A randomized, 12-week study of the effects of extended-release paliperidone (paliperidone ER) and olanzapine on metabolic profile, weight, insulin resistance, and β-cell function in schizophrenic patients

Polypharmacy Management of Antipsychotics in Patients with Schizophrenia

Schizophrenia is a chronic psychiatric disease that is characterized by psychotic symptoms, including positive, negative, affective, and aggressive symptoms, as well as cognitive dysfunction, and is primarily treated using drug therapy, the continuation of which is essential to prevent recurrence/recrudescence. Various second-generation antipsychotics with pharmacological properties or adverse events that differ from those of conventional antipsychotics have recently been introduced, and pharmaceutical management is required for drug efficacy assessments and adverse event monitoring/management of these drugs. Antipsychotic monotherapy (APM) is the gold standard treatment for schizophrenia and is recommended in various guidelines. However, a subgroup of patients with schizophrenia do not or only partially respond to APM. Therefore, antipsychotic polypharmacy (APP), in which ≥2 antipsychotics are combined, has been routinely utilized to compensate for insufficient responses to APM in clinical practice. APP has recently been proposed as an evidence-based treatment option, but does not consider clinicians' experience. However, the risk of APP-related adverse events is high. The application of APP needs to be carefully reviewed, whilst taking into consideration patient backgrounds. Furthermore, the risk of APP-related adverse events is higher in elderly patients than in the general population; therefore, caution is needed. This review discusses the merits of APP, matters that need to be considered, and a switch from APP to APM, and also focuses on the application of APP in clinical practice.

Antipsychotic-Induced Constipation: A Review of the Pathogenesis, Clinical Diagnosis, and Treatment

Antipsychotic-induced gastrointestinal hypomotility and, in particular, its manifestation of constipation are common adverse effects in patients with schizophrenia in clinical practice. Serious complications of antipsychotic-induced constipation include ileus, ischaemic bowel disease, colon perforation, aspiration pneumonia, and bacterial septicaemia, which can be life threatening if left untreated, especially in patients prescribed clozapine. The aim of this paper is to review the latest research on the epidemiology, clinical examination methods, pathophysiology, and treatment options and preventive measures for antipsychotic-induced constipation. While clinicians are normally aware of the overall side effects caused by antipsychotics, constipation is often an under-recognized condition despite its relatively high incidence and its impact on daily living. The incidence of constipation differs among individual antipsychotics, but more than 50% of patients prescribed antipsychotics suffer from constipation. Limited fluid intake, poor dietary habits, and a sedentary lifestyle can also worsen constipation. The mechanisms of antipsychotic-induced constipation may be antagonism of cholinergic, histaminergic, and serotonergic receptors, with both parent drug and metabolite(s) contributing to the effects on gastrointestinal motility. Numerous methods, mainly divided into scale evaluations and objective examinations, are applied to evaluate antipsychotic-induced constipation; however, objective examinations have a greater ability to identify cases of gastrointestinal hypomotility since there is often an under-reporting of symptoms in subjective reporting and scale evaluation due to a higher pain threshold, an inability to express pain sensations, and a lack of symptom awareness in these patients. Antipsychotic drug-induced constipation should be closely monitored in patients receiving these medications, with timely intervention to avoid serious gastrointestinal consequences. There is currently no consensus on the efficacy of laxatives in these patients. Further in-depth studies should explore the underlying mechanisms and devise optimal therapeutic approaches to minimize constipation during antipsychotic treatment.

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.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40261-021-01000-1.

Interventions for preventing type 2 diabetes in adults with mental disorders in low- and middle-income countries

BACKGROUND

The prevalence of type 2 diabetes is increased in individuals with mental disorders. Much of the burden of disease falls on the populations of low- and middle-income countries (LMICs).

OBJECTIVES

To assess the effects of pharmacological, behaviour change, and organisational interventions versus active and non-active comparators in the prevention or delay of type 2 diabetes among people with mental illness in LMICs.

SEARCH METHODS

We searched the Cochrane Common Mental Disorders Controlled Trials Register, CENTRAL, MEDLINE, Embase and six other databases, as well as three international trials registries. We also searched conference proceedings and checked the reference lists of relevant systematic reviews. Searches are current up to 20 February 2020.

SELECTION CRITERIA

Randomized controlled trials (RCTs) of pharmacological, behavioural or organisational interventions targeting the prevention or delay of type 2 diabetes in adults with mental disorders in LMICs.

DATA COLLECTION AND ANALYSIS

Pairs of review authors working independently performed data extraction and risk of bias assessments. We conducted meta-analyses using random-effects models.

