Effects of Olanzapine Combined With Samidorphan on Weight Gain in Schizophrenia: A 24-Week Phase 3 Study

Nutrition and schizophrenia: associations worthy of continued revaluation

BACKGROUND

Accumulating evidence have shown that diet and nutrition play significant roles in mental illness, such as depression, anxiety and bipolar disorder. However, comprehensive evaluation of the relationship between nutrition and schizophrenia is lacking.

OBJECTIVE

The present review aims to synthetic elaborate the associations between nutrition and schizophrenia. Relevant studies on dietary patterns, macronutrients, micronutrients were performed through a literature search to synthesize the extracted data.

SUMMARY

Dietary interventions may help prevent the occurrence of schizophrenia, or delay symptoms: Healthy diets like nutritious plant-based foods and high-quality protein, have been linked to reducing the risk or symptoms of schizophrenia. Moreover, diet high in saturated fat and sugar is linked to more serious outcomes of schizophrenia. Additionally, when N-acetylcysteine acts as an adjuvant therapy, the overall symptoms of schizophrenia are significantly reduced. Also nascent evidence showed mental disorders may be related to intestinal microbiota dysfunction. Our study offered important insights into the dietary habits of patients with schizophrenia and the potential impact of nutritional factors on the disease. We also emphasized the need for further research, particularly in the form of large randomized double-blind controlled trials, to better understand the effects of nutrients on schizophrenia symptoms in different populations and disease types.

Fatty acid desaturase 1/2 (FADS1 and FADS2), fatty acid desaturase indices, and their relationships with metabolic syndrome in female adults with first-episode schizophrenia after antipsychotic medications

OBJECTIVE

Although antipsychotics constitute the best treatment for patients with schizophrenia, this treatment class carries a high risk of metabolic disarrangements thus developing metabolic syndrome (MetS). Altered fatty acid (FA) composition and desaturase indices have been associated with several metabolic diseases, including MetS. Herein, we determined fatty acid desaturase 1 (FADS1) and FADS2 gene expressions, serum delta-5 desaturase (D5D) and D6D indices in female adults with first-episode schizophrenia after olanzapine medication, as well as their relationship with the incidence of MetS.

METHODS

This study prospectively recruited 120 female patients with first-episode schizophrenia who completed 6-month olanzapine medication. Among these female patients, 31 patients developed MetS and 89 patients did not.

RESULTS

The mRNA expression levels of FADS1 and FADS2 in patients were analyzed according to the presence of MetS and evaluation times with results of two-way ANOVAs (FADS1: PMetS = 0.0006, Ptime = 0.004, Pinteraction = 0.010; FADS2: PMetS = 0.012, Ptime < 0.0001, Pinteraction = 0.001). The D5D and D6D indices in patients were analyzed according to the presence of MetS and evaluation times with results of two-way ANOVAs (D5D: PMetS = 0.002, Ptime = 0.009, Pinteraction = 0.014; D6D: PMetS = 0.011, Ptime = 0.006, Pinteraction = 0.0001). The SCD-16 and SCD-18 indices in patients were analyzed according to the presence of MetS and evaluation times (SCD-16: PMetS = 0.005, Ptime = 0.009, Pinteraction = 0.016; SCD-18: PMetS = 0.037, Ptime = 0.382, Pinteraction = 0.163). The following multiple comparisons test showed the MetS exhibited reduced FADS1 mRNA expression and D5D index, increased FADS2 mRNA expression and D6D index, concomitant with an enhanced SCD-16 index, compared to the non-MetS did not after 6-month olanzapine medication.

CONCLUSION

The study suggests changes of FADS1, FADS2 expressions, and fatty acid desaturase indices including D5D, D6D, and SCD-16 may be associated with the development of MetS in female adults with first-episode schizophrenia after olanzapine medication.

Tolerability and safety outcomes of first-line oral second-generation antipsychotics in patients with schizophrenia

INTRODUCTION

Antipsychotics are the foundation of pharmacologic treatment for schizophrenia. There are many oral antipsychotics available and given that these medications are generally considered comparably efficacious when titrated to an adequate dose, their varied tolerability, and safety profiles become critically important for medication selection.

AREAS COVERED

This paper reviews tolerability and safety considerations for first-line second-generation oral antipsychotics currently approved for the treatment of schizophrenia in the USA. Excluded from consideration are clozapine and non-oral formulations.

EXPERT OPINION

Among antipsychotics, there are many differences in adverse reactions observed in clinical trials, such as variable likelihood to cause sedation vs insomnia, weight gain and abnormalities in glucose/lipid metabolism, hyperprolactinemia, potential for impact on the QT interval, and motoric adverse effects. Additional safety data that can help with medication selection include safety in pregnancy and lactation, and potential for drug-drug interactions. Ultimately, working with patients to personalize treatment by focusing on safety and individual tolerability considerations for various adverse effects can help in building a therapeutic alliance and improving patients' outcomes.

Shared and unique characteristics of metabolic syndrome in psychotic disorders: a review

Introduction

People with psychosis spectrum disorders (PSD) face an elevated risk of metabolic syndrome (MetS), which may reduce their life expectancy by nearly 20%. Pinpointing the shared and specific characteristics and clinical implications of MetS in PSD is crucial for designing interventions to reduce this risk, but an up-to-date review on MetS across the psychosis spectrum is lacking.

Methods

This narrative review fills this gap by examining the clinical literature on characteristics and implications of MetS in both distinct PSD and transdiagnostically, i.e., across traditional categorical diagnoses, with a focus on psychiatric and cardio-metabolic management.

Results

We discuss common and specific characteristics of MetS in PSD, as well as factors contributing to MetS development in PSD patients, including unhealthy lifestyle factors, genetic predisposition, pro-inflammatory state, drugs consumption, antipsychotic medication, and psychotic symptoms. We highlight the importance of early identification and management of cardio-metabolic risk in PSD patients, as well as the existing gaps in the literature, for instance in the screening for MetS in younger PSD patients. We compare hypotheses-generating clinical associations and characteristics of MetS in different PSD, concluding by reviewing the existing recommendations and challenges in screening, monitoring, and managing MetS in PSD.

Conclusion

Early identification and management of MetS are crucial to mitigate the long-term cardio-metabolic toll in PSD patients. Interventions should focus on healthy lifestyle and appropriate pharmacological and behavioral interventions. Further translational and clinical research is needed to develop targeted interventions and personalized treatment approaches for this vulnerable population, aiming at improving physical health and overall well-being.

A Comprehensive Review of Novel FDA-Approved Psychiatric Medications (2018-2022)

Mental health disorders are among the top leading causes of disease burden worldwide and many patients have high levels of treatment resistance. Even though medications offer improvement to some patients, antidepressants are only effective in about half of those treated, and schizophrenia is treatment-refractory in about one-third of patients. One way to combat this disparity is to improve medication development and discovery for psychiatric disorders through evidence-based research. Recently, most psychiatric medications approved by the United States Food and Drug Administration (FDA) are for increased tolerability or extended release. Because of the slow, incremental progress, there is a pressing need to explore novel medications with new indications or mechanisms of action to treat the expanding population with mental disorders, especially in those who are fully or partially recalcitrant to first-line medication options. This review aims to present the newest FDA medications with new indications, establish the clinical need for each, and discuss future directions in drug development. We searched and reviewed novel psychiatric medications approved by the FDA from 2018 to 2022. We then analyzed each medication in the United States Clinical Trials Registry and gathered updated results for efficacy and safety information. We also searched PubMed/MEDLINE (Medical Literature Analysis and Retrieval System Online), Scopus, Web of Science, Elsevier, and Google Scholar to understand how these new indications met current clinical needs. Finally, we inquired about related technological implications that will lead the field of psychopharmacology now and in the years to come. We found 12 novel psychiatric medications approved by the FDA from 2018 to 2022, representing a very small percentage of the total FDA approvals during that period. These psychiatric medications with novel mechanisms or improved efficacy and safety  are expected to provide further options for treating mental health disorders; promising results will lead to new patterns of research.

