A review of the pharmacology, efficacy and tolerability of recently approved and upcoming oral antipsychotics: an evidence-based medicine approach

Nasal Delivery to the Brain: Harnessing Nanoparticles for Effective Drug Transport

The nose-to-brain drug-delivery system has emerged as a promising strategy to overcome the challenges associated with conventional drug administration for central nervous system disorders. This emerging field is driven by the anatomical advantages of the nasal route, enabling the direct transport of drugs from the nasal cavity to the brain, thereby circumventing the blood-brain barrier. This review highlights the significance of the anatomical features of the nasal cavity, emphasizing its high permeability and rich blood supply that facilitate rapid drug absorption and onset of action, rendering it a promising domain for neurological therapeutics. Exploring recent developments and innovations in different nanocarriers such as liposomes, polymeric nanoparticles, solid lipid nanoparticles, dendrimers, micelles, nanoemulsions, nanosuspensions, carbon nanotubes, mesoporous silica nanoparticles, and nanogels unveils their diverse functions in improving drug-delivery efficiency and targeting specificity within this system. To minimize the potential risk of nanoparticle-induced toxicity in the nasal mucosa, this article also delves into the latest advancements in the formulation strategies commonly involving surface modifications, incorporating cutting-edge materials, the adjustment of particle properties, and the development of novel formulations to improve drug stability, release kinetics, and targeting specificity. These approaches aim to enhance drug absorption while minimizing adverse effects. These strategies hold the potential to catalyze the advancement of safer and more efficient nose-to-brain drug-delivery systems, consequently revolutionizing treatments for neurological disorders. This review provides a valuable resource for researchers, clinicians, and pharmaceutical-industry professionals seeking to advance the development of effective and safe therapies for central nervous system disorders.

Efficacy of HP-3070, A Once-Daily Asenapine Transdermal System, in the Treatment of Adults with Schizophrenia: A PANSS Five-Factor Analysis

Introduction

HP-3070, a once-daily asenapine transdermal system, is the first antipsychotic "patch" formulation FDA approved for adults with schizophrenia. Positive and Negative Syndrome Scale (PANSS) score items can be grouped into a five-factor structure to describe specific schizophrenia symptom domains. This post hoc analysis of data from a pivotal study evaluated HP-3070's efficacy by examining these factors.

Methods

In a phase 3 study, adults with an acute exacerbation of schizophrenia were randomized to six weeks of treatment with HP-3070 3.8mg/24h, 7.6mg/24h, or placebo. An analysis was performed using the five PANSS factor domains (negative symptoms, positive symptoms, disorganized thought, uncontrolled hostility/excitement, anxiety/depression). Mixed-model repeated-measures (MMRM) analysis included change from baseline (CFB) in PANSS factor score as the repeated dependent variable, with country, treatment, visit, treatment by visit interaction, and baseline PANSS score as covariates.

Results

The analysis included 607 patients. Treatment with HP-3070 3.8mg/24h resulted in a statistically significant LS mean CFB (improvement) vs placebo at Weeks 4-6 for all domains except for anxiety/depression, where a numerical difference was observed in favor of active treatments. Among the domains, the positive symptom factor demonstrated the numerically greatest LS mean (SE) difference from placebo in CFB, which for HP-3070 7.6mg/24h was -2.0 [0.57] and for HP-3070 3.8mg/24h was -2.3 [0.57]; P<0.001 for both. Treatment effect size for the positive symptom factor using Cohen's d (95% confidence intervals) was 0.39 (0.17, 0.61) for HP-3070 7.6mg/24h and 0.45 (0.20, 0.64) for HP-3070 3.8mg/24h.

Discussion

Post hoc analysis using a PANSS five-factor model suggests that HP-3070 may address a broad range of symptoms in people with schizophrenia.

Evidence for Therapeutic Drug Monitoring of Atypical Antipsychotics

Second-generation antipsychotics (SGAs), also known as atypical antipsychotics, are a newer class of antipsychotic drugs used to treat schizophrenia, bipolar disorder, and related psychiatric conditions. The plasma concentration of antipsychotic drugs is a valid measure of the drug at its primary target structure in the brain, and therefore determines the efficacy and safety of these drugs. However, despite the well-known high variability in pharmacokinetics of these substances, psychiatric medication is usually administered in uniform dosage schedules. Therapeutic drug monitoring (TDM), as the specific method that can help personalised medicine in dose adjustment according to the characteristics of the individual patient, minimizing the risk of toxicity, monitoring adherence, and increasing cost-effectiveness in the treatment, thus seems to be an elegant tool to solve this problem. Non-response to therapeutic doses, uncertain adherence to medication, suboptimal tolerability, or pharmacokinetic drug-drug interactions are typical indications for TDM of SGAs. This review aims to summarize an overview of the current knowledge and evidence of the possibilities to tailor the dosage of selected SGAs using TDM, including the necessary pharmacokinetic parameters for personalised pharmacotherapy.

The role of the D3 dopamine receptor and its partial agonist cariprazine in patients with schizophrenia and substance use disorder

INTRODUCTION

Comorbidity of substance use disorder (SUD) with schizophrenia, referred to as dual disorder (DD), significantly increases morbidity and mortality compared to schizophrenia alone. A dopaminergic dysregulation seems to be a common pathophysiological basis of the comorbidity.

AREAS COVERED

This article reports the current evidence on the role of dopamine dysregulations in DD, the pharmacological profile of cariprazine, a partial agonist of D3 and D2 dopamine receptors, and first clinical observations that may support its usefulness in the therapy of DD. PubMed/MEDLINE was searched for the keywords 'cariprazine,' 'schizophrenia,' 'dual disorder,' 'dopamine,' and 'dopamine receptor.' Preclinical and clinical studies, and reviews published in English were retrieved.

EXPERT OPINION

Although the management of DD remains challenging, and the evidence for pharmacologic treatments is still unsatisfactory, cariprazine may be a candidate medication in DD due to its unique mechanism of action. Preliminary clinical experiences suggest that cariprazine has both antipsychotic and anticraving properties and should be considered early in patients with DD.

G protein-coupled receptors in neurodegenerative diseases and psychiatric disorders

Neuropsychiatric disorders are multifactorial disorders with diverse aetiological factors. Identifying treatment targets is challenging because the diseases are resulting from heterogeneous biological, genetic, and environmental factors. Nevertheless, the increasing understanding of G protein-coupled receptor (GPCR) opens a new possibility in drug discovery. Harnessing our knowledge of molecular mechanisms and structural information of GPCRs will be advantageous for developing effective drugs. This review provides an overview of the role of GPCRs in various neurodegenerative and psychiatric diseases. Besides, we highlight the emerging opportunities of novel GPCR targets and address recent progress in GPCR drug development.

Seventy Years of Antipsychotic Development: A Critical Review

Since the mid-1950s discovery of the first effective antipsychotic medications (APM), we have only been able to improve the tolerability but not the overall efficacy of currently available APMs, as reflected by effectiveness trials in Europe and the United States. This inability to develop more effective APMs is attributable to multiple factors, including failure to create and use assessment tools to assess core symptom domains in schizophrenia, move beyond the dopaminergic hypothesis and to develop "me too" drugs, imposing ill-defined research domain criteria, and lacking federal funding for clinical trials. The classification of APMs is also confusing, including second-generation, partial agonists, and multimodal APMs in the same class of APMs, despite significant differences in their mechanisms of action. Other factors stagnating drug development include inadequate sample sizes to address heterogeneity, lack of statistical measures correlating with clinical significance, using the atheoretical basis of psychiatric diagnoses, failure to control placebo response, and high cost of newer and perhaps more tolerable APMs. Furthermore, there has been a failure to develop early predictors of antipsychotic response and various tools to optimize an APM response. Finally, some mental health providers are also responsible for the suboptimal use of APMs, by using excessive maintenance doses, often with irrational polypharmacy, further compromising effectiveness and medication adherence. However, some bright spots in antipsychotic development include improved tolerability of APMs and long-acting injectables to address the high prevalence of medication nonadherence. This review critically reviews 70 years of antipsychotic development, the reasons behind the failure to develop more effective APMs, and suggestions for future direction.

