder model.

Post-traumatic stress disorder (PTSD) is a severe chronic mental illness that develops in individuals exposed to life-threatening trauma and is characterized by hyperarousal, flashbacks and nightmares. The serotonergic (5-HT) and noradrenergic (NE) systems are deeply involved in the pathogenesis of PTSD. We have previously reported a novel anxiolytic compound, ACH-000029, that modulates 5-HT and α1-adrenergic receptors and induces acute anxiolytic-like effects in rodents. Here, we investigated the potential of ACH-000029 to prevent anxiety-like behavior in the single prolonged stress (SPS) PTSD model. Mice were subjected to the SPS procedure, followed by a 7-day treatment with ACH-000029 and, for comparison, with the α1-adrenergic antagonist prazosin. Animals were behaviorally assessed using social interaction, elevated plus maze and open field tests. Interestingly, treatment with ACH-000029 but not with prazosin ameliorated the SPS-induced sociability impairment and anxiety-like behavior. The brain-wide c-fos mapping, used as a surrogate for brain activity, indicated the brain structures that were altered by SPS and putatively involved in the anxiolytic-like effect of ACH-000029. The SPS protocol produced long-lasting impairment of regions involved in stress-anxiety response, such as the amygdala, prefrontal cortex, globus pallidus and superior colliculus. ACH-000029 treatment reversed the SPS-induced c-fos changes in the globus pallidus, lateral septum and entorhinal cortex and exclusively modulated c-fos levels in subregions from the retrosplenial cortex, cerebellum, superior colliculus and ventromedial hypothalamus. These results support the hypothesis that the dual regulation of 5-HT and α1-adrenergic receptors is required to alleviate PTSD symptoms and suggest a possible role of ACH-000029 as a PTSD treatment.

Serotonergic system may be involved in alterations of sleep homeostasis in spontaneously hypertensive rats.

Hypertension is associated with sleep disorders. Spontaneously hypertensive rats are derived from Wistar-Kyoto rats and widely used in research on hypertension. The present study investigated the propensity to sleep and electroencephalographic spectrum changes over 24 hr in spontaneously hypertensive rats, and proposed the involvement of the serotonergic system in these alterations. Time-course analysis showed that spontaneously hypertensive rats exhibit hyperarousal during the light phase but hypersomnia during the dark phase. Spontaneously hypertensive rats also exhibited less slight fluctuation in electroencephalographic delta power density over 24 hr as compared with Wistar-Kyoto rats, suggesting that the accumulation or elimination of sleep pressure was disrupted. Sleep deprivation disrupted the regulation of sleep homeostasis in spontaneously hypertensive rats, reflected by less sleep time and poor sleep quality during the recovery period. The density and activity of serotonergic neurons in the dorsal raphe nucleus were higher in spontaneously hypertensive rats compared with Wistar-Kyoto rats. Interestingly, we observed the absence of fluctuations in 5-hydroxytryptamine and 5-hydroxyindoleacetic acid across the sleep, wake, sleep deprivation and sleep recovery stages in spontaneously hypertensive rats, which were dramatically different from Wistar-Kyoto rats. These results indicate that the disruption of sleep-wake pattern and sleep homeostasis in spontaneously hypertensive rats might be related to abnormalities of the serotonergic system.

Dose-Finding Study of Lorexys for Hypoactive Sexual Desire Disorder in Premenopausal Women.

