Role of serotonin 5-HT2C and histamine H1 receptors in antipsychotic-induced diabetes: A pharmacoepidemiological-pharmacodynamic study in VigiBase

Unraveling antipsychotic induced weight gain in schizophrenia - A proof-of-concept study exploring the impact of the cumulative historical occupancy of different receptors by antipsychotics

Obesity is a common complication in schizophrenia contributing to increased mortality rates. We present a proof-of-concept study displaying a new method to investigate the impact of antipsychotic drugs (APs) on obesity in terms of their cumulative historical receptor occupancy (CHRO) in 150 selected from 174 patients with schizophrenia. Based on a thorough medication history, we estimated CHRO of serotonin 5-HT2C, histamine H1, dopamine D2 and muscarinic M3 receptors and studied their relationship with different metabolic outcome variables utilizing stepwise regression analysis and structural equation modelling (SEM). Stepwise regression analysis revealed a significant positive relationship of Body Mass Index (BMI) with H1-CHRO, but a negative relationship with M3-CHRO. Moreover, H1-CHRO was associated with increased triglyceride concentration, while 5-HT2C-CHRO was associated with increased waist circumference and blood pressure. SEM, while confirming the diverging effects of H1-/5-HT2C- and M3-CHRO on obesity, suggested that their effect on other metabolic variables was indirect, i.e. mediated by obesity. Our results suggest that the metabolic side effects of antipsychotics can be described by their cumulative historical receptor occupancy with unique contributions of the different receptors. In particular, M3 receptor antagonism seems to exert a protective effect, confirming findings from rodent M3 receptor knock out models. These findings may provide a framework for estimating the metabolic burden of future APs, guiding the development of drugs with more favorable metabolic profiles.

Impact of cariprazine on body weight and blood pressure among adults with bipolar I disorder, schizophrenia, or major depressive disorder in a real-world setting

BACKGROUND

Atypical antipsychotics are a common treatment for serious mental illness, but many are associated with adverse effects, including weight gain and cardiovascular issues, and real-world experience may differ from clinical trial data. Cariprazine has previously demonstrated a favorable safety and tolerability profile in clinical trials. Here, we evaluated the effects of cariprazine on body weight and blood pressure for bipolar I disorder (BP-I), schizophrenia, or as adjunctive treatment for major depressive disorder (MDD) using real-world data.

METHODS

Symphony Health's Integrated Dataverse® with electronic medical record access (3/1/2015-10/31/2018) was used to identify adults (≥ 18 years) diagnosed with BP-I depression, BP-I mania/mixed, schizophrenia, or MDD, with ≥ 2 cariprazine dispensings (first dispensing = index) and continuous clinical activity for ≥ 12 months pre-index (baseline) and ≥ 3 months post-index. The on-treatment period spanned from index to cariprazine discontinuation, exposure to another atypical or long-acting injectable antipsychotic, or end of clinical activity/data availability. Outcomes included estimated annual linear trajectories for weight, body mass index (BMI), systolic blood pressure (SBP), and diastolic blood pressure (DBP) during baseline and on treatment. Changes were estimated using linear mixed-effects models fitted over measurements pre-index and on treatment; 95% CIs were derived from nonparametric bootstrap procedures.

RESULTS

The body weight analysis included 612 patients (BP-I, n = 331 [BP-I depression, n = 172; BP-I mania/mixed, n = 159]; schizophrenia, n = 75; MDD, n = 206). The mean patient age was 43.4 years, 75.2% were female, and the mean (SD) on-treatment period was 219 (185) days. Among patients with measurements before and during cariprazine treatment, estimated annual weight trajectories were + 3.55 (95% CI 2.38, 4.59) kg/year before cariprazine initiation and + 0.91 (- 1.17, 2.82) kg/year during cariprazine treatment. Additionally, annual linear trajectories evaluated across the on-treatment period were + 0.31 (- 0.42, 1.01) kg/m2/year for BMI, - 2.38 (- 4.27, - 0.76) mmHg/year for SBP, and - 0.57 (- 1.75, 0.61) mmHg/year for DBP.

CONCLUSION

In this real-world analysis, cariprazine was associated with an estimated weight gain of + 0.91 kg/year and had minimal impact on BMI and blood pressure when evaluated up to 12 months.

Pharmacovigilance in Action: Utilizing VigiBase Data to Improve Clozapine Safety

Purpose

Clozapine is an antipsychotic which was approved in 1989 for treatment-resistant schizophrenia in the United States (US). There were few randomized trials before its approval and potentially lethal clozapine adverse drug reactions (ADRs), such as agranulocytosis and myocarditis were identified by pharmacovigilance. VigiBase, the WHO global database, is a cornerstone of international pharmacovigilance efforts for ADR identification during post-marketing surveillance. This systematic review of the literature explores additional contributions to the knowledge of clozapine ADRs from recent VigiBase studies.

Methods

Using the terms "clozapine AND VigiBase" we conducted an article search in PubMed on September 5, 2024. Of the 29 articles, 11 were excluded and 18 described in the Results section.

Results

All clozapine ADRs were described in two VigiBase studies. One on pregnancy indicated no increased risk with clozapine compared with other antipsychotics; the other reported 191,557 clozapine ADRs, including 22,956 fatal outcomes through January 15, 2023, and paid attention to the reporting style of the top 4 reporting countries (the US, the United Kingdom, Canada and Australia). Infections were described in three VigiBase studies where clozapine treatment was associated with infections, respiratory aspiration, and pneumonia. Rapid titration can lead to localized clozapine-induced inflammations including myocarditis, pericarditis or pancreatitis, or generalized inflammations such as drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome. Clozapine-induced inflammation was described in four VigiBase studies, two focused on all ages (myocarditis and DRESS) and two on youth (myocarditis and another on pericarditis and pancreatitis). Other specific ADRs were described in nine VigiBase studies (hematological malignancies, rhabdomyolysis, sialorrhea, seizures, diabetes mellitus, drug-induced parkinsonism, withdrawal symptoms, and suicidal behaviors).

Conclusion

The spectrum of respiratory aspiration - aspiration pneumonia - pneumonia and other infections are significant causes of fatal outcomes in clozapine-treated patients. Clozapine had anti-suicidal effects versus other antipsychotics across all VigiBase labels of suicidal behavior.

Antipsychotic drugs for anorexia nervosa

OBJECTIVES

This is a protocol for a Cochrane Review (intervention). The objectives are as follows: To assess the effects of antipsychotic drugs (both first- and second-generation antipsychotics) compared to placebo on body weight gain, psychological symptoms, acceptability, and adverse events for people with anorexia nervosa.

Hepatotoxicity of antipsychotics: an exploratory pharmacoepidemiologic and pharmacodynamic study integrating FAERS data and in vitro receptor-binding affinities

Introduction

Antipsychotic psychopharmacotherapy is associated with the risk of drug-induced liver injury (DILI). However, understanding specific risk factors remains challenging due to limited data. This study investigates the relationship between receptor binding affinities and occupancies of antipsychotics and their associated hepatotoxic risks.

Methods

A disproportionality analysis with calculation of the Reporting Odds Ratio (ROR) and the Information Component (IC) was conducted using data from the FDA Adverse Event Reporting System (FAERS) to identify signals related to the Standardised MedDRA Query "drug-related hepatic disorders", which served as a proxy for drug-induced hepatotoxicity. This was followed by a pharmacoepidemiologic-pharmacodynamic approach to investigate the relationship between the ROR and substance-related receptor binding affinities and occupancy, which was estimated based on in vitro receptor-binding profiles.

Results

Significant signals were identified for several antipsychotics, including chlorpromazine, loxapine, olanzapine, and quetiapine, with chlorpromazine and loxapine showing the highest RORs for DILI. Gender-specific analysis revealed a higher frequency of signals in female patients. Statistically significant negative correlations were identified between the ROR for drug-related hepatic disorders and the affinity for serotonin receptor 5-HT1A (r (17) = -0.68, p = 0.0012), while a positive correlation was observed for cholinergic receptors (r (17) = 0.46, p = 0.048). No significant correlations were found related to other receptors or drug properties.

Conclusion

Our findings suggest that the serotonin and probably the cholinergic system may play a role in the development of DILI related to antipsychotic medications. The identification of antipsychotics with a higher association with DILI, such as chlorpromazine, underscores the need for careful monitoring in clinical practice. However, our findings need further longitudinal studies to confirm causality. A better understanding of the associations may inform clinical decision-making, particularly in patients with an increased susceptibility to liver damage.