Mini Review on Cariprazine: A Promising Antipsychotic Agent

Cariprazine is a piperazine derivative approved by the USFDA in 2015 as a novel atypical antipsychotic drug (APD) to treat adults with schizophrenia and bipolar manic or mixed episodes in adults. However, due to the partial agonist action on dopamine D₂, D₃ receptors, and serotonin 5-HT_1A receptors as well as the antagonist effect on 5-HT_2A, 5-HT_2B, and H₁ receptors, cariprazine differs pharmacologically from other APDs, both typical and atypical. Moreover, cariprazine also has a unique pharmacokinetic profile due to the formation of two clinically significant metabolites: desmethyl-cariprazine (DCAR) and desmethyl-cariprazine (DDCAR). They are eliminated by CYP3A4 and also, to a lesser extent, by CYP2D6. Here, we also review the effectiveness, safety, as well as current clinical update of cariprazine in bipolar I disorder associated with/without mania and schizophrenia through randomized and post-hoc analysis. The potential benefits of cariprazine as a promising therapeutic alternative in addressing major clinical requirements for better therapy of such severe neuropsychiatric conditions were demonstrated in this summarized review study.

Drug-drug interactions involving combinations of antipsychotic agents with antidiabetic, lipid-lowering, and weight loss drugs

INTRODUCTION

Patients with severe mental illness (SMI) have a high risk for diabetes, dyslipidemia, and other components of metabolic syndrome. Patients with these metabolic comorbidities and cardiac risk factors should receive not only antipsychotics but also medications aiming to reduce cardiovascular risk. Therefore, many patients may be exposed to clinically relevant drug-drug interactions.

AREAS COVERED

This narrative review summarizes data regarding the known or potential drug-drug interactions between antipsychotics and medications treating metabolic syndrome components, except for hypertension, which has been summarized elsewhere. A literature search in PubMed and Scopus up to 7/31/2021 was performed regarding interactions between antipsychotics and drugs used to treat metabolic syndrome components, aiming to inform clinicians' choice of medication for patients with SMI and cardiometabolic risk factors in need of pharmacologic interventions.

EXPERT OPINION

The cytochrome P450 system and, to a lesser extent, the P-glycoprotein transporter is involved in the pharmacokinetic interactions between antipsychotics and some statins or saxagliptin. Regarding pharmacodynamic interactions, the available information is based mostly on small studies, and for newer classes, like PCSK9 inhibitors or SGLT2 inhibitors, data are still lacking. However, there is sufficient information to guide clinicians in the process of selecting safer antipsychotic-cardiometabolic risk reduction drug combinations.

Twenty-year effects of antipsychotics in schizophrenia and affective psychotic disorders

BACKGROUND

Studies that examine course and outcome in psychosis have reported considerable heterogeneity in terms of recovery, remission, employment, symptom presentation, social outcomes, and antipsychotic medication effects. Even with demonstrated heterogeneity in course and outcome, prophylactic antipsychotic maintenance therapy remains the prominent practice, particularly in participants with schizophrenia. Lack of efficacy in maintenance antipsychotic treatment and concerns over health detriments gives cause to re-examine guidelines.

METHODS

This study was conducted as part of the Chicago follow-up study designed as a naturalistic prospective longitudinal research study to investigate the course, outcome, symptomatology, and effects of antipsychotic medication on recovery and rehospitalization in participants with serious mental illness disorders. A total of 139 participants with 734 observations were included in the analysis. GEE logistic models were applied to adjust for confounding factors measured at index hospitalization and follow-ups.

RESULTS

Our data show that the majority of participants with schizophrenia or affective psychosis experience future episodes of psychosis at some point during the 20-year follow-up. There was a significant diagnostic difference between groups showing an increase in the number of future episodes of psychosis in participants with schizophrenia. Participants with schizophrenia not on antipsychotics after the first 2 years have better outcomes than participants prescribed antipsychotics. The adjusted odds ratio of not on antipsychotic medication was 5.989 (95% CI 3.588-9.993) for recovery and 0.134 (95% CI 0.070-0.259) for rehospitalization. That is, regardless of diagnosis, after the second year, the absence of antipsychotics predicted a higher probability of recovery and lower probability of rehospitalization at subsequent follow-ups after adjusting for confounders.

CONCLUSION

This study reports multiple findings that bring into question the use of continuous antipsychotic medications, regardless of diagnosis. Even when the confound by indication for prescribing antipsychotic medication is controlled for, participants with schizophrenia and affective psychosis do better than their medicated cohorts, strongly confirming the importance of exposing the role of aiDSP and antipsychotic drug resistance.

Drug-drug interactions involving antipsychotics and antihypertensives

INTRODUCTION

Antipsychotics represent the mainstay in the treatment of patients diagnosed with major psychiatric disorders. Hypertension, among other components of metabolic syndrome, is a common finding in these patients. For their psychiatric and physical morbidity, many patients receive polypharmacy, exposing them to the risk of clinically relevant drug-drug interactions.

AREAS COVERED

This review summarizes the knowledge regarding the known or potential drug-drug interactions between antipsychotics and the main drug classes used in the treatment of hypertension. We aimed to provide the clinician an insight into the pharmacokinetic and pharmacodynamic interactions between these drugs for a better choice of combinations of drugs to treat both the mental illness and cardiovascular risk factors. For this, we performed a literature search in PubMed and Scopus databases, up to 31 July 2021.

EXPERT OPINION

The main pharmacokinetic interactions between antipsychotics and antihypertensive drugs involve mainly the cytochrome P450 system. The pharmacodynamic interactions are produced by multiple mechanisms, leading to concurrent binding to the same receptors. The data available regarding drug-drug interactions is mostly based on case reports and small studies and therefore should be interpreted with caution. The current knowledge is sufficiently strong to guide clinicians in selecting safer drug combinations as summarized here.

Efficacy and Safety of Low-Dose Brexpiprazole for Acute Schizophrenia: Meta-Analysis of Randomized Placebo-Controlled Trials

PURPOSE

The purpose of this meta-analysis was to compare the efficacy and safety profile of low-dose brexpiprazole (<2 mg/d) compared to placebo and standard-dose brexpiprazole (2-4 mg/d).

PATIENTS AND METHODS

We identified relevant studies pertaining to the specific purpose of our meta-analysis by searching PubMed, Web of Science, Embase, Cochrane library, and PsycINFO using the search terms "schizophrenia" or "schizophrenic" AND "brexpiprazole" or "REXULTI". We systematically reviewed all randomized controlled trials (RCTs) comparing low-dose brexpiprazole with placebo. Primary efficacy outcomes were the PANSS total score change and response rate. Primary safety outcomes were total treatment discontinuation rate, and total serious adverse events (SAEs). Risk ratios (RR) and standardized mean differences (SMDs) were pooled implementing a random effect model.

RESULTS

Four RCTs (2178 patients) were included for effect assessment of low-dose brexpiprazole treatment on the patients with acute schizophrenia. Low-dose brexpiprazole was not superior to placebo (SMD = -0.11, 95% CI = -0.23, 0.02, P = 0.10, I² = 0%), and significantly inferior to standard-dose brexpiprazole (SMD = 0.15, 95% CI = 0.03, 0.26, P = 0.01, I² = 0%) for PANSS total score change. Low-dose brexpiprazole did not result in significant difference for response rate when compared to placebo and standard-dose brexpiprazole (RR = 1.16, 95% CI = 0.95, 1.41, P = 0.14, I² = 25%; RR = 0.92, 95% CI = 0.76, 1.12, P = 0.40, I² = 38%, respectively). For ratio of total discontinuation, low-dose brexpiprazole did not exhibit significant difference when compared to placebo (RR = 0.95, 95% CI = 0.81, 1.11, P = 0.53, I² = 0%) and standard-dose brexpiprazole group (RR = 1.11, 95% CI = 0.95, 1.29, P = 0.19, I² = 0%). Total SAEs in low-dose brexpiprazole group did not differ significantly from placebo and standard-dose brexpiprazole group (RR = 0.96, 95% CI = 0.52, 1.80, P = 0.90, I² = 0%; RR = 1.29, 95% CI = 0.65, 2.57, P = 0.47, I² = 26%, respectively).

CONCLUSION

The results indicated that low-dose brexpiprazole may be not superior for improving the efficacy and safety for acute schizophrenia compared to placebo and standard-dose brexpiprazole, and may cause additional risk of increasing body weight. Therefore, using low-dose brexpiprazole in acute schizophrenia patients may be not recommended.

