Metabolic effects of paliperidone extended release versus oral olanzapine in patients with schizophrenia: a prospective, randomized, controlled trial

Oral and long-acting antipsychotics for relapse prevention in schizophrenia-spectrum disorders: a network meta-analysis of 92 randomized trials including 22,645 participants

According to current evidence and guidelines, continued antipsychotic treatment is key for preventing relapse in people with schizophrenia-spectrum disorders, but evidence-based recommendations for the choice of the individual antipsychotic for maintenance treatment are lacking. Although oral antipsychotics are often prescribed first line for practical reasons, long-acting injectable antipsychotics (LAIs) are a valuable resource to tackle adherence issues since the earliest phase of disease. Medline, EMBASE, PsycINFO, CENTRAL and CINAHL databases and online registers were searched to identify randomized controlled trials comparing LAIs or oral antipsychotics head-to-head or against placebo, published until June 2021. Relative risks and standardized mean differences were pooled using random-effects pairwise and network meta-analysis. The primary outcomes were relapse and dropout due to adverse events. We used the Cochrane Risk of Bias tool to assess study quality, and the CINeMA approach to assess the confidence of pooled estimates. Of 100 eligible trials, 92 (N=22,645) provided usable data for meta-analyses. Regarding relapse prevention, the vast majority of the 31 included treatments outperformed placebo. Compared to placebo, "high" confidence in the results was found for (in descending order of effect magnitude) amisulpride-oral (OS), olanzapine-OS, aripiprazole-LAI, olanzapine-LAI, aripiprazole-OS, paliperidone-OS, and ziprasidone-OS. "Moderate" confidence in the results was found for paliperidone-LAI 1-monthly, iloperidone-OS, fluphenazine-OS, brexpiprazole-OS, paliperidone-LAI 1-monthly, asenapine-OS, haloperidol-OS, quetiapine-OS, cariprazine-OS, and lurasidone-OS. Regarding tolerability, none of the antipsychotics was significantly worse than placebo, but confidence was poor, with only aripiprazole (both LAI and OS) showing "moderate" confidence levels. Based on these findings, olanzapine, aripiprazole and paliperidone are the best choices for the maintenance treatment of schizophrenia-spectrum disorders, considering that both LAI and oral formulations of these antipsychotics are among the best-performing treatments and have the highest confidence of evidence for relapse prevention. This finding is of particular relevance for low- and middle-income countries and constrained-resource settings, where few medications may be selected. Results from this network meta-analysis can inform clinical guidelines and national and international drug regulation policies.

Second-Generation Antipsychotic Drugs for Patients with Schizophrenia: Systematic Literature Review and Meta-analysis of Metabolic and Cardiovascular Side Effects

BACKGROUND AND OBJECTIVES

Second-generation antipsychotics (SGAs) for schizophrenia show different risk profiles, whose evidence has been evaluated through comparative reviews on randomized controlled trials (RCTs) and observational studies.

METHODS

We performed a systematic review and meta-analysis of weight gains, metabolic and cardiovascular side effects of SGAs, relying on both RCTs and observational studies, by comparing variations between the start of treatment and the end of follow-up. The systematic review refers to papers published from June 2009 to November 2020. PRISMA criteria were followed. No restrictions on heterogeneity level have been considered for meta-analysis. A test for the summary effect measure and heterogeneity (I2 metric) was used.

RESULTS

Seventy-nine papers were selected from 3076 studies (61% RCTs, 39% observational studies). Olanzapine and risperidone reported the greatest weight gain and olanzapine the largest BMI increase. Paliperidone showed the highest increase in total cholesterol, but is the only drug reporting an increase in the HDL cholesterol. Quetiapine XR showed the highest decrease in fasting glucose. Lurasidone showed the lowest increase in body weight and a reduction in BMI and was also the only treatment reporting a decrease in total cholesterol and triglycerides. The highest increase in systolic and diastolic blood pressure was reported by quetiapine XR.

CONCLUSIONS

Despite some limitations (differences in the mean dosages per patient and other side effects not included) this paper provides the first complete meta-analysis on SGAs in variations on metabolic risk profile between start of treatment and end of follow-up, with useful results for clinical practice and possibly for future economic evaluation studies.