Insights from pharmacovigilance and pharmacodynamics on cardiovascular safety signals of NSAIDs

Background and Aim

Non-steroidal anti-inflammatory drugs (NSAIDs) are commonly used to treat fever, pain, and inflammation. Concerns regarding their cardiovascular safety have been raised. However, the underlying mechanism behind these events remains unknown. We aim to investigate the cardiovascular safety signals and receptor mechanisms of NSAIDs, employing a comprehensive approach that integrates pharmacovigilance and pharmacodynamics.

Methods

This study utilized a pharmacovigilance-pharmacodynamic approach to evaluate the cardiovascular safety of NSAIDs and explore potential receptor mechanisms involved. Data were analyzed using the OpenVigil 2.1 web application, which grants access to the FDA Adverse Event Reporting System (FAERS) database, in conjunction with the BindingDB database, which provides target information on the pharmacodynamic properties of NSAIDs. Disproportionality analysis employing the Empirical Bayes Geometric Mean (EBGM) and Reporting Odds Ratio (ROR) methods was conducted to identify signals for reporting cardiovascular-related adverse drug events (ADEs) associated with 13 NSAIDs. This analysis encompassed three System Organ Classes (SOCs) associated with the cardiovascular system: blood and lymphatic system disorders, cardiac disorders, and vascular disorders. The primary targets were identified through the receptor-NSAID interaction network. Ordinary least squares (OLS) regression models explored the relationship between pharmacovigilance signals and receptor occupancy rate.

Results

A total of 201,231 reports of cardiovascular-related ADEs were identified among the 13 NSAIDs. Dizziness, anemia, and hypertension were the most frequently reported Preferred Terms (PTs). Overall, nimesulide and parecoxib exhibited the strongest signal strengths of ADEs at SOC levels related to the cardiovascular system. On the other hand, our data presented naproxen and diclofenac as drugs of comparatively low signal strength. Cyclooxygenase-1 (COX-1) and cyclooxygenase-2 (COX-2) were identified as central targets. OLS regression analysis revealed that the normalized occupancy rate for either COX-1 or COX-2 was significantly inversely correlated with the log-transformed signal measures for blood and lymphatic system disorders and vascular disorders, and positively correlated with cardiac disorders and vascular disorders, respectively. This suggests that higher COX-2 receptor occupancy is associated with an increased cardiovascular risk from NSAIDs.

Conclusion

Cardiovascular safety of NSAIDs may depend on pharmacodynamic properties, specifically, the percentage of the occupied cyclooxygenase isoenzymes. More studies are needed to explore these relations and improve the prescription process.

Towards full recovery with lurasidone: effective doses in the treatment of agitation, affective, positive, and cognitive symptoms in schizophrenia and of dual psychosis

The management of schizophrenia necessitates a comprehensive treatment paradigm that considers individual patient nuances and the efficacy of lurasidone in addressing schizophrenia symptoms, particularly at elevated dosages. Numerous randomized trials have affirmed the efficacy of lurasidone across various dimensions of schizophrenia, demonstrating marked enhancements in positive, negative and cognitive symptoms compared to a placebo. In addition, lurasidone exhibits potential in ameliorating agitation amongst acutely ill patients, showcasing greater efficacy at higher doses. However, despite the favourable outcomes observed with higher lurasidone doses, routine clinical practice often opts for lower doses, potentially limiting its maximal therapeutic impact. Furthermore, lurasidone also shows efficacy in reducing post-psychotic depression in dual psychosis. Moreover, practical insights into lurasidone usage encompass swift dose escalation within a 1-5-day span and recommended combination strategies with other medications such as benzodiazepines for insomnia or agitation, beta-blockers for akathisia, and antihistamines or antimuscarinic drugs for patients transitioning rapidly from antipsychotics with substantial antihistamine and/or anticholinergic effects. Finally, a series of clinical cases is presented, highlighting benefits of lurasidone in terms of cognitive function, functional recovery and other therapeutic aspects for the management of schizophrenia.

Molecular dynamics and free energy calculations of clozapine bound to D2 and H1 receptors reveal a cardiometabolic mitigated derivative

Most atypical antipsychotics derive from a high dropout of drug treatments due to adverse cardiometabolic side effects. These side effects are caused, in part, by the H1 receptor blockade. The current work sought a clozapine derivative with a reduced affinity for the H1 receptor while maintaining its therapeutic effect linked to D2 receptor binding. Explicit molecular dynamics simulations and end-point free energy calculations of clozapine in complex with the D2 and H1 receptors embedded in cholesterol-rich lipid bilayers were performed to analyze the intermolecular interactions and address the relevance of clozapine-functional groups. Based on that, free energy perturbation calculations were performed to measure the change in free energy of clozapine structural modifications. Our results indicate the best clozapine derivative is the iodine atom substitution for chlorine. The latter is mainly due to electrostatic interaction loss for the H1 receptor, while the halogen orientation out of the D2 active site reduces the impact on the affinity.Communicated by Ramaswamy H. Sarma.

Exploring the underlying mechanisms of drug-induced impulse control disorders: a pharmacovigilance-pharmacodynamic study

INTRODUCTION

Impulse control disorders (e.g. pathological gambling, hypersexuality) may develop as adverse reactions to drugs. Pathogenetic hypotheses have mainly focused on D3-receptor agonism, and switching to alternatives with different pharmacologic mechanisms represents a common management strategy. Nonetheless, treatment failure is common and gaining pathophysiological insights is needed.

AIM

We aimed to identify targets potentially contributing to pathologic impulsivity.

METHOD

We performed a pharmacovigilance-pharmacodynamic study on dopamine agonists and antipsychotics using the Food and Drug Administration Adverse Event Reporting System (January 2004-December 2021). We estimated disproportionate reporting using the Bayesian information component. Using online public databases (IUPHAR, ChEMBL, PDSP, DrugBank), we calculated drug occupancies. To identify the targets potentially contributing to impulsivity, we fitted univariate regression models interpolating information components and occupancies within dopamine agonists and antipsychotics. Sensitivity analyses were performed to check for the robustness of the results.

RESULTS

Among 19 887 reports of impulsivity, 5898 recorded an antipsychotic, and 3100 a dopamine agonist. The more robust signals concerned aripiprazole (N = 3091; median information component [95% confidence interval] = 4.51[4.45-4.55]) and brexpiprazole (229; 4.00[3.78-4.16]) for antipsychotics, pergolide (105; 5.82[5.50-6.06]) and pramipexole (2009; 5.43[5.36-5.48]) for dopamine agonists. Robust, significant positive associations between drug occupancy and impulsivity reporting were found for D3 within dopamine agonists (beta = 1.52; P-value = 0.047) and 5-HT1a within antipsychotics (1.92, 0.029).

CONCLUSION

Our results supported the role of D3-receptor agonism in inducing impulsivity in dopamine receptor agonists and identified a potential role of 5-HT1a receptor agonism in antipsychotics. Investigating these receptors may drive towards a better management of drug-induced impulsivity.

Enhanced Bystander BRET (ebBRET) Biosensors as Biophysical Tools to Map the Signaling Profile of Neuropsychiatric Drugs Targeting GPCRs

Bioluminescence resonance energy transfer (BRET) is a non-radiative energy transfer between a bioluminescent donor and a fluorescent acceptor with far-reaching applications in detecting physiologically relevant protein-protein interactions. The recently developed enhanced bystander BRET (ebBRET) biosensors have made it possible to rapidly determine the signaling profile of a series of ligands across a large number of GPCRs and their signaling repertoires, which has tremendous implications in the drug discovery process. Here we describe BRET and the ebBRET biosensors as investigational tools in establishing functional selectivity downstream of GPCRs.

Selective serotonin reuptake inhibitors and the risk of type 2 diabetes mellitus in youths

BACKGROUND

Selective serotonin reuptake inhibitors (SSRIs) have been associated with type 2 diabetes mellitus (T2DM) in youths, possibly via 5-HT_2C, H₁ receptors and serotonin transporter (SERT). SSRIs have similar affinity for SERT but variable affinity for 5-HT_2C and H₁. This study assessed whether SSRIs with strong affinity for 5-HT_2C and H₁ (relative to SERT) were associated with T2DM risk compared with weak-affinity SSRIs.