Long-Term Treatment with Atypical Antipsychotic Iloperidone Modulates Cytochrome P450 2D (CYP2D) Expression and Activity in the Liver and Brain via Different Mechanisms

CYP2D enzymes engage in the synthesis of endogenous neuroactive substances (dopamine, serotonin) and in the metabolism of neurosteroids. The present work investigates the effect of iloperidone on CYP2D enzyme expression and activity in rat brains and livers. Iloperidone exerted a weak direct inhibitory effect on CYP2D activity in vitro in the liver and brain microsomes (K_i = 11.5 μM and K_i = 462 μM, respectively). However, a two-week treatment with iloperidone (1 mg/kg ip.) produced a significant decrease in the activity of liver CYP2D, which correlated positively with the reduced CYP2D1, CYP2D2 and CYP2D4 protein and mRNA levels. Like in the liver, iloperidone reduced CYP2D activity and protein levels in the frontal cortex and cerebellum but enhanced these levels in the nucleus accumbens, striatum and substantia nigra. Chronic iloperidone did not change the brain CYP2D4 mRNA levels, except in the striatum, where they were significantly increased. In conclusion, by affecting CYP2D activity in the brain, iloperidone may modify its pharmacological effect, via influencing the rate of dopamine and serotonin synthesis or the metabolism of neurosteroids. By elevating the CYP2D expression/activity in the substantia nigra and striatum (i.e., in the dopaminergic nigrostriatal pathway), iloperidone may attenuate extrapyramidal symptoms, while by decreasing the CYP2D activity and metabolism of neurosteroiods in the frontal cortex and cerebellum, iloperidone can have beneficial effects in the treatment of schizophrenia. In the liver, pharmacokinetic interactions involving chronic iloperidone and CYP2D substrates are likely to occur.

Prevalence of Pre-existing Conditions Relevant for Adverse Events and Potential Drug-Drug Interactions Associated with Augmentation Therapies Among Patients with Treatment-Resistant Depression

INTRODUCTION

Pre-existing conditions relevant for adverse events (AE) and the potential for drug-drug interactions (DDIs) may limit safe pharmacotherapeutic augmentation options for patients with major depressive disorder (MDD). This concern may be heightened among patients with treatment-resistant depression (TRD), who often have comorbid medical disorders.

METHODS

Adults with MDD and ≥ 1 antidepressant claim within the first observed major depressive episode were identified in the MarketScan® Databases. Those initiating a new regimen after two regimens at adequate dose and duration were considered to have TRD. The index date was defined at TRD onset or on a random antidepressant claim among patients with non-TRD MDD. Pre-existing conditions 12 months pre-index and potential DDIs 3 months pre/post-index associated with specific non-antidepressant augmentation therapies, including atypical antipsychotics (APs), buspirone, psychostimulants, anticonvulsants, thyroid hormone, and lithium were compared between 1:1 matched TRD and non-TRD MDD cohorts.

RESULTS

Overall, 3414 patients with TRD and non-TRD MDD (mean age 39.7 years, 69% female) were matched. Relative to non-TRD MDD, patients with TRD had 33% higher likelihood of ≥ 1 pre-existing condition relevant for AEs listed in product labels of non-antidepressant augmentation therapies (p < 0.001). Patients with TRD vs. non-TRD MDD had 12.9 and 6.4 times higher likelihood of ≥ 2 and ≥ 3 DDIs, respectively, based on their medication regimen (all p < 0.001).

CONCLUSION

Pre-existing conditions relevant for listed AEs and potential DDIs limit safe augmentation options in MDD, particularly among patients with TRD. Payer prior authorization policies requiring several augmentation therapy trials to access novel treatments may complicate clinical management of this population.

The Effect of Chronic Iloperidone Treatment on Cytochrome P450 Expression and Activity in the Rat Liver: Involvement of Neuroendocrine Mechanisms

In order to achieve a desired therapeutic effect in schizophrenia patients and to maintain their mental wellbeing, pharmacological therapy needs to be continued for a long time, usually from the onset of symptoms and for the rest of the patients' lives. The aim of our present research is to find out the in vivo effect of chronic treatment with atypical neuroleptic iloperidone on the expression and activity of cytochrome P450 (CYP) in rat liver. Male Wistar rats received a once-daily intraperitoneal injection of iloperidone (1 mg/kg) for a period of two weeks. Twenty-four hours after the last dose, livers were excised to study cytochrome P450 expression (mRNA and protein) and activity, pituitaries were isolated to determine growth hormone-releasing hormone (GHRH), and blood was collected for measuring serum concentrations of hormones and interleukin. The results showed a broad spectrum of changes in the expression and activity of liver CYP enzymes, which are important for drug metabolism (CYP1A, CYP2B, CYP2C, and CYP3A) and xenobiotic toxicity (CYP2E1). Iloperidone decreased the expression and activity of CYP1A2, CP2B1/2, CYP2C11, and CYP3A1/2 enzymes but increased that of CYP2E1. The CYP2C6 enzyme remained unchanged. At the same time, the level of GHRH, GH, and corticosterone decreased while that of T₃ increased, with no changes in IL-2 and IL-6. The presented results indicate neuroendocrine regulation of the investigated CYP enzymes during chronic iloperidone treatment and suggest a possibility of pharmacokinetic/metabolic interactions produced by the neuroleptic during prolonged combined treatment with drugs that are substrates of iloperidone-affected CYP enzymes.

Continuation rate for asenapine and brexpiprazole treatment in patients with schizophrenia

INTRODUCTION

The current study sought to compare the treatment continuation rates of asenapine and brexpiprazole while specifically investigating the factors influencing this index and the clinical efficacy of brexpiprazole.

METHODS

Retrospective study on patients with schizophrenia who were prescribed either asenapine (n = 73) or brexpiprazole (n = 136), as part of their routine medical care.

RESULTS

The treatment continuation rates for asenapine and brexpiprazole were 19.0% and 38.6% at 52 weeks, with that of brexpiprazole found to be significantly higher than that of asenapine (p = .002). Moreover, age was found to be a significant factor affecting the treatment continuation rate for brexpiprazole (p = .03). Additionally, patients with a longer continuation duration had significantly lower Clinical Global Impression-Severity of Illness (CGI-S) scale scores compared to those who discontinued early (p = .04). The continuation rate was also significantly higher for those who began using the drug as outpatients compared to those first administered the drug as inpatients (p = .04). Furthermore, disease duration, CGI-S scale, and continuation duration significantly affected the clinical efficacy of brexipiprazole (p < .05 for all).

CONCLUSIONS

The continuation rate for brexpiprazole increases as the age of the patient increases, as disease severity decreases, and if the patient first uses the drug as an outpatient. Shorter disease duration and longer drug administration may lead to improved clinical efficacy. These results suggest that brexpiprazole is an effective treatment option for maintenance therapy of schizophrenia.

Experimental Serotonergic Agents for the Treatment of Schizophrenia

Schizophrenia remains one of the most chronic and highly disabling mental disorder. To date, the pathomechanism of schizophrenia is not fully understood and current treatments are characterized by some limitations. First- and second-generation antipsychotics have shown clinical efficacy in treating positive symptoms, while are poorly effective on both negative symptoms and cognitive deficits. Moreover, they can involve many metabolic and neurological side effects, leading to low therapeutic compliance. Many evidence suggested that serotonin may play a complex role in the neurobiology of schizophrenia. Therefore, new drugs targeting 5-HT receptors (5-HTRs) have become an important area of research in schizophrenia in the hope that treatment efficacy may be improved without inducing side effects observed with currently available antipsychotics. Research using the main database sources was conducted to obtain an overview of preclinical and clinical pharmacological 5-HTR-targeted therapies in patients with schizophrenia. We identified 17 experimental serotonergic agents, under study for their potential use in schizophrenia treatment. Particularly, AVN-211, LuAF-35700 and Brilaroxazine are currently under clinical development. Moreover, some compounds showed some pro-cognitive and antipsychotic-like properties in animal models, while other agents showed contradictory effects in improving symptoms and were removed from the development program. Although some serotonergic drugs seem promising for improving the treatment of schizophrenia, further studies regarding the pathophysiological mechanisms of schizophrenia and novel compounds as well as high-quality trials are necessary in order to improve schizophrenia outcomes.

Rationale and neurobiological effects of treatment with antipsychotics in patients with chronic schizophrenia considering dopamine supersensitivity

The long-term treatment of patients with schizophrenia often involves the management of relapses for most patients and the development of treatment resistance in some patients. To stabilize the clinical course and allow as many patients as possible to recover, clinicians need to recognize dopamine supersensitivity, which can be provoked by administration of high dosages of antipsychotics, and deal with it properly. However, no treatment guidelines have addressed this issue. The present review summarized the characteristics of long-acting injectable antipsychotics, dopamine partial agonists, and clozapine in relation to dopamine supersensitivity from the viewpoints of receptor profiles and pharmacokinetics. The potential merits and limitations of these medicines are discussed, as well as the risks of treating patients with established dopamine supersensitivity with these classes of drugs. Finally, the review discussed the biological influence of antipsychotic treatment on the human brain based on findings regarding the relationship between the hippocampus and antipsychotics.

