Brexpiprazole: so far so good

Anxiety disorders, PTSD and OCD: systematic review of approved psychiatric medications (2008-2024) and pipeline phase III medications

Objective

This systematic review examines psychiatric medications approved by the FDA for anxiety disorders, post-traumatic stress disorder (PTSD) and obsessive-compulsive disorder (OCD) from 2008 to 2024 and describes the mechanism of action, indications for both labelled and off-label uses, evidence for efficacy, dosing and adverse effects for each medication.

Methods

The methodology involved a literature search of the PubMed database for studies published from 1 January 2008 to 31 December 2024 on FDA-approved psychiatric medications and phase III pipeline medications, using the keywords: "anxiety" OR "PTSD" OR "OCD" AND "psychopharm*" OR "medic*" OR "pharm*". The authors conducted independent assessments of the resulting articles and reached a consensus on eligible studies to include in this systematic review.

Results

Our review revealed that, in the past 16 years, the FDA approved only two medications for anxiety disorders (a delayed-release form of duloxetine for generalized anxiety disorder and an extended-release form of lorazepam) and none for PTSD or OCD. We also identified 14 pipeline medications for anxiety disorders, eight for PTSD and one for OCD, all of which are currently in phase III clinical trials.

Conclusion

Our results showed a paucity of new medications for anxiety disorders and none for PTSD and OCD in the past 16 years. However, phase III psychiatric medications for anxiety disorders, PTSD and OCD seem to show several agents with novel mechanisms of action, various modes of administration, and improved side-effect profiles.

Exposure-Response Modeling in Adults and Adolescents With Schizophrenia to Support the Extrapolation of Brexpiprazole Efficacy to Adolescents

In order to accelerate drug development and avoid unnecessary drug trials in vulnerable pediatric populations, the US Food and Drug Administration (FDA) released a general advice letter to sponsors permitting the effectiveness of atypical antipsychotics for the treatment of schizophrenia in adults to be extrapolated to adolescents. Extrapolation is based on the evidence-based assumptions that (1) disease characteristics and (2) response to therapy, are similar in adults and adolescents. Whereas the FDA validated the extrapolation approach using data from multiple drug development programs, aripiprazole data are the most relevant to confirm the validity of the extrapolation approach for brexpiprazole, since aripiprazole and brexpiprazole both modulate dopaminergic and serotonergic signaling in the brain. The aims of this analysis were (1) to quantitatively assess the aripiprazole exposure (average steady-state concentration)-response (Positive and Negative Syndrome Scale total score change from baseline) similarity between adults and adolescents with schizophrenia, (2) to extend the aripiprazole exposure-response modeling to brexpiprazole using adult data, and (3) to use the brexpiprazole model to predict schizophrenia symptom response in adolescents. Disease-drug-dropout models were developed using patient-level data from clinical studies of aripiprazole (1007 adults, 294 adolescents) and brexpiprazole (1235 adults) in schizophrenia. The aripiprazole model demonstrated similar exposure-response between adults and adolescents with schizophrenia, validating the extrapolation approach. Extrapolation of the brexpiprazole adult exposure-response model to adolescents predicted the efficacy of brexpiprazole in adolescents aged 13-17 years with schizophrenia.

Definition, assessment and treatment of cognitive impairment associated with schizophrenia: expert opinion and practical recommendations

A considerable proportion of patients with schizophrenia perform below population norms on standardized neuropsychological tests, and the performance of those performing within normal range is lower than predicted based on parental education. Cognitive impairment predates the onset of psychosis, is observed during symptom remission and in non-affected first-degree relatives of patients. At the present time, cognitive deficits are regarded as key features of schizophrenia, important determinants of poor psychosocial outcome and targets for both pharmacological and non-pharmacological treatment strategies. A group of eight key opinion leaders reviewed and discussed latest advances in scientific research and current good clinical practices on assessment, management, and treatment of CIAS. In the present paper they summarize the current evidence, identify main gaps between current knowledge and mental health services clinical practice, and provide practical recommendations to reduce the gap.

Insights into the Medical Evaluation of Ekbom Syndrome: An Overview

Ekbom syndrome, also known as delusional parasitosis (DP) or delusional infestation, is an uncommon psychiatric disorder distinguished by an enduring conviction of parasitic infestation, persisting notwithstanding the presence of medical evidence to the contrary. Primarily affecting middle-aged women, DP can manifest either as isolated psychological distress or as a component within a more intricate psychiatric framework, substantially influencing the quality of life for affected individuals. Its pathophysiological mechanism involves uncertain dopaminergic imbalances and dysfunction in the dopamine transporter system. Dermatologists often play a pivotal role in diagnosis, as patients first seek dermatological assessments of their signs and symptoms. However, DP frequently originates from underlying psychiatric disorders or medical variables, manifesting with neurological and infectious causative factors. The diagnostic complexity is attributed to patients' resolute convictions, leading to delayed psychiatric intervention. First-line DP treatment involves antipsychotics, with newer agents demonstrating promising prospects, but the lack of standardized protocols poses a significant therapeutic challenge. In this narrative review, both a comprehensive approach to this uncommon pathology and an update on the state of knowledge in this medical subfield focused on optimizing the management of DP are provided. The complexity of DP underlying its uncommon nature and the incomplete understanding of its pathophysiology highlight the need for further research through multicenter studies and multidisciplinary teams to enhance therapeutic efficacy and safety.

Brexpiprazole Attenuates Aggression, Suicidality and Substance Use in Borderline Personality Disorder: A Case Series

Background: Borderline personality disorder (BPD) is a heterogeneous and highly comorbid disorder. Suicidality, aggression and substance abuse are common presentations of BPD. Our case series is the first to highlight the role of brexpiprazole in improving these symptoms in patients with BPD. Case presentation: We describe three cases demonstrating the role of brexpiprazole in improving BPD's prominent features and comorbidities. All cases improved when brexpiprazole was added to their treatment regime. Case 1: A 26-year-old woman who was diagnosed with BPD and cyclothymia, presented to the psychiatric emergency unit with impulsive suicidal behaviour. Case 2: A 43-year-old woman suffering from BPD sought help due to her violent behaviour and emotional dysregulation. Case 3: A 22-year-old woman with underlying attention deficit and hyperactivity disorder, polysubstance use disorder and BPD presented with dysregulated emotions. Conclusions: Our case series provides anecdotal evidence of the potential role of brexpiprazole in attenuating suicidality, aggression and substance abuse in patients with BPD. We postulate that brexpiprazole's high affinity for the 5HT1A/5HT2A receptors, coupled with its low intrinsic effect on the D2/D3 receptor system, is fundamental in its actions to stabilise the aberrant dopaminergic and serotonergic signalling in BPD. Future research should focus on well-designed clinical trials investigating the efficacy of brexpiprazole in patients with BPD.