METHODS

Using the UK Clinical Practice Research Datalink, we assembled a cohort of patients aged 5-24, newly prescribed a strong-affinity SSRI (citalopram, escitalopram, fluoxetine) or weak affinity (paroxetine, sertraline, fluvoxamine) between 1990 and 2019. We controlled for confounding using standardized mortality ratio weighting, estimated from calendar time-specific propensity scores. We used weighted Cox proportional hazards models to estimate hazard ratios (HRs) of incident T2DM with 95 % confidence intervals (CIs).

RESULTS

The cohort included 347,368 new users of strong-affinity SSRIs and 131,359 of weak-affinity SSRIs. Strong-affinity SSRIs were not associated with an increased T2DM risk compared with weak-affinity SSRIs (incidence rate 2.8 vs 2.7 per 1000 person-years; HR 1.03, 95 % CI 0.85-1.25). T2DM risk did not vary with duration of use, age or sex. However, the HR was numerically higher in youths with normal or low weight (HR 1.30, 95 % CI 0.85-1.98) and with prior antipsychotic use (HR 1.62, 95 % CI 0.83-3.18).

LIMITATIONS

Median duration of SSRI use, in line with real-world SSRI prescribing, was relatively short.

CONCLUSION

T2DM risk did not differ between strong- and weak-affinity SSRIs, providing reassurance for clinicians when choosing between SSRIs in youths.

Clozapine's multiple cellular mechanisms: What do we know after more than fifty years? A systematic review and critical assessment of translational mechanisms relevant for innovative strategies in treatment-resistant schizophrenia

Almost fifty years after its first introduction into clinical care, clozapine remains the only evidence-based pharmacological option for treatment-resistant schizophrenia (TRS), which affects approximately 30% of patients with schizophrenia. Despite the long-time experience with clozapine, the specific mechanism of action (MOA) responsible for its superior efficacy among antipsychotics is still elusive, both at the receptor and intracellular signaling level. This systematic review is aimed at critically assessing the role and specific relevance of clozapine's multimodal actions, dissecting those mechanisms that under a translational perspective could shed light on molecular targets worth to be considered for further innovative antipsychotic development. In vivo and in vitro preclinical findings, supported by innovative techniques and methods, together with pharmacogenomic and in vivo functional studies, point to multiple and possibly overlapping MOAs. To better explore this crucial issue, the specific affinity for 5-HT₂R, D1R, α_2c, and muscarinic receptors, the relatively low occupancy at dopamine D2R, the interaction with receptor dimers, as well as the potential confounder effects resulting in biased ligand action, and lastly, the role of the moiety responsible for lipophilic and alkaline features of clozapine are highlighted. Finally, the role of transcription and protein changes at the synaptic level, and the possibility that clozapine can directly impact synaptic architecture are addressed. Although clozapine's exact MOAs that contribute to its unique efficacy and some of its severe adverse effects have not been fully understood, relevant information can be gleaned from recent mechanistic understandings that may help design much needed additional therapeutic strategies for TRS.

Lurasidone-induced hyperosmolar hyperglycemic syndrome: A case report

INTRODUCTION

Lurasidone has few metabolic adverse effects and is recommended as an alternative when other antipsychotic drugs considerably increase body weight or blood sugar concentrations.

CASE PRESENTATION

An 81-year-old man with bipolar disorder developed hyperosmolar hyperglycemic syndrome as a side effect of lurasidone. Routine monitoring of blood glucose concentrations led to the early detection and treatment of this disease, preventing life-threatening complications.

DISCUSSION AND CONCLUSION

We describe a rare case of lurasidone-induced hyperosmolar hyperglycemic syndrome. The mortality rate of this syndrome is estimated to be up to 20%. This rate is significantly higher than that of diabetic ketoacidosis (currently <2%). Although lurasidone is considered to have a low risk of raising blood glucose concentrations, symptoms of hyperglycemia must be evaluated and blood glucose concentrations should be monitored regularly.

The type rather than the daily dose or number of antipsychotics affects the incidence of hyperglycemic progression

There have been concerns that antipsychotics increase the incidence of hyperglycemic progression. Many factors have been suggested to contribute to the risk of antipsychotic-induced hyperglycemic progression, including the type, daily dose, and number of antipsychotics; however, few studies have examined these relationships. This study aimed to examine the affect of antipsychotic treatment-associated factors on hyperglycemic progression, after adjustment for the affect of background factors suggested to be associated with hyperglycemic progression. This was a nationwide, multicenter, prospective cohort study examining the incidence of hyperglycemic progression during a 12 mo period following the initiation of newly prescribed antipsychotic medication. Demographic data, medication history, and blood test values were collected from 631 study participants with normal blood glucose levels at baseline for 12 mo. The primary endpoint (incidence of hyperglycemic progression) was defined as progression from normal to prediabetic or probable diabetic status, and was evaluated based on the Japanese monitoring guidance in patients with schizophrenia. To further examine the affect of antipsychotics on glucose metabolism over time, we examined changes in HbA1c levels 3, 6, and 12 mo after the initiation of treatment with each antipsychotic. We found that treatment with zotepine and clozapine was associated with a significantly high incidence of hyperglycemic progression. Furthermore, changes in HbA1c levels 6 mo after the initiation of zotepine treatment were significantly higher than those following blonanserin and haloperidol treatments. In contrast, there was no significant difference in the change in total cholesterol, triglycerides, HDL cholesterol, and BMI during the same period. Moreover, the "daily dose" and "number" of antipsychotics did not show an association with the incidence of hyperglycemic progression. However, in a post hoc analysis in which the antipsychotics were divided into two groups according to the strength of blockade of H₁, M₁, M₃, and 5-HT_2C receptors, the incidence of hyperglycemic progression was higher in the medium- and high-daily dose groups than in the low-daily dose group in the antipsychotic group with strong blockade of these receptors. Our study indicated that the type of antipsychotic had a greater affect on the incidence of hyperglycemic progression than the daily dose of antipsychotics or their number. Among these, zotepine was most likely to increase the incidence of hyperglycemic progression, suggesting the need for caution when these antipsychotics are prescribed.

Enhanced intestinal protein fermentation in schizophrenia

BACKGROUND

Emerging findings highlighted the associations of mental illness to nutrition and dysbiosis in the intestinal microbiota, but the underlying mechanisms, especially in schizophrenia (SZ), remain unclarified.

METHODS

We conducted a case-control study of SZ patients (case to control=100:52) by performing sequencing of the gut metagenome; measurement of fecal and plasma non-targeted metabolome; including short-, medium-, and long-chain fatty acids; and targeted metabolites, along with recorded details of daily intakes of food.

RESULTS

The metagenome analysis uncovered enrichment of asaccharolytic species and reduced abundance of carbohydrate catabolism pathways and enzymes in the gut of SZ patients, but increased abundance of peptidases in contrast to their significantly reduced protein intake. Fecal metabolome analysis identified increased concentrations of many protein catabolism products, including amino acids (AAs), urea, branched short-chain fatty acids, and various nitrogenous derivates of aromatic AAs in SZ patients. Protein synthesis, represented by the abundance of AA-biosynthesis pathways and aminoacyl-tRNA transferases in metagenome, was significantly decreased. The AUCs (area under the curve) of the diagnostic random forest models based on their abundance achieved 85% and 91%, respectively. The fecal levels of AA-fermentative enzymes and products uniformly showed positive correlations with the severity of psychiatric symptoms.

CONCLUSIONS

Our findings revealed apparent dysbiosis in the intestinal microbiome of SZ patients, where microbial metabolism is dominated by protein fermentation and shift from carbohydrate fermentation and protein synthesis in healthy conditions. The aberrant macronutrient metabolism by gut microbes highlights the importance of nutrition care and the potential for developing microbiota-targeted therapeutics in SZ.