Asenapine: an atypical antipsychotic with atypical formulations

Asenapine is a second-generation (atypical) antipsychotic medication not available in a pill that can be swallowed; rather, it is commercialized in sublingual and transdermal formulations. This is a consequence of extensive first-pass metabolism if ingested. The sublingual formulation is approved in many jurisdictions for the treatment of schizophrenia and manic or mixed episodes associated with bipolar I disorder and is available generically. The efficacy profile is well characterized in a number of clinical trials, including an off-label use for the management of agitation. Obstacles to its use include food and drink restrictions, twice-daily dosing and adverse effects such as dysgeusia (distorted, altered, or unpleasant taste) and oral hypoesthesia (numbness). Transdermal asenapine was approved by the US Food and Drug Administration in 2019 for the treatment of schizophrenia in adults. Efficacy was established in a registrational study examining acutely ill inpatients with schizophrenia. The patch needs to changed once daily. Obstacles to its use include the potential for skin reactions such as erythema and pruritis, and being a branded product, it is more costly than other options. This is a narrative review of the chemistry and pharmacokinetics/pharmacodynamics of asenapine, as well as summarizing the efficacy and tolerability of both sublingual and transdermal asenapine, and its possible place in treatment.

In vitro inhibition of human cytochrome P450 enzymes by the novel atypical antipsychotic drug asenapine: a prediction of possible drug-drug interactions

BACKGROUND

Inhibition of cytochrome P450 (CYP) enzymes is the most common cause of harmful drug-drug interactions. The present study aimed at examining the inhibitory effect of the novel antipsychotic drug asenapine on the main CYP enzymes in human liver.

METHODS

The experiments were performed in vitro using pooled human liver microsomes and the human cDNA-expressed CYP enzymes: CYP1A2, CYP2C9, CYP2C19, CYP2D6, and CYP3A4 (Supersomes). Activities of CYP enzymes were determined using the CYP-specific reactions: caffeine 3-N-demethylation (CYP1A2), diclofenac 4'-hydroxylation (CYP2C9), perazine N-demethylation (CYP2C19), bufuralol 1'-hydroxylation (CYP2D6), and testosterone 6β-hydroxylation (CYP3A4). The rates of the CYP-specific reactions were assessed in the absence and presence of asenapine using HPLC.

RESULTS

The obtained results showed that both in human liver microsomes and Supersomes asenapine potently and to a similar degree inhibited the activity of CYP1A2 via a mixed mechanism (K_i = 3.2 μM in liver microsomes and Supersomes) and CYP2D6 via a competitive mechanism (K_i = 1.75 and 1.89 μM in microsomes and Supersomes, respectively). Moreover, asenapine attenuated the CYP3A4 activity via a non-competitive mechanism (K_i = 31.3 and 27.3 μM in microsomes and Supersomes, respectively). In contrast, asenapine did not affect the activity of CYP2C9 or CYP2C19.

CONCLUSION

The potent inhibition of CYP1A2 and CYP2D6 by asenapine, demonstrated in vitro, will most probably be observed also in vivo, since the calculated K_i values are close to the presumed concentration range for asenapine in the liver in vivo. Therefore, pharmacokinetic interactions involving asenapine and CYP2D6 or CYP1A2 substrates are likely to occur during their co-administration to patients.

Efficacy and safety of lurasidone versus placebo as adjunctive to mood stabilizers in bipolar I depression: A meta-analysis

BACKGROUND

Few evidence-based treatments and guidelines reflect greater uncertainty regarding consensus treatment algorithms than those for unipolar disorder. This meta-analysis aimed to evaluate the efficacy and side effects of lurasidone by comparing with placebo in bipolar I depression.

METHODS

Electronic databases, such as PubMed, the Cochrane Library, Web of Science, and Embase, were searched until May 30, 2018, for randomized controlled trials on comparison lurasidone therapy with placebo. The primary efficacy assessment included MADRS total score and CGI-BP-S total score, the secondary efficacy assessment included the response and the remission rates and the safety and tolerability were also evaluated applying the Simpson-Angus Scale.

RESULTS

The meta-analysis compromised 7 studies. Efficacy analysis suggested that lurasidone was more effective than placebo: MADRS total score (MD:-4.31, 95%CI: (-6.93,-1.7), P = 0.001) and the CGI-BP-S total score (MD:-0.37, 95%CI: (-0.59,-0.15), P = 0.0008) were obtained for both lurasidone-treated and placebo groups. Response rates (RR: 1.73, 95%CI: (1.46, 2.05), P < 0.00001) and Remission rates (RR: 1.57, 95%CI: (1.38, 1.79), P < 0.00001). The safety analysis between lurasidone and placebo showed no difference: at least one event (RR: 1.12, 95% CI :(1.00, 1.26), p = 0.05 and the influence on glucose (MD: 0.35, 95% CI :(-1.09, 1.79), p = 0.63.

LIMITATION

The present conclusion is limited by the limited included studies. The different dose of lurasidone should be considered in the future.

CONCLUSION

Compared with placebo, adjunctive lurasidone significantly improved depressive symptoms and is very well tolerated with minimal side effects on the endocrine and cardiovascular systems in clinical patients with bipolar I depression. Key words: Bipolar I depression; Lurasidone; Meta-analysis; Remission rates; Adverse effect.

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.

Dopamine: Functions, Signaling, and Association with Neurological Diseases

The dopaminergic system plays important roles in neuromodulation, such as motor control, motivation, reward, cognitive function, maternal, and reproductive behaviors. Dopamine is a neurotransmitter, synthesized in both central nervous system and the periphery, that exerts its actions upon binding to G protein-coupled receptors. Dopamine receptors are widely expressed in the body and function in both the peripheral and the central nervous systems. Dopaminergic signaling pathways are crucial to the maintenance of physiological processes and an unbalanced activity may lead to dysfunctions that are related to neurodegenerative diseases. Unveiling the neurobiology and the molecular mechanisms that underlie these illnesses may contribute to the development of new therapies that could promote a better quality of life for patients worldwide. In this review, we summarize the aspects of dopamine as a catecholaminergic neurotransmitter and discuss dopamine signaling pathways elicited through dopamine receptor activation in normal brain function. Furthermore, we describe the potential involvement of these signaling pathways in evoking the onset and progression of some diseases in the nervous system, such as Parkinson's, Schizophrenia, Huntington's, Attention Deficit and Hyperactivity Disorder, and Addiction. A brief description of new dopaminergic drugs recently approved and under development treatments for these ailments is also provided.

Resistance is not futile: treatment-refractory schizophrenia - overview, evaluation and treatment

INTRODUCTION

Schizophrenia is a debilitating condition with three main symptom domains: positive, negative, and cognitive. Approximately one-third of persons with schizophrenia will fail to respond to treatment. Growing evidence suggests that treatment-resistant (refractory) schizophrenia (TRS) may be a distinct condition from treatment-respondent schizophrenia. There is limited evidence on effective treatments for TRS, and a lack of standardized diagnostic criteria for TRS has hampered research. Areas covered: A literature search was conducted using Pubmed.gov and the EMBASE literature database. The authors discuss the pragmatic definitions of TRS and review treatments consisting of antipsychotic monotherapy and augmentation strategies. Expert opinion: Currently available first-line antipsychotic medications are generally effective at treating the positive symptoms of schizophrenia, leaving residual negative and cognitive symptoms. Before diagnosing TRS, rule out any pharmacodynamic or pharmacokinetic failures. Most evidence supports clozapine as having the most efficacy for TRS. If clozapine is used, it should be optimized, and serum levels should be at least 350-420 ng/ml. If clozapine is unable to be tolerated, some evidence suggests olanzapine at dosages up to 40mg/day can be useful. Augmentation strategies have weak evidence. Tailoring treatment to the specific domain is the preferred approach, and the use of a structured assessment/outcome measure is encouraged.

Predicting parkinsonism side-effects of antipsychotic polypharmacy prescribed in secondary mental healthcare

BACKGROUND

Computer-modelling approaches have the potential to predict the interactions between different antipsychotics and provide guidance for polypharmacy.

AIMS

To evaluate the accuracy of the quantitative systems pharmacology platform to predict parkinsonism side-effects in patients prescribed antipsychotic polypharmacy.

METHODS

Using anonymized data from South London and Maudsley NHS Foundation Trust electronic health records we applied quantitative systems pharmacology, a neurophysiology-based computer model of humanized neuronal circuits, to predict the risk for parkinsonism symptoms in patients with schizophrenia prescribed two concomitant antipsychotics. The performance of the quantitative systems pharmacology model was compared with the performance of simple parameters such as: combination of affinity constants (1/K_sum); sum of D₂R occupancies (D₂R) and chlorpromazine equivalent dose.