Third-Generation Antipsychotics and Lurasidone in the Treatment of Substance-Induced Psychoses: A Narrative Review

This narrative review explores the efficacy and tolerability of third-generation antipsychotics (TGAs)-aripiprazole, cariprazine, brexpiprazole, and lurasidone-for the management of substance-induced psychosis (SIP). SIP is a psychiatric condition triggered by substance misuse or withdrawal, characterized by unique features distinct from those of primary psychotic disorders. These distinctive features include a heightened prevalence of positive symptoms, such as hallucinations and delusions, in addition to a spectrum of mood and cognitive disturbances. This review comprehensively investigates various substances, such as cannabinoids, cocaine, amphetamines, and LSD, which exhibit a greater propensity for inducing psychosis. TGAs exhibit substantial promise in addressing both psychotic symptoms and issues related to substance misuse. This review elucidates the distinctive pharmacological properties of each TGA, their intricate interactions with neurotransmitters, and their potential utility in the treatment of SIP. We advocate for further research to delineate the long-term effects of TGAs in this context and underscore the necessity for adopting an integrated approach that combines pharmacological and psychological interventions. Our findings underscore the intricate and multifaceted nature of treating SIP, highlighting the potential role of TGAs within therapeutic strategies.

Preclinical evidence for the use of the atypical antipsychotic, brexpiprazole, for opioid use disorder

Opioid addiction is characterized by adaptations in the mesolimbic dopamine system that occur during chronic opioid use. Alterations in dopaminergic transmission contribute to pathological drug-seeking behavior and other symptoms associated with opioid withdrawal following drug discontinuation, making drug abstinence challenging and contributing to high rates of relapse among those suffering from substance use disorder. Recently, the use of dopamine partial agonists has been proposed as a potential strategy to restore dopaminergic signalling during drug withdrawal, while avoiding the adverse side effects associated with stronger modulators of dopaminergic transmission. We investigated the effects of the atypical antipsychotic brexpiprazole, which is a partial agonist at dopamine D2 and D3 receptors, in a mouse model of opioid dependence. The development of opioid dependence in mice is characterized by locomotor sensitization, analgesic tolerance, opioid-induced hyperalgesia, and drug-seeking behavior. We set up four paradigms to model the effects of brexpiprazole on each of these adaptations that occur during chronic opioid use in male and female C57BL/6J mice. Concomitant treatment of brexpiprazole during chronic morphine administration attenuated the development of locomotor sensitization. Brexpiprazole treatment abolished morphine place preference and blocked reinstatement of this behavior following extinction. Brexpiprazole treatment did not alter morphine analgesia, nor did it impact the development of morphine tolerance. However, brexpiprazole treatment did prevent the expression of opioid-induced hyperalgesia in a tail-withdrawal assay, while failing to improve somatic withdrawal symptoms. Altogether, these results provide preclinical evidence for the efficacy of brexpiprazole as a modulator of dopamine-dependent behaviors during opioid use and withdrawal.

The pharmacogenetics of the new-generation antipsychotics - A scoping review focused on patients with severe psychiatric disorders

Exploring the possible correlations between gene variations and the clinical effects of the new-generation antipsychotics is considered essential in the framework of personalized medicine. It is expected that pharmacogenetic data will be useful for increasing the treatment efficacy, tolerability, therapeutic adherence, functional recovery, and quality of life in patients with severe psychiatric disorders (SPD). This scoping review investigated the available evidence about the pharmacokinetics, pharmacodynamics, and pharmacogenetics of five new-generation antipsychotics, i.e., cariprazine, brexpiprazole, aripiprazole, lumateperone, and pimavanserin. Based on the analysis of 25 primary and secondary sources and the review of these agents' summaries of product characteristics, aripiprazole benefits from the most relevant data about the impact of gene variability on its pharmacokinetics and pharmacodynamics, with significant consequences on this antipsychotic's efficacy and tolerability. The determination of the CYP2D6 metabolizer status is important when administering aripiprazole, either as monotherapy or associated with other pharmacological agents. Allelic variability in genes encoding dopamine D2, D3, and serotonin, 5HT2A, 5HT2C receptors, COMT, BDNF, and dopamine transporter DAT1 was also associated with different adverse events or variations in the clinical efficacy of aripiprazole. Brexpiprazole also benefits from specific recommendations regarding the CYP2D6 metabolizer status and the risks of associating this antipsychotic with strong/moderate CYP2D6 or CYP3A4 inhibitors. US Food and Drug Administration (FDA) and European Medicines Agency (EMA) recommendations about cariprazine refer to possible pharmacokinetic interactions with strong CYP3A4 inhibitors or inducers. Pharmacogenetic data about cariprazine is sparse, and relevant information regarding gene-drug interactions for lumateperone and pimavanserin is yet lacking. In conclusion, more studies are needed to detect the influence of gene variations on the pharmacokinetics and pharmacodynamics of new-generation antipsychotics. This type of research could increase the ability of clinicians to predict favorable responses to specific antipsychotics and to improve the tolerability of the treatment regimen in patients with SPD.

Drug repurposing: re-inventing therapies for cancer without re-entering the development pipeline—a review

While majority of the current treatment approaches for cancer remain expensive and are associated with several side effects, development of new treatment modalities takes a significant period of research, time, and expenditure. An alternative novel approach is drug repurposing that focuses on finding new applications for the previously clinically approved drugs. The process of drug repurposing has also been facilitated by current advances in the field of proteomics, genomics, and information computational biology. This approach not only provides cheaper, effective, and potentially safer drugs with less side effects but also increases the processing pace of drug development. In this review, we wish to highlight some recent developments in the area of drug repurposing in cancer with a specific focus on the repurposing potential of anti-psychotic, anti-inflammatory and anti-viral drugs, anti-diabetic, antibacterial, and anti-fungal drugs.

Pharmacological strategies for sexual recovery in men undergoing antipsychotic treatment

INTRODUCTION

: First- and second-generation antipsychotics are highly accountable for causing a plethora of medical side effects, ranging from metabolic imbalances to sexual dysfunction (SD), that frequently undermine patient-doctor relationships. Nevertheless, to date antipsychotics are one of the best treatment options for dealing with numerous either acute or chronic conditions like agitation, suicidality, depression, dementia, and of course psychosis. For these reasons, clinicians need to handle them wisely to preserve patients' sexual health, avoid poor therapeutic adherence and prevent high rates of therapy drop-out.

AREAS COVERED

: This article reviews the literature on pharmacologic approaches for management strategies in men who are administered with antipsychotics and developed SD. The etiology of antipsychotic-induced SD is also discussed.