Transcriptome Profiling of Dysregulated GPCRs Reveals Overlapping Patterns across Psychiatric Disorders and Age-Disease Interactions

G-protein-coupled receptors (GPCRs) play an integral role in the neurobiology of psychiatric disorders. Almost all neurotransmitters involved in psychiatric disorders act through GPCRs, and GPCRs are the most common targets of therapeutic drugs currently used in the treatment of psychiatric disorders. However, the roles of GPCRs in the etiology and pathophysiology of psychiatric disorders are not fully understood. Using publically available datasets, we performed a comprehensive analysis of the transcriptomic signatures of G-protein-linked signaling across the major psychiatric disorders: autism spectrum disorder (ASD), schizophrenia (SCZ), bipolar disorder (BP), and major depressive disorder (MDD). We also used the BrainSpan transcriptomic dataset of the developing human brain to examine whether GPCRs that exhibit chronological age-associated expressions have a higher tendency to be dysregulated in psychiatric disorders than age-independent GPCRs. We found that most GPCR genes were differentially expressed in the four disorders and that the GPCR superfamily as a gene cluster was overrepresented in the four disorders. We also identified a greater amplitude of gene expression changes in GPCRs than other gene families in the four psychiatric disorders. Further, dysregulated GPCRs overlapped across the four psychiatric disorders, with SCZ exhibiting the highest overlap with the three other disorders. Finally, the results revealed a greater tendency of age-associated GPCRs to be dysregulated in ASD than random GPCRs. Our results substantiate the central role of GPCR signaling pathways in the etiology and pathophysiology of psychiatric disorders. Furthermore, our study suggests that common GPCRs' signaling may mediate distinct phenotypic presentations across psychiatric disorders. Consequently, targeting these GPCRs could serve as a common therapeutic strategy to treat specific clinical symptoms across psychiatric disorders.

Hyponatremia Following Antipsychotic Treatment: In Silico Pharmacodynamics Analysis of Spontaneous Reports From the US Food and Drug Administration Adverse Event Reporting System Database and an Updated Systematic Review

BACKGROUND

Hyponatremia associated with antipsychotic drugs is a rare but potentially life-threatening adverse drug reaction; the underlying pharmacological mechanism has not yet been explained.

METHODS

We investigated the relationship between pharmacological targets of antipsychotic drugs and the occurrence of hyponatremia by conducting a nested case-control study using the Food and Drug Administration Adverse Event Reporting System database. Multiple logistic regression was used to determine the associations between antipsychotics receptor occupancy and hyponatremia. We also performed a systematic review of clinical studies on this association.

RESULTS

Of 139 816 reports involving at least 1 antipsychotic, 1.1% reported hyponatremia. Olanzapine was the most frequently suspected drug (27%). A significant positive association was found between dopamine D3, D4, and hyponatremia, while adrenergic α 1, serotonin 5-HT1A, and 5-HT2A receptor occupancies were negatively associated. A multivariable stepwise regression model showed that dopamine D3 (adj. odds ratio = 1.21; 95% CI = 1.09-1.34; P < .05) predicted the risk for hyponatremia (P < .05), while serotonin 5-HT2A occupancy (Adj. odds ratio = 0.78; 95% CI = 0.68-0.90; P < .01) exhibited a protective effect against hyponatremia. Among the 11 studies included in the systematic review, incidence rates of hyponatremia diverged between 0.003% and 86%, whereas the odds of developing hyponatremia from effect studies ranged between 0.83 and 3.47.

CONCLUSIONS

Antipsychotic drugs having a combined modest occupancy for D3 and 5-HT2A receptors and higher levels of D3 receptor occupancy correspond to different degrees of risk for hyponatremia. Based on the few, relatively large-scale available studies, atypical antipsychotics have a more attenuated risk profile for hyponatremia.

Characteristics of voluntary reporting of adverse drug events related to antipsychotics in Australia: 14-year analysis

BACKGROUND

Retrospective analyses of large databases of treated patients can provide useful links to the presence of drug misuse or rare and infrequent adverse effects, such as agranulocytosis, diabetic ketoacidosis or neuroleptic malignant syndrome. The aim of this study is to describe the adverse effects to antipsychotics reported in the Australian Database of Adverse Event Notifications (DAEN).

METHODS

Data were collected from the DAEN - a spontaneous reporting database. The database, which covered the period from January 2004 to December 2017, was obtained from the Therapeutic Goods Administration (TGA) website (www.TGA.gov). The drugs selected for this investigation are the following: aripiprazole, clozapine, olanzapine, paliperidone, risperidone, ziprasidone, quetiapine, haloperidol and pimozide. All data were analysed descriptively. Comparison of reporting and management of adverse events between adults (older than 20 years) and children (5-19 years) was undertaken using chi squared test, where p < 0.05 is significant.

RESULTS

A total of 7122 adverse events associated with the antipsychotics aripiprazole, clozapine, haloperidol, olanzapine, paliperidone, pimozide, quetiapine and risperidone were reported to the TGA between January 2004 and December 2017. On average, there were 2.6 adverse events reported for each case. The most common adverse event reported for antipsychotics was neuroleptic malignant syndrome. There were no significant differences in the number of co-medications, formulations, indications, therapeutic dose, hospital admission and overdose among the antipsychotics between paediatric and adult populations. However, there were significant differences between causality, death and the management of adverse events between adult and paediatric populations (5-19 years) (p < 0.05, chi squared test).

CONCLUSION

The antipsychotic drug associated with the highest adverse events in adults was clozapine, followed by olanzapine. The most common adverse event in adults, and reported with a number of antipsychotic drugs, was neuroleptic malignant syndrome. In children, the highest numbers of adverse events reported in the database were associated with risperidone, clozapine and olanzapine.

PLAIN LANGUAGE SUMMARY

Adverse events reported of antipsychoticsBackground: Retrospective analyses of large databases of treated patients can provide useful clues to the presence of drug misuse or rare and infrequent adverse effects associated with antipsychotics. The drugs selected for this investigation are the following: aripiprazole, clozapine, olanzapine, paliperidone, risperidone, ziprasidone, quetiapine, haloperidol and pimozide.Methods: All data were analysed descriptively and investigated for any associations between the variables collected. Comparison of reporting and management of adverse events between adults (older than 20 years) and children (5-19 years) was undertaken using chi squared test, where p < 0.05 is significant.Results: The antipsychotic drug associated with the highest adverse events was clozapine, followed by olanzapine. In children, the highest numbers of adverse events reported in the database were associated with risperidone, clozapine and olanzapine. The most common adverse event in adults, and reported with a number of antipsychotic drugs, was neuroleptic malignant syndrome.Conclusion: There were significant differences between causality, death and the management of adverse events between adult and paediatric populations (5-19 years).Keywords: Antipsychotics, adverse effects, adverse events, safety.

Discovery of a new class of multi-target heterocycle piperidine derivatives as potential antipsychotics with pro-cognitive effect

A series of benzoisoxazoleylpiperidine derivatives were synthesized by using the multi-target strategies and their potent affinities for dopamine (DA), serotonin (5-HT) and human histamine H₃ receptors have been evaluated. Of these compounds, the promising candidate 4w displayed high affinities for D₂, D₃, 5-HT_1A, 5-HT_2A and H₃, a moderate affinity for 5-HT₆, negligible effects on the human ether-a-go-go-related gene (hERG) channel, low affinities for off-target receptors (5-HT_2C, adrenergic α₁ and H₁). In addition, the animal behavioral study revealed that, compared to risperidone, compound 4w significantly inhibited apomorphine-induced climbing and MK-801-induced movement behaviors with a high threshold for catalepsy and low liabilities for weight gain and hyperprolactinemia. Results from the conditioned avoidance response test and novel object recognition task demonstrated that 4w had pro-cognitive effects. Thus, the antipsychotic drug-like activities of 4w indicate that it may be a potential polypharmacological antipsychotic candidate drug.

Association of Low-Dose Quetiapine and Diabetes

IMPORTANCE

Quetiapine has been associated with increased risk of type 2 diabetes when used in medium or high doses for the treatment of severe mental disorders. It is not known whether low doses, commonly used off-label for sedative-hypnotic purposes, are also associated with increased risk of type 2 diabetes.

OBJECTIVE

To investigate whether there is an association between prescription of low-dose quetiapine and the risk of type 2 diabetes.

DESIGN, SETTING, AND PARTICIPANTS

This cohort study examined nationwide Danish health registers for data regarding new users of quetiapine (n = 185 938) or selective serotonin reuptake inhibitors (SSRIs) (n = 1 031 920) who were aged 18 years or older between January 1, 1998, and December 31, 2018. Individuals with schizophrenia or bipolar disorder were excluded. Quetiapine-initiators were matched 1:1 with initiators of SSRIs, using a high-dimensional propensity score (hdPS). Maximum follow-up was 5 years. Association with cumulative dose was investigated, using a case-control approach nested among quetiapine users. Data analysis was performed from May to September 2020.

EXPOSURES

Dispensing of quetiapine or SSRIs. Quetiapine prescriptions were limited to tablet strengths of 25 mg and 50 mg to focus on low-dose use.