INTRODUCTION: Prior medication treatment for hypoactive sexual desire disorder (HSDD) in women has left about half the subjects without benefit. Lorexys (LOR), a proprietary combination of the stimulating/excitatory dopamine-norepinephrine reuptake inhibitor bupropion (BUP) and the sedating/inhibitory serotonergic agonist-antagonist trazodone (TRZ), was developed as a multifunctional solution for this problem. AIM: Test efficacy, safety, and tolerability of LOR in a range of doses in a combined phase IB/IIA study in premenopausal outpatients with HSDD. METHODS: Otherwise healthy premenopausal women from 25-50 years of age with HSDD were tested in an open-label, active-control, one-way crossover study, with three 4-week treatments of extended-release TRZ and/or sustained-release BUP. Evaluations were made before and after each treatment. A washout of at least a week followed each treatment. The order of treatments was a standard dose of BUP; a subtherapeutic dose of BUP and TRZ (LOR-low); and a threshold-therapeutic dose of BUP and TRZ (LOR-mod). A midpoint interim analysis was planned to consider adapting doses for efficacy or safety. MAIN OUTCOME MEASURE: The primary efficacy measure was the Female Sexual Function Index, Desire domain; the main secondary efficacy measures included the Female Sexual Distress Scale-Revised 13th item, on bother about low desire, and a Patient's Global Impression of Change. The main outcome comparison was the proportions of responders. Safety measures were elicited adverse events, Epworth Sleepiness Scale, Columbia Suicide Severity Rating Scale 6-item SCREEN version, vital signs, electrocardiograms, and standard laboratory tests. RESULTS: Interim analysis did not require altering doses. Most evaluable subjects responded to LOR-mod (at the standard thresholds for response based on minimum clinically relevant difference from baseline, 79% on Female Sexual Function Index, Desire domain, 87% on Female Sexual Distress Scale-Revised Item 13, and 79% on Patient's Global Impression of Change; each P < .05 vs BUP). As expected, close to half responded to BUP (38%, 45%, and 52%, respectively). Response to LOR-low was intermediate (not significant vs BUP). Sensitivity analyses to compensate for carryover effects supported the efficacy of LOR-mod. Elicited adverse events showed the expected profile of TRZ, but led to no sedative-type dropouts or worsening on the Epworth Sleepiness Scale. CLINICAL IMPLICATIONS: The open-label 1-way crossover design of this phase IB/IIA study limits conclusions, but the consistency of responder analyses showing superiority of LOR-mod dose over control, and the lack of central depressant dropouts, favor further development in double-blind placebo-control trials. STRENGTH & LIMITATIONS: Strengths include large margins of efficacy over control agent, rapid onset of action, and rigorous safety assessment. Limitations are open-label, cross-over design/lack of placebo control and 1-month duration of exposure. CONCLUSION: Moderate-dose LOR was generally well-tolerated and was significantly more effective than BUP (active control). The results seem highly favorable compared to previously tested agents. Pyke RE, Clayton AH. Dose-Finding Study of Lorexys for Hypoactive Sexual Desire Disorder in Premenopausal Women. J Sex Med 2019;16:1885-1894.

Targeting Serotonin1A Receptors for Treating Chronic Pain and Depression.

The association of chronic pain with depression is becoming increasingly recognized. Treating both the conditions together is essential for an effective treatment outcome. In this regard, it is important to identify a shared mechanism involved in the association of chronic pain with depression. Central serotonin (5-hydroxytryptamine; 5-HT) neurotransmission has long been known to participate in the processing of signals related to pain. It also plays a key role in the pathogenesis and treatment of depression. Although functional responses to serotonin are mediated via the activation of multiple receptor types and subtypes, the 5-HT1A subtype is involved in the processing of nociception as well as the pathogenesis and treatment of depression. This receptor is located presynaptically, as an autoreceptor, on the perikaryon and dendritic spines of serotonin-containing neurons. It is also expressed as a heteroreceptor on neurons receiving input from serotonergic neurons. This article targets the 5-HT1A receptors to show that indiscriminate activation of pre and postsynaptic 5-HT1A receptors is likely to produce no therapeutic benefits; biased activation of the 5-HT heteroreceptors may be a useful strategy for treating chronic pain and depression individually as well as in a comorbid condition.

Inhibition of peripheral serotonin synthesis by LP533401 and disturbances in calciotropic hormones attenuated excessive osteoblastogenesis with simultaneous improvement of bone mineral status in 5/6 nephrectomized rats.

Chronic kidney disease (CKD) is a pathological condition associated with renal osteodystrophy for which there are limited treatment options. Gut-derived serotonin (GDS) is one of the key signaling factors controlling the osteoblast proliferation. Previously, we shown that inhibition of GDS synthesis by LP533401 improved bone mineral status of rats with 5/6 nephrectomy-induced CKD model. Here, we investigated whether the use of LP533401 can modify GDS-dependent molecular pathway involved in osteoblast formation and bone mineralization in CKD rats. The 8-weeks of pharmacological manipulation after a complete CKD development reduced GDS and lead to the advantage of endogenous vitamin D [25(OH)D] over serotonin and parathyroid hormone (PTH) in rats treated with LP533401. The imbalance between GDS - 25(OH)D - PTH resulted in the intensified expression of cAMP- responsive element-binding protein (Creb), whereas the expression of myelocytomatosis oncogene (c-Myc) was simultaneously reduced. This lead to disruption of Foxo1- activating transcription factor 4 (Atf4) complex, and decrease in the expression of the major osteogenic markers. The weakening of excessive osteoblastogenesis was associated with better bone mineral status in all rats with CKD, and especially in LP533401-treated animals. In conclusion, the inhibition of GDS synthesis resulted in the mitigation of osteoblastogenesis observed in CKD, which translated into improvement of bone mineral status. This study provides key mechanistic insights into how modification of GDS-dependent molecular pathway affects bone mineral status in CKD and lays the groundwork for translating the role of functional serotonin signaling in the origin of impaired bone mineral status in patients with CKD.

Preclinical characterization of ACH-000029, a novel anxiolytic compound acting on serotonergic and alpha-adrenergic receptors.