MAIN RESULTS

One hospital-based RCT with 150 participants (99 participants with schizophrenia) addressed our review's primary outcome of prevention or delay of type 2 diabetes onset. Low-certainty evidence from this study did not show a difference between atypical and typical antipsychotics in the development of diabetes at six weeks (risk ratio (RR) 0.46, 95% confidence interval (CI) 0.03 to 7.05) (among a total 99 participants with schizophrenia, 68 were in atypical and 31 were in typical antipsychotic groups; 55 participants without mental illness were not considered in the analysis). An additional 29 RCTs with 2481 participants assessed one or more of the review's secondary outcomes. All studies were conducted in hospital settings and reported on pharmacological interventions. One study, which we could not include in our meta-analysis, included an intervention with pharmacological and behaviour change components. We identified no studies of organisational interventions. Low- to moderate-certainty evidence suggests there may be no difference between the use of atypical and typical antipsychotics for the outcomes of drop-outs from care (RR 1.31, 95% CI 0.63 to 2.69; two studies with 144 participants), and fasting blood glucose levels (mean difference (MD) 0.05 lower, 95% CI 0.10 to 0.00; two studies with 211 participants). Participants who receive typical antipsychotics may have a lower body mass index (BMI) at follow-up than participants who receive atypical antipsychotics (MD 0.57, 95% CI 0.33 to 0.81; two studies with 141 participants; moderate certainty of evidence), and may have lower total cholesterol levels eight weeks after starting treatment (MD 0.35, 95% CI 0.27 to 0.43; one study with 112 participants). There was moderate certainty evidence suggesting no difference between the use of metformin and placebo for the outcomes of drop-outs from care (RR 1.22, 95% CI 0.09 to 16.35; three studies with 158 participants). There was moderate-to-high certainty evidence of no difference between metformin and placebo for fasting blood glucose levels (endpoint data: MD -0.35, 95% CI -0.60 to -0.11; change from baseline data: MD 0.01, 95% CI -0.21 to 0.22; five studies with 264 participants). There was high certainty evidence that BMI was lower for participants receiving metformin compared with those receiving a placebo (MD -1.37, 95% CI -2.04 to -0.70; five studies with 264 participants; high certainty of evidence). There was no difference between metformin and placebo for the outcomes of waist circumference, blood pressure and cholesterol levels. Low-certainty evidence from one study (48 participants) suggests there may be no difference between the use of melatonin and placebo for the outcome of drop-outs from care (RR 1.00, 95% CI 0.38 to 2.66). Fasting blood glucose is probably reduced more in participants treated with melatonin compared with placebo (endpoint data: MD -0.17, 95% CI -0.35 to 0.01; change from baseline data: MD -0.24, 95% CI -0.39 to -0.09; three studies with 202 participants, moderate-certainty evidence). There was no difference between melatonin and placebo for the outcomes of waist circumference, blood pressure and cholesterol levels. Very low-certainty evidence from one study (25 participants) suggests that drop-outs may be higher in participants treated with a tricyclic antidepressant (TCA) compared with those receiving a selective serotonin reuptake inhibitor (SSRI) (RR 0.34, 95% CI 0.11 to 1.01). It is uncertain if there is no difference in fasting blood glucose levels between these groups (MD -0.39, 95% CI -0.88 to 0.10; three studies with 141 participants, moderate-certainty evidence). It is uncertain if there is no difference in BMI and depression between the TCA and SSRI antidepressant groups.

AUTHORS' CONCLUSIONS

Only one study reported data on our primary outcome of interest, providing low-certainty evidence that there may be no difference in risk between atypical and typical antipsychotics for the outcome of developing type 2 diabetes. We are therefore not able to draw conclusions on the prevention of type 2 diabetes in people with mental disorders in LMICs. For studies reporting on secondary outcomes, there was evidence of risk of bias in the results. There is a need for further studies with participants from LMICs with mental disorders, particularly on behaviour change and on organisational interventions targeting prevention of type 2 diabetes in these populations.

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.

Signals of Adverse Drug Reactions of Paliperidone Compared to Other Atypical Antipsychotics Using the Korean Adverse Event Reporting System Database

BACKGROUND AND OBJECTIVES

Schizophrenia is a severe public health problem and one of the top ten causes of disability, affecting about 1.1% of the world's population. Paliperidone is a new atypical antipsychotic used to treat schizophrenia. Several case reports about unexpected adverse drug reactions of paliperidone have been consistently reported around the world. The purpose of this study was to detect signals of adverse events (AEs) after paliperidone treatment using the Korea Institute of Drug Safety and Risk Management-Korea Adverse Event Reporting System database (KIDS-KD).