MAIN OUTCOMES AND MEASURES

Incident type 2 diabetes was defined as first filling of an antidiabetic medication, first register diagnosis of type 2 diabetes or first hemoglobin A1C measurement greater than or equal to 6.4% (≥48 mmol/mol). Incidence rates (IRs), incidence rate ratios (IRRs), and number-needed-to-harm (NNH) were calculated for full and matched cohorts using as-treated and intention-to-treat approaches. Odds ratios (ORs) were calculated for the association with cumulative quetiapine dose.

RESULTS

Altogether, 896 285 patients were included in the full cohort; 538 164 (60%) were female and the median (interquartile range) age was 47 (33-67) years. There were 57 701 low-dose quetiapine initiators and 838 584 SSRI initiators. The matched cohort consisted of 54 616 pairs. In as-treated analyses, the incidence of type 2 diabetes during treatment with low-dose quetiapine (425 cases) was 9.59 cases/1000 person-years (PY) (95% CI, 8.72-10.5/1000 PY), which was slightly higher than for SSRI users (8462 cases; IR, 8.13/1000 PY; 95% CI, 7.96-8.30/1000 PY), resulting in a significant IRR of 1.18 (95% CI, 1.07-1.30) and NNH of 684 (95% CI, 418-1873). However, the between-group difference was nonsignificant in the hdPS-matched cohort (IR, 9.49 vs IR, 9.58; IRR, 0.99; 95% CI, 0.87-1.13). The case-control analysis found no dose-response association of low-dose quetiapine with diabetes (OR for doubling of the cumulative dose: 1.02; 95% CI, 0.95-1.09; P = .54), but in sensitivity analyses higher daily doses were associated with diabetes (all tablet strengths: OR, 1.08; 95% CI, 1.03-1.13).

CONCLUSIONS AND RELEVANCE

In this cohort study, use of low-dose quetiapine was not associated with excess risk of type 2 diabetes in comparison with SSRIs.

Exploring a Safety Signal of Antipsychotic-Associated Pneumonia: A Pharmacovigilance-Pharmacodynamic Study

An association between antipsychotic drugs and pneumonia has been demonstrated in several studies; however, the risk for pneumonia caused by specific antipsychotics has not been extensively studied. The underlying mechanism is still unknown, and several receptor mechanisms have been proposed. Therefore, using a combined pharmacovigilance-pharmacodynamic approach, we aimed to investigate safety signals of US Food and Drug Administration (FDA)-approved antipsychotics for reporting pneumonia and the potential receptor mechanisms involved. A disproportionality analysis was performed to detect a signal for reporting "infective-pneumonia" and "pneumonia-aspiration" and antipsychotics using reports submitted between 2004 and 2019 to the FDA adverse events spontaneous reporting system (FAERS) database. Disproportionality was estimated using the crude and the adjusted reporting odds ratio (aROR) and its 95% confidence interval (CI) in a multivariable logistic regression. Linear regressions investigated the relationship between aROR and receptor occupancy, which was estimated using in vitro receptor-binding profiles. Safety signals for reporting infective-pneumonia were identified for clozapine (LL = 95% 3.4, n = 546 [aROR: 4.8]) as well as olanzapine (LL = 95% 1.5, n = 250 [aROR: 2.1]) compared with haloperidol, while aRORs were associated with higher occupancies of muscarinic receptors (beta = .125, P-value = .016), yet other anti-muscarinic drugs were not included as potential confounders. No safety signals for reporting pneumonia-aspiration were detected for individual antipsychotics. Multiple antipsychotic use was associated with both reporting infective-pneumonia (LL 95%: 1.1, n = 369 [aROR:1.2]) and pneumonia-aspiration (LL 95%: 1.7, n = 194 [aROR: 2.0]). Considering the limitations of disproportionality analysis, further pharmacovigilance data and clinical causality assessment are needed to validate this safety signal.

Safety of antipsychotic drugs: A systematic review of disproportionality analysis studies

Antipsychotic drugs are commonly prescribed, mainly for the treatment of schizophrenia and other psychotic disorders. Disproportionality analysis of pharmacovigilance data from national and international databases have been recently utilized to investigate the side-effect profiles of antipsychotics and have provided unique insights of their safety. Among several national and international spontaneous reporting databases the databases of the World Health Organization (VigiBase), of the European Medicines Agency (EudraVigilance) and the US Food and Drug Administration (FAERS) incorporate millions of Individual Case Safety Reports. The aim of our study was to systematically review published disproportionality analyses on antipsychotic drugs, in order to summarize the current state of methodology and potential strengths of this analysis while highlighting safety signal generated for these pharmacological group. PubMed was searched using a search algorithm combining terms for antipsychotic drugs and disproportionality analysis. A total of 39 articles were found to be eligible corresponding to 38 original disproportionality studies. Different measures of disproportionality were used in each study: reporting odds ratio (ROR), proportional reporting ratio (PRR), empirical Bayes geometric mean (EBGM) and the information component (IC). Despite the inherent limitations of the pharmacovigilance databases disproportionality analysis provides complemented evidence from RCTs on the safety of antipsychotics, especially regarding participants often excluded from RCTs, such as pregnant and breastfeeding women, children and participants with drug abuse, comorbidities or concomitant medications.

Towards personalized pharmacology: Antipsychotics and schizophrenia

Since the discovery of the first antipsychotic in 1952, many antipsychotic drugs have been developed, each with different pharmacokinetic and pharmacodynamic properties. The pharmacological heterogeneity of antipsychotic drugs should allow a personalized drug prescription adapted to the different clinical picture of schizophrenia. Schizophrenia is a chronic disease, during which 3 stages of pharmacological intervention can be identified: the first episode psychotic (FEP), the phase of therapeutic stabilization that can progress to situations of resistance, and the question of long-term prescription. During FEP, the choice of the first antipsychotic treatment seems to be underpinned by its safety profile in relation to the patient for whom it is prescribed, according to the adage start low and go-slow. The therapeutic stabilization phase is based on treatment optimization through a rigorous evaluation of the benefits-harm balance, with the use of tools such as personalized therapeutic drug monitoring and pharmacogenetics. Generally speaking, while some antipsychotic drugs seem to present a more favorable efficacy profile in certain situations, the differences are small, whereas the differences in safety are more important and should be considered in the first line. Individual factors such as the presence of co-morbidities, as well as previously experienced treatments must also be taken into account. Finally, the question of maintaining the prescription of antipsychotic drugs over the long term arises in view of the iatrogenic risk with controversial current data. Overall, the personalized prescription of antipsychotic drugs in schizophrenia remains limited by a lack of data in the literature, justifying the development of clinical studies in this field. But at present, the dogma remains that of primum non nocere.

A Review of Switching Strategies for Patients with Schizophrenia Comorbid with Metabolic Syndrome or Metabolic Abnormalities

Metabolic syndrome (MetS) in patients with schizophrenia occurs 2-3 times more frequently than in the general population. Antipsychotic medication is a primary risk factor for patients with MetS. In particular, the widely used second-generation antipsychotics can affect glucose and lipid metabolism and can induce insulin resistance and other metabolic abnormalities through various receptors. Notably, the metabolic risks of various antipsychotics may differ because of their different pharmacological affinity to MetS-related receptors. Several previous studies have shown that switching from high to low metabolic risk antipsychotics may improve patients' metabolic parameters. The current review aims to discuss the strategies for switching antipsychotic medications and the impact on metabolic abnormalities in patients with schizophrenia.

The More, the Merrier…? Antipsychotic Polypharmacy Treatment Strategies in Schizophrenia From a Pharmacology Perspective

Antipsychotic polypharmacy/drug combination treatment (APP) is a remarkably common practice in the schizophrenia context, given the lack of general support in treatment Guidelines. There is also a vast literature on APP outcomes, but a paucity of high-quality evidence-based data to guide and optimize adequate use of APP. This seems particularly true regarding many pharmacology-based considerations involved in APP treatment strategies. This paper first briefly summarizes clinical literature related to the use of APP. Against this backdrop, the pharmacological target profile features are then described of frequently used antipsychotic agents, in relation to estimated free plasma exposure levels at clinically efficacious dosing. APP strategies based on the properties of these drugs are then scrutinized and gauged within the background literature framework. The anticipated usefulness of APP from the pharmacological standpoint is detailed regarding efficacy, adverse effect (AE)/tolerability, and safety perspective, including why, when, and how it may be used to its advantage. For the purpose, a number of theoretically beneficial combinations as well as instances with suboptimal-and even futile-APP approaches are exemplified and discussed from the rational pharmacodynamic and pharmacokinetic pros and cons point-of-view. In this exposé, particular attention is paid to the utility and features of 3rd Generation Antipsychotic dopamine (DA) D2-D3 agonists within an APP setting.