EXPERT OPINION

: Clinicians must consider sexual life as a major health domain. To do so, a first step would be to measure and monitor sexual function by means of psychometric tools. Secondly, primary prevention should be conducted when choosing antipsychotics, i.e., picking sex-sparing compounds like aripiprazole or brexpiprazole. Thirdly, if sexolytic compounds cannot be dismissed, such as first-generation antipsychotics, risperidone, paliperidone, or amisulpride, then aripiprazole 5-20 mg/day adjunctive therapy has proven to be most effective in normalizing prolactin levels and consequently treating antipsychotic-induced SD.

Polypharmacology: The science of multi-targeting molecules

Polypharmacology is a concept where a molecule can interact with two or more targets simultaneously. It offers many advantages as compared to the conventional single-targeting molecules. A multi-targeting drug is much more efficacious due to its cumulative efficacy at all of its individual targets making it much more effective in complex and multifactorial diseases like cancer, where multiple proteins and pathways are involved in the onset and development of the disease. For a molecule to be polypharmacologic in nature, it needs to possess promiscuity which is the ability to interact with multiple targets; and at the same time avoid binding to antitargets which would otherwise result in off-target adverse effects. There are certain structural features and physicochemical properties which when present would help researchers to predict if the designed molecule would possess promiscuity or not. Promiscuity can also be identified via advanced state-of-the-art computational methods. In this review, we also elaborate on the methods by which one can intentionally incorporate promiscuity in their molecules and make them polypharmacologic. The polypharmacology paradigm of "one drug-multiple targets" has numerous applications especially in drug repurposing where an already established drug is redeveloped for a new indication. Though designing a polypharmacological drug is much more difficult than designing a single-targeting drug, with the current technologies and information regarding different diseases and chemical functional groups, it is plausible for researchers to intentionally design a polypharmacological drug and unlock its advantages.

Efficacy and safety of adjunctive serotonin-dopamine activity modulators in major depression: A meta-analysis of randomized controlled trials

Serotonin dopamine activity modulators have been approved as an adjunctive treatment to antidepressants in patients with inadequate response. These drugs have been proposed to have a beneficial effect on cognition, sleep-related problems, and other affective symptoms in patients of depression. Previous studies have shown inconsistent evidence and have not reported a pooled effect of the two drugs of this class viz., aripiprazole and brexpiprazole. This meta-analysis evaluated the effect of augmentation with serotonin dopamine activity modulator (SDAM) drugs in patients with major depression. The meta-analysis protocol was made as per PRISMA-P guidelines and registered in PROSPERO. PubMed/MEDLINE, Cochrane Clinical Trial registry, EudraCT databases were searched with prespecified search terms. A random-effects meta-analysis was performed using the meta package in R software. Fifteen studies were included in this meta-analysis. The random effects model analysis observed a pooled effect of 1.55 [95% CI 1.32-1.84; prediction interval: 0.95-2.55, z = 5.19 (p < 0.0001)] for remission between the SDAM and placebo groups. A pooled effect of 1.58 [95% CI 1.37-1.83; prediction interval: 1.00-2.51, z = 6.34 (p<0.0001)] for adverse events and 0.72 [95% CI 0.48-1.08) prediction interval: 0.46-1.12] [z = -1.58 (p = 0.113)] for serious adverse events was observed. No significant publication bias was noticed. The quality of the evidence was rated as high. Adjunct SDAM increased remission in patients and had no significant effect on serious adverse events compared to placebo. Therefore, we conclude that SDAM drugs can be an effective and safe antidepressant augmentation strategy in MDD patients. This article is protected by copyright. All rights reserved.

Engineered PLGA microspheres for extended release of brexpiprazole: in vitro and in vivo studies

OBJECTIVE

To develop poly(d,l-lactide-co-glycolide) (PLGA) microspheres to achieve controlled and sustained release of brexpiprazole in vivo.

METHODS

Brexpiprazole microspheres were prepared by oil-in-water emulsion-solvent evaporation method and evaluated for morphology, particle size, encapsulation efficiency, drug loading, conformation and compatibility of drug and polymer, in vitro release, and in vivo pharmacokinetics. By establishing the relationship between in vitro and in vivo release, it helps identify the appropriate in vitro release conditions to explore release profiles of brexpiprazole microspheres.

RESULTS

Porous PLGA microspheres with near spherical morphology were obtained displaying an average diameter of 20.43 ± 0.06 μm, a drug loading capacity of 27.24 ± 0.33% and an encapsulation efficiency of 81.87 ± 1.07%. Fourier transform infrared spectroscopy (FTIR), powder X-ray diffraction (PXRD), and differential scanning calorimetry (DSC) analysis showed that some drugs encapsulated in the microspheres remained in the amorphous state and some were in the crystalline state. Different release setups resulted in different release kinetics. The dialysis release setup displayed a cumulative release of about 65% within 60 days, while the sample-and-separate setup showed a cumulative release of about 77% within 35 days. Per pharmacokinetic studies in rats, a burst phase in the plasma concentration-time curve was observed after intramuscular injection in the first 2 h followed by a clear zero-order release phase. Overall, brexpiprazole achieved in vivo sustained release from PLGA microspheres for up to 40 days.

CONCLUSION

A PLGA microsphere loaded with brexpiprazole was successfully developed and demonstrated potential for extended-release of therapeutics for schizophrenia treatment.

TPN672: A Novel Serotonin-Dopamine Receptor Modulator for the Treatment of Schizophrenia

TPN672 [7-(2-(4-(benzothiophen-4-yl) piperazin-1-yl)ethyl)quinolin-2(1H)-one maleate] is a novel antipsychotic candidate with high affinity for serotonin and dopamine receptors that is currently in clinical trial for the treatment of psychiatric disorders. In vitro binding study showed that TPN672 exhibited extremely high affinity for serotonin 1A receptor (5-HT1AR) (K i = 0.23 nM) and 5-HT2AR (K i = 2.58 nM) as well as moderate affinity for D3R (K i = 11.55 nM) and D2R (K i = 17.91 nM). In vitro functional assays demonstrated that TPN672 acted as a potent 5-HT1AR agonist, D2R/D3R partial agonist, and 5-HT2AR antagonist. TPN672 displayed robust antipsychotic efficacy in rodent models (e.g., blocking phencyclidine-induced hyperactivity), significantly better than aripiprazole, and ameliorated negative symptoms and cognitive deficits in the sociability test, dark avoidance response, Morris water maze test, and novel object recognition test. The results of electrophysiological experiments showed that TPN672 might inhibit the excitability of the glutamate system through activating 5-HT1AR in medial prefrontal cortex, thereby improving cognitive and negative symptoms. Moreover, the safety margin (the ratio of minimum catalepsy-inducing dose to minimum effective dose) of TPN672 was about 10-fold, which was superior to aripiprazole. In conclusion, TPN672 is a promising new drug candidate for the treatment of schizophrenia and has been shown to be more effective in attenuating negative symptoms and cognitive deficits while having lower risk of extrapyramidal symptoms and hyperprolactinemia. SIGNIFICANCE STATEMENT: TPN672 is a promising new drug candidate for the treatment of schizophrenia and has been shown to be more effective in attenuating negative symptoms and cognitive deficits while having a lower risk of extrapyramidal symptoms and hyperprolactinemia. A phase I clinical trial is now under way to test its tolerance, pharmacokinetics, and pharmacodynamic effects in human volunteers. Accordingly, the present results will have significant impact on the development of new antischizophrenia drugs.