RESULTS

We identified 832 patients with schizophrenia who were receiving two antipsychotics for six or more months, between 1 January 2007 and 31 December 2014. The area under the receiver operating characteristic (AUROC) curve for the quantitative systems pharmacology model was 0.66 ( p = 0.01), while AUROCs for D₂R, 1/K_sum and chlorpromazine equivalent dose were 0.52 ( p = 0.350), 0.53 ( p = 0.347) and 0.52 ( p = 0.330) respectively.

CONCLUSION

Our results indicate that quantitative systems pharmacology has the potential to predict the risk of parkinsonism associated with antipsychotic polypharmacy from minimal source information, and thus might have potential decision-support applicability in clinical settings.

Antipsychotic-Related Movement Disorders: Drug-Induced Parkinsonism vs. Tardive Dyskinesia-Key Differences in Pathophysiology and Clinical Management

Introduction

Drug-induced parkinsonism (DIP) and tardive dyskinesia (TD) are stigmatizing movement disorders associated with exposure to dopamine receptor blocking agents such as antipsychotics, but they differ in their pathophysiology and clinical management. Treatment for one may worsen the other, and there are important diagnostic clues that assist in making an accurate assessment and instituting a rational treatment plan.

Methods

A literature review was executed to identify articles relating to the presentation, pathophysiology, epidemiology, and management of DIP and TD.

Results

DIP and TD prevalence estimates range from approximately 20 to 35% among antipsychotic users, but may be higher in select populations. DIP often presents as bradykinesia and rigidity, as well as rhythmic tremor, and the majority of cases appear within hours to weeks of initiation of therapy with an antipsychotic, or if dosage of the antipsychotic is increased. TD onset is delayed, typically appearing after at least 3 months or longer of treatment, and patients will commonly present with involuntary, abnormal facial movements such as lip smacking, puckering, chewing, or tongue protrusion. DIP often resolves with discontinuation of the causative agent, but TD may be permanent. Broadly, proposed mechanisms underlying these adverse events include decreased dopamine concentrations in the nigrostriatal pathway of the striatum and dopamine hypersensitivity, for DIP and TD, respectively. Pharmacologic treatment approaches for DIP have commonly included anticholinergic agents such as benztropine; however, anticholinergic medications can make TD worse. Switching the antipsychotic medication to one with lower propensity for DIP is an option for some patients. Amantadine, a non-anticholinergic agent used for the treatment of DIP, may be preferred in patients with comorbid DIP and TD. In TD, treatment options include the new reversible vesicular monoamine 2 transporter inhibitors, valbenazine and deutetrabenazine.

Conclusions

It is important for clinicians to be able to recognize DIP and TD in patients using antipsychotics so that they can minimize the impact of these adverse events on their patients’ quality of life. Accurate diagnosis will drive the selection of the correct treatment.

Plain Language Summary

Plain language summary available for this article.

Supported liquid extraction and LC–MS-MS determination of iloperidone and olanzapine in rat plasma: Application to a pharmacokinetic study

A sensitive, selective rapid bioanalytical assay method was developed and quantification of iloperidone (ILP) and olanzapine (OLZ) in rat plasma was done by mass spectrometry. Systematic sample preparation and extraction procedure were carried out by supported liquid extraction using dichloromethane to extract both the eluents (ILP and OLZ) from rat plasma samples. The extorted samples were injected on a selective Waters XTerra® C18 reverse-phase bonded column (250 × 4.6 mm i.d., 5 μm) using acetonitrile and 15 mM ammonium formate containing 0.05% trifluoroacetic acid (60:40 v/v) for isocratic elution mode and detected by mass spectrometry. Calibration curves were drawn with the respective assay statistical data and showed linear regression coefficients greater than 0.9996 over the concentration ranges 2–5,000 ng/mL for ILP and OLZ, respectively. The absolute mean recoveries were found to be in the replicate range of 87.12–94.47%, respectively. The obtained results by the method revealed good intra and interday assay performance in terms of 1.70–5.90% precision and 0–5% accuracy. The validated bioassay method has been successfully applied to the pharmacokinetics in rats.

A Long-Term, Open-Label Study to Evaluate the Safety and Tolerability of Brexpiprazole as Maintenance Treatment in Adults with Schizophrenia

BACKGROUND

Brexpiprazole is a serotonin-dopamine activity modulator with efficacy in acute schizophrenia and relapse prevention. The aim of this Phase 3, multicenter study was to assess the long-term safety, tolerability, and efficacy of treatment with brexpiprazole flexible-dose 1-4 mg/d.

METHODS

Patients rolled over into this 52-week open-label study (amended to 26 weeks towards the end) from 3 randomized, double-blind, placebo-controlled Phase 3 studies. De novo patients, not part of the previous studies, were also enrolled. The primary outcome variable was the frequency and severity of treatment-emergent adverse events. Efficacy was assessed as a secondary objective using the Positive and Negative Syndrome Scale and the Personal and Social Performance scale.

RESULTS

A total of 1072 patients was enrolled (952 for 52 weeks and 120 for 26 weeks), 47.4% of whom completed the study. Among patients who took at least one dose of brexpiprazole, 14.6% discontinued due to treatment-emergent adverse events, most commonly schizophrenia (8.8%) and psychotic disorder (1.5%). Treatment-emergent adverse events with an incidence of ≥5% were schizophrenia (11.6%), insomnia (8.6%), weight increased (7.8%), headache (6.4%), and agitation (5.4%). Most treatment-emergent adverse events were mild or moderate in severity. The mean increase in body weight from baseline to week 26 was 1.3 kg and to week 52 was 2.1 kg. There were no clinically relevant findings related to prolactin, lipids, and glucose, or QT prolongation. On average, patients' symptoms and functioning showed continual improvement.

CONCLUSIONS

Treatment with brexpiprazole 1-4 mg/d was generally well tolerated for up to 52 weeks in patients with schizophrenia.

CLINICALTRIALS.GOV IDENTIFIER

NCT01397786 (https://clinicaltrials.gov/show/NCT01397786).

Efficacy and Acceptability of Cariprazine in Acute Exacerbation of Schizophrenia: Meta-Analysis of Randomized Placebo-Controlled Trials

PURPOSE

The purpose of this study was to assess the efficacy and acceptability of cariprazine treatment in acute exacerbation of schizophrenia.

METHODS

This review included randomized controlled trials of patients with acute exacerbation of schizophrenia in relation to efficacy and acceptability. The efficacy outcomes were assessed by pooling standardized mean differences (SMDs) calculated from the difference in the reduction in the mean of the Positive and Negative Syndrome Scale (PANSS) total score, PANSS positive and negative scores, and response rate. The primary acceptability outcomes were determined by pooling the risk ratios (RRs) of discontinuation for any reason, the incidence of serious adverse events, and treatment emergent events.

FINDINGS

Four randomized controlled trials consisting of 1843 patients met all inclusion and exclusion criteria. Efficacy analysis showed significant positive effects in relation to cariprazine therapy (SMD: -0.37, P < 0.00001 for PANSS total score change; SMD: -0.32, P < 0.00001 for PANSS positive score change; SMD: -0.32, P < 0.0001 for PANSS negative score change; RR, 1.41; 95% confidence interval [CI], 1.19-1.67; P < 0.0001 for response rate). For primary acceptability outcomes, less patients taking cariprazine discontinued treatment for any reason compared with patients receiving placebo (RR, 0.90; 95% CI, 0.78-1.04; P = 0.16). Significantly less patients on cariprazine had serious adverse events during the double-blind treatment period compared with patients taking placebo (RR, 0.55; 95% CI, 0.34-0.89; P = 0.01). Significantly more patients on cariprazine had treatment emergent events compared with those receiving placebo (RR, 1.10; 95% CI, 1.03-1.18; P = 0.006).

IMPLICATIONS

Results suggest that cariprazine may be an effective and acceptable treatment for schizophrenia and future research is warranted.

Cariprazine for the Treatment of Bipolar Disorder

PURPOSE

To review the data regarding a new antipsychotic, cariprazine.

CONCLUSIONS

Cariprazine is a dopamine D3, D2 partial agonist, with greater affinity to D3. It has been examined for schizophrenia, bipolar mania, bipolar depression, and unipolar depression. It has demonstrated efficacy in schizophrenia and mania, and has recently been approved by the U.S. Food and Drug Administration. However, it has a more inconsistent effect in depression, both unipolar and bipolar. Adverse effects include extrapyramidal symptoms, akathisia, and gastrointestinal distress.

PRACTICE IMPLICATIONS

Cariprazine will be a promising addition in the treatment of patients with acute mania and schizophrenia.

Lurasidone in the Treatment of Bipolar Depression: Systematic Review of Systematic Reviews

INTRODUCTION

A burgeoning number of systematic reviews considering lurasidone in the treatment of bipolar depression have occurred since its Food and Drug Administration extended approval in 2013. While a paucity of available quantitative evidence still precludes preliminary meta-analysis on the matter, the present quality assessment of systematic review of systematic reviews, nonetheless, aims at highlighting current essential information on the topic.