METHODS

We applied data-mining techniques based on a disproportionality analysis to KIDS-KD consisting of spontaneously reported AE reports related to atypical antipsychotics between January 2009 and December 2018. We calculated three data-mining indices of paliperidone compared to all other atypical antipsychotics. We defined signals that satisfied all three criteria of the indices. We checked if the signals identified were included in the drug labels for South Korea, the USA, the UK, Japan, Germany, and France.

RESULTS

The total number of suspected AE reports related to all atypical antipsychotics in the KIDS-KD from January 2009 to December 2018 was 43,970. Among those, the number of AE reports related to paliperidone was 9453. Overall, 13 signals such as seborrhea, hallucination, obesity, gingivitis, and intervertebral disorder were classified into newly detected meaningful signals.

CONCLUSION

We detected new AE signals of paliperidone that were not listed on the drug labels of six countries, and many that were related to psychotic symptoms, metabolic problems, and endocrine disorders.

Immunoendocrine Peripheral Effects Induced by Atypical Antipsychotics

Atypical antipsychotics (AAP) or second-generation antipsychotics are the clinical option for schizophrenia treatment during acute psychoses, but they are also indicated for maintenance during lifetime, even though they are being used for other psychiatric conditions in clinical practice such as affective disorders and autism spectrum disorder, among others. These drugs are differentiated from typical antipsychotics based on their clinical profile and are a better choice because they cause fewer side effects regarding extrapyramidal symptoms (EPS). Even though they provide clear therapeutic benefits, AAP induce peripheral effects that trigger phenotypic, functional, and systemic changes outside the Central Nervous System (CNS). Metabolic disease is frequently associated with AAP and significantly impacts the patient's quality of life. However, other peripheral changes of clinical relevance are present during AAP treatment, such as alterations in the immune and endocrine systems as well as the intestinal microbiome. These less studied alterations also have a significant impact in the patient's health status. This manuscript aims to revise the peripheral immunological, endocrine, and intestinal microbiome changes induced by AAP consumption recommended in the clinical guidelines for schizophrenia and other psychiatric disorders.

Association of blood cell counts with the risk of olanzapine- or clozapine-induced dyslipidemia in Chinese schizophrenia patients

OBJECTIVE

The aim of this study was to investigate correlation of peripheral blood cell counts with the dyslipidemia induced by olanzapine or clozapine in Chinese schizophrenia patients.

METHODS

A total of 703 eligible schizophrenia patients were enrolled . The counts of red blood cell (RBC), platelet, white blood cell (WBC) and its subtypes, and serum lipids were determined for all participants before and after 2-4 weeks of olanzapine or clozapine treatment.

RESULTS

The two representative second-generation antipsychotics (SGAs), olanzapine and clozapine, markedly caused dyslipidemia in Chinese schizophrenia patients. The tertiles of total RBC counts were positively associated with the odds of having abnormal triglyceride (p < .01) and high-density lipoprotein cholesterol (HDL-C) levels (.05). The tertiles of platelet counts were also positively associated with the odds of having abnormal total cholesterol (.03), low-density lipoprotein cholesterol (p < .01), HDL-C (.01), and non-HDL-C (p < .01). However, the counts of WBC and its some subtypes were negatively correlated with the risk of dyslipidemia in these patients.

CONCLUSION

The profile of peripheral blood cells may be an early biomarker for predicting the risk of metabolic disorders and cardiovascular diseases in schizophrenia patients treated with SGAs.

T4 and waist:hip ratio as biomarkers of antipsychotic-induced weight gain in Han Chinese inpatients with schizophrenia

Second-generation antipsychotic agents (SGAs) cause serious metabolic side effects, including weight gain, dyslipidemia, and glucose metabolism abnormalities, which occur by unknown mechanisms. Therefore, the search for prospective markers for antipsychotic-induced weight gain (AIWG) has been of major interest. So far, predictive factors predisposing patients to the develop obesity and related metabolic disturbances induced by SGAs have been relatively less studied among large samples of Chinese schizophrenic patients. In this study, 264 Han Chinese inpatients diagnosed with schizophrenia or schizoaffective disorder initiated treatment with olanzapine (n=131) or risperidone (n=133) and were followed for 12weeks. Anthropometric measurements and laboratory analyses of thyroid hormone, fasting plasma glucose (FPG), and lipid levels were conducted as part of routine medical care. The results showed baseline thyroxine (T₄) and waist:hip ratio (WHR)were negatively correlated to AIWG (T₄: r_s=-0.154, P=0.014; WHR: r_s=-0.199, P=0.008). Correlations remained significant after multiple regression analyses. The two treatment groups statistically differed for changes in body mass index, WHR, LDL cholesterol, and FPG; in both groups FPG decreased at first and then increased. Our findings suggest basal T₄ and WHR may serve as early biomarkers for weight gain as a side effect of single-SGA treatment.