Activation of the PERK-CHOP signaling pathway during endoplasmic reticulum stress contributes to olanzapine-induced dyslipidemia

Olanzapine (OLZ) is a widely prescribed antipsychotic drug with a relatively ideal effect in the treatment of schizophrenia (SCZ). However, its severe metabolic side effects often deteriorate clinical therapeutic compliance and mental rehabilitation. The peripheral mechanism of OLZ-induced metabolic disorders remains abstruse for its muti-target activities. Endoplasmic reticulum (ER) stress is implicated in cellular energy metabolism and the progression of psychiatric disorders. In this study, we investigated the role of ER stress in the development of OLZ-induced dyslipidemia. A cohort of 146 SCZ patients receiving OLZ monotherapy was recruited, and blood samples and clinical data were collected at baseline, and in the 4th week, 12th week, and 24th week of the treatment. This case-control study revealed that OLZ treatment significantly elevated serum levels of endoplasmic reticulum (ER) stress markers GRP78, ATF4, and CHOP in SCZ patients with dyslipidemia. In HepG2 cells, treatment with OLZ (25, 50 μM) dose-dependently enhanced hepatic de novo lipogenesis accompanied by SREBPs activation, and simultaneously triggered ER stress. Inhibition of ER stress by tauroursodeoxycholate (TUDCA) and 4-phenyl butyric acid (4-PBA) attenuated OLZ-induced lipid dysregulation in vitro and in vivo. Moreover, we demonstrated that activation of PERK-CHOP signaling during ER stress was a major contributor to OLZ-triggered abnormal lipid metabolism in the liver, suggesting that PERK could be a potential target for ameliorating the development of OLZ-mediated lipid dysfunction. Taken together, ER stress inhibitors could be a potentially effective intervention against OLZ-induced dyslipidemia in SCZ.

Psychotropic Drug-Related Weight Gain and Its Treatment

Psychotropic drug-related weight gain (PDWG) is a common occurrence and is highly associated with non-initiation, discontinuation, and dissatisfaction with psychiatric drugs. Moreover, PDWG intersects with the elevated risk for obesity and associated morbidity that has been amply reported in the psychiatric population. Evidence indicates that differential liability for PDWG exists for antipsychotics, antidepressants, and anticonvulsants. During the past two decades, agents within these classes have become available with significantly lower or no liability for PDWG and as such should be prioritized. Although lithium is associated with weight gain, the overall extent of weight gain is significantly lower than previously estimated. The benefit of lifestyle and behavioral modification for obesity and/or PDWG in psychiatric populations is established, with effectiveness similar to that in the general population. Metformin is the most studied pharmacological treatment in the prevention and treatment of PDWG, and promising data are emerging for glucagon-like peptide-1 (GLP-1) receptor agonists (e.g., liraglutide, exenatide, semaglutide). Most pharmacologic antidotes for PDWG are supported with low-confidence data (e.g., topiramate, histamine-2 receptor antagonists). Future vistas for pharmacologic treatment for PDWG include large, adequately controlled studies with GLP-1 receptor agonists and possibly GLP-1/glucose-dependent insulinotropic polypeptide co-agonists (e.g., tirzepatide) as well as specific dietary modifications.

Olanzapine-Samidorphan for Schizophrenia: A Systematic Review and Meta-Analysis

Background and Objective

United States Food and Drug Administration (USFDA) recently approved a novel combination of olanzapine-samidorphan (OLZSAM) for managing olanzapine-associated adverse events (weight gain) in adult patients with schizophrenia and bipolar disorder. To opine about the safety and efficacy of OLZSAM, authors performed a systematic review and meta-analysis to convene justifiable evidence.

Methods

A thorough literature search was performed through the databases Embase, Cochrane Library, PubMed, and clinicaltrials.gov, from inception to September 2022, with the keywords: 'olanzapine and samidorphan' and schizophrenia; and "ALKS3831" and "lybalvi." Clinical trials published in English that analyzed the efficacy and safety of OLZSAM were included. The significant outcomes included in this study were change from baseline (CFB) in Positive and Negative Syndrome Scale (PANSS) at the end of the study, the proportion of patients with weight gain at the end of the study, the proportion of patients with at least one adverse event, and the incidence of drug discontinuation due to adverse events.

Results

The change in PANSS score at the end of the study was comparable among groups receiving OLZSAM and olanzapine alone: standardized mean difference (SMD) = 0.04; 95% CI = -0.09 to 0.17; p = 0.57. The OLZSAM group reported less incidence of weight gain: risk ratio (RR) = 0.91; 95% CI = 0.62-1.34; p = 0.63, and any adverse event: RR = 0.99; 95% CI = 0.90-1.09; p = 0.81. Drug discontinuation incidence was higher in the OLZSAM group: RR = 1.22; 95% CI = 0.84-1.79; p = 0.30.

Conclusions

The combination OLZSAM showed comparable efficacy to olanzapine alone in schizophrenia patients, with relatively less incidence of weight gain and adverse events; however, the drug discontinuation due to adverse events was more in the OLZSAM group.

Insulin Resistance/Diabetes and Schizophrenia: Potential Shared Genetic Factors and Implications for Better Management of Patients with Schizophrenia

Schizophrenia is a complex psychotic disorder with co-occurring conditions, including insulin resistance and type 2 diabetes (T2D). It is well established that T2D and its precursors (i.e., insulin resistance) are more prevalent in patients with schizophrenia who are treated with antipsychotics, as well as in antipsychotic-naïve patients experiencing their first episode of psychosis, compared with the general population. However, the mechanism(s) underlying the increased susceptibility, shared genetics, and possible cause-effect relationship between schizophrenia and T2D remain largely unknown. The objective of this narrative review was to synthesize important studies, including Mendelian randomization (MR) analyses that have integrated genome-wide association studies (GWAS), as well as results from in vitro models, in vivo models, and observational studies of patients with schizophrenia. Both GWAS and MR studies have found that schizophrenia and T2D/insulin resistance share genetic risk factors, and this may mediate a connection between peripheral or brain insulin resistance and T2D with cognition impairment and an increased risk of developing prediabetes and T2D in schizophrenia. Moreover, accumulating evidence supports a causal role for insulin resistance in schizophrenia and emphasizes the importance of a genetic basis for susceptibility to T2D in patients with schizophrenia before they receive psychotic treatment. The present findings and observations may have clinical implications for the development of better strategies to treat patients with schizophrenia, with both pharmacological (i.e., samidorphan, empagliflozin) and/or nonpharmacological (i.e., lifestyle changes) approaches. Additionally, this review may benefit the design of future studies by physicians and clinical investigators.

Challenges, unmet needs and future directions - a critical evaluation of the clinical trial landscape in schizophrenia research

INTRODUCTION

Developing novel antipsychotic mechanisms of action and repurposing established compounds for the treatment of schizophrenia is of utmost importance to improve relevant symptom domains and to improve the risk/benefit ratio of antipsychotic compounds. Novel trial design concepts, pathophysiology-based targeted treatment approaches, or even the return to old values may improve schizophrenia outcomes in the future.

AREAS COVERED

In this review of the clinical trial landscape in schizophrenia, we present an overview of the challenges and gaps in current clinical trials and elaborate on potential solutions to improve the outcomes of people with schizophrenia.

EXPERT OPINION

The classic parallel group design may limit substantial advantages in drug approval or repurposing. Collaborative approaches between regulatory authorities, industry, academia, and funding agencies are needed to overcome barriers in clinical schizophrenia research to allow for meaningful outcome improvements for the patients.

Long-Acting Injectable Antipsychotics-A Review on Formulation and In Vitro Dissolution

Long-acting injectable (LAI) neuroleptics constitute an effective therapeutical alternative for individuals suffering from persistent mental illness. These injectable pharmaceuticals help patients manage their condition better and improve long-term outcomes by preventing relapses and improving compliance. This review aims to analyse the current formulation aspects of LAI neuroleptics, with particular emphasis on analysis of drug release profiles as a critical test to guarantee drug quality and relevant therapeutical activity. While there is no officially approved procedure for depot parenteral drug formulations, various dissolution tests which were developed by LAI manufacturers are described. In vitro dissolution tests also possess a critical function in the estimation of the in vivo performance of a drug formulation. For that reason, thorough inspection of the in vitro-in vivo correlation (IVIVC) is also discussed.