Effects of olanzapine treatment on lipid profiles in patients with schizophrenia: a systematic review and meta-analysis

Olanzapine-induced dyslipidemia significantly increases the risk of cardiovascular disease in patients with schizophrenia. However, the clinical features of olanzapine-induced dyslipidemia remain hitherto unclear because of inconsistencies in the literature. This meta-analysis thus investigated the effects of olanzapine treatment on lipid profiles among patients with schizophrenia. Studies of the effects of olanzapine on lipids were obtained through the PubMed, Web of science, The Cochrane Library and Embase databases (up to January 1, 2020). Twenty-one studies and 1790 schizophrenia patients who received olanzapine therapy were included in our analysis. An olanzapine-induced increase was observed in plasma triglyceride (TG), total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels in patients with schizophrenia (all P < 0.05). Moreover, the time points analyzed included the following: baseline, 4 weeks, 6 weeks, 8 weeks, 12 weeks, and ≥ 24 weeks (data of ≥ 24 weeks were integrated). The significant elevation of TG, TC, and LDL-C was observed in patients with schizophrenia already by 4 weeks of olanzapine therapy (all P < 0.05), with no obvious changes observed in high-density lipoprotein cholesterol (HDL-C) (P > 0.05). In conclusion, olanzapine-induced dyslipidemia, characterized by increased TG, TC, and LDL-C levels, was observed in patients with schizophrenia already by 4 weeks of olanzapine treatment.

Long-term effectiveness of oral second-generation antipsychotics in patients with schizophrenia and related disorders: a systematic review and meta-analysis of direct head-to-head comparisons

Second-generation antipsychotics (SGAs) are recommended for maintenance treatment in schizophrenia. However, comparative long-term effectiveness among SGAs is unclear. Here we provide a systematic review and meta-analysis of randomized trials lasting ≥⃒6 months comparing SGAs head-to-head in schizophrenia and related disorders. The primary outcome was all-cause discontinuation. Secondary outcomes included efficacy and tolerability, i.e., psychopathology, inefficacy-related and intolerability-related discontinuation, relapse, hospitalization, remission, functioning, quality of life, and adverse events. Pooled risk ratio and standardized mean difference were calculated using random-effects models. Across 59 studies (N=45,787), lasting 47.4±32.1 weeks (range 24-186), no consistent superiority of any SGA emerged across efficacy and tolerability outcomes. Regarding all-cause discontinuation, clozapine, olanzapine and risperidone were significantly (p<0.05) superior to several other SGAs, while quetiapine was inferior to several other SGAs. As to psychopathology, clozapine and olanzapine were superior to several other SGAs, while quetiapine and ziprasidone were inferior to several other SGAs. Data for other efficacy outcomes were sparse. Regarding intolerability-related discontinuation, risperidone was superior and clozapine was inferior to several other SGAs. Concerning weight gain, olanzapine was worse than all other compared non-clozapine SGAs, and risperidone was significantly worse than several other SGAs. As to prolactin increase, risperidone and amisulpride were significantly worse than several other SGAs. Regarding parkinsonism, olanzapine was superior to risperidone, without significant differences pertaining to akathisia. Concerning sedation and somnolence, clozapine and quetiapine were significantly worse than some other SGAs. In summary, different long-term SGA efficacy and tolerability patterns emerged. The long-term risk-benefit profiles of specific SGAs need to be tailored to individual patients to optimize maintenance treatment outcomes.

Switching to paliperidone extended release in patients with schizophrenia dissatisfied with previous olanzapine treatment: Post hoc analysis of an open-label, prospective study

OBJECTIVE

This post hoc analysis of an open-label, single-arm, multicenter study was designed to assess the efficacy, safety, and tolerability of paliperidone extended release (ER) in Chinese patients with non-acute schizophrenia, after switching from olanzapine.

METHODS

Patients with schizophrenia who were dissatisfied with prior olanzapine treatment switched to flexible paliperidone ER (3-12 mg/day) based on clinical judgment. Change from baseline to week 12 in Positive and Negative Syndrome Scale (PANSS) total scores (primary endpoint), PANSS subscale scores, response rate, Clinical Global Impression-Severity (CGI-S) score, personal and social performance (PSP) scores, patient satisfaction with treatment score, change in sleep quality, level of daytime sleepiness and safety were evaluated.

RESULTS

Out of 118 enrolled patients, 95 (81%) completed the study. Mean duration of study was 76.9 (23.85) days. The primary endpoint, mean (SD) PANSS total score changed significantly from baseline to endpoint (-19.6 [18.71], P <.0001). Secondary endpoints including PANSS subscale score, PSP, patient satisfaction and daytime drowsiness also significantly improved (P <.001). Most commonly reported (≥1%) treatment-emergent adverse events were akathisia (n = 14 [12%]) and insomnia (n = 9 [8%]).

CONCLUSIONS

Switching to flexible-dosed paliperidone ER in patients dissatisfied with prior olanzapine treatment achieved good efficacy and tolerability consistently over 12 weeks.