Irritability in Mood Disorders: Neurobiological Underpinnings and Implications for Pharmacological Intervention

Feeling irritable is a common experience, both in health and disease. In the context of psychiatric illnesses, it is a transdiagnostic phenomenon that features across all ages, and often causes significant distress and impairment. In mood disorders, irritability is near ubiquitous and plays a central role in diagnosis and yet, despite its prevalence, it remains poorly understood. A neurobiological model of irritability posits that, in children and adolescents, it is consequent upon deficits in reward and threat processing, involving regions such as the amygdala and frontal cortices. In comparison, in adults with mood disorders, the few studies that have been conducted implicate the amygdala, orbitofrontal cortices, and hypothalamus; however, the patterns of activity in these areas are at variance with the findings in youth. These age-related differences seem to extend to the neurochemistry of irritability, with links between increased monoamine transmission and irritability evident in adults, but aberrant levels of, and responses to, dopamine in youth. Presently, there are no specific treatments that have significant efficacy in reducing irritability in mood disorders. However, treatments that hold some potential and warrant further exploration include agents that act on serotonergic and dopaminergic systems, especially as irritability may serve as a prognostic indicator for overall clinical responsiveness to specific medications. Therefore, for understanding and treatment of irritability to advance meaningfully, it is imperative that an accurate definition and means of measuring irritability are developed. To achieve this, it is necessary that the subjective experience of irritability, both in health and illness, is better understood. These insights will inform an accurate, comprehensive, and valid interrogation of the qualities of irritability in health and illness, and allow not only a clinical appreciation of the phenomenon, but also a deeper understanding of its important role within the development and manifestation of mood disorders.

Brexpiprazole for the Treatment of Schizophrenia and Major Depressive Disorder: A Comprehensive Review of Pharmacological Considerations in Clinical Practice

Mood and psychotic disorders are a group of illnesses that affect behavior and cognition. Schizophrenia is characterized by positive symptoms, such as delusions and hallucinations, as well as negative symptoms. Major depressive disorder (MDD) is a mood disorder that affects the patient's emotions, energy, and motivation. Brexpiprazole works as a partial agonist at serotonin 5-hydroxytryptamine1A and dopamine D2 receptors and an antagonist at serotonin 5-hydroxytryptamine2A. Schizophrenia and MDD have a wide range of risk factors, both biological and environmental. Third generation antipsychotics, which include brexpiprazole, are the latest group of drugs to reach the market, demonstrating efficacy and tolerability. Patients with acute schizophrenia have responded well to brexpiprazole. In this regard, in patients who have MDD plus anxiety symptoms, brexpiprazole can be effective as an adjunctive therapy and can reduce anxiety symptoms. In summary, brexpiprazole has proved to be an effective alternative to typical or first and second-generation atypical antipsychotics.

Time to re-engage psychiatric drug discovery by strengthening confidence in preclinical psychopharmacology

BACKGROUND

There is urgent need for new medications for psychiatric disorders. Mental illness is expected to become the leading cause of disability worldwide by 2030. Yet, the last two decades have seen the pharmaceutical industry withdraw from psychiatric drug discovery after costly late-stage trial failures in which clinical efficacy predicted pre-clinically has not materialised, leading to a crisis in confidence in preclinical psychopharmacology.

METHODS

Based on a review of the relevant literature, we formulated some principles for improving investment in translational neuroscience aimed at psychiatric drug discovery.

RESULTS

We propose the following 8 principles that could be used, in various combinations, to enhance CNS drug discovery: (1) consider incorporating the NIMH Research Domain Criteria (RDoC) approach; (2) engage the power of translational and systems neuroscience approaches; (3) use disease-relevant experimental perturbations; (4) identify molecular targets via genomic analysis and patient-derived pluripotent stem cells; (5) embrace holistic neuroscience: a partnership with psychoneuroimmunology; (6) use translational measures of neuronal activation; (7) validate the reproducibility of findings by independent collaboration; and (8) learn and reflect. We provide recent examples of promising animal-to-human translation of drug discovery projects and highlight some that present re-purposing opportunities.

CONCLUSIONS

We hope that this review will re-awaken the pharma industry and mental health advocates to the opportunities for improving psychiatric pharmacotherapy and so restore confidence and justify re-investment in the field.

Regulation of Reactive Oxygen Species-Mediated Damage in the Pathogenesis of Schizophrenia

The biochemical integrity of the brain is paramount to the function of the central nervous system, and oxidative stress is a key contributor to cerebral biochemical impairment. Oxidative stress, which occurs when an imbalance arises between the production of reactive oxygen species (ROS) and the efficacy of the antioxidant defense mechanism, is believed to play a role in the pathophysiology of various brain disorders. One such disorder, schizophrenia, not only causes lifelong disability but also induces severe emotional distress; however, because of its onset in early adolescence or adulthood and its progressive development, consuming natural antioxidant products may help regulate the pathogenesis of schizophrenia. Therefore, elucidating the functions of ROS and dietary antioxidants in the pathogenesis of schizophrenia could help formulate improved therapeutic strategies for its prevention and treatment. This review focuses specifically on the roles of ROS and oxidative damage in the pathophysiology of schizophrenia, as well as the effects of nutrition, antipsychotic use, cognitive therapies, and quality of life on patients with schizophrenia. By improving our understanding of the effects of various nutrients on schizophrenia, it may become possible to develop nutritional strategies and supplements to treat the disorder, alleviate its symptoms, and facilitate long-term recovery.

Up-to-date expert opinion on the safety of recently developed antipsychotics

Introduction There are several new and emerging antipsychotic medication strategies recently marketed or under clinical development for the treatment of several mental disorders. There is the need to provide an up-to-date overview on the safety of this new generation of antipsychotic medications, which includes also the third-generation antipsychotics (TGA). Areas covered The authors aimed at providing a synthesis of the most current evidence about the safety profile of the recently developed and/or marketed antipsychotics. Qualitative synthesis followed an electronic search made inquiring of the following databases: MEDLINE, Embase, PsycINFO, and the Cochrane Library from inception until March 2020, combining free terms and MESH headings for the topics of TGA and recently developed and/or marketed antipsychotics as following: ((safety OR adverse events OR side effects) AND ((brexpiprazole OR cariprazine OR inhaled loxapine OR lumateperone (ITI-007) OR lurasidone OR pimavanserin OR roluperidone (MIN-101) OR transdermal patch asenapine)). Expert opinion Overall, newer antipsychotics display a good safety profile, with a well-demonstrated lower metabolic liability compared to second-generation antipsychotics. Furthermore, TGA appear to specifically target negative symptomatology and improving cognitive domains. Abbreviations Aps=Antipsychotic Drugs; AEs = Adverse Effects; EPS = Extrapyramidal Symptoms; NMS = Neuroleptic malignant syndrome; D = Dopamine; K_i = Inhibitory Constant; 5-HT = Serotonin; ECG = Electrocardiogram; H = Histamine; M = Muscarinic; BMI = Body Mass Index.