The Diagnostic Workup, Screening, and Treatment Approaches for Patients with Delusional Infestation

Delusional infestation (DI) is a psychiatric disorder defined by the fixed, false belief that one has been infested by an organism without evidence to support this. Patients may present with skin lesions and report abnormal cutaneous sensations. The diagnostic workup for patients presenting with delusional infestation is essential to ensuring accurate diagnosis in ruling out other explanations for symptoms and investigating potential secondary causes of DI. In addition to a comprehensive history and physical examination, laboratory workup should be considered depending on the clinical picture. Antipsychotic medications are the most common drugs used in management of adults with DI and tailor the choice of treatment according to patient characteristics. This article serves as a guide for dermatologists, psychiatrists, and other clinicians as it reviews the workup and screening that should be considered when managing a patient with delusional infestation and subsequent treatment protocols once the diagnosis has been made.

Antipsychotic-Induced Weight Gain in Severe Mental Illness: Risk Factors and Special Considerations

PURPOSE OF REVIEW

Weight gain is a disconcerting issue experienced by patients treated with antipsychotics (APs). This review summarizes current knowledge on the prevalence, etiology, and risk factors for antipsychotic-induced weight gain (AIWG), and evidence for interventions, including special considerations.

RECENT FINDINGS

Predisposing risk factors for AIWG include lack of prior AP exposure, sex, and age. AP dose and duration of exposure are additional treatment-related factors that may contribute to this issue. Among current approaches to target AIWG, metformin has the most evidence to support its use, and this is increasingly reflected in clinical guidelines. While lifestyle approaches are recommended, cost-effectiveness and scalability represent limitations. More research is needed to identify newer treatment options and inform clinical recommendations for AIWG. Concerns around scope of practice in psychiatry to address AIWG and related comorbidities will require enhanced training opportunities and interdisciplinary collaborations, as well as updated position statements/practice guidelines emphasizing prevention.

Effects of Combined Therapy of Olanzapine and Samidorphan on Safety and Metabolic Parameters in Schizophrenia Patients: A Meta-Analysis

Purpose

This meta-analysis intended to evaluate the safety and metabolic effects of the combination of olanzapine (OLZ) and samidorphan (SAM) in the treatment of schizophrenia (SCZ) patients.

Patients and Methods

We searched for the English and Chinese databases for randomized controlled trials (RCTs) on the OLZ combined with SAM for SCZ. The English databases included PubMed, Web of Science, EMbase, and Cochrane Library, however, Chinese databases included Chinese Biology Medicine (CBM), VIP, Wanfang, and China National Knowledge Infrastructure (CNKI). All database searches were due by May 31, 2023. Using Review Manager 5.4 software, a meta-analysis was conducted following a literature review and data extraction.

Results

This study included five RCTs involving 1781 patients. Regarding safety, the meta-analysis revealed that the probability of weight gain was reduced in the OLZ and SAM group than in the OLZ group (RR = 0.83, 95% CI (0.69, 0.99), P < 0.05). Statistically, the incidence of severe adverse safety events, dry mouth, headache, drowsiness, death, and suicidal perception events was insignificant (P > 0.05); in terms of metabolism, compared with the OLZ group, the OLZ plus SAM group reduced total cholesterol (TC) levels (MD = -3.58, 95% CI (-6.81, -0.34), P < 0.05). However, it had no significant effect on metabolic indices, including low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides, glucose, and insulin index (P > 0.05).

Conclusion

In patients with SCZ, treatment with the combination of OLZ and SAM decreased the incidence of weight gain adverse events and TC levels; nevertheless, it did not affect other adverse events or metabolic parameters. These findings provide clinicians with evidence-based guidance and support for drug selection. However, it is crucial to confirm these findings through further high-quality research.

Promising translatable pharmacological interventions for body weight management in individuals with severe mental illness - a narrative review

INTRODUCTION

Psychotropic medications, especially antipsychotics, have been consistently shown to cause weight gain in individuals with severe mental illness (SMI), a population inherently challenged by poor physical health. Consequently, compared to the general population, this contributes to an increased cardiometabolic burden, including the risk of type 2 diabetes, dyslipidemia, and hypertension. Furthermore, comorbid obesity leads to treatment nonadherence, decreased quality of life, and increased risk of relapse, posing a challenge in the management of mental health. To address this, emerging agents investigated in the general population with potential to mitigate weight gain were explored to assess translatability to the SMI population.

AREAS COVERED

A literature search was conducted including agents approved for the management of obesity in the general population, along with upcoming agents under investigation in phase III trials with weight loss properties.

EXPERT OPINION

Metformin and topiramate along with lifestyle interventions are commonly prescribed for weight gain in individuals with SMI; however, their weight loss potential is modest at best. This review identified tirzepatide and cagrilintide-semaglutide among others as promising agents for adjunctive pharmacological management of weight gain.

Antipsychotic-Induced Metabolic Syndrome: A Review

Schizophrenia, a serious psychiatric disorder, is among the top 10 global causes of disability and affects nearly 1% of the world population. Antipsychotics constitute the best treatment for patients with schizophrenia, however, this treatment class carries a high risk of metabolic syndrome, including lipid abnormalities. Indeed, the risk of metabolic syndrome would be increased in the population with schizophrenia compared to the general population. The objective is to summarize the prevalence, the mechanisms, and the potential treatments of antipsychotic-induced metabolic syndrome. This is a narrative review of the literature. We searched the electronic database Medline, accessed through PubMed, to find studies that investigated the prevalence and treatments of metabolic syndrome in the adult population using antipsychotics. The prevalence of metabolic syndrome in patients treated with antipsychotics ranges from 37% to 63%. Antipsychotic iatrogenic effects include weight gain/increased waist circumference, dyslipidemia, insulin resistance/type 2 diabetes, and hypertension. Clozapine and olanzapine are reported to precipitate the onset of metabolic syndrome features. In patients with metabolic syndrome, an antipsychotic with less metabolic side effects such as lurasidone, lumateperone, ziprasidone, and aripiprazole should be prioritized. Unlike medications, aerobic exercise and dietetic counseling were found to be efficient as the nonpharmacologic treatment of antipsychotic-induced metabolic syndrome. Few pharmacological treatments were proven effective against weight gain in this patient population. The risk of metabolic syndrome induced by antipsychotics should be early recognized and closely monitored. Primary and secondary prevention of metabolic syndrome or onset of its feature might help reduce the risk of death for patients using antipsychotics.

Increased Metabolic Potential, Efficacy, and Safety of Emerging Treatments in Schizophrenia

Patients with schizophrenia experience a broad range of detrimental health outcomes resulting from illness severity, heterogeneity of disease, lifestyle behaviors, and adverse effects of antipsychotics. Because of these various factors, patients with schizophrenia have a much higher risk of cardiometabolic abnormalities than people without psychiatric illness. Although exposure to many antipsychotics increases cardiometabolic risk factors, mortality is higher in patients who are not treated versus those who are treated with antipsychotics. This indicates both direct and indirect benefits of adequately treated illness, as well as the need for beneficial medications that result in fewer cardiometabolic risk factors and comorbidities. The aim of the current narrative review was to outline the association between cardiometabolic dysfunction and schizophrenia, as well as discuss the confluence of factors that increase cardiometabolic risk in this patient population. An increased understanding of the pathophysiology of schizophrenia has guided discovery of novel treatments that do not directly target dopamine and that not only do not add, but may potentially minimize relevant cardiometabolic burden for these patients. Key discoveries that have advanced the understanding of the neural circuitry and pathophysiology of schizophrenia now provide possible pathways toward the development of new and effective treatments that may mitigate the risk of metabolic dysfunction in these patients. Novel targets and preclinical and clinical data on emerging treatments, such as glycine transport inhibitors, nicotinic and muscarinic receptor agonists, and trace amine-associated receptor-1 agonists, offer promise toward relevant therapeutic advancements. Numerous areas of investigation currently exist with the potential to considerably progress our knowledge and treatment of schizophrenia.

Calorie-restricted diet mitigates weight gain and metabolic abnormalities in obese women with schizophrenia: a randomized controlled trial

Background

Obesity is a prevalent health problem in patients with schizophrenia, and calorie restriction diet (CRD) achieved effective weight loss and metabolic improvement; however, these have not been rigorously evaluated in obese patients with schizophrenia.