The Wnt Signaling Pathway Effector TCF7L2 Mediates Olanzapine-Induced Weight Gain and Insulin Resistance

Olanzapine is a widely used atypical antipsychotic medication for treatment of schizophrenia and is often associated with serious metabolic abnormalities including weight gain and impaired glucose tolerance. These metabolic side effects are severe clinical problems but the underpinning mechanism remains poorly understood. Recently, growing evidence suggests that Wnt signaling pathway has a critical role in the pathogenesis of schizophrenia and molecular cascades of antipsychotics action, of which Wnt signaling pathway key effector TCF7L2 is strongly associated with glucose homeostasis. In this study, we aim to explore the characteristics of metabolic disturbance induced by olanzapine and to elucidate the role of TCF7L2 in this process. C57BL/6 mice were subject to olanzapine (4 mg/kg/day), or olanzapine plus metformin (150 mg/kg/day), or saline, respectively, for 8 weeks. Metabolic indices and TCF7L2 expression levels in liver, skeletal muscle, adipose, and pancreatic tissues were closely monitored. Olanzapine challenge induced remarkably increased body weight, fasting insulin, homeostasis model assessment-insulin resistance index, and TCF7L2 protein expression in liver, skeletal muscle, and adipose tissues. Notably, these effects could be effectively ameliorated by metformin. In addition, we found that olanzapine-induced body weight gain and insulin resistance actively influence the expression of TCF7L2 in liver and skeletal muscle, and elevated level of insulin determines the increased expression of TCF7L2 in adipose tissue. Our results demonstrate that TCF7L2 participates in olanzapine-induced metabolic disturbance, which presents a novel mechanism for olanzapine-induced metabolic disturbance and a potential therapeutic target to prevent the associated metabolic side effects.

Oral glucose tolerance test performance in olanzapine-treated schizophrenia-spectrum patients is predicted by BMI and triglycerides but not olanzapine dose or duration

OBJECTIVE

Olanzapine, an atypical antipsychotic, is associated with glucoregulatory abnormalities, but the nature of this link is not fully elucidated. This is the first olanzapine oral glucose tolerance test (oGTT) study to consider treatment dose and duration, and to compare complementary indices respectively assessing insulin sensitivity (Matsuda index) and resistance (homeostasis model assessment).

METHODS

Body mass index (BMI), body composition, plasma lipids, and oGTT were measured in olanzapine-treated nondiabetic patients with DSM-IV-TR diagnosis of schizophrenia or schizoaffective disorder (n = 35).

RESULTS

While only one previously undiagnosed participant met diabetes criteria based on fasting plasma glucose alone (≥126 mg/dL), seven were diagnosed with oGTT (2-hr plasma glucose ≥200 mg/dL). Multiple regression analyses revealed that the Matsuda index correlated with BMI (p < 0.0001) and plasma triglycerides (p = 0.01), but not with age, olanzapine dose, olanzapine treatment duration, or plasma cholesterol. Homeostasis model assessment and fasting plasma glucose correlated with triglycerides only (p < 0.0001 for both).

CONCLUSIONS

Our data suggest that BMI and triglycerides may be implicated in olanzapine-related glucoregulatory abnormalities. The lack of correlation between glucoregulatory abnormalities and olanzapine dose or treatment duration suggests preexisting metabolic disturbances and/or disturbances arising early in the course of treatment. Clinicians prescribing antipsychotics should consider oGTT, especially in patients with obesity and/or hypertriglyceridemia.

Paliperidone for the treatment of schizophrenia and schizoaffective disorders - a drug safety evaluation

INTRODUCTION

Paliperidone, the major active metabolite of risperidone, is a second-generation antipsychotic that has been developed as an extended-release (ER) oral formulation and a long-acting injectable paliperidone palmitate (PP) formulation. Paliperidone has demonstrated efficacy in the reduction of acute schizophrenia symptoms and clinical benefits were maintained also in the long-term treatments. Paliperidone ER and PP are generally well tolerated with a predictable adverse event profile. Areas covered: Data from studies evaluating safety and tolerability in the acute and maintenance treatment of schizophrenia with paliperidone are reviewed. The reported treatment-emergent adverse events of these formulations are discussed. Expert opinion: In the treatment of schizophrenia and schizoaffective disorders the safety profile has a central role because it can enhance patient compliance. In fact treatment-emergent adverse events are one of the main causes of discontinuation in these patients. In particular the main limitation in the administration of paliperidone could be represented by the onset of hyperprolactinemia (especially in women) and of mild parkinsonism. Paliperidone has a high impact on current long-term drug strategies, especially given the new 3 month long-acting injectable formulation of PP.