Anxiety disorders are serious and common mental diseases, yet there is still a need for the development of more effective anxiolytics with better safety profiles than benzodiazepines and serotonin reuptake inhibitors. The serotonergic and noradrenergic systems have reciprocal interactions and are intricately related to the pathogenesis of anxiety. In this study, the anxiolytic-like effect of the novel compound ACH-000029, 3-(2-(4-(2-methoxyphenyl) piperazine-1-yl) ethyl) quinazoline-4(3H)-one, is reported. This compound acts at selected serotonergic (5-HT1A and 5-HT1D partial agonism and 5-HT2A antagonism) and α-adrenergic (α-1A, 1B and 1D antagonism) receptors, with good selectivity over other G-protein-coupled receptors. ACH-000029 exhibited high blood-brain barrier permeation and acute anxiolytic effects in the marble burying (MB) and light-dark box (LDB) models of anxiety over the dose ranges of 8-32 mg/kg i.p. and 16-30 mg/kg p.o. The anxiolytic activity was comparable to that observed for serotonin reuptake inhibitors (paroxetine and fluoxetine) and benzodiazepines (alprazolam, diazepam and clobazam). The analysis of the whole-brain c-fos expression following oral dosing showed that ACH-000029 regulated regions highly associated with the processing of environmental stimuli and anxiety behavior, such as the amygdala, paraventricular nucleus of the thalamus, retrosplenial dorsal, pallidum, bed nuclei of the stria terminalis, and locus ceruleus. No safety concerns were identified for ACH-000029 in the functional observational battery up to 50 mg/kg i.p. and in the nonprecipitated withdrawal test up to 30 mg/kg p.o. twice daily for 20 days. This work supports the further development of ACH-000029 as a drug candidate for the treatment of anxiety disorders. The analysis of the in vitro pharmacology and brain regions regulated by this compound may also lead to the exploration of other indications within the psychiatry field.

Optimal dose of selective serotonin reuptake inhibitors, venlafaxine, and mirtazapine in major depression: a systematic review and dose-response meta-analysis.

BACKGROUND: Depression is the single largest contributor to non-fatal health loss worldwide. Second-generation antidepressants are the first-line option for pharmacological management of depression. Optimising their use is crucial in reducing the burden of depression; however, debate about their dose dependency and their optimal target dose is ongoing. We have aimed to summarise the currently available best evidence to inform this clinical question. METHODS: We did a systematic review and dose-response meta-analysis of double-blind, randomised controlled trials that examined fixed doses of five selective serotonin reuptake inhibitors (SSRIs; citalopram, escitalopram, fluoxetine, paroxetine, and sertraline), venlafaxine, or mirtazapine in the acute treatment of adults (aged 18 years or older) with major depression, identified from the Cochrane Central Register of Controlled Trials, CINAHL, Embase, LILACS, MEDLINE, PsycINFO, AMED, PSYNDEX, websites of drug licensing agencies and pharmaceutical companies, and trial registries. We imposed no language restrictions, and the search was updated until Jan 8, 2016. Doses of SSRIs were converted to fluoxetine equivalents. Trials of antidepressants for patients with depression and a serious concomitant physical illness were excluded. The main outcomes were efficacy (treatment response defined as 50% or greater reduction in depression severity), tolerability (dropouts due to adverse effects), and acceptability (dropouts for any reasons), all after a median of 8 weeks of treatment (range 4-12 weeks). We used a random-effects, dose-response meta-analysis model with flexible splines for SSRIs, venlafaxine, and mirtazapine. FINDINGS: 28 554 records were identified through our search (24 524 published and 4030 unpublished records). 561 published and 121 unpublished full-text records were assessed for eligibility, and 77 studies were included (19 364 participants; mean age 42·5 years, SD 11·0; 7156 [60·9%] of 11 749 reported were women). For SSRIs (99 treatment groups), the dose-efficacy curve showed a gradual increase up to doses between 20 mg and 40 mg fluoxetine equivalents, and a flat to decreasing trend through the higher licensed doses up to 80 mg fluoxetine equivalents. Dropouts due to adverse effects increased steeply through the examined range. The relationship between the dose and dropouts for any reason indicated optimal acceptability for the SSRIs in the lower licensed range between 20 mg and 40 mg fluoxetine equivalents. Venlafaxine (16 treatment groups) had an initially increasing dose-efficacy relationship up to around 75-150 mg, followed by a more modest increase, whereas for mirtazapine (11 treatment groups) efficacy increased up to a dose of about 30 mg and then decreased. Both venlafaxine and mirtazapine showed optimal acceptability in the lower range of their licensed dose. These results were robust to several sensitivity analyses. INTERPRETATION: For the most commonly used second-generation antidepressants, the lower range of the licensed dose achieves the optimal balance between efficacy, tolerability, and acceptability in the acute treatment of major depression. FUNDING: Japan Society for the Promotion of Science, Swiss National Science Foundation, and National Institute for Health Research.