Innovative approaches in CNS clinical drug development: Quantitative systems pharmacology

Clinical trials involving brain disorders are notoriously difficult to set up and run. Innovative ways to develop effective prevention and treatment strategies for central nervous system (CNS) diseases are urgently needed. New approaches that are likely to renew or at least modify the paradigms used so far have been recently proposed. Quantitative systems pharmacology (QSP) uses mathematical computerized models to characterize biological systems, disease processes and CNS drug pharmacology. Integrated experimental medicine should increase the probability and predictability of success while controlling clinical trials costs. Finally, the societal perspective and patient empowerment also offer additional approaches to demonstrate the benefit of a new drug in the CNS field.

Design, Synthesis and Biological Investigation of Flavone Derivatives as Potential Multi-Receptor Atypical Antipsychotics

The design of a series of novel flavone derivatives was synthesized as potential broad-spectrum antipsychotics by using multi-receptor affinity strategy between dopamine receptors and serotonin receptors. Among them, 7-(4-(4-(6-fluorobenzo[d]isoxazol-3-yl) piperidin- 1-yl) butoxy)-2,2-dimethylchroman-4-one (6j) exhibited a promising preclinical profile. Compound 6j not only showed high affinity for dopamine D₂, D₃, and serotonin 5-HT_1A, 5-HT_2A receptors, but was also endowed with low to moderate activities on 5-HT_2C, α₁, and H₁ receptors, indicating a low liability to induce side effects such as weight gain, orthostatic hypotension and QT prolongation. In vivo behavioral studies suggested that 6j has favorable effects in alleviating the schizophrenia-like symptoms without causing catalepsy. Taken together, compound 6j has the potential to be further developed as a novel atypical antipsychotic.

The association between receptor binding affinity and metabolic side effect profile of antipsychotics and major cardio- and cerebrovascular events: A case/non-case study using VigiBase

Antipsychotics (APs) have been associated with major adverse cardio- and cerebrovascular events (MACCE), but the underlying mechanisms are unclear. Our aim was to elucidate the association between APs, stratified for receptor affinity and metabolic side effects (MSE), in the reporting of MACCE. A case/non-case study was conducted using data from the WHO global Individual Case Safety Report (ICSR) database, VigiBase, among all reports associated with an AP. Cases were ICSRs of MACCE, while non-cases were all other adverse drug reactions (ADRs). APs were classified by AP group, the degree of receptor affinity for adrenergic, dopaminergic, muscarinic, histaminic, and serotoninergic receptors and by MSE profile. The strength of the association was estimated with logistic regression and expressed as crude and adjusted reporting odds ratios (ROR_adj.) with corresponding 95% confidence intervals (95%CIs). We identified 4987 reports of MACCE and 328,907 reports of other ADRs. Atypical APs (ROR_adj. 2.46; 95%CI 2.20-2.74) were significantly associated with the reporting of MACCE compared to typical ones. APs with high affinity for Adrenergic alfa-1 (ROR_adj. 2.98; 95%CI 1.93-4.59), Histaminic H₁ (ROR_adj. 2.31; 95%CI 1.98-2.68), Muscarinic M₁ (ROR_adj. 1.87; 95%CI 1.74-2.01), and Serotoninergic 5-HT_2A (ROR_adj. 3.19; 95%CI 2.07-4.92) were associated with a higher risk of reporting of MACCE compared to low affinity. APs with higher-risk of MSE were associated with higher risk of reporting of MACCE (ROR_adj. 1.88; 95%CI 1.73-2.05) compared to the lower-risk. APs with high affinity for Adrenergic alfa-1, Histaminic H₁, Muscarinic M₁, and Serotoninergic 5-HT_2A receptors and with high-risk of MSE may explain the occurrence of those events.

Association between polymorphisms of LEP, LEPR, DRD2, HTR2A and HTR2C genes and risperidone- or clozapine-induced hyperglycemia

Objective

To determine whether genetic polymorphisms related to pharmacodynamics with metabolic adverse effects, namely leptin promoter (LEP) rs7799039, leptin receptor rs1137101, dopamine D2 rs4436578, serotonin 5-HT2A rs6313, and serotonin 5-HT2C rs518147 and rs12836771, are associated with hyperglycemia induced by risperidone or clozapine in adult Thai patients with psychosis.

Methods

A total of 180 patients treated with risperidone-based (n=130) or clozapine-based (n=50) regimens were included in this study. Blood samples were analyzed for genotyping of the candidate genes and biochemical testing. Genotyping was performed by conducting a TaqMan real-time polymerase chain reaction-based analysis.

Results

The prevalence of hyperglycemia was higher in patients receiving clozapine (64.0%) than in those receiving risperidone (30.8%). Among the candidate genes, only the LEP rs7799039 polymorphism demonstrated a significant association with hyperglycemia (χ²=9.879, P=0.008) in patients treated with risperidone; patients with the AA genotype had the highest risk (41.1%), followed by those with AG (20.8%) and GG (0%) genotypes. Using the recessive genetic model (AA vs AG + GG), the odds ratio and 95% CI were 3.28 and 1.44 −7.50, respectively. None of the genes were associated with hyperglycemia in patients treated with clozapine. A binary logistic regression revealed that the LEP rs7799039 polymorphism demonstrated a significant association with hyperglycemia, independent of body-mass index (BMI) in patients receiving risperidone; the odds ratio (95% CI) was 3.188 (1.399–7.262), P=0.006. By contrast, none of the pharmacodynamic genetic factors, except for BMI, were significantly associated with hyperglycemia in patients receiving clozapine.

Conclusion

The risk of type 2 diabetes mellitus is associated with the LEP rs7799039 polymorphism in Thai adults receiving risperidone but not in those receiving clozapine. Clarifying underlying mechanisms and risk of hyperglycemia provides an opportunity to prevent impaired glucose metabolism in patients receiving risperidone or clozapine.

Brain signalling systems: A target for treating type I diabetes mellitus

From early to later stages of Type I Diabetes Mellitus (TIDM), signalling molecules including brain indolamines and protein kinases are altered significantly, and that has been implicated in the Metabolic Disorders (MD) as well as impairment of retinal, renal, neuronal and cardiovascular systems. Considerable attention has been focused to the effects of diabetes on these signalling systems. However, the exact pathophysiological mechanisms of these signals are not completely understood in TIDM, but it is likely that hyperglycemia, acidosis, and insulin resistance play significant roles. Insulin maintains normal glycemic levels and it acts by binding to its receptor, so that it activates the receptor's tyrosine kinase activity, resulting in phosphorylation of several substrates. Those substrates provide binding/interaction sites for signalling molecules, including serine/threonine kinases and indolamines. For more than two decades, our research has been focused on the mechanisms of protein kinases, CaM Kinase and Serotonin transporter mediated alterations of indolamines in TIDM. In this review, we have also discussed how discrete areas of brain respond to insulin or some of the pharmacological agents that triggers or restores these signalling molecules, and it may be useful for the treatment of specific region wise changes/disorders of diabetic brain.

Interest of pharmacoepidemiology for the study of psychotropic drugs

In psychiatry, drug evaluation using pharmacoepidemiological methods has been of growing interest in recent decades. Studies based on observational databases are particularly useful for psychotropic drugs due to their important prevalence in populations, and their use over long period. The authors discussed the specific interest of pharmacoepidemiological studies in the field of psychiatry through two examples: first, the use of antidepressants, and, second, the risks associated with antipsychotics.