Association between the HTR2C rs1414334 C/G gene polymorphism and the development of the metabolic syndrome in patients treated with atypical antipsychotics

Few studies have assessed the association between the rs1414334 C/G polymorphism in the HTR2C gene and the development of the metabolic syndrome in patients treated with atypical antipsychotics. To provide further evidence, a cross-sectional study was conducted in Spain between 2012 and 2013 in 166 patients with these characteristics. In these patients, the association between the polymorphism and the presence of the metabolic syndrome was determined by implementing binary logistic regression models adjusted for variables associated with the metabolic syndrome. We did not confirm previous claims that the C allele of the polymorphism was linked to the metabolic syndrome: the association was in the opposite direction and non-significant. This conclusion held after taking gender and lifestyle variables into account.

A Flexible-Dose Study of Paliperidone ER in Patients With Nonacute Schizophrenia Previously Treated Unsuccessfully With Oral Olanzapine

OBJECTIVE

The goal of this study was to explore the tolerability, safety, and treatment response of switching from oral olanzapine to paliperidone extended release (ER).

METHODS

Adult patients with nonacute schizophrenia who had been treated unsuccessfully with oral olanzapine were switched to flexible doses of paliperidone ER (3 to 12 mg/d). The primary efficacy outcome was a ≥ 20% improvement in Positive and Negative Syndrome Scale (PANSS) total scores from baseline to endpoint for patients who switched medications because of lack of efficacy with olanzapine and noninferiority versus previous olanzapine treatment (mean endpoint change in PANSS total scores vs. baseline of ≤ 5 points) for patients who switched for reasons other than lack of efficacy. Safety and tolerability were assessed by monitoring adverse events, extrapyramidal symptoms, and weight change.

RESULTS

Of 396 patients, 65.2% were men, mean age was 40.0 ± 12.0 years, and 75.5% had paranoid schizophrenia. Among the patients whose main reason for switching was lack of efficacy, an improvement in the PANSS total score of ≥ 20% occurred in 57.4% of patients. Noninferiority was confirmed for each subgroup of patients whose main reason for switching was something other than lack of efficacy. Paliperidone ER was generally well tolerated. Extrapyramidal symptoms as measured by total Extrapyramidal Symptom Rating Scale scores showed statistically significant and clinically relevant improvements at endpoint, the average weight decreased by 0.8 ± 5.2 kg at endpoint, and a clinically relevant weight gain of ≥ 7% occurred in 8.0% of patients.

CONCLUSION

Paliperidone ER flexibly-dosed over 6 months was well tolerated and associated with a meaningful clinical response in patients with nonacute schizophrenia who had previously been unsuccessfully treated with oral olanzapine.

Systematic Literature Review of the Methods Used to Compare Newer Second-Generation Agents for the Management of Schizophrenia: A focus on Health Technology Assessment

BACKGROUND

The challenges of comparative effectiveness to support health technology assessment (HTA) agencies are important considerations in the choices of antipsychotic medications for the treatment of schizophrenia.

OBJECTIVES

Our aim was to assess the study methods used and outcomes reported in the published literature to address the question of comparative effectiveness of newer antipsychotic agents and the adequacy and availability of evidence to support HTA agencies.

DATA SOURCE

A systematic search of the PubMed database from 1 January 2009 to 30 September 2013 was conducted to identify studies evaluating new atypical antipsychotics reporting on comparative effectiveness.

STUDY SELECTION

The systematic review comprised of studies on schizophrenia patients where at least two drugs were being compared and at least one treatment group received one of the following second-generation antipsychotics: risperidone, olanzapine, aripiprazole, paliperidone, asenapine, iloperidone, lurasidone, and quetiapine. The included studies were also required to have an efficacy, safety or economic outcome, such as Positive and Negative Syndrome Scale (PANSS) score, weight gain, resource utilization, or costs.

STUDY APPRAISAL AND SYNTHESIS METHODS

Two reviewers (BW and GK) independently applied the inclusion criteria. Disagreements between reviewers were resolved by consensus, referring to the original sources. Information on the methodology and outcomes was collected for each included study. This included study description, head-to-head drug comparison, patient population, study methodology, statistical methods, reported outcomes, study support, and journal type.