METHODS

Both published and unpublished systematic reviews about lurasidone mono- or adjunctive therapy in the treatment of bipolar depression were searched by two independent authors inquiring PubMed/Cochrane/Embase/Scopus from inception until October 2016.

RESULTS

Twelve included systematic reviews were of moderate-to-high quality and consistent in covering the handful of RCTs available to date, suggesting the promising efficacy, safety, and tolerability profile of lurasidone. Concordance on the drug profile seems to be corroborated by a steadily increasing number of convergent qualitative reports on the matter.

LIMITATIONS

Publication, sponsorship, language, citation, and measurement biases.

CONCLUSIONS

Despite being preliminary in nature, this overview stipulates the effectiveness of lurasidone in the acute treatment of Type I bipolar depression overall. As outlined by most of the reviewed evidence, recommendations for future research should include further controlled trials of extended duration.

Activating and Sedating Adverse Effects of Second-Generation Antipsychotics in the Treatment of Schizophrenia and Major Depressive Disorder: Absolute Risk Increase and Number Needed to Harm

PURPOSE/BACKGROUND

Activating and sedating adverse effects of antipsychotics can be obstacles to their use.

METHODS/PROCEDURES

This study quantified the activating and sedating properties of first-line oral second-generation antipsychotics by examining the rates of adverse reactions as reported in product labeling for the indications of schizophrenia and adjunctive treatment of major depressive disorder. Additional data sources included regulatory documents, study synopses, and published study reports. Attributable risk increase and number needed to harm (NNH) were calculated for each agent versus placebo.

FINDINGS/RESULTS

Heterogeneity among the different antipsychotics regarding activating or sedating adverse events was observed, with some agents displaying the potential for both activating and sedating properties. For agents indicated for the treatment of schizophrenia, predominantly activating medications include lurasidone (NNH, 11 for akathisia vs 20 for somnolence) and cariprazine (NNH, 15 for akathisia vs 65 for somnolence-combined terms). Similarly activating and sedating are risperidone (NNH, 15 for akathisia vs 13 for sedation) and aripiprazole (NNH, 31 for akathisia vs 34 for somnolence). Predominantly sedating are olanzapine, quetiapine immediate and extended release, ziprasidone, asenapine, and iloperidone. Agents that are neither activating nor sedating are paliperidone and brexpiprazole. For major depressive disorder, the overall findings regarding activation and sedation appear similar to those seen with schizophrenia. Data extracted were limited to those available from registrational studies that contributed to the adverse event tables contained in the product labels. Postregistrational comparative studies may yield different outcomes.

IMPLICATIONS/CONCLUSIONS

Differences in tolerability profiles regarding activation and sedation have implications in terms of selecting the optimal antipsychotic for a given individual.

The effect of brexpiprazole in adult outpatients with early-episode schizophrenia: an exploratory study

The aim of this study was to evaluate flexibly dosed brexpiprazole for early-episode schizophrenia through the assessment of efficacy, social functioning, and tolerability. This was an exploratory, 16-week, open-label, flexible-dose (1, 2, 3, or 4 mg/day; target dose 3 mg/day) study in outpatients with early-episode schizophrenia (18-35 years old, ≤5 years' duration of illness). Efficacy was assessed by the Positive and Negative Syndrome Scale score (PANSS) and social functioning was assessed by changes from baseline in PANSS modified prosocial subscale, personal and social performance (PSP), and specific levels of functioning (SLOF) scales. Safety and tolerability were also evaluated. Overall, 25/49 patients completed the study. Symptoms of schizophrenia improved over the entire treatment period, as evidenced by reductions in PANSS total score from baseline (least squares mean change at week 16: -10.2). Improvements in social functioning were shown by least squares mean changes from baseline at week 16 in the PANSS prosocial subscale (-2.0), PSP (6.6), and SLOF (13.1). Brexpiprazole was generally well tolerated; the most common adverse events were insomnia (7/49 patients), somnolence (4/49), sedation, weight increase, and nausea (each 3/49). Brexpiprazole may represent a novel and effective treatment strategy for patients with early-episode schizophrenia and may be effective for improving social function.

Switching from Inadequate Adjunctive or Combination Treatment Options to Brexpiprazole Adjunctive to Antidepressant: An Open-Label Study on the Effects on Depressive Symptoms and Cognitive and Physical Functioning

BACKGROUND

Approximately 50% of patients with major depressive disorder do not respond adequately to their antidepressant treatment, underscoring the need for more effective treatment options. The objective of this study was to investigate the effect of adjunctive brexpiprazole on depressive symptoms in patients with major depressive disorder who were not responding to adjunctive or combination therapy of their current antidepressant treatments with several different classes of agents (NCT02012218).

METHODS

In this 6-week, open-label, phase 3b study, patients with major depressive disorder who had an inadequate response to ≥1 adjunctive or combination therapy, in addition to history of ≥1 failure to monotherapy antidepressant treatment, were switched to adjunctive brexpiprazole. Efficacy was assessed by change from baseline to week 6 in Montgomery-Åsberg Depression Rating Scale total score. Patient functioning was assessed using the Sheehan Disability Scale and the Cognitive and Physical Functioning Questionnaire. Safety and tolerability were also assessed.

RESULTS

A total of 51/61 (83.6%) patients completed 6 weeks of treatment with adjunctive brexpiprazole. Improvements in depressive symptoms were observed (least squares mean change from baseline to week 6 in Montgomery-Åsberg Depression Rating Scale total score, -17.3 [P < .0001]) as well as improvements in general and cognitive functioning (mean changes from baseline to week 6: Sheehan Disability Scale, -3.1 [P < .0001]; Massachusetts General Hospital-Cognitive and Physical Functioning Questionnaire, -9.2 [P < .0001]). The most common adverse event was fatigue (14.8%); akathisia was reported by 8.2% of patients.

CONCLUSIONS

In patients with major depressive disorder who had switched to open-label adjunctive brexpiprazole following inadequate response to previous adjunctive or combination therapy, improvements were observed in depressive symptoms, general functioning, cognitive function, and energy/alertness.

Schizophrenia relapse, patient considerations, and potential role of lurasidone

When treating persons with schizophrenia, delaying time to relapse is a main goal. Antipsychotic medication has been the primary treatment approach, and there are a variety of different choices available. Lurasidone is a second-generation (atypical) antipsychotic agent that is approved for the treatment of schizophrenia and bipolar depression. Three long-term studies of lurasidone have examined time to relapse in persons with schizophrenia, including a classic placebo-controlled randomized withdrawal study and two 12-month active comparator studies (vs risperidone and vs quetiapine extended-release). Lurasidone 40-80 mg/d evidenced superiority over placebo (number needed to treat [NNT] vs placebo for relapse, 9). Lurasidone 40-160 mg/d was noninferior to quetiapine extended-release 200-800 mg/d on the outcome of relapse, and was superior on the outcome of avoidance of hospitalization (NNT 8) and the outcome of remission (NNT 7). Lurasidone demonstrated a lower risk for long-term weight gain than the active comparators. Demonstrated differences in tolerability profiles among the different choices of antipsychotics make it possible to attempt to match up an individual patient to the best choice for such patient based on past history of tolerability, comorbidities, and personal preferences, potentially improving adherence.

The effect of brexpiprazole (OPC-34712) and aripiprazole in adult patients with acute schizophrenia: results from a randomized, exploratory study

The aim of this study was to explore the effects of brexpiprazole and aripiprazole on efficacy, cognitive functioning, and safety in patients with acute schizophrenia. Patients who would benefit from hospitalization/continued hospitalization for acute relapse of schizophrenia were enrolled and randomized (2 : 1) to target doses of open-label brexpiprazole 3 mg/day or aripiprazole 15 mg/day for 6 weeks. Outcomes included change from baseline to week 6 in the Positive and Negative Syndrome Scale total score, Barratt Impulsiveness Scale 11-item score, and Cogstate computerized cognitive test battery scores. Patients treated with brexpiprazole (n=64) or aripiprazole (n=33) showed reductions in symptoms of schizophrenia as assessed by Positive and Negative Syndrome Scale total score (-22.9 and -19.4, respectively). A modest reduction in impulsivity was observed with brexpiprazole, but not aripiprazole (mean change in the Barratt Impulsiveness Scale 11-item total score: -2.7 and 0.1, respectively). No change in Cogstate scores was observed for either treatment. Brexpiprazole was well tolerated and the incidence of akathisia was lower in patients treated with brexpiprazole (9.4%) than aripiprazole (21.2%). Clinically relevant improvements in psychopathology were observed in patients with acute schizophrenia treated with brexpiprazole or aripiprazole. Brexpiprazole was well tolerated, with a lower incidence of akathisia than aripiprazole.