Interest of pharmacoepidemiology for pharmacodynamics and analysis of the mechanism of action of drugs

Pharmacology is often divided in separate branches, such as molecular and cellular pharmacology, pharmacokinetics, pharmacodynamics, experimental and/or preclinical pharmacology, clinical pharmacology (and therapeutics), pharmacogenetics, pharmacogenomics, pharmacovigilance, pharmacoepidemiology, pharmacoeconomics… This enumeration gives a global picture of different scientific areas, which are however dealing with the same question. Another mindset should be a global interactive and continuous approach, which could be designed as "human pharmacology". An original and attractive way to illustrate this continuous approach is to combine pharmacodynamics and pharmacovigilance and/or pharmacoepidemiologic data. Coupling disproportionality analyses in pharmacovigilance databases or computerized health databases, with pharmacological characteristics of drugs (receptor affinity, for example) allows investigating in humans, the mechanism of adverse drug reactions. Examples of such analyses investigating the risk of movement disorders, diabetes related to psychoactive drugs, or the risk of adverse cardiac outcomes with different drugs (classical drugs or protein kinase inhibitors) are given. The increasing number of research works investigating this topic underlines the importance of this relatively new approach, which gives significant inputs for the better knowledge of drug safety.

Physiologically Based Modeling Approach to Predict Dopamine D2 Receptor Occupancy of Antipsychotics in Brain: Translation From Rat to Human

Receptor occupancy (RO) is a translational biomarker for assessing drug efficacy and safety. We aimed to apply a physiologically based pharmacokinetic (PBPK) modeling approach to predict the brain dopamine D2 RO time profiles of antipsychotics. Clozapine and risperidone were modeled together with their active metabolites, norclozapine and paliperidone, First, in PK‐Sim a rat PBPK model was developed and optimized using literature plasma PK data. Then, blood‐brain barrier parameters including the expression and efflux transport kinetics of P‐glycoprotein were optimized using literature microdialysis data on brain extracellular fluid (brainECF), which were further adapted when translating the rat PBPK model into the human PBPK model. Based on the simulated drug and metabolite concentrations in brainECF, drug‐D2 receptor binding kinetics (association and dissociation rates) were incorporated in MoBi to predict RO. From an extensive literature search, 32 plasma PK data sets (16 from rat and 16 from human studies) and 23 striatum RO data sets (13 from rat and 10 from human studies) were prepared and compared with the model predictions. The rat PBPK‐RO model adequately predicted the plasma concentrations of the parent drugs and metabolites and the RO levels. The human PBPK‐RO model also captured the plasma PK and RO levels despite the large interindividual and interstudy variability, although it tended to underestimate the plasma concentrations and RO measured at late time points after risperidone dosing. The developed human PBPK‐RO model was successfully applied to predict the plasma PK and RO changes observed after risperidone dose reduction in a clinical trial in schizophrenic patients.

What is pharmacoepidemiology? Definition, methods, interest and clinical applications

Clinical evaluation of drugs before approval is based on the experimental design of clinical trial with randomization of drug exposure. Unfortunately, conclusions of clinical trials are necessarily limited to patients included into the trials. It is thus necessary to compare these experimental data coming from clinical trials with the real use of drugs in clinical practice. Pharmacoepidemiology is the study of interactions between drugs and human populations, investigating, in real conditions of life, benefits, risks and use of drugs. Pharmacoepidemiology applies to drugs the methods and/or reasoning of both pharmacology and epidemiology. The development of pharmacoepidemiology should improve the "rational drug use".

Detecting a potential safety signal of antidepressants and type 2 diabetes: a pharmacovigilance-pharmacodynamic study

AIMS

Recent data suggest that antidepressants are associated with incident diabetes but the possible pharmacological mechanism is still questioned. The aim of the present study was to evaluate antidepressant's risk for reporting diabetes using disproportionality analysis of the FDA adverse events spontaneous reporting system (FAERS) database and to investigate possible receptor/transporter mechanisms involved.

METHODS

Data from 2004 to 2017 were analysed using OpenVigil2 and adjusted reporting odds ratio (aROR) for reporting diabetes was calculated for 22 antidepressants. Events included in the narrow scope of the SMQ 'hyperglycaemia/new-onset diabetes mellitus' were defined as cases and all the other events as non-cases. The pharmacodynamic profile was extracted using the PDSP and IUPHAR/BPS databases and the occupancy on receptors (serotonin, alpha adrenoreceptors, dopamine, muscarinic, histamine) and transporters (SERT, NET, DAT) was estimated. The relationship between aROR for diabetes and receptor occupancy was investigated with Pearson's correlation coefficient (r) and univariate linear regression.

RESULTS

Six antidepressants were associated with diabetes: nortriptyline with aROR [95% CI] of 2.01 [1.41-2.87], doxepin 1.97 [1.31-2.97], imipramine 1.82 [1.09-3.06], sertraline 1.47 [1.29-1.68], mirtazapine 1.33 [1.04-1.69] and amitriptyline 1.31 [1.09-1.59]. Strong positive correlation coefficients between occupancy and aROR for diabetes were identified for the receptors M₁ , M₃ , M₄ , M₅ and H₁ .

CONCLUSION

Most of the tricyclic antidepressants, mirtazapine and sertraline seem to be associated with reporting diabetes in FAERS. Higher degrees of occupancy on muscarinic receptors and H₁ may be a plausible pharmacological mechanism. Further clinical assessment and pharmacovigilance data is needed to validate this potential safety signal.

Antipsychotics use: 2006-2013 trends in prevalence and incidence and characterization of users

PURPOSE

The present study was conducted to describe antipsychotic (AP) prevalent and incident use, characteristics of AP users, and their trends in the French population.

METHODS

A cross-sectional study was repeated yearly from January 1, 2007 to December 31, 2013 (for prevalence analysis) or to December 31, 2012 (for incidence analysis) using the French Health Insurance reimbursement database (Echantillon Généraliste de Bénéficiaires, EGB). For each year studied, prevalent and incident AP users were described in terms of age and gender overall, and according to the type of AP (FGAPs or SGAPs) used at index date. In addition, concurrent medications and comorbidities that a priori contraindicate the use of drugs having atropinic properties were researched.

RESULTS

Prevalence and incidence remained relatively stable along the 2007-2013 period. Trends slightly decreased, from 2.07% (n = 10,252) to 2.05% (n = 11,015) for prevalence, and from 0.73% (n = 3461) to 0.66% (n = 3363) for incidence, especially in elderly, in contrast of children and adolescents (+ 39% for prevalence, from 184 to 271). The number of coprescribed drugs was found high (median = 5) and remained constant over time. In 2013, about 7% of prevalent AP users presented with a comorbidity increasing the risk of atropinic ADRs, and 36% used at least one concurrent atropinic drug. In incident AP users, these numbers were of 8 and 29%, respectively.

CONCLUSIONS

The present study highlighted a marked shift from FGAPs toward SGAPs, as well as an increase in AP use in children and adolescents in France.

Antipsychotic Drugs: From Receptor-binding Profiles to Metabolic Side Effects

BACKGROUND

Antipsychotic-induced metabolic side effects are major concerns in psychopharmacology and clinical psychiatry. Their pathogenetic mechanisms are still not elucidated.

METHODS

Herein, we review the impact of neurotransmitters on metabolic regulation, providing insights into antipsychotic-induced metabolic side effects.

RESULTS

Antipsychotic drugs seem to interfere with feeding behaviors and energy balance, processes that control metabolic regulation. Reward and energy balance centers in central nervous system constitute the central level of metabolic regulation. The peripheral level consists of skeletal muscles, the liver, the pancreas, the adipose tissue and neuroendocrine connections. Neurotransmitter receptors have crucial roles in metabolic regulation and they are also targets of antipsychotic drugs. Interaction of antipsychotics with neurotransmitters could have both protective and harmful effects on metabolism.

CONCLUSION

Emerging evidence suggests that antipsychotics have different liabilities to induce obesity, diabetes and dyslipidemia. However this diversity cannot be explained merely by drugs'pharmacodynamic profiles, highlighting the need for further research.

Unresolved Issues for Utilization of Atypical Antipsychotics in Schizophrenia: Antipsychotic Polypharmacy and Metabolic Syndrome

Atypical antipsychotics (AAP) are the prevailing form of schizophrenia treatment today due to their low side effects and superior efficacy. Nevertheless, some issues still need to be addressed. First, there are still a large number of patients with treatment-resistant schizophrenia (TRS), which has led to a growing trend to resort to AAP polypharmacy with few side effects. Most clinical treatment guidelines recommend clozapine monotherapy in TRS, but around one third of schizophrenic patients fail to respond to clozapine. For these patients, with clozapine-resistant schizophrenia AAP polypharmacy is a common strategy with a continually growing evidence base. Second, AAP generally have great risks for developing metabolic syndrome, such as weight gain, abnormality in glucose, and lipid metabolism. These metabolic side effects have become huge stumbling blocks in today's schizophrenia treatment that aims to improve patients' quality of life as well as symptoms. The exact reasons why this particular syndrome occurs in patients treated with AAP is as yet unclear though factors such as interaction of AAP with neurotransmitter receptors, genetic pholymorphisms, type of AAPs, length of AAP use, and life style of schizophrenic patients that may contribute to its development. The present article aimed to review the evidence underlying these key issues and provide the most reasonable interpretations to expand the overall scope of antipsychotics usage.