Post-hoc analysis investigating the safety and efficacy of brexpiprazole in Japanese patients with schizophrenia who were switched from other antipsychotics in a long-term study (Secondary Publication)

A post hoc analysis was performed using data obtained over eight weeks from 200 Japanese patients with schizophrenia who were switched to brexpiprazole monotherapy in a long‐term treatment study. The 8‐week period comprised of a 4‐week switching phase and a 4‐week post‐switch phase. For the antipsychotic switching schedule, brexpiprazole was first administered at 1 mg/day and increased to 2 mg/day by the end of week 4. Concurrently, the previous antipsychotic(s) was/were tapered gradually from the start of week 3 and discontinued by the end of week 4. Brexpiprazole could then be increased up to 4 mg/day according to the CGI‐I criteria. At week 8, 1.8%, 23.2%, 25.0%, and 50% of patients were administered daily brexpiprazole doses of 1, 2, 3, and 4 mg, respectively. The discontinuation rate at week 8 was 17.0%. The major reasons for discontinuation were consent withdrawal (9.5%), occurrence of adverse events (5.5%), and physician's decision (2.0%). Commonly reported adverse events were nasopharyngitis (13.5%), schizophrenia (9.0%), insomnia (6.5%), headache (5.5%), and akathisia (5.5%). The discontinuation rate was 4.9% for patients who were switched from aripiprazole as the primary antipsychotic and 25.4% for those who were switched from other antipsychotics. Owing to the serious adverse events that led to treatment discontinuation, careful switching to brexpiprazole is necessary in patients who previously used olanzapine as their primary antipsychotic.

A post hoc analysis was performed using data obtained over eight weeks from 200 Japanese patients with schizophrenia who were switched to brexpiprazole monotherapy in a long‐term treatment study. The 8‐week period comprised of a 4‐week switching phase and a 4‐week post‐switch phase. The discontinuation rate was 4.9% for patients who were switched from aripiprazole as the primary antipsychotic and 25.4% for those who were switched from other antipsychotics.

Dopamine Receptor Partial Agonists for the Treatment of Bipolar Disorder

Bipolar disorder is a chronic, disabling, and costly illness with frequent relapses and recurrences, high rates of co-morbid conditions, and poor adherence to treatment. Mood stabilizers and antipsychotics are the cornerstones of treatment. Dopamine receptor partial agonists are a novel class of antipsychotic agents with original pharmacodynamic properties. Among them, two have been approved by the US Food and Drug Administration for the treatment of bipolar disorder. Aripiprazole (oral formulation) has been approved as monotherapy for the treatment of manic/mixed episodes in adult and pediatric populations and for maintenance treatment in adults, and as adjunctive treatment to mood stabilizers, for the acute treatment of manic/mixed episodes and for maintenance in adults. An intramuscular formulation of aripiprazole has been approved for the treatment of agitation in mania and a long-acting injectable formulation has been approved as maintenance treatment. In the USA, cariprazine has been approved as monotherapy for the acute treatment of manic/mixed as well as bipolar depressive episodes. Brexpiprazole is not yet approved to treat bipolar disorder. The evidence supporting these indications is reviewed via an analysis of clinical registration trials as well as additional studies, on the basis of a systematic literature search. Further studies dealing with other aspects of bipolar illness are also presented. Aripiprazole and cariprazine are efficacious and generally well tolerated agents that have shown cost effectiveness, and may therefore enrich our therapeutic armamentarium for bipolar illness. Brexpiprazole, which displays an overall promising tolerability profile, deserves further efficacy studies.

Health Care Cost in Patients With Schizophrenia Treated With Brexpiprazole Versus Other Oral Atypical Antipsychotic Therapy

PURPOSE

Brexpiprazole is an oral atypical antipsychotic (OAA) for the treatment of schizophrenia (SCZ). This study compared all-cause and psychiatric inpatient hospitalization and medical costs in adult patients with SCZ newly treated with brexpiprazole versus other US Food and Drug Administration-approved OAAs in a real-world setting.

METHODS

This retrospective cohort study analyzed data from: (1) the IBM MarketScan Commercial and Medicare Supplemental databases, and the MarketScan Multi-State Medicaid database; and (2) the de-identified Optum Clinformatics Datamart. Adult patients were identified if they had SCZ and initiated either brexpiprazole or another OAA during the study identification period (July 1, 2015, to September 30, 2016, for MarketScan Commercial and Medicare Supplemental and for Optum; July 1, 2015, to June 30, 2016, for MarketScan Multi-State Medicaid) and had ≥12 months of continuous enrollment before (baseline) and after (follow-up) the first treatment date. Linear regression analyses were performed to test associations between treatment groups (brexpiprazole vs another OAA) and costs (total and medical); negative binomial regression models were used to estimate number of hospitalizations per year, adjusting for baseline characteristics and medication adherence to index treatment during the 12-month follow-up.

FINDINGS

The final study sample consisted of 6254 patients with SCZ: 176 initiated brexpiprazole; 391, ziprasidone; 453, paliperidone; 523, lurasidone; 786, aripiprazole; 1234, quetiapine; 1264, olanzapine; and 1427, risperidone. Controlling for baseline characteristics and medication adherence, the adjusted number of hospitalizations (both all-cause and psychiatric), all-cause total costs, and all-cause medical costs did not differ across groups. Brexpiprazole users had the lowest mean psychiatric costs among all OAA users ($12,013; 95% bootstrap CI, 7488-16,538). Compared with brexpiprazole users, paliperidone (incidence rate ratio [95% CI], 1.52 [1.05-2.19]; P = 0.027) and quetiapine (incidence rate ratio [95% CI], 1.47 [1.04-2.07]; P = 0.029) users had more psychiatric hospitalizations per year. Paliperidone had higher psychiatric costs than brexpiprazole (total, $32,066 [95% bootstrap CI, 28,779-35,353] vs $23,851 [18,907-28,795]; medical, $19,343 [16,294-22,392] vs $12,013 [7488-16,538]). Psychiatric medical costs were also $6744 higher in olanzapine users (95% bootstrap CI, 1694-11,795; P = 0.009) than in brexpiprazole users.