Asenapine: A Review in Schizophrenia

Asenapine (Saphris(®), Sycrest(®)) is an atypical antipsychotic that is administered sublingually twice daily and is approved for schizophrenia in the USA, Japan and other countries, but not in the EU. This article reviews the pharmacology, clinical efficacy and tolerability profile of asenapine in the treatment of adults with schizophrenia. Clinical trials with asenapine have demonstrated efficacy in terms of both positive and negative symptoms of schizophrenia, although findings have not always been consistent. Across three short-term (6-week) studies in acute schizophrenia (including one in Asian patients), asenapine was generally superior to placebo and had broadly similar efficacy to active controls in improving total scores on the Positive and Negative Syndrome Scale. A meta-analysis of four short-term trials with asenapine (that also included a negative study and a failed trial) also showed significant benefit with asenapine over placebo. In longer-term trials and extensions (up to ≈3 years' duration), asenapine was effective relative to placebo in preventing relapse in schizophrenia, but was less effective than olanzapine in patients with schizophrenia or schizoaffective disorder (according to intent-to-treat LOCF analysis). However, in two trials in patients with persistent negative symptoms of schizophrenia, asenapine and olanzapine were similarly effective in reducing negative symptoms at week 26, with asenapine providing better results than olanzapine at week 52 in one of the extensions. The most frequently reported adverse events with asenapine are somnolence, akathisia and oral hypoesthesia. Although potentially associated with more extrapyramidal symptoms, asenapine appears to have less weight gain and metabolic effects than some other antipsychotic agents, such as olanzapine.

Efficacy of brexpiprazole in patients with acute schizophrenia: Review of three randomized, double-blind, placebo-controlled studies

Brexpiprazole, a serotonin-dopamine activity modulator, is a partial agonist at 5-HT1A and dopamine D2 receptors, and antagonist at 5-HT2A and noradrenaline α1B and α2C receptors, all at similar potency. Efficacy of brexpiprazole was evaluated in patients with acutely exacerbated schizophrenia in three short-term, randomized, double-blind, placebo-controlled studies. In a Phase 2 study, patients were randomized to brexpiprazole 0.25mg (fixed dose), 1.0±0.5mg, 2.5±0.5mg, 5.0±1mg (flexible-dose ranges), placebo, or aripiprazole 15±5mg. In two Phase 3 studies, patients were randomized to fixed-dose brexpiprazole 0.25mg, 1mg, 2mg, or 4mg, or placebo. For this review, brexpiprazole 2mg and 4mg arms from the Phase 3 studies were combined. Primary efficacy endpoint was change in Positive and Negative Syndrome Scale (PANSS) total score from baseline at week 6; key secondary endpoint was change in Clinical Global Impression-Severity of illness (CGI-S) score at week 6. Primary outcome moderator analyses explored effects of sex, age, race, and illness duration. There were no statistically significant differences vs. placebo in the Phase 2 brexpiprazole and aripiprazole groups for primary and key secondary endpoints. Combined brexpiprazole 2mg (n=359) and 4mg (n=359) were superior to placebo (n=358) in change in PANSS total score (least square mean difference from placebo: -5.46, p=0.0004, and -6.69, p<0.0001, respectively) and CGI-S (-0.25, p=0.0035, and -0.38, p<0.0001, respectively). Changes from baseline in efficacy endpoints were minimal in the 0.25mg group, while the 1mg group exhibited suboptimal improvement. No relevant moderators were identified. Meta-analysis of the pivotal studies indicates brexpiprazole 2mg and 4mg are effective in treating acute schizophrenia.

Overview of short- and long-term tolerability and safety of brexpiprazole in patients with schizophrenia

Second-generation antipsychotics have demonstrated efficacy for patients with schizophrenia but are associated with wide-ranging side effects. Brexpiprazole, a serotonin-dopamine activity modulator, has demonstrated efficacy in adult patients with schizophrenia. This paper provides an overview of the safety and tolerability of brexpiprazole in patients with schizophrenia through examination of pooled safety data from one Phase 2 and two Phase 3 6-week, short-term studies, and two open-label, 52-week, long-term studies. In the short-term studies, there were no reports of treatment-emergent adverse events (TEAEs) with an incidence≥5% and twice that of placebo in patients treated with brexpiprazole 2-4mg. In the long-term studies, TEAEs reported by ≥5% of patients were schizophrenia (10.7%), insomnia (8.0%), weight increase (7.7%), headache (6.0%), and agitation (5.2%). Akathisia rates were low in the short- (5.8%, pooled brexpiprazole group) and long-term studies (4.6%). Sedation rates were low in the short- (2.3%, pooled brexpiprazole group) and long-term studies (0.9%). Mean body weight increase was 1.1kg in both short- and long-term studies. For all studies, changes from baseline to last visit in laboratory parameters, electrocardiogram values, and vital signs were small and not clinically relevant. Changes in lipid profiles or other metabolic parameters were also small. Collectively, these studies suggest that brexpiprazole was well tolerated, with a favorable safety profile that does not exhibit significant rates of important adverse events that can be seen with existing antipsychotics (akathisia, sedation, weight gain, or QTc prolongation), and therefore may provide a useful treatment option for patients with schizophrenia. ClinicalTrials.gov: NCT00905307; NCT01396421; NCT01393613; NCT01649557; NCT01397786.

Royal Australian and New Zealand College of Psychiatrists clinical practice guidelines for the management of schizophrenia and related disorders

OBJECTIVES

This guideline provides recommendations for the clinical management of schizophrenia and related disorders for health professionals working in Australia and New Zealand. It aims to encourage all clinicians to adopt best practice principles. The recommendations represent the consensus of a group of Australian and New Zealand experts in the management of schizophrenia and related disorders. This guideline includes the management of ultra-high risk syndromes, first-episode psychoses and prolonged psychoses, including psychoses associated with substance use. It takes a holistic approach, addressing all aspects of the care of people with schizophrenia and related disorders, not only correct diagnosis and symptom relief but also optimal recovery of social function.

METHODS

The writing group planned the scope and individual members drafted sections according to their area of interest and expertise, with reference to existing systematic reviews and informal literature reviews undertaken for this guideline. In addition, experts in specific areas contributed to the relevant sections. All members of the writing group reviewed the entire document. The writing group also considered relevant international clinical practice guidelines. Evidence-based recommendations were formulated when the writing group judged that there was sufficient evidence on a topic. Where evidence was weak or lacking, consensus-based recommendations were formulated. Consensus-based recommendations are based on the consensus of a group of experts in the field and are informed by their agreement as a group, according to their collective clinical and research knowledge and experience. Key considerations were selected and reviewed by the writing group. To encourage wide community participation, the Royal Australian and New Zealand College of Psychiatrists invited review by its committees and members, an expert advisory committee and key stakeholders including professional bodies and special interest groups.

RESULTS

The clinical practice guideline for the management of schizophrenia and related disorders reflects an increasing emphasis on early intervention, physical health, psychosocial treatments, cultural considerations and improving vocational outcomes. The guideline uses a clinical staging model as a framework for recommendations regarding assessment, treatment and ongoing care. This guideline also refers its readers to selected published guidelines or statements directly relevant to Australian and New Zealand practice.

CONCLUSIONS

This clinical practice guideline for the management of schizophrenia and related disorders aims to improve care for people with these disorders living in Australia and New Zealand. It advocates a respectful, collaborative approach; optimal evidence-based treatment; and consideration of the specific needs of those in adverse circumstances or facing additional challenges.

Brexpiprazole: A Review in Schizophrenia

Oral brexpiprazole (Rexulti(®)) is a partial dopamine D2 agonist, which also has activity at several other receptors. This article reviews the pharmacological properties of brexpiprazole and its clinical efficacy and tolerability in patients with schizophrenia; its use in patients with major depressive disorder is beyond the scope of this review. Brexpiprazole 2-4 mg/day was generally effective in short-term, phase III studies at improving Positive and Negative Symptom Scale scores and other schizophrenia symptoms in patients with acute schizophrenia. Moreover, maintenance treatment with brexpiprazole 1-4 mg/day was associated with a significantly longer time to exacerbation of disease or impending relapse than placebo. The drug was well tolerated in clinical trials, with most serious adverse events in the short term being associated with the underlying disorder. Overall, oral brexpiprazole is a useful treatment option for the treatment of patients with schizophrenia.