Objective

To measure the effects of CRD on weight loss and metabolic status in hospitalized obese women with schizophrenia during a 4-week period.

Methods

Participants were randomly assigned to two groups in a 1:1 ratio. The intervention group (n = 47) was asked to follow a CRD and the control group (n = 48) a normal diet for 4 weeks. Outcomes of body weight, body composition, as well as metabolic parameters were measured at baseline and following the intervention period.

Results

Forty-five participants completed the 4-week research in both the intervention and control groups. Compared to the normal diet, adherence to the CRD significantly decreased body weight (2.38 ± 1.30 kg), body mass index (0.94 ± 0.52 kg/m²), waist circumference (4.34 ± 2.75 cm), hip circumference (3.37 ± 2.36 cm), mid-upper circumferences, triceps skin-fold thickness, fat mass and free fat mass with large effect sizes (p = <0.001, ηp² range between 0.145 and 0.571), as well as total cholesterol (0.69 ± 0.70 mmol/L) with a medium effect size (p = 0.028, ηp² = 0.054). There were no differences between the CRD and control groups in terms of pre-post changes in triglycerides, high- and low-density lipoprotein-cholesterols, as well as systolic and diastolic blood pressures (p > 0.05).

Conclusion

CRD is preventative of weight gain, but not apparent in intervention for metabolic status in hospitalized obese women with schizophrenia.Clinical trial registration: http://www.chictr.org.cn, ChiCTR-INR-16009185.

Receptors Involved in Mental Disorders and the Use of Clozapine, Chlorpromazine, Olanzapine, and Aripiprazole to Treat Mental Disorders

Mental illnesses are a global health challenge, and effective medicines are needed to treat these conditions. Psychotropic drugs are commonly prescribed to manage mental disorders, such as schizophrenia, but unfortunately, they can cause significant and undesirable side effects, such as myocarditis, erectile dysfunction, and obesity. Furthermore, some schizophrenic patients may not respond to psychotropic drugs, a condition called schizophrenia-treatment resistance. Fortunately, clozapine is a promising option for patients who exhibit treatment resistance. Unlike chlorpromazine, scientists have found that clozapine has fewer neurological side effects. Additionally, olanzapine and aripiprazole are well-known for their moderating effects on psychosis and are widely used in clinical practice. To further maximize drug efficacy, it is critical to deeply understand the receptors or signaling pathways central to the nervous system, such as serotonin, histamine, trace amines, dopamine, and G-protein coupled receptors. This article provides an overview of the receptors mentioned above, as well as the antipsychotics that interact with them, such as olanzapine, aripiprazole, clozapine, and chlorpromazine. Additionally, this article discusses the general pharmacology of these medications.

Reduction in Multiple Cardiometabolic Risk Factors With Combined Olanzapine/Samidorphan Compared With Olanzapine: Post Hoc Analyses From a 24-Week Phase 3 Study

BACKGROUND AND HYPOTHESES

Weight gain and adverse cardiometabolic effects often limit the clinical utility of olanzapine. In ENLIGHTEN-2, combining olanzapine with the opioid receptor antagonist samidorphan (OLZ/SAM) mitigated olanzapine-associated weight gain. These analyses tested the hypothesis that OLZ/SAM would be associated with reduced adverse cardiometabolic effects compared with olanzapine.

STUDY DESIGN

This phase 3 double-blind study randomized adults with schizophrenia to OLZ/SAM or olanzapine for 24 weeks. Post hoc analyses assessed changes from baseline to week 24 in cardiometabolic risk parameters, including body mass index (BMI), risk of developing obesity (BMI ≥30 kg/m2) or metabolic syndrome, waist circumference, along with mean and potentially clinically significant changes in blood pressure, glucose, and lipids.

RESULTS

After 24 weeks' treatment, compared with olanzapine, OLZ/SAM was associated with smaller least-squares mean (LSM) changes from baseline in systolic blood pressure (LSM difference, -2.63 mm Hg; 95% CI: -4.78, -0.47), diastolic blood pressure (LSM difference, -0.75 mm Hg; 95% CI: -2.31, 0.80), and BMI (LSM difference, -0.65 kg/m2; 95% CI: -1.01, -0.28). OLZ/SAM treatment was also associated with reduced risk of shifting from normal blood pressure to stage 1/2 hypertension (odds ratio [OR], 0.48; 95% CI: 0.24, 0.96), becoming obese (OR, 0.52; 95% CI: 0.32, 0.82), and developing metabolic syndrome (OR, 0.55; 95% CI: 0.31, 0.99) compared with olanzapine. No treatment group differences were noted for risk of hyperglycemia or hyperlipidemia.

CONCLUSIONS

OLZ/SAM treatment was associated with lower risk of worsening cardiometabolic risk factors related to obesity, hypertension, and metabolic syndrome relative to olanzapine. NCT02694328, https://clinicaltrials.gov/ct2/show/NCT02694328.

Recent Advances in Psychopharmacology: From Bench to Bedside Novel Trends in Schizophrenia

Research in the field of psychopharmacology is ongoing to develop novel compounds which can revolutionize the treatment of psychiatric disorders. The concept of bench-to-bedside is a tedious process, transforming the initial research performed in the laboratories into novel treatment options. Schizophrenia (SCZ) is a chronic psychiatric illness with significant morbidity and mortality. SCZ not only presents with psychotic symptoms including hallucinations and delusions but also with negative and cognitive symptoms. The negative symptoms include the diminished ability to express emotions, loss of pleasure, and motivation with minimal social interactions. Conventional antipsychotics primarily target positive symptoms with minimal therapeutic benefits for negative and cognitive symptoms along with metabolic side effects. Researchers have explored novel targets to develop new compounds to overcome the above limitations. The glutamatergic system has provided new hope in treating schizophrenia by targeting negative and cognitive symptoms. Other receptor modulators, including serotonergic, phosphodiesterase, trans-amine-associated receptors, etc., are novel targets for developing new compounds. Future research is required in this field to explore novel compounds and establish their efficacy and safety for the treatment of schizophrenia. Last but not least, pharmacogenomics has effectively utilized genetic information to develop novel compounds by minimizing the risk of failure of the clinical trials and enhancing efficacy and safety.

The future of psychopharmacology: a critical appraisal of ongoing phase 2/3 trials, and of some current trends aiming to de-risk trial programmes of novel agents

Despite considerable progress in pharmacotherapy over the past seven decades, many mental disorders remain insufficiently treated. This situation is in part due to the limited knowledge of the pathophysiology of these disorders and the lack of biological markers to stratify and individualize patient selection, but also to a still restricted number of mechanisms of action being targeted in monotherapy or combination/augmentation treatment, as well as to a variety of challenges threatening the successful development and testing of new drugs. In this paper, we first provide an overview of the most promising drugs with innovative mechanisms of action that are undergoing phase 2 or 3 testing for schizophrenia, bipolar disorder, major depressive disorder, anxiety and trauma-related disorders, substance use disorders, and dementia. Promising repurposing of established medications for new psychiatric indications, as well as variations in the modulation of dopamine, noradrenaline and serotonin receptor functioning, are also considered. We then critically discuss the clinical trial parameters that need to be considered in depth when developing and testing new pharmacological agents for the treatment of mental disorders. Hurdles and perils threatening success of new drug development and testing include inadequacy and imprecision of inclusion/exclusion criteria and ratings, sub-optimally suited clinical trial participants, multiple factors contributing to a large/increasing placebo effect, and problems with statistical analyses. This information should be considered in order to de-risk trial programmes of novel agents or known agents for novel psychiatric indications, increasing their chances of success.

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.