IMPLICATIONS

Patients with SCZ treated with brexpiprazole had fewer psychiatric hospitalizations and lower psychiatric costs than those treated with paliperidone. Differences in the number of all-cause hospitalizations and medical costs among treatments were not statistically significant. Although treatment decisions are driven by a number of factors (eg, clinical circumstances and drug costs), choice of OAA may affect health care costs.

Management of Dementia-Related Psychosis, Agitation and Aggression: A Review of the Pharmacology and Clinical Effects of Potential Drug Candidates

Along with cognitive decline, 90% of patients with dementia experience behavioral and psychological symptoms of dementia, such as psychosis, aggression, agitation, and depression. Atypical antipsychotics are commonly prescribed off-label to manage certain symptoms, despite warnings from the regulatory agencies regarding the increased risk of mortality associated with their use in elderly patients. Moreover, these compounds display a limited clinical efficacy, mostly owing to the fact that they were developed to treat schizophrenia, a disease characterized by neurobiological deficits. Thus, to improve clinical efficacy, it has been suggested that patients with dementia should be treated with exclusively designed and developed drugs that interact with pharmacologically relevant targets. Within this context, numerous studies have suggested druggable targets that might achieve therapeutically acceptable pharmacological profiles. Based on this, several different drug candidates have been proposed that are being investigated in clinical trials for behavioral and psychological symptoms of dementia. We highlight the recent advances toward the development of therapeutic agents for dementia-related psychosis and agitation/aggression and discuss the relationship between the relevant biological targets and their etiology. In addition, we review the compounds that are in the early stage of development (discovery or preclinical phase) and those that are currently being investigated in clinical trials for dementia-related psychosis and agitation/aggression. We also discuss the mechanism of action of these compounds and their pharmacological utility in patients with dementia.

Synthesis and Biological Evaluation of Five-Atom-Linker-Based Arylpiperazine Derivatives with an Atypical Antipsychotic Profile

Herein we describe a focused set of new arylpiperazine derivatives as potential broad-spectrum antipsychotics. The general structure contains a quinolinone-like moiety, an arylpiperazine moiety, and a five-atom linker. Among them, 7-(5-(4-(benzo[d]isothiazol-4-yl)piperazin-1-yl)pentyl)quinolin-2(1H)-one (S6) shows a promising preclinical profile. Compound S6, characterized by partial D₂ R agonism, 5-HT_1A R agonism, 5-HT_2A R antagonism, and blockade of SERT activities, was found to decrease psychosis- and depressive-like symptoms in rodents. The polypharmacological profile of S6 could provide opportunities for the treatment of various other central nervous system disorders such as anxiety, depression, and psychoses associated with dementia. Furthermore, S6 demonstrated acceptable safety, toxicology, and pharmacokinetic profiles, and has been selected as a preclinical candidate for further evaluation in schizophrenia.

Real-World Economic Outcomes of Brexpiprazole and Extended-Release Quetiapine Adjunctive Use in Major Depressive Disorder

Purpose

Major depressive disorder (MDD) is a chronic mental disorder with a substantial clinical and economic burden. Despite the efficacy of adjunctive atypical antipsychotics (AAP) for augmentation in patients with major depressive disorder (MDD) who failed first-line antidepressant therapy (ADT), little is known of the impact of AAP choices on healthcare resource use and costs in real-world practice. Therefore, this study compared real-world healthcare utilization and costs in patients with MDD treated with brexpiprazole or extended-release (XR) quetiapine as adjunctive treatment to ADT.

Patients and methods

Adults with MDD starting adjunctive treatment with brexpiprazole (n=844) or extended-release (XR) quetiapine (n=688) were identified in the adjudicated health plan claims data (07/2014 – 09/2016). Resource use and healthcare costs in the 6 months following treatment initiation were compared between non-matched populations, and between propensity score-matched groups, and by multivariable regression analyses.

Results

During follow-up, unadjusted all-cause hospitalization (6.6% vs 12.5%) and ED visits (17.0% vs 27.5%) were lower with brexpiprazole compared to quetiapine XR (both p<0.001). Brexpiprazole-treated patients had significantly lower mean medical costs (US$6,421 vs US$8,545, p=0.0123) but higher mean pharmacy costs (US$7,401 vs US$4,691, p<0.0001) than quetiapine XR-treated patients did. Total healthcare costs were not significantly different between the two cohorts. Propensity score-matched comparisons of 397 patients in each cohort showed no statistically significant difference in all-cause hospitalization, ED visits, and total healthcare costs; and significantly lower medical costs (US$5,719 vs US$8,602, p=0.0092) but higher pharmacy costs (US$7,091 vs US$5,091, p=0.0007) in brexpiprazole compared to quetiapine XR. In multivariable regressions, brexpiprazole was associated with 16.1% lower medical costs (p=0.0186) and 9.4% higher total healthcare costs (p=0.0463) as compared to quetiapine XR.

Conclusion

Significantly lower medical costs were observed in patients with MDD treated with brexpiprazole vs quetiapine XR.

The clozapine to norclozapine ratio: a narrative review of the clinical utility to minimize metabolic risk and enhance clozapine efficacy

Introduction: Clozapine remains the most effective antipsychotic for treatment-refractory schizophrenia. However, ~40% of the patients respond insufficiently to clozapine. Clozapine's effects, both beneficial and adverse, have been proposed to be partially attributable to its main metabolite, N-desmethylclozapine (NDMC). However, the relation of the clozapine to norclozapine ratio (CLZ:NDMC; optimally defined as ~2) to clinical response and metabolic outcomes is not clear.Areas covered: This narrative review comprehensively examines the clinical utility of the CLZ:NDMC ratio to reduce metabolic risk and increase treatment efficacy. The association of the CLZ:NDMC ratio with changes in psychopathology, cognitive functioning, and cardiometabolic burden will be explored, as well as adjunctive treatments and their effects.Expert opinion: The literature suggests a positive association between the CLZ:NDMC ratio and better cardiometabolic outcomes. Conversely, the CLZ:NDMC ratio appears inversely associated with better cognitive functioning but less consistently with other psychiatric domains. The CLZ:NDMC ratio may be useful for predicting and monitoring cardiometabolic adverse effects and optimizing potential cognitive benefits of clozapine. Future studies are required to replicate these findings, which if substantiated, would encourage examination of adjunctive treatments aiming to alter the CLZ:NDMC ratio to best meet the needs of the individual patient, thereby broadening clozapine's clinical utility.