RESULTS

A total of 198 studies were identified from electronic search methods. The largest category of studies was randomized controlled trials [RCTs] (N = 73; 36.9%), which were largely directed at the regulatory endpoint. Fewer studies were undertaken for HTA-purposes cohort studies (N = 53; 26.8%), meta-analyses (N = 32; 16.2%), economic studies (N = 14; 7.1%), and cross-sectional studies (N = 13; 6.6%). Direct head-to-head comparisons preferred by HTA were dominated by the comparison involving olanzapine and risperidone, representing 149 (75.3%) and 119 (60.1%) studies, respectively. RCTs, which are the primary study type for regulatory submissions, showed a lack of bias. Studies aimed at HTA were not as well performed. Cohort studies suffered from bias in the selection of comparison groups, lack of control for confounders, and differential dropout rates. As a group, cross-sectional studies scored poorly for bias, with a primary failure to identify a representative sample. Economic studies showed highly variable bias, with bias in the representation of effectiveness data, model assumptions without validation, and lack of sensitivity analyses.

LIMITATIONS

One limitation of this systematic review is that it only included studies from 2009 to 2013, potentially excluding some earlier comparator studies, particularly those involving first-generation antipsychotics.

CONCLUSIONS

This review of comparative effectiveness studies of second-generation antipsychotic agents for schizophrenic patients revealed a wide range of study types, study methodologies, and outcomes. For traditional efficacy outcomes and select safety outcomes, there is strong evidence from many well-conducted studies; however, there are fewer studies of types preferred by HTA with limited head-to-head comparisons and a higher risk of bias in the execution of these studies.

Effects of paliperidone extended release on functioning level and symptoms of patients with recent onset schizophrenia: An open-label, single-arm, flexible-dose, 12-months follow-up study

BACKGROUND

Response to antipsychotic treatment is better in the early stages of schizophrenia.

AIMS

The primary objective of this non-randomized, single-arm, multicenter clinical trial was to explore the response to treatment and safety of a flexible dose of paliperidone (mean = 6.42 mg/day) in patients with recent onset schizophrenia (< 3 years after the first episode/hospitalization).

METHODS

Severity of clinical symptoms was evaluated by the Positive and Negative Syndrome Scale (PANSS), functioning was assessed using the Global Assessment of Functioning (GAF) scale and the Personal and Social Performance Scale (PSP).

RESULTS

In a total of 85 patients enrolled, 80 patients were eligible. Total PSP score at baseline (50.2 ± 11.6) increased at all visits. Total PSP score was 65.4 ± 12.1 at month 12 (P < 0.001). GAF scores were significantly higher at all visits compared with baseline (P = 0.001). It was 62.4 ± 12.5 with an increase of 42.9% at month 12 (P < 0.001). PANSS Positive and Negative subscales and General psychopathology subscale scores showed significant reductions beginning with month 3 and were 11.9 ± 3.8 (29.3%; P < 0.001), 13.7 ± 5.6 (27.3% P < 0.001) and 27.8 ± 7.1 (23.2%; P < 0.001) at month 12, respectively. Twelve patients (14.3%) had a serious adverse event. The most common adverse events were insomnia (17.9%), nausea (8.3%), akathisia (4.8%), anxiety (4.8%) and depression (4.8%). Body weight values at the end of the study were significantly higher compared with baseline.

CONCLUSION

The present study demonstrates that flexible dose of paliperidone resulted in a significant improvement in functioning and reduction in symptoms in patients with recent onset schizophrenia.

Deciphering discord: How Drosophila research has enhanced our understanding of the importance of FMRP in different spatial and temporal contexts

Fragile X Syndrome (FXS) is the most common heritable form of intellectual impairment as well as the leading monogenetic cause of autism. In addition to its canonical definition as a neurodevelopmental disease, recent findings in the clinic suggest that FXS is a systemic disorder that is characterized by a variety of heterogeneous phenotypes. Efforts to study FXS pathogenesis have been aided by the development and characterization of animal models of the disease. Research efforts in Drosophila melanogaster have revealed key insights into the mechanistic underpinnings of FXS. While much remains unknown, it is increasingly apparent that FXS involves a myriad of spatially and temporally specific alterations in cellular function. Consequently, the literature is filled with numerous discordant findings. Researchers and clinicians alike must be cognizant of this dissonance, as it will likely be important for the design of preclinical studies to assess the efficacy of therapeutic strategies to improve the lives of FXS patients.

Weight gain and antipsychotics: a drug safety review

INTRODUCTION

Second-generation antipsychotics (SGAs) are widely used in several psychiatric disease entities and exert to a different extent a risk for antipsychotic-induced weight gain (AIWG). As AIWG is associated with an increase in metabolic syndrome or cardiovascular events, knowledge of these risks is crucial for further monitoring and the initiation of counteractive measures.

AREAS COVERED

We searched PubMed and Web of Sciences for randomized-controlled trials and naturalistic observational studies published between 2010 and 2014 with sample sizes exceeding 100, including all marketed SGAs apart from zotepine, and providing data on weight increase. We also summarized relevant systematic reviews and meta-analyses of head-to-head comparisons.