Adjunctive Brexpiprazole: A Review in Major Depressive Disorder

Brexpiprazole (Rexulti(®)) is a serotonin-dopamine activity modulator, with a unique receptor binding profile and low intrinsic D2 activity suggestive of a lower potential than aripiprazole to cause activation-like adverse effects, such as akathisia. The drug was recently approved by the US FDA for adjunctive therapy with antidepressant treatment (ADT) in patients with major depressive disorder (MDD). In two phase III trials, adjunctive oral brexpiprazole 2 or 3 mg once daily was more effective than monotherapy with ADT in improving depressive symptoms in adults with MDD who demonstrated an incomplete response to previous treatment with ADT. Adjunctive brexpiprazole was generally well tolerated in clinical trials, which included treatment periods of up to 52 weeks. Results of ongoing trials should help position the drug in the treatment of MDD. In the meantime, brexpiprazole provides a valid option for patients with persistent symptoms despite standard antidepressant therapy.

WEIGHT GAIN AND ANTIPSYCHOTICS. DATA FROM EUFEST STUDY

Context

Schizophrenia is a chronic disease most frequently necessitating lifelong antipsychotic treatment. Selecting which antipsychotic is to be prescribed in an individual schizophrenia patient represents an important clinical decision that need to take into account efficacy and side effects.

Objective

Evaluating weight gain related with one year antipsychotic treatment in antipsychotic naive first-episode schizophrenia patients.

Design

This study is an analysis of weight gain associated with typical or atypical antipsychotics used in European First Episode Schizophrenia Trial (EUFEST) study.

Subjects and Methods

113 first episode naïve antipsychotic schizophrenia patients included in EUFEST - Romanian cohort, who were randomized to one of the 5 treatment arms. Weight was obtained at baseline, 3, 6, 9 and 12 months for the 5 antipsychotics (typical-Haloperidol; atypical-Olanzapine, Amisulpride, Ziprasidone, Quetiapine).

Results

There are no statistically significant differences between groups treated with typical or atypical antipsychotics or between any individual antipsychotics concerning weight gain during the study. Weight gain was the highest in the first 3 months (57.49%) for all the studied neuroleptics. At the end of the study, the less increase was observed with ziprasidone (3.87 kg) and the highest with olanzapine (9.83 kg).

Conclusion

Increase in weight has taken place for each individual neuroleptic, but also as a group (all neuroleptics) in the first three months (57.49%). Therefore, we should address the issue of weight gain with great care, especially in first period of antipsychotic administration, in order to fast deploy intervention tailored to maintain pre-treatment weight.

Switching to iloperidone: An omnibus of clinically relevant observations from a 12-week, open-label, randomized clinical trial in 500 persons with schizophrenia

OBJECTIVE

To describe secondary analyses from a 12-week, randomized, open-label trial where adult schizophrenia outpatients receiving risperidone, olanzapine, or aripiprazole were switched to iloperidone.

METHODS

Patients were randomized into two groups: one where the antecedent antipsychotic dose was titrated downwards to zero over 2 weeks (n=240), and the other group where the antecedent antipsychotic was abruptly stopped (n=260). Adaptations of the Clinical Global Impression scale were used to evaluate clinical changes. Other assessments included the reporting of adverse events (AEs), study discontinuation, body weight, and metabolic variables.

RESULTS

Improvement was steady throughout the study for both gradual- and immediate-switch groups starting at Week 1 and continuing through Week 12. Discontinuations due to AEs in the first 2 weeks of treatment were higher for the immediate-switch group compared with the gradual-switch group (10.8% vs. 5.4%, NNT 19, 95% CI 10-151). Fewer patients in the gradual-switch group experienced dizziness as an AE, whereas a higher percentage of patients in the immediate-switch group exhibited earlier onset of a therapeutic response within the first 2 weeks; both groups were comparable thereafter with low rates of dizziness and similar efficacy outcomes.

CONCLUSIONS

Switching to iloperidone can be accomplished either with a gradual crossover or immediate discontinuation of the prior antipsychotic; however, the immediate-switch method is associated with greater proportion of initial dizziness. The observed outcomes are consistent with what has been previously reported regarding iloperidone's favorable akathisia/EPS profile and modest impact on somnolence/sedation, body weight, and metabolic variables.

The preclinical profile of brexpiprazole: what is its clinical relevance for the treatment of psychiatric disorders?

Brexpiprazole is a serotonin-dopamine activity modulator in clinical development for schizophrenia, adjunctive treatment of major depressive disorder, agitation in Alzheimer's disease and post-traumatic stress disorder. It is a partial agonist at 5-HT1A and D2 receptors with similar potency, and an antagonist at 5-HT2A and adrenergic α1B/2C receptors. Compared with aripiprazole, brexpiprazole is more potent at 5-HT1A receptors and displays less intrinsic activity at D2 receptors. This unique serotonin and dopamine modulatory activity has shown robust antipsychotic, antidepressant-like and anxiolytic activities, and limited extrapyramidal symptom liability with pro-cognitive efficacy in animal models. Phase III clinical trials have been successfully completed in schizophrenia and adjunctive use in major depressive disorder, with the US FDA approval obtained for these uses; Phase III studies in Alzheimer's disease and post-traumatic stress disorder are ongoing.

Brexpiprazole for schizophrenia and as adjunct for major depressive disorder: a systematic review of the efficacy and safety profile for this newly approved antipsychotic - what is the number needed to treat, number needed to harm and likelihood to be helped or harmed?

OBJECTIVE

To describe the efficacy, tolerability and safety of brexpiprazole for the treatment of schizophrenia and as adjunct for major depressive disorder (MDD).

DATA SOURCES

The pivotal registration trials were accessed by querying http://www.ncbi.nlm.nih.gov/pubmed/ and http://www.clinicaltrials.gov, for the search terms 'brexpiprazole' OR 'OPC-34712', and by also querying the EMBASE (Elsevier) commercial database for clinical poster abstracts, and by asking the manufacturer for copies of posters presented at congresses. Product labelling provided additional information.

STUDY SELECTION

All available clinical reports of studies were identified.

DATA EXTRACTION

Descriptions of the principal results and calculation of number needed to treat (NNT) and number needed to harm (NNH) for relevant dichotomous outcomes were extracted from the available study reports and other sources of information.

DATA SYNTHESIS

Brexpiprazole is a new dopamine D2 receptor partial agonist that received approval for the treatment of schizophrenia and for adjunctive use for the treatment of MDD based on a clinical trial development programme that included two pivotal Phase III trials of brexpiprazole monotherapy in acute schizophrenia, and two pivotal Phase III trials of adjunctive brexpiprazole in acute MDD in patients who demonstrated inadequate response to standard antidepressant therapy. In addition, results from a 52-week relapse prevention/maintenance randomised placebo-controlled withdrawal study in patients with schizophrenia are available. In these trials, brexpiprazole was administered once daily and titrated to target doses. The recommended dose for the treatment of schizophrenia is 2-4 mg/day and that for MDD, 2 mg/day. Pooling together all the available data for the recommended target dose of brexpiprazole for acute schizophrenia from the above studies, the percentage of responders is 45.5% vs. 31.0% for placebo, yielding a NNT of 7 (95% CI 5-12). In the relapse prevention/maintenance trial, significantly fewer patients relapsed in the brexpiprazole group compared with placebo (13.5% vs. 38.5%), resulting in a NNT of 4 (95% CI 3-8). When the results for brexpiprazole 1, 2 and 3 mg from the two Phase III MDD trials are pooled together, 23.2% of the patients receiving brexpiprazole were responders, vs. 14.5% for placebo, yielding a NNT of 12 (95% CI 8-26). Brexpiprazole was well tolerated - for schizophrenia, discontinuation rates because of an adverse event (AE) were overall lower for patients receiving brexpiprazole vs. placebo, and for MDD a total of 3% of brexpiprazole-treated patients and 1% of placebo-treated patients discontinued because of AEs, resulting in a NNH of 53 (95% CI 30-235). Although the most commonly encountered AE noted in product labelling was akathisia (5.5% in the acute schizophrenia trials and 8.6% in the MDD trials), differences from placebo were small, generating a non-significant NNH of 112 for patients with schizophrenia and a modest NNH of 15 (95% CI 11-23) for patients with MDD. Short-term weight gain appears modest; however, more outliers with an increase of ≥ 7% of body weight were evident in open-label 52-week safety studies. Effects on glucose and lipids were small. Minimal effects on prolactin were observed, and no clinically relevant effects on the ECG QT interval were evident.

CONCLUSIONS

Clinical trials of brexpiprazole support its efficacy at the recommended target dose of 2-4 mg/day for the treatment of schizophrenia, and at the recommended target dose of 2 mg/day as adjunct to antidepressant medication for the treatment of MDD. Head-to-head comparisons with other available agents among patients with schizophrenia and MDD in the 'real world' are needed.