Current Agents in Development for Treating Behavioral and Psychological Symptoms Associated with Dementia

Behavioral and psychological symptoms associated with dementia are highly prevalent and are associated with an increased risk of institutionalization and mortality. Current pharmacological treatments for these symptoms include cholinesterase inhibitors, antipsychotics, and selective serotonin reuptake inhibitors. When used for treating behavioral and psychological symptoms associated with dementia, they are associated with limited efficacy and/or serious adverse events. As such, there has been extensive research into novel agents with varying mechanisms of action targeting behavioral and psychological symptoms associated with dementia. In this article, we present the results of a comprehensive literature search and review that evaluates current agents that have completed or are currently in clinical trials for treating behavioral and psychological symptoms associated with dementia as a primary outcome. We highlight novel agents from miscellaneous drug classes, such as dextromethorphan/quinidine, bupropion/dextromethorphan, lumateperone, deudextromethorphan/quinidine, methylphenidate and scyllo-inositol, and drugs from various therapeutic classes (including atypical antipsychotics, selective serotonin reuptake inhibitors, and cannabinoids) that have demonstrated promising results and were generally well tolerated. Future research with large appropriately powered studies using validated outcome measures for behavioral and psychological symptoms associated with dementia should be conducted to further establish the clinical utility of these agents.

Medication-Induced Akathisia with Newly Approved Antipsychotics in Patients with a Severe Mental Illness: A Systematic Review and Meta-Analysis

BACKGROUND

Akathisia is a common and distressing movement disorder that can be associated with the use of antipsychotics. It is characterized by a subjective (inner restlessness) and an objective (excessive movements) component. Akathisia can have a negative impact on clinical outcome and even lead to treatment discontinuation. Although medication-induced akathisia is more commonly associated with the use of first-generation antipsychotics (FGAs), it also occurs with second-generation antipsychotics (SGAs), including the newly approved antipsychotics (NAPs) asenapine, lurasidone, iloperidone, cariprazine, and brexpiprazole. Until now, no meta-analysis has been published on the risk of akathisia for all NAPs, as monotherapy or adjunctive treatment, in patients with a severe mental illness.

OBJECTIVE

The primary objectives of this systematic review and meta-analysis were to (i) compare akathisia incidence rates of the NAPs, as monotherapy or adjunctive treatment, in adult patients with a severe mental illness (i.e., schizophrenia, bipolar disorder, or major depressive disorder), using data from published and unpublished randomized controlled trials; and (ii) examine the role of several study characteristics explaining differences in akathisia incidence rates between studies.

METHODS

A systematic literature search, using the PubMed, EMBASE, and Cochrane Library databases (until October 2018), was conducted for English-language placebo- as well as active-controlled clinical trials, including subjective (percentage of patients reporting akathisia) and/or scale-defined medication-induced akathisia incidence rates with NAPs (as monotherapy or as adjunctive treatment) in adult patients with schizophrenia, bipolar disorder, or major depressive disorder. Additional unpublished clinical trials were identified through the ClinicalTrials.gov electronic database. Two meta-analyses (incidence rates and odds ratio [OR] [placebo vs. active] of medication-induced akathisia with NAPs) were performed to obtain an optimal estimation of akathisia risks of adult patients with a severe mental illness under these treatment conditions and to assess the role of study characteristics.

RESULTS

Two hundred and thirteen reports were selected as potentially eligible for our meta-analysis. Of these, 48 met the inclusion criteria. Eight records, identified through the ClinicalTrials.gov database and cross-referencing, and which fulfilled the inclusion criteria, were added, resulting in a total of 56 records (iloperidone = 5, asenapine = 11, lurasidone = 15, brexpiprazole = 13, cariprazine = 12). The estimated weighted mean incidence rate of akathisia was 7.7% (95% confidence interval [CI] 6.5-9.1), with estimates being 3.9% (95% CI 2.4-6.3) for iloperidone, 6.8% (95% CI 5.1-9.0) for asenapine, 10.0% (95% CI 7.4-13.5) for brexpiprazole, 12.7% (95% CI 10.1-16.1) for lurasidone, and 17.2% (95% CI 13.4-22.1) for cariprazine. After Tukey-adjustment for multiple testing, the incidence rate of akathisia was significantly (p < 0.05) lower for iloperidone than for brexpiprazole, lurasidone, and cariprazine. In addition, the incidence rate of akathisia was significantly (p < 0.05) lower for asenapine than for lurasidone and cariprazine. Finally, the incidence rate of akathisia was significantly (p < 0.05) lower for brexpiprazole than for cariprazine. Type of medication (p < 0.0001), diagnosis (p = 0.02), and race (p = 0.0003) significantly explained part of the heterogeneity of the incidence estimates of akathisia between studies. The estimated weighted OR of akathisia under medication, compared with placebo, was 2.43 (95% CI 1.91-3.10). The OR was smallest for iloperidone (OR 1.20; 95% CI 0.42-3.45) and increased for brexpiprazole (OR 2.04; 95% CI 1.09-3.83), asenapine (OR 2.37; 95% CI 1.32-4.27), lurasidone (OR 3.74; 95% CI 2.32-6.02), and cariprazine (OR 4.35; 95% CI 2.80-6.75). Only type of medication (p = 0.03) explained systematic differences in the OR for akathisia between placebo versus active treatment across studies. After Tukey-adjustment for multiple testing, no significant differences between these ORs were found. The severity of akathisia with NAPs generally is mild to moderate, only leading to treatment discontinuation in a minority of cases (< 5%).

CONCLUSIONS

The use of a NAP raises the akathisia risk more than two-fold when compared with patients receiving placebo. Although distinctions between the different NAPs were not clear in placebo-controlled trials, the results of our meta-analyses and systematic review generally indicate that these differences more than likely reflect real differences, with iloperidone showing the most and cariprazine showing the least benign akathisia profile. Moreover, due to patient characteristics and methodological issues, incidence rates of akathisia with NAPs found in this meta-analysis may even be an underestimation of true incidence rates.

Brexpiprazole: A Review in Schizophrenia

Brexpiprazole (Rxulti^®, Rexulti^®) is an oral atypical antipsychotic agent approved for the treatment of schizophrenia in the EU (in adult patients) and the USA, as well as in some other countries, including Japan. Like aripiprazole, it is a partial agonist at dopamine D₂ and serotonin 5-HT_1A receptors and an antagonist at serotonin 5-HT_2A receptors. However, brexpiprazole displays less intrinsic activity at D₂ receptors and, coupled with actions at 5HT_1A, 5HT_2A and noradrenaline α_1B receptors that are at least as potent as its action at D₂ receptors, is predicted to demonstrate a lower propensity for activating adverse events and extrapyramidal symptoms than aripiprazole. Brexpiprazole 2-4 mg/day produced statistically significant and clinically meaningful improvements in overall symptomatology and psychosocial functioning compared with placebo in adults with acute exacerbation of schizophrenia. As maintenance treatment, brexpiprazole 1-4 mg/day significantly delayed the time to relapse compared with placebo in patients who were already stabilized on the drug and was associated with stabilization or continued improvement in patients' symptoms and functioning. Brexpiprazole was generally well tolerated, exhibiting an adverse event profile characterized by a relatively low incidence of activating and sedating adverse effects, small changes in QT interval and metabolic parameters that were not clinically significant, and moderate weight gain. Clinical evidence to date suggests it usefully extends the range of therapeutic options for schizophrenia.