EXPERT OPINION

Recently published data still support the hierarchical ranking of SGAs already proposed in previous reviews ranking clozapine and olanzapine as having the highest risk, followed by amisulpride, asenapine, iloperidone, paliperidone, quetiapine, risperidone and sertindole in the middle, and aripiprazole, lurasidone and ziprasidone with the lowest risk. Number needed to harm varied considerably in our meta-analysis. Younger patients and patients with a lower baseline body mass index are most vulnerable. The greatest amount of weight gain occurs within the first weeks of treatment. AIWG occurs in all diagnostic groups and is also common in treatment with first-generation antipsychotics; therefore, awareness of this adverse event is essential for anyone prescribing antipsychotics.

Clinical effectiveness and resource utilization of paliperidone ER for schizophrenia: Pharmacoepidemiologic International Longitudinal Antipsychotic Registry (PILAR)

OBJECTIVE

To document prescribing patterns in clinical practice and assess long-term outcomes related to initiation of paliperidone ER and other oral antipsychotics among patients with schizophrenia in a naturalistic setting.

RESEARCH DESIGN AND METHODS

An international, non-interventional, naturalistic study of adult patients (≥18 years) with schizophrenia. Patients were assigned to the relevant treatment group (paliperidone ER or 'all other oral antipsychotics') after switching to, or initiating, oral antipsychotic treatment. Retrospective 12 month data collection was followed by 12 month prospective data collection, with 3-monthly assessments. The primary endpoint was time to all-cause discontinuation of new medication. Secondary endpoints included Clinical Global Impression-Severity (CGI-S) score, Clinical Global Impression-Schizophrenia (CGI-SCH) score, Personal and Social Performance (PSP) score, health-related quality of life (HR-QoL) and quality of sleep, evaluation of healthcare resource utilization and patient's treatment satisfaction.

RESULTS

A total of 4051 patients were included in the intent-to-treat (ITT) analysis set. All-cause study discontinuation rates were comparable between the paliperidone ER group (16.8%) and the 'all other oral antipsychotics' group (15.5%). There was no difference in the time to discontinuation of newly initiated antipsychotic treatments between paliperidone ER and 'all other oral antipsychotics' groups. Paliperidone ER was associated with greater improvements from baseline to endpoint in both the PSP scale score (+14.2 vs +13.1, p = 0.041) and the physical component of quality of life (SF-12 Physical scores; +3.9 vs +2.9, p = 0.003) compared to 'all other oral antipsychotics'. Improvements in mean CGI-S score, CGI-SCH score, HR-QoL, quality of sleep and daytime drowsiness, as well as patients' treatment satisfaction were comparable between treatment groups. The incidence of adverse events was comparable between groups.

CONCLUSIONS

This study provides valuable data on the prescribing habits and treatment outcomes associated with use of paliperidone ER in everyday clinical practice, and supports previous findings of the favorable functional improvement and treatment satisfaction associated with paliperidone ER.

CLINICAL TRIAL REGISTRATION

NCT00696813; R076477SCH4015 (Register of German Association of Research-based Pharmaceutical Companies [VFA] http://www.vfa.de/de/arzneimittel-forschung/datenbanken-zu-arzneimitteln/nisdb).

Paliperidone extended-release: safety and tolerability from a metabolic profile perspective

Pharmacologic management strategies for schizophrenia, a relatively common psychotic disorder, include the use of typical and atypical antipsychotic drugs. In general, typical (or conventional) antipsychotics have a proven track record in effectively managing the positive symptoms of schizophrenia but sometimes lack efficacy in treating negative symptoms. The conventional agents are also associated with adverse neurologic effects such as extrapyramidal symptoms (EPS). The development of atypical antipsychotics has partly ameliorated the issue of EPS induced by typical antipsychotics. However, several of these atypical antipsychotic agents have been associated with adverse metabolic effects, including weight gain, dyslipidemia, and increased serum glucose levels. Paliperidone (9-hydroxy-riperidone) extended-release (ER) is an atypical antipsychotic indicated for the treatment of schizophrenia which utilizes a patented oral osmotic system technology that provides constant drug delivery over the course of the day. The efficacy and safety of paliperidone ER in patients with schizophrenia have been established. This review focuses on the metabolic safety of paliperidone ER in patients with schizophrenia. Clinical trials have demonstrated a lack of significant change in lipid profiles with paliperidone ER; furthermore, reported incidences of glucose-related adverse events in clinical trials were very low and similar to those seen with placebo. While dose-related increases in bodyweight of 1-2 kg have been observed with paliperidone ER, there are few reports of clinically relevant increases in bodyweight during treatment. Placebo-controlled trials indicate that the risk of developing metabolic disorders with paliperidone ER is low and similar to that seen with placebo. Furthermore, the ER formulation of paliperidone may offer potential advantages over atypical antipsychotics such as risperidone, particularly with regard to side effects and compliance, but comparative studies are needed.