The Difficult Path to the Discovery of Novel Treatments in Psychiatric Disorders

CNS diseases, including psychiatric disorders, represent a significant opportunity for the discovery and development of new drugs and therapeutic treatments with the potential to have a significant impact on human health. CNS diseases, however, present particular challenges to therapeutic discovery efforts, and psychiatric diseases/disorders may be among the most difficult. With specific exceptions such as psychostimulants for ADHD, a large number of psychiatric patients are resistant to existing treatments. In addition, clinicians have no way of knowing which psychiatric patients will respond to which drugs. By definition, psychiatric diagnoses are syndromal in nature; determinations of efficacy are often self-reported, and drug discovery is largely model-based. While such models of psychiatric disease are amenable to screening for new drugs, whether cellular or whole-animal based, they have only modest face validity and, more importantly, predictive validity. Multiple academic, pharmaceutical industry, and government agencies are dedicated to the translation of new findings about the neurobiology of major psychiatric disorders into the discovery and advancement of novel therapies. The collaboration of these agencies provide a pathway for developing new therapeutics. These efforts will be greatly helped by recent advances in understanding the genetic bases of psychiatric disorders, the ongoing search for diagnostic and therapy-responsive biomarkers, and the validation of new animal models.

Second to none: rationale, timing, and clinical management of clozapine use in schizophrenia

Despite its enduring relevance as the single most effective and important evidence-based treatment for schizophrenia, underutilization of clozapine remains considerable. To a substantial degree, this is attributable to a reluctance of psychiatrists to offer clozapine due to its relatively large side-effect burden and the complexity of its use. This underscores the necessity for continued education regarding both the vital nature and the intricacies of clozapine treatment. This narrative review summarizes all clinically relevant areas of evidence, which support clozapine's wide-ranging superior efficacy - for treatment-resistant schizophrenia (TRS) and beyond - and make its safe use eminently feasible. Converging evidence indicates that TRS constitutes a distinct albeit heterogeneous subgroup of schizophrenias primarily responsive to clozapine. Most importantly, the predominantly early onset of treatment resistance and the considerable decline in response rates associated with its delayed initiation make clozapine an essential treatment option throughout the course of illness, beginning with the first psychotic episode. To maximize patients' benefits, systematic early recognition efforts based on stringent use of TRS criteria, a timely offer of clozapine, thorough side-effect screening and management as well as consistent use of therapeutic drug monitoring and established augmentation strategies for suboptimal responders are crucial. To minimize permanent all-cause discontinuation, re-challenges after neutropenia or myocarditis should be considered. Owing to clozapine's unique efficacy, comorbid conditions including substance use and most somatic disorders should not dissuade but rather encourage clinicians to consider clozapine. Moreover, treatment decisions need to be informed by the late onset of clozapine's full effects, which for reduced suicidality and mortality rates may not even be readily apparent. Overall, the singular extent of its efficacy combined with the high level of patient satisfaction continues to distinguish clozapine from all other available antipsychotics.

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.

Olanzapine/samidorphan combination consistently mitigates weight gain across various subgroups of patients

OBJECTIVE

A combination of olanzapine and the opioid receptor antagonist samidorphan (OLZ/SAM) has been approved in the United States for the treatment of adults with schizophrenia or adults with bipolar I disorder. In a phase 3 study in adults with schizophrenia (ENLIGHTEN-2), OLZ/SAM treatment was associated with significantly less weight gain compared with olanzapine. Prespecified subgroup analyses explored the consistency of the weight mitigation effect of OLZ/SAM vs olanzapine across demographic subgroups in ENLIGHTEN-2.

METHODS

The multicenter, randomized, double-blind ENLIGHTEN-2 study (NCT02694328) included outpatients aged 18-55 years with a diagnosis of schizophrenia based on DSM-5 criteria, a body mass index (BMI) of 18 to 30 kg/m2, and stable body weight (self-reported change ≤5% for ≥3 months before study entry). Patients were randomized 1:1 to receive OLZ/SAM or olanzapine for 24 weeks. Co-primary endpoints (previously reported) were percent change in body weight and proportion of patients with at least 10% weight gain from baseline at week 24. Prespecified exploratory subgroup analyses by sex, age, self-reported race, and baseline BMI were conducted.

RESULTS

At week 24, treatment with OLZ/SAM resulted in numerically less percent weight gain than with olanzapine across all subgroups evaluated. The proportion of patients with at least 10% weight gain was smaller in each subgroup treated with OLZ/SAM vs olanzapine.

CONCLUSION

In these exploratory subgroup analyses from the ENLIGHTEN-2 study, weight-mitigating effects of OLZ/SAM vs olanzapine were observed consistently across patient subgroups and were in line with results from the overall study population.

Pharmacological interventions for prevention of weight gain in people with schizophrenia

BACKGROUND

Antipsychotic-induced weight gain is an extremely common problem in people with schizophrenia and is associated with increased morbidity and mortality. Adjunctive pharmacological interventions may be necessary to help manage antipsychotic-induced weight gain. This review splits and updates a previous Cochrane Review that focused on both pharmacological and behavioural approaches to this problem.

OBJECTIVES

To determine the effectiveness of pharmacological interventions for preventing antipsychotic-induced weight gain in people with schizophrenia.

SEARCH METHODS

The Cochrane Schizophrenia Information Specialist searched Cochrane Schizophrenia's Register of Trials on 10 February 2021. There are no language, date, document type, or publication status limitations for inclusion of records in the register.

SELECTION CRITERIA

We included all randomised controlled trials (RCTs) that examined any adjunctive pharmacological intervention for preventing weight gain in people with schizophrenia or schizophrenia-like illnesses who use antipsychotic medications.

DATA COLLECTION AND ANALYSIS

At least two review authors independently extracted data and assessed the quality of included studies. For continuous outcomes, we combined mean differences (MD) in endpoint and change data in the analysis. For dichotomous outcomes, we calculated risk ratios (RR). We assessed risk of bias for included studies and used GRADE to judge certainty of evidence and create summary of findings tables. The primary outcomes for this review were clinically important change in weight, clinically important change in body mass index (BMI), leaving the study early, compliance with treatment, and frequency of nausea. The included studies rarely reported these outcomes, so, post hoc, we added two new outcomes, average endpoint/change in weight and average endpoint/change in BMI.

MAIN RESULTS

Seventeen RCTs, with a total of 1388 participants, met the inclusion criteria for the review. Five studies investigated metformin, three topiramate, three H2 antagonists, three monoamine modulators, and one each investigated monoamine modulators plus betahistine, melatonin and samidorphan. The comparator in all studies was placebo or no treatment (i.e. standard care alone). We synthesised all studies in a quantitative meta-analysis. Most studies inadequately reported their methods of allocation concealment and blinding of participants and personnel. The resulting risk of bias and often small sample sizes limited the overall certainty of the evidence. Only one reboxetine study reported the primary outcome, number of participants with clinically important change in weight. Fewer people in the treatment condition experienced weight gains of more than 5% and more than 7% of their bodyweight than those in the placebo group (> 5% weight gain RR 0.27, 95% confidence interval (CI) 0.11 to 0.65; 1 study, 43 participants; > 7% weight gain RR 0.24, 95% CI 0.07 to 0.83; 1 study, 43 participants; very low-certainty evidence). No studies reported the primary outcomes, 'clinically important change in BMI', or 'compliance with treatment'. However, several studies reported 'average endpoint/change in body weight' or 'average endpoint/change in BMI'. Metformin may be effective in preventing weight gain (MD -4.03 kg, 95% CI -5.78 to -2.28; 4 studies, 131 participants; low-certainty evidence); and BMI increase (MD -1.63 kg/m2, 95% CI -2.96 to -0.29; 5 studies, 227 participants; low-certainty evidence). Other agents that may be slightly effective in preventing weight gain include H2 antagonists such as nizatidine, famotidine and ranitidine (MD -1.32 kg, 95% CI -2.09 to -0.56; 3 studies, 248 participants; low-certainty evidence) and monoamine modulators such as reboxetine and fluoxetine (weight: MD -1.89 kg, 95% CI -3.31 to -0.47; 3 studies, 103 participants; low-certainty evidence; BMI: MD -0.66 kg/m2, 95% CI -1.05 to -0.26; 3 studies, 103 participants; low-certainty evidence). Topiramate did not appear effective in preventing weight gain (MD -4.82 kg, 95% CI -9.99 to 0.35; 3 studies, 168 participants; very low-certainty evidence). For all agents, there was no difference between groups in terms of individuals leaving the study or reports of nausea. However, the results of these outcomes are uncertain given the very low-certainty evidence.