Efficacy and metabolic effects of lurasidone versus brexpiprazole in schizophrenia: a network meta-analysis

Aim: To assess the relative efficacy and metabolic effects of lurasidone and brexpiprazole in the acute treatment of schizophrenia. Methods: Five lurasidone and three brexpiprazole trials were identified. In the absence of head-to-head trials, a Bayesian network meta-analysis comparing lurasidone and brexpiprazole was performed. Results: Nonstatistically significant differences in efficacy measures were observed between lurasidone and brexpiprazole. Significant differences favoring lurasidone for weight change (-0.69 kg; 95% CrI: -1.22 to -0.15), total cholesterol (-7.60 mg/dl; 95% CrI: -13.94 to -1.22), and low-density lipoprotein (-6.58 mg/dl; 95% CrI: -12.11 to -1.04) were observed, with a trend indicating half the risk of experiencing ≥7% weight gain. Conclusion: This network meta-analysis suggested that lurasidone had similar efficacy and fewer metabolic effects than brexpiprazole in patients with acute schizophrenia.

Perioperative implications of common and newer psychotropic medications used in clinical practice

Psychotropic medications are widely prescribed by clinicians as both primary therapy for a variety of psychiatric and neurodegenerative diseases and as adjunctive analgesics for use in the perioperative period. It is critical to understand various modes of action, drug-drug interactions, side effects, and clinical implications. Health care providers must understand how these medications interact with anesthetics, as well as other drugs used in perioperative care. We review relevant psychiatric and neurodegenerative diseases, psychotropic medications used to treat them, and how these medications interact with anesthetics and drugs used in perioperative care. We will also discuss emerging psychotropic drugs and the challenges they may create during the perioperative period. Future direction of investigation into the role of these drugs during the perioperative period and implications is also discussed.

Brexpiprazole: a new leaf on the partial dopamine agonist branch

OBJECTIVES

Brexpiprazole is a new dopamine partial agonist antipsychotic in the same class as aripiprazole. This paper will briefly review brexpiprazole and compare it with aripiprazole.

CONCLUSIONS

Brexpiprazole and aripiprazole are both partial agonists at dopamine D₂, and serotonin 5-HT_1A and antagonists at serotonin 5-HT_2A and noradrenergic α_1B receptors. However, the two drugs are significantly different in potencies at various receptors; neurochemical profiles predict that brexpiprazole may be comparable with aripiprazole in its antipsychotic efficacy but may cause less akathisia, extrapyramidal side effects (EPS) and activation. In pivotal trials brexpiprazole demonstrated antipsychotic efficacy in short and long-term studies; it was also found to be an effective adjunct in patients with major depression resistant to antidepressants. Akathisia can occur early in treatment with brexpiprazole, as can minor weight gain and prolactin elevation. Indirect data extrapolations from pivotal studies suggest that brexpiprazole and aripiprazole have comparable efficacy but brexpiprazole may cause less akathisia. Like aripiprazole, brexpiprazole has been approved in the USA for use in schizophrenia and antidepressant-resistant depression. Although much more clinical experience is needed, brexpiprazole appears to be distinct from aripiprazole and a promising new 'metabolically-friendly' antipsychotic option for treatment of psychoses and mood disorders.

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.

Adjunctive Brexpiprazole as a Novel Effective Strategy for Treating Major Depressive Disorder: A Systematic Review and Meta-Analysis

PURPOSE/BACKGROUND

Brexpiprazole was approved for adjunctive treatment of major depressive disorder (MDD) in 2015. Because only a small number of randomized controlled trials have investigated the use of brexpiprazole in MDD, we performed a meta-analysis.

METHODS/PROCEDURES

We systematically searched literatures in PubMed, Cochrane Library database, EMBASE, Google Scholar, and clinicaltrials.gov up to January 2016. The primary efficacy measure was the mean change in total Montgomery-Åsberg Depression Rating Scale (MADRS) score from baseline. Secondary efficacy measures were the mean change in total Hamilton Rating Scale for Depression (17 items) score from baseline and the response (≥50% reduction in MADRS total score) and remission (MADRS total score ≤ 10 with ≥50% reduction) rates.

FINDINGS/RESULTS

Four studies fulfilled the inclusion criteria and were included in the analysis. Brexpiprazole showed superior efficacy over placebo with effect sizes (mean differences) of -1.76 (95% confidence interval [CI], -2.45 to -1.07) for MADRS and -1.21 (95% CI, -1.71 to -0.72) for the 17-item Hamilton Rating Scale for Depression. The risk ratios for response and remission were 1.57 (95% CI, 1.29-1.91) and 1.55 (95% CI, 1.22-1.96), respectively. The incidences of discontinuation due to adverse events, akathisia, and weight increase were higher in the brexpiprazole group than in the placebo group, with risk ratios of 3.44 (95% CI, 1.52-7.80), 3.39 (95% CI, 2.08-5.51), and 4.36 (95% CI, 2.45-7.77), respectively, and the incidence of akathisia was related to the brexpiprazole dose.

IMPLICATIONS/CONCLUSIONS

Although our results suggest that brexpiprazole could be an effective adjunctive agent for MDD, they should be cautiously translated into clinical practice because the meta-analysis was based on only a handful of randomized controlled trials.

Adjunctive treatment of brexpiprazole with fluoxetine shows a rapid antidepressant effect in social defeat stress model: Role of BDNF-TrkB signaling

Addition of low doses of the atypical antipsychotic drug brexpiprazole with selective serotonin reuptake inhibitors (SSRIs) could promote antidepressant effect in patients with major depressive disorder although the precise mechanisms underlying the action of the combination are unknown. Combination of low dose of brexpiprazole (0.1 mg/kg) and SSRI fluoxetine (10 mg/kg) could promote a rapid antidepressant effect in social defeat stress model although brexpiprazole or fluoxetine alone did not show antidepressant effect. Furthermore, the combination significantly improved alterations in the brain-derived neurotrophic factor (BDNF) - TrkB signaling and dendritic spine density in the prefrontal cortex, hippocampus, and nucleus accumbens in the susceptible mice after social defeat stress. Interestingly, TrkB antagonist ANA-12 significantly blocked beneficial effects of combination of brexpiprazole and fluoxetine on depression-like phenotype. These results suggest that BDNF-TrkB signaling plays a role in the rapid antidepressant action of the combination of brexpiprazole and fluoxetine.