CYP2C19*17 protects against metabolic complications of clozapine treatment

OBJECTIVES

Clozapine (CZ) is the most effective drug for managing treatment-resistant schizophrenic disorders. Its use has been limited due to adverse effects, which include weight gain and new-onset diabetes, but the incidence of these varies between patients.

METHODS

We investigated 187 Clozapine Clinic patients (of whom 137 consented for genotyping) for the presence of CYP2C19*17 and its association with CZ and norclozapine (NCZ) levels, and clinical outcomes.

RESULTS

Thirty-nine percent of genotyped patients were carriers of the CYP2C 19*17 polymorphism. This group demonstrated significantly higher NCZ serum levels, and significantly lower fasting glucose (5.66 ± 1.19 vs 6.72 ± 3.01 mmol/l, P = 0.009) and Hb1Ac (35.36 ± 4.78 vs 49.40 ± 20.60 mmol/mol, P = 0.006) levels compared to non-carriers of this polymorphism. CZ-treated patients with CYP2C19*17/*17 had a significantly lower prevalence of diabetes as well as a higher likelihood of clinical improvement of their schizophrenia, compared to those without this polymorphism (P = 0.012 and P = 0.031, respectively).

CONCLUSIONS

Our data suggest that CYP2C19*17 ultra-rapid-metaboliser status is a protective factor against the development of diabetes during clozapine treatment, and increases the likelihood of improvement in schizophrenia. The role of NCZ in treatment response and side effects, including metabolic syndrome, warrants further pharmacogenetic, pharmacokinetic and pharmacodynamic studies.

Serotonin and Its Receptor as a New Antioxidant Therapeutic Target for Diabetic Kidney Disease

Diabetic kidney disease (DKD) is a widespread chronic microvascular complication of diabetes mellitus (DM), affects almost 30-50% of patients, and represents a leading cause of death of DM. Serotonin or 5-hydroxytryptamine (5-HT) is a multifunctional bioamine that has crucial roles in many physiological pathways. Recently, emerging evidence from experimental and clinical studies has demonstrated that 5-HT is involved in the pathogenesis of diabetic vascular complications. The 5-HT receptor (5-HTR) antagonists exert renoprotective effects by suppressing oxidative stress, suggesting that 5-HTR can be used as a potential target for treating DKD. In this review, therefore, we summarize the published information available for the involvement of 5-HT and 5-HTR antagonists in the pathogenesis of various diabetic complications with a particular focus of DKD. We conclude that 5-HTR is a potential therapeutic target for treating DKD, as it has been successfully applied in animal models and has currently being investigated in randomized and controlled clinical trials.

Adverse drug reactions of botulinum neurotoxin type A in children with cerebral palsy: a pharmaco-epidemiological study in VigiBase

AIM

The aim of this study was to assess the risk of adverse drug reactions (ADRs) with botulinum neurotoxin type A (BoNT-A) in children with cerebral palsy (CP) using the World Health Organization global individual case safety report (ICSR) database, VigiBase.

METHOD

We extracted all children ICSRs for ADRs with BoNT-A used as anti-spastic drug in CP recorded between 1995 and 2015 in VigiBase. We also performed a case/non-case method (disproportionality analysis) to assess the link between exposure to BoNT-A and each ADR of interest in children and adults, calculating reporting odds ratios (RORs).

RESULTS

In VigiBase, 162 ICSRs were registered. They involved mainly males (n=95, 59%) and mean (SD) age was 7 years 11 months (4y 4mo). The most frequent ADR was dysphagia (27 ICSRs, 17%) followed by asthenia and muscular weakness (25 ICSRs each, 16%). Nineteen ICSRs (12%) were lethal. There was a significant association between BoNT-A and death in children (ROR=11.1 95%, confidence interval [CI] 7.0-17.7) but not in adults.

INTERPRETATION

In children with CP, most ADRs seem to be linked to a systemic spread of BoNT-A. Our study suggests a higher risk of ADRs with BoNT-A in children than in adults.

The Obesity-Impulsivity Axis: Potential Metabolic Interventions in Chronic Psychiatric Patients

Pathological impulsivity is encountered in a broad range of psychiatric conditions and is thought to be a risk factor for aggression directed against oneself or others. Recently, a strong association was found between impulsivity and obesity which may explain the high prevalence of metabolic disorders in individuals with mental illness even in the absence of exposure to psychotropic drugs. As the overlapping neurobiology of impulsivity and obesity is being unraveled, the question asked louder and louder is whether they should be treated concomitantly. The treatment of obesity and metabolic dysregulations in chronic psychiatric patients is currently underutilized and often initiated late, making correction more difficult to achieve. Addressing obesity and metabolic dysfunction in a preventive manner may not only lower morbidity and mortality but also the excessive impulsivity, decreasing the risk for aggression. In this review, we take a look beyond psychopharmacological interventions and discuss dietary and physical therapy approaches.

An original pharmacoepidemiological-pharmacodynamic method: application to antipsychotic-induced movement disorders

AIMS

Pharmacovigilance databases are usually used to detect new potential signals that are relevant for drug safety. They are seldom used for explanatory purposes, e.g. to understand the mechanisms of adverse drug reactions (ADRs). The aim of the present study was to combine pharmacovigilance and pharmacodynamic data to investigate the association between dopamine D2, serotonin 5HT2A, and muscarinic M1 receptor occupancy and the risks of antipsychotic drug (AP)-induced movement disorders.

METHODS

First, we performed a case-noncase analysis using spontaneous reports from the World Health Organization (WHO) Global Individual Case Safety Report (ICSR) database, VigiBase®. We thus measured the risk of reporting movement disorders compared with all other ADRs [expressed as a reporting odds ratio (ROR)] for APs. Second, we performed a linear regression analysis to explore the association between the estimated risk of reporting for individual drugs and their receptor occupancy properties, for D2, 5HT2A and M1 receptors.

RESULTS

Compared with second-generation APs, first-generation APs were found to be significantly more associated with the reporting of movement disorders in general but also with dystonia, Parkinsonism, akathisia and tardive dyskinesia, irrespective of gender. A significant inverse correlation was found between the ROR for movement disorders and the receptor occupancy of 5HT2A [P < 0.001; R²  = 0.51; slope = -0.014; 95% confidence interval (CI) (-0.029, 0.001)], M1 (P < 0.001; R²  = 0.56; slope = -0.014; 95% CI (-0.028, 0.001) but not D2 dopamine (P = 0.54; R²  = 0.02; slope = -0.003; 95% CI (-0.007, 0.001) receptors.

CONCLUSIONS

Using the example of AP-induced movement disorders, the present study underlines the value of the pharmacoepidemiological-pharmacodynamic method to explore ADR mechanisms in humans and real-life settings.

Translational research on cognitive and behavioural disorders in neurological and psychiatric diseases

The important medical and social burden of nervous system diseases contrasts with the currently limited therapeutic armamentarium and with the difficulty encountered in developing new therapeutic options. These failures can be explained by the conjunction of various phenomena related to the limitations of animal models, the narrow focus of research on precise pathophysiological mechanisms, and methodological issues in clinical trials. It is perhaps the paradigm itself of the way research is conducted that may be the real reason for our incapacity to find effective strategies. The purpose of this workshop was to define overall lines of research that could lead to the development of effective novel therapeutic solutions. Research has long focused on diseases per se rather than on cognitive and behavioural dimensions common to several diseases. Their expression is often partial and variable, but can today be well-characterised using neurophysiological or imaging methods. This dimensional or syndromic vision should enable a new insight to the question, taking a transnosographic approach to re-position research and to propose: translational models exploring the same functions in animal models and in humans; identification of homogeneous groups of patients defined according to the clinical, anatomico-functional and molecular characteristics; and preclinical and clinical developments enriched by the use of cognitive-behavioural, biological neurological, and imaging biomarkers. For this mutation to be successful, it must be accompanied by synchronised action from the public authorities and by ad hoc measures from the regulatory agencies.