AUTHORS' CONCLUSIONS

There is low-certainty evidence to suggest that metformin may be effective in preventing weight gain. Interpretation of this result and those for other agents, is limited by the small number of studies, small sample size, and short study duration. In future, we need studies that are adequately powered and with longer treatment durations to further evaluate the efficacy and safety of interventions for managing weight gain.

Olanzapine/Samidorphan: A New Option for the Treatment of Adults With Schizophrenia or Bipolar I Disorder

Objective

To review the pharmacology, pharmacokinetics, and efficacy and safety data of a combination of olanzapine and samidorphan (OLZ/SAM) for the treatment of schizophrenia and bipolar I disorder, which mitigates the possible unwanted side effects of weight gain associated with olanzapine (OLZ).

Data Sources

The review was done with a bibliographic survey of studies using MEDLINE/PubMed (January 1999-May 2021) database using the keywords olanzapine and samidorphan. Abstracts, scientific posters, and information from the manufacturer's product labeling were evaluated for inclusion. Inclusion criteria: phase 2, phase 3, and open-labeled studies that evaluated the use of OLZ/SAM for the treatment of schizophrenia and bipolar I disorder.

Data Synthesis

We have included one phase 2 dose-ranging exploratory study, two phase 3 efficacy and safety studies, and several open-label extension studies without a comparator. For the treatment of schizophrenia, OLZ/SAM and OLZ alone were analyzed in 2 randomized, double-blind comparison studies of approximately 960 patients. Analysis indicated that OLZ (5-20 mg)/SAM (10 mg) significantly mitigated the side effect of weight gain compared with OLZ alone (control) while maintaining antipsychotic efficacy. For bipolar I disorder, OLZ/SAM was approved as an acute treatment for manic or mixed episodes, as well as an adjunct to valproate or lithium for manic/mixed episodes based on bridging strategy allowed by the Food and Drug Administration.

Relevance to Patient Care and Clinical Practice

The combination of olanzapine and samidorphan demonstrated efficacy for the treatment of schizophrenia with a dosage range of 5 to 20 mg OLZ to a 10-mg fixed dose of samidorphan. Advantages of this drug combination include once-daily dosing, favorable tolerability, and most importantly, mitigation of weight gain, which may encourage adherence, when compared with OLZ alone.

Conclusion

The new combination treatment of OLZ/SAM is a unique antipsychotic formulation to provide the recognized efficacious treatment of OLZ, while mitigating the weight gain and possibly the weight-related adverse effects secondary to OLZ monotherapy.

Samidorphan for the treatment of weight gain associated with olanzapine in patients with schizophrenia and bipolar disorder

INTRODUCTION

Olanzapine (OLZ) is one of the most effective antipsychotic agents, however, its clinical utility has been limited by weight gain. Samidorphan (SAM) is aμ-opioid receptor antagonist and it can reduce the weight gain associated with OLZ. A combination of OLZ and SAM (OLZ/SAM) has been developed to provide the antipsychotic efficacy of OLZ, while mitigating OLZ-associated weight gain.

AREAS COVERED

A comprehensive literature search was conducted in PubMed. Key search terms included SAM and weight gain associated with OLZ. The pharmacological action, clinical efficacy, and safety of SAM were reviewed.

EXPERT OPINION

OLZ can lead to weight gain. SAM is a new drug that acts as an opioid receptor antagonist that can decrease weight gain. SAM mitigates OLZ-associated weight gain while preserving the antipsychotic efficacy of OLZ. Clinical trials have confirmed that OLZ/SAM significantly improved psychotic symptoms, and resulted in significantly less weight gain than OLZ. OLZ/SAM was well tolerated. Therefore, it is a potential new treatment option for schizophrenia.

Opioid antagonists to prevent olanzapine-induced weight gain: A systematic review

Introduction

Olanzapine (OLZ) is a second generation antipsychotic that is approved for the treatment of schizophrenia, bipolar disorder type 1 as monotherapy (acute manic or mixed episodes, maintenance), or as an add-on to lithium or valproate (manic or mixed episodes). It is one of the most effective antipsychotics for the treatment of schizophrenia, but concerns remain due to its significant metabolic adverse effects. Notably, OLZ has one of the highest rates of weight gain among all antipsychotic drugs. Previous studies report on potential mitigation of weight gain with opioid antagonists. A systematic review was conducted to summarize the impact of these agents on weight and BMI when used as adjuncts to OLZ.

Methods

A systematic review of randomized controlled trials was conducted with 3 searches between March 2, 2021 and March 27, 2022.

Results

Six studies met inclusion criteria, 5 of which assessed OLZ and samidorphan (SAM) and 1 of which assessed OLZ and naltrexone compared with OLZ monotherapy. A total of 1752 patients were included with 952 receiving SAM and 14 receiving naltrexone as an adjunct to OLZ. SAM was shown to mitigate OLZ-induced weight gain by 1.0 kg. Only 1 study assessed naltrexone with no statistically significant results for weight gain.

Discussion

SAM is effective at reducing OLZ-induced weight gain. Naltrexone did not reduce OLZ-induced increases in weight or BMI. However, there is a paucity of data on other opioid antagonists as adjuncts to OLZ treatment to prevent increases in weight or BMI.

Long-term treatment of antipsychotics and combined therapy with other psychotropic medications inducing weight gain in patients with non-affective psychotic disorder: Evidence from GROUP, a longitudinal study

INTRODUCTION

Antipsychotics (APs) can cause weight gain. Little is known about changes in weight when APs are combined with other psychotropics. This study examines the weight change in patients undergoing long-term treatment with APs or with AP combined with other psychotropics.

METHODS

Patients with non-affective psychotic disorder from the GROUP study were divided into three groups: AP medication group (APm) (n = 100), AP in combination with other psychotropics (APc) (n = 73), and medication-free (Meds-free) (n = 100). Weight change was examined at inclusion and after three years using a paired-sample t-test. An Independent-sample t-test was performed to evaluate weight change among patients taking clozapine, olanzapine, and quetiapine and individuals not taking these medications. Linear regression was performed to evaluate the association between covariates and weight.

RESULTS

Patients in the APm group [mean = 1.800 kg, t(99)=2.849, 95% CI(0.546, 3.054), p = 0.005] and the APc group [mean = 1.877 kg, t(72)=2.688, 95% CI(0.485, 3.268), p = 0.009] showed significant weight gain. Patients taking clozapine, olanzapine or quetiapine showed significant weight gain compared to those not taking these medications [mean difference=1.707 kg, t(271)= 2.061, 95% CI(0.077, 3.337), p = 0.040)].

CONCLUSION

Patients receiving APs and APs with other psychotropics gain weight during long-term treatment. It is possible that weight gain is mainly driven by APs.

Risk of Drug-induced Movement Disorders with Newer Antipsychotic Agents

Background:

The last decade has seen development of numerous novel antipsychotic drugs with unique mechanisms including long-acting formulations for clinical use. A comparative assessment of these new drugs with each other and previous antipsychotics have not been performed with regards to risk for drug-induced movement disorders (DIMD).

Methods:

Medline was searched from January 2010 to February 2022 for primary research articles and review articles in English using the search terms “extrapyramidal” and “tardive” with individual drug names of novel antipsychotics.

Results:

We identified articles describing the risk of DIMD with 6 novel antipsychotics, 4 novel formulations, and 3 experimental antipsychotics. Both short- and long-term data generally showed comparable to lower risk of DIMD with novel antipsychotics and recent long-acting formulations compared to previously marketed antipsychotics.

Discussion:

Several novel antipsychotics, particularly lumateperone and pimavanserin, show promise in being able to treat psychosis while reducing the risk of DIMD. Long-acting paliperidone may reduce risk of DIMD while other long-acting injectable formulations of SGA have similar risk of DIMD compared to oral formulations. New drug targets for treating psychosis without dopamine blockade also show promise.

Samidorphan/olanzapine combination therapy for schizophrenia: Efficacy, tolerance and adverse outcomes of regimen, evidence-based review of clinical trials

Introduction

Objectives

Methods

Results

Conclusion

•

FDA approved a combination dose of olanzapine and samidorphan (OLZ/SAM) for treatment of schizophrenia and bipolar I disorder.