Dosing and switching of paliperidone ER in patients with schizophrenia: recommendations for clinical practice

Many patients with schizophrenia receive long-term treatment with antipsychotic medication. Switching of antipsychotic medication due to lack of efficacy, tolerability issues, and partial/non-adherence is common. Despite this, consensus strategies for switching between antipsychotics are lacking. This manuscript provides practical recommendations for switching antipsychotic medication to ensure optimal management of patients with schizophrenia, with a particular focus on paliperidone extended release (ER). The authors drew on their clinical experience supported by detailed discussion of literature describing antipsychotic switching techniques and strategies and findings from paliperidone ER clinical trials. Antipsychotic switching strategies should be individualized and take into consideration the pharmacokinetic (PK) and pharmacodynamic (PD) properties of the pre- and post-switch medication. The use of temporary concomitant medications may be appropriate in some scenarios. Abrupt withdrawal of pre-switch medication may be appropriate in some instances but carries a greater risk of rebound and withdrawal symptoms than other strategies. Cross-tapering is the method most widely used in clinical practice. Paliperidone ER can be initiated without dose titration. The EU SmPC recommended dose of paliperidone ER is 6 mg/day; but doses should be individualized within the approved range of 3-12 mg/day. Higher doses may be required due to insufficient efficacy of the previous antipsychotic or in patients with acute symptoms. Recently diagnosed patients, those with renal impairment, or patients who have previously experienced tolerability issues with other antipsychotics may require lower doses. When switching from risperidone, higher doses of paliperidone ER may be required compared with risperidone. When switching from antipsychotics that have sedative and/or significant anticholinergic activity, the pre-switch antipsychotic should be tapered off gradually. Antipsychotics with less sedating and little anticholinergic activity can be tapered off over a shorter period. Temporary concomitant sedative medication may be beneficial when switching from antipsychotics with relatively higher sedative propensities. Switching from another antipsychotic to paliperidone ER requires individualized switching strategies and dosing, dependent on the characteristics of the patient and the PK and PD properties of the pre-switch medication. Cross-tapering strategies should be considered as a means of reducing the risk of rebound and withdrawal symptoms.

Metformin and berberine prevent olanzapine-induced weight gain in rats

Olanzapine is a first line medication for the treatment of schizophrenia, but it is also one of the atypical antipsychotics carrying the highest risk of weight gain. Metformin was reported to produce significant attenuation of antipsychotic-induced weight gain in patients, while the study of preventing olanzapine-induced weight gain in an animal model is absent. Berberine, an herbal alkaloid, was shown in our previous studies to prevent fat accumulation in vitro and in vivo. Utilizing a well-replicated rat model of olanzapine-induced weight gain, here we demonstrated that two weeks of metformin or berberine treatment significantly prevented the olanzapine-induced weight gain and white fat accumulation. Neither metformin nor berberine treatment demonstrated a significant inhibition of olanzapine-increased food intake. But interestingly, a significant loss of brown adipose tissue caused by olanzapine treatment was prevented by the addition of metformin or berberine. Our gene expression analysis also demonstrated that the weight gain prevention efficacy of metformin or berberine treatment was associated with changes in the expression of multiple key genes controlling energy expenditure. This study not only demonstrates a significant preventive efficacy of metformin and berberine treatment on olanzapine-induced weight gain in rats, but also suggests a potential mechanism of action for preventing olanzapine-reduced energy expenditure.

The effects of olanzapine on genome-wide DNA methylation in the hippocampus and cerebellum

Background

The mechanism of action of olanzapine in treating schizophrenia is not clear. This research reports the effects of a therapeutic equivalent treatment of olanzapine on DNA methylation in a rat model in vivo.

Genome-wide DNA methylation was assessed using a MeDIP-chip analysis. All methylated DNA immunoprecipitation (MeDIP), sample labelling, hybridization and processing were performed by Arraystar Inc (Rockville, MD, USA). The identified gene promoters showing significant alterations to DNA methylation were then subjected to Ingenuity Pathway Analysis (Ingenuity System Inc, CA, USA).