•

Overall, OLZ/SAM showed a significant reduction in symptoms for long-term treatment.

•

Major adverse events included nervous system disorders, blood, metabolic or nutritional changes.

Olanzapine/Samidorphan: A New Combination Treatment for Schizophrenia and Bipolar I Disorder Intended to Reduce Weight Gain

Olanzapine is a second-generation antipsychotic with established efficacy in several psychiatric disease states, but its use is limited because of weight gain and metabolic side effects. Samidorphan is a novel opioid antagonist that binds to mu-opioid, kappa-opioid, and delta-opioid receptors and is hypothesized to reduce cravings for high-calorie foods thus attenuating antipsychotic-induced weight gain. The combination product olanzapine/samidorphan was approved by the US Food and Drug Administration in June 2021 for the treatment of schizophrenia and bipolar I disorder; this article reviews the pharmacological properties of oral olanzapine/samidorphan and its clinical efficacy and tolerability with a focus on mitigation of olanzapine-induced weight gain in these patient populations. In clinical trials, the combination of olanzapine/samidorphan was associated with significantly less weight gain and smaller increases in waist circumference as compared with olanzapine monotherapy. Olanzapine/samidorphan demonstrated similar efficacy as olanzapine monotherapy and was well tolerated. Weight gain and metabolic side effects associated with olanzapine monotherapy can result in tolerability issues and potentially medication nonadherence. Olanzapine/samidorphan is an effective treatment for schizophrenia and bipolar I disorder with less weight gain than olanzapine monotherapy.

Existing and emerging pharmacological approaches to the treatment of mania: A critical overview

Manic episodes are a defining, frequent and dramatically disabling occurrence in the course of Bipolar Disorder type I. Current pharmacotherapy of mania lists a good number of agents, but differences in efficacy and safety profiles among these agents must be considered in order to tailor personalized therapies, especially when the long-term course of the illness is considered. There is wide room and need to ameliorate current pharmacological approaches to mania, but ongoing pharmacological research on the topic is scant. In this work we try to critically assess clinical factors and patients' characteristics that may influence the treatment choice for manic episodes. In addition, we conduct a narrative review on experimental pharmacology of bipolar mania and psychotic disorders, presenting a critical overview on agents which could represent treatment alternatives for a manic episode in the next future. Results show limited novel or ongoing research on agents acting as mood stabilizers (Ebselen, Valnoctamide and Eslicarbazepine did not reach statistical significance in demonstrating antimanic efficacy). As for the emerging experimental antipsychotic, some of them (including KarXT, SEP-363856, RO6889450, ALKS3831) have demonstrated good antipsychotic efficacy and a favorable safety profile, but little is known about their use in patients with bipolar disorder and specifically designed trials are needed. Lastly, some benefits for the treatment of mania could be expected to come in the next future from non-mood stabilizers/non-antipsychotic agents (especially PKC inhibitors like Endoxifen): long-term trials are needed to confirm positive results in terms of long-term efficacy and safety.

Effect of Co-Treatment of Olanzapine with SEP-363856 in Mice Models of Schizophrenia

Olanzapine is a commonly used drug in the treatment of schizophrenia, but its clinical application has been restricted by metabolic-related side effects. In order to mitigate the weight gain side effects caused by olanzapine, other drugs with different targets were selected for combined use and evaluated in animal models of schizophrenia. SEP-363856 is a novel psychotropic agent which is under phase III clinical trials for schizophrenia treatment. The aim of the research was to evaluate whether co-administration of olanzapine and SEP-363856 exerts synergistic anti-schizophrenic effects in the apomorphine (APO)-induced climbing test, the MK-801-induced hyperactivity test, and the Morris water maze test, and therefore reduces the weight gain side effects induced by olanzapine. Through isobolographic analysis, the results showed a synergistic interaction in the climbing test; the experimental ED30 (3 mg/kg) was significantly smaller (p < 0.05) than the theoretical ED30 (5 mg/kg). Additionally, such potentiating effects appeared additive in the MK-801 challenge experiment. Co-treatment with an effective dose of olanzapine and a low dose of SEP-363856 reversed MK-801-induced cognitive impairment symptoms in mice. Moreover, combination treatment with olanzapine and SEP-363856 controls sustained weight gain in mice with chronic exposure to olanzapine. These results support further clinical trials to test the effectiveness of co-treatment of olanzapine and SEP-363856 for controlling symptoms and weight gain in patients with schizophrenia during antipsychotic treatments.

Olanzapine-samidorphan combination tablets for the treatment of schizophrenia and bipolar I disorder - what is it, and will it be used?

INTRODUCTION

: Although olanzapine remains one of the most efficacious antipsychotic medications for the treatment of schizophrenia, there are significant tolerability concerns related to its weight and metabolic profile. Olanzapine-samidorphan combination tablets (OLZ/SAM), branded as Lybalvi, is a newly FDA approved formulation aimed at attenuating antipsychotic induced weight gain via modulation of the endogenous opioid system with samidorphan, while retaining the robust antipsychotic efficacy of olanzapine.

AREAS COVERED

: We reviewed the published literature of OLZ/SAM for the management of schizophrenia using the US National Library of Medicine's PubMed.gov resource. Topics covered in this narrative review include the pharmacokinetics, pharmacodynamics, tolerability, and efficacy of OLZ/SAM.

EXPERT OPINION

: OLZ/SAM is an effective and well tolerated pharmacologic option in mitigating olanzapine induced weight gain while retaining olanzapine's efficacy. It has a limited effect on metabolic laboratory parameters and cumulatively tends to limit weight gain rather than promote weight loss. Additional research will be needed to determine its effectiveness compared to alternative strategies to attenuate antipsychotic induced weight gain.

Olanzapine and samidorphan combination treatment: A systematic review

INTRODUCTION

The overarching aim of this review is to synthesize the efficacy, tolerability, and weight-mitigation effects of the olanzapine/samidorphan (OLZ/SAM) combination treatment in adults with schizophrenia and bipolar disorder-I.

METHODS

A systematic search of PubMed, Web of Science, Embase, and The Cochrane Library was conducted on August 15th, 2021. Studies were included if they investigated the use of OLZ/SAM treatment in patients with schizophrenia or bipolar disorder-I, and reported the clinical outcomes: efficacy, change in weight or waist circumference, tolerability, pharmacokinetics, or change in metabolic parameters. A narrative synthesis was undertaken of the data.

RESULTS

Eight studies met the inclusion criteria. All identified studies were conducted in adults with schizophrenia. Compared to OLZ-monotherapy, OLZ/SAM was associated with decreased odds of developing clinically significant (>10%) weight gain (OR=0.50, 95% CI:0.31,0.80; p= 0.003) and increase in waist circumference (risk difference = -17.1% 95% CI:-26.3,-7.8) from baseline measurements respectively. In another study, OLZ was 2.7 times more associated with clinically significant weight gain as compared to OLZ/SAM (OR=2.73, 95% CI:1.11, 6.67; p = 0.023). The clinical efficacy of OLZ/SAM remained similar to OLZ with improved tolerability in both short- and long-term studies with no significantly altered pharmacokinetic properties of the constituent agents.

CONCLUSION

OLZ/SAM-treatment is associated with mitigated weight-gain liability when compared to OLZ-monotherapy in adults with schizophrenia. Additional studies are needed to ascertain patient acceptability, appropriate selection and sequencing of OLZ/SAM in the treatment algorithms for adults with schizophrenia (and BD-I), as well as to determine cost-effectiveness and long-term metabolic effects.

Opioid antagonism mitigates antipsychotic-associated weight gain: focus on olanzapine

BACKGROUND

The endogenous opioid system affects metabolism, including weight regulation. Evidence from preclinical and clinical studies provides a rationale for targeting this system to mitigate weight-related side effects of antipsychotics. This review describes the role of the opioid system in regulating weight and metabolism, examines the effects of opioid receptor antagonism on those functions, and explores the use of opioid antagonists to mitigate antipsychotic-associated weight gain and/or metabolic effects.

METHODS

A PubMed literature search was conducted to identify representative opioid antagonists and associated preclinical and clinical studies examining their potential for the regulation of weight and metabolism.

RESULTS

The mu opioid receptor (MOR), delta opioid receptor (DOR), and kappa opioid receptor (KOR) types have overlapping but distinct patterns of central and peripheral expression, and each contributes to the regulation of body weight and metabolism. Three representative opioid antagonists (eg, naltrexone, samidorphan, and LY255582) were identified for illustration. These opioid antagonists differed in their receptor binding and pharmacokinetic profiles, including oral bioavailability, systemic clearance, and half-life, and were associated with varying effects on food intake, energy utilization, and metabolic dysregulation.

CONCLUSIONS

Preclinical and clinical data suggest that antagonism of the endogenous opioid system is a mechanism to address antipsychotic-associated weight gain and metabolic dysregulation. However, evidence suggests that the differing roles of MOR, DOR, and KOR in metabolism, together with the differences in receptor binding, pharmacokinetic, and functional activity profiles of the opioid receptor antagonists discussed in this review, likely contribute to their differential pharmacodynamic effects and clinical outcomes observed regarding antipsychotic-associated weight gain.

Insulin and glucose metabolism with olanzapine and a combination of olanzapine and samidorphan: exploratory phase 1 results in healthy volunteers

A combination of olanzapine and samidorphan (OLZ/SAM) received US Food and Drug Administration approval in May 2021 for the treatment of adults with schizophrenia or bipolar I disorder. OLZ/SAM provides the efficacy of olanzapine, while mitigating olanzapine-associated weight gain. This exploratory study characterized the metabolic profile of OLZ/SAM in healthy volunteers to gain mechanistic insights. Volunteers received once-daily oral 10 mg/10 mg OLZ/SAM, 10 mg olanzapine, or placebo for 21 days. Assessments included insulin sensitivity during an oral glucose tolerance test (OGTT), hyperinsulinemic-euglycemic clamp, other measures of glucose/lipid metabolism, and adverse event (AE) monitoring. Treatment effects were estimated with analysis of covariance. In total, 60 subjects were randomized (double-blind; placebo, n = 12; olanzapine, n = 24; OLZ/SAM, n = 24). Olanzapine resulted in hyperinsulinemia and reduced insulin sensitivity during an OGTT at day 19, changes not observed with OLZ/SAM or placebo. Insulin sensitivity, measured by hyperinsulinemic-euglycemic clamp, was decreased in all treatment groups relative to baseline, but this effect was greatest with olanzapine and OLZ/SAM. Although postprandial (OGTT) glucose and fasting cholesterol concentrations were similarly increased with olanzapine or OLZ/SAM, other early metabolic effects were distinct, including post-OGTT C-peptide concentrations and aspects of energy metabolism. Forty-nine subjects (81.7%) experienced at least 1 AE, most mild or moderate in severity. OLZ/SAM appeared to mitigate some of olanzapine's unfavorable postprandial metabolic effects (e.g., hyperinsulinemia, elevated C-peptide) in this exploratory study. These findings supplement the body of evidence from completed or ongoing OLZ/SAM clinical trials supporting its role in the treatment of schizophrenia and bipolar I disorder.

Olanzapine/Samidorphan: New Drug Approved for Treating Bipolar I Disorder and Schizophrenia

OBJECTIVE

To describe the approval of olanzapine/samidorphan, compare the clinical trial data, and summarize key findings, with a focus on impact to clinical practice.

DATA SOURCES

A literature search of PubMed was performed (March 2006 to November 2021) using the following search terms: Lybalvi, olanzapine/samidorphan, olanzapine, antipsychotic, bipolar disorder, and schizophrenia. Product monographs, review articles, and randomized control trials were reviewed.

STUDY SELECTION AND DATA EXTRACTION

Relevant English-language studies conducted in humans were considered. Primary use of Phase III clinical drug approval trials preferred; supplementary trial analysis evaluated to provide context.

DATA SYNTHESIS

In June 2021, the Food and Drug Administration (FDA) approved Lybalvi^® (olanzapine/samidorphan) for indications including treatment of adults with schizophrenia and/or bipolar I disorder (acute manic episodes or acute episodes with mixed features) through the multi-stage ENLIGHTEN clinical trials. Participants were enrolled in 4-week, 24-week, and 52-week studies to evaluate the safety and efficacy of olanzapine/samidorphan. Subsequent secondary analysis evaluated metabolic effects.

RELEVANCE TO PATIENT CARE AND CLINICAL PRACTICE

This review details the pharmacologic, pharmacokinetic, associated dosing and indications, and adverse effects for the drug combination olanzapine/samidorphan. Better understanding of novel drug mechanisms will help to expand on the potential role and place for use in clinical practice.

CONCLUSION

When treating complex patients with schizophrenia, the olanzapine/samidorphan combination has limited effect on medication-induced weight gain often associated with antipsychotic olanzapine monotherapy. Additional studies are needed to further define the role of olanzapine/samidorphan in bipolar I disorder and clinical practice.

Present and future antipsychotic drugs: a systematic review of the putative mechanisms of action for efficacy and a critical appraisal under a translational perspective

Antipsychotics represent the mainstay of schizophrenia pharmacological therapy, and their role has been expanded in the last years to mood disorders treatment. Although introduced in 1952, many years of research were required before an accurate picture of how antipsychotics work began to emerge. Despite the well-recognized characterization of antipsychotics in typical and atypical based on their liability to induce motor adverse events, their main action at dopamine D2R to elicit the "anti-psychotic" effect, as well as the multimodal action at other classes of receptors, their effects on intracellular mechanisms starting with receptor occupancy is still not completely understood. Significant lines of evidence converge on the impact of these compounds on multiple molecular signaling pathways implicated in the regulation of early genes and growth factors, dendritic spine shape, brain inflammation, and immune response, tuning overall the function and architecture of the synapse. Here we present, based on PRISMA approach, a comprehensive and systematic review of the above mechanisms under a translational perspective to disentangle those intracellular actions and signaling that may underline clinically relevant effects and represent potential targets for further innovative strategies in antipsychotic therapy.

In vivo Characterization of the Opioid Receptor-Binding Profiles of Samidorphan and Naltrexone in Rats: Comparisons at Clinically Relevant Concentrations

INTRODUCTION

The atypical antipsychotic olanzapine is approved for the treatment of schizophrenia and bipolar I disorder; however, weight gain and metabolic dysregulation associated with olanzapine therapy have limited its clinical utility. In clinical studies, treatment with the combination of olanzapine and the opioid receptor antagonist samidorphan (OLZ/SAM) mitigated olanzapine-associated weight gain while providing antipsychotic efficacy similar to that of olanzapine. Although samidorphan is structurally similar to the opioid receptor antagonist naltrexone, the two differ in their pharmacokinetics and in vitro binding affinities to mu, delta, and kappa opioid receptors (MOR, DOR, and KOR, respectively). The objective of this series of nonclinical studies was to compare the in vivo binding profiles of samidorphan and naltrexone and their receptor occupancies at MOR, DOR, and KOR in rat brains.

METHODS

Male rats were injected with samidorphan or naltrexone to obtain total and unbound plasma and brain concentrations representing levels observed in humans at clinically relevant oral doses. Subsequently, samidorphan and naltrexone brain receptor occupancy at MOR, DOR, and KOR was measured using ultra-performance liquid chromatography and high-resolution accurate-mass mass spectrometry.

RESULTS

A dose-dependent increase in samidorphan occupancy was observed at MOR, DOR, and KOR (EC₅₀: 5.1, 54.7, and 42.9 nM, respectively). Occupancy of naltrexone at MOR (EC₅₀: 15.5 nM) and KOR was dose dependent; minimal DOR occupancy was detected. At the clinically relevant unbound brain concentration of 23.1 nM, samidorphan bound to MOR, DOR, and KOR with 93.2%, 36.1%, and 41.9% occupancy, respectively. At 33.5 nM, naltrexone bound to MOR and KOR with 79.4% and 9.4% occupancy, respectively, with no binding at DOR.

DISCUSSION

At clinically relevant concentrations, samidorphan occupied MOR, DOR, and KOR, whereas naltrexone occupied only MOR and KOR. The binding profile of samidorphan differs from that of naltrexone, with potential clinical implications.