Results

The results show that olanzapine causes an increase in methylation in 1,140, 1,294 and 1,313 genes and a decrease in methylation in 633, 565 and 532 genes in the hippocampus, cerebellum and liver, respectively. Most genes affected are tissue specific. Only 41 affected genes (approximately 3%) showed an increase and no gene showed a decrease in methylation in all three tissues. Further, the two brain regions shared 123 affected genes (approximately 10%). The affected genes are enriched in pathways affecting dopamine signalling, molecular transport, nervous system development and functions in the hippocampus; ephrin receptor signalling and synaptic long-term potentiation in the cerebellum; and tissue morphology, cellular assembly and organization in the liver. Also, the affected genes included those previously implicated in psychosis.

Conclusions

The known functions of affected genes suggest that the observed epigenetic changes may underlie the amelioration of symptoms as well as accounting for certain adverse effects including the metabolic syndrome. The results give insights into the mechanism of action of olanzapine, therapeutic effects and the side effects of antipsychotics.

Olanzapine induced DNA methylation changes support the dopamine hypothesis of psychosis

Background

The dopamine (DA) hypothesis of schizophrenia proposes the mental illness is caused by excessive transmission of dopamine in selected brain regions. Multiple lines of evidence, including blockage of dopamine receptors by antipsychotic drugs that are used to treat schizophrenia, support the hypothesis. However, the dopamine D2 receptor (DRD2) blockade cannot explain some important aspects of the therapeutic effect of antipsychotic drugs. In this study, we hypothesized that antipsychotic drugs could affect the transcription of genes in the DA pathway by altering their epigenetic profile.

Methods

To test this hypothesis, we examined the effect of olanzapine, a commonly used atypical antipsychotic drug, on the DNA methylation status of genes from DA neurotransmission in the brain and liver of rats. Genomic DNA isolated from hippocampus, cerebellum, and liver of olanzapine treated (n = 2) and control (n = 2) rats were analyzed using rat specific methylation arrays.

Results

Our results show that olanzapine causes methylation changes in genes encoding for DA receptors (dopamine D1 receptor, dopamine D2 receptor and dopamine D5 receptor), a DA transporter (solute carrier family 18 member 2), a DA synthesis (differential display clone 8), and a DA metabolism (catechol-O-methyltransferase). We assessed a total of 40 genes in the DA pathway and found 19 to be differentially methylated between olanzapine treated and control rats. Most (17/19) genes showed an increase in methylation, in their promoter regions with in silico analysis strongly indicating a functional potential to suppress transcription in the brain.

Conclusion

Our results suggest that chronic olanzapine may reduce DA activity by altering gene methylation. It may also explain the delayed therapeutic effect of antipsychotics, which occurs despite rapid dopamine blockade. Furthermore, given the common nature of epigenetic variation, this lends insight into the differential therapeutic response of psychotic patients who display adequate blockage of dopamine receptors.

Cost effectiveness of paliperidone palmitate versus risperidone long-acting injectable and olanzapine pamoate for the treatment of patients with schizophrenia in Sweden

OBJECTIVE

To model the cost effectiveness of paliperidone palmitate (paliperidone long-acting injectable; PLAI), a new once-monthly long-acting antipsychotic therapy, compared with risperidone long-acting injectable (RLAI) and olanzapine pamoate (OLAI), in multi-episode patients (two or more relapses) with schizophrenia in Sweden.

METHODS

A Markov decision analytic model was developed to simulate the history of a cohort of multi-episode patients transitioning through different health states on a monthly basis over a 5-year time horizon from the perspective of the Swedish healthcare system. Therapeutic strategies consisted of starting treatment with RLAI (mean dose 37.5 mg every 2 weeks), PLAI (mean dose 75 mg equivalent (eq.) every month) or OLAI (150 mg every 2 weeks or 300 mg every 4 weeks). Probability of relapse, level of adherence, side-effects (extrapyramidal symptoms, tardive dyskinesia, weight gain and diabetes) and treatment discontinuation (switch) were derived from long-term observational data when feasible. Incremental cost-effectiveness outcomes, discounted at 3% annually, included cost per quality-adjusted life-year (QALY) and cost per relapse avoided (expressed in 2009 Swedish Krona SEK).

RESULTS

Relative to RLAI and OLAI, PLAI is economically dominant: more effective (additional QALYs, less relapses) and less costly treatment option over a 5-year time horizon. The results were robust when tested in sensitivity analysis.

LIMITATIONS

The impact of once-monthly treatment on adherence levels is not yet known, and not all variables that could impact on real-world outcomes and costs were included in this model.

CONCLUSION

PLAI was cost saving from a Swedish payer perspective compared with RLAI and OLAI in the long-term treatment of multi-episode (two or more relapses) schizophrenia patients.