Metabolic adverse effects of olanzapine on cognitive dysfunction: A possible relationship between BDNF and TNF-alpha

OBJECTIVE

There is accumulating evidence indicating that long-term treatment with second-generation antipsychotics (SGAs) results in metabolic syndrome (MetS) and cognitive impairment. This evidence suggests an intrinsic link between antipsychotic-induced MetS and cognitive dysfunction in schizophrenia patients. Olanzapine is a commonly prescribed SGA with a significantly higher MetS risk than that of most antipsychotics. In this study, we hypothesized that olanzapine-induced MetS may exacerbate cognitive dysfunction in patients with schizophrenia.

METHODS

A sample of 216 schizophrenia patients receiving long-term olanzapine monotherapy were divided into two groups, MetS and non-MetS, based on the diagnostic criteria of the National Cholesterol Education Program's Adult Treatment Panel III. We also recruited 72 healthy individuals for a control group. Cognitive function was evaluated using the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Plasma brain-derived neurotrophic factor (BDNF) and tumor necrosis factor-alpha (TNF-alpha) were measured by an enzyme-linked immunosorbent assay for 108 patients and 47 controls.

RESULTS

Among the 216 schizophrenia patients receiving olanzapine monotherapy, MetS was found in 95/216 (44%). Patients with MetS had more negative symptoms, higher total scores in PANSS (Ps<0.05) and lower immediate memory, attention, delayed memory and total scores in RBANS (Ps<0.01). Stepwise multivariate linear regression analysis revealed that increased glucose was the independent risk factor for cognitive dysfunction (t=-2.57, P=0.01). Patients with MetS had significantly lower BDNF (F=6.49, P=0.012) and higher TNF-alpha (F=5.08, P=0.026) levels than those without MetS. There was a negative correlation between the BDNF and TNF-alpha levels in the patients (r=-0.196, P=0.042).

CONCLUSION

Our findings provide evidence suggesting that the metabolic adverse effects of olanzapine may aggravate cognitive dysfunction in patients with schizophrenia through an interaction between BDNF and TNF-alpha.

Critical evaluation of paliperidone in the treatment of schizophrenia in Chinese patients: a systematic literature review

BACKGROUND

Paliperidone (9-hydroxyrisperidone), the major active metabolite of risperidone, has been introduced as a novel atypical antipsychotic agent in many countries. It is available both as an oral extended-release (ER) formulation and as a long-acting injection (paliperidone palmitate, PP), which have been approved for treating schizophrenia in the People's Republic of China since 2009 and 2012, respectively. This systematic review summarizes the efficacy, effectiveness, and safety of paliperidone in the treatment of schizophrenia in the Chinese population.

METHODS

A systematic literature search was conducted on the databases covering international and Chinese core journals, published from January 1, 2008, to May 22, 2015.

RESULTS

A total of 122 publications were retrieved, of which 63 studies were identified for inclusion; most studies were related to paliperidone ER (n=53), nine were related to PP, and one study was related to both agents. Paliperidone ER demonstrated at least comparable efficacy with active comparators, including risperidone, olanzapine, ziprasidone, or aripiprazole, and was found to be superior with respect to the onset of action and improvement in the Personal and Social Performance Scale score. Paliperidone ER appeared to be associated with a lower risk of metabolic syndromes; the most common treatment-emergent adverse events were extrapyramidal symptoms, akathisia, insomnia, and somnolence. Results from interventional and observational studies showed that PP was also an effective and well-tolerated treatment for Chinese patients with schizophrenia. The findings were generally consistent with those observed in non-Chinese populations.

CONCLUSION

Both paliperidone ER and PP were effective and well-tolerated agents for the treatment of schizophrenia in the Chinese population according to the data we reviewed. No new safety signals specific for the Chinese population were raised for paliperidone. Further studies may be needed to collect more data on long-term treatment of schizophrenia in the People's Republic of China.

Paliperidone extended-release tablets in Chinese patients with schizophrenia: meta-analysis of randomized controlled trials

BACKGROUND

Previous meta-analyses have compared paliperidone extended-release (ER) tablets with other antipsychotics, but none have involved Chinese patients or studies from People's Republic of China. Further, the results of these meta-analyses may not be applicable to Chinese patients. In the present study, we evaluated the efficacy, safety, and acceptability of paliperidone ER compared with other second-generation antipsychotics (SGAs) for Chinese patients with schizophrenia.

METHODS

Randomized controlled studies of paliperidone ER and other SGAs as oral monotherapy in the acute phase treatment of schizophrenia were retrieved from Medline, Embase, and the Cochrane Library (CENTRAL), as well as from Chinese databases including the China National Knowledge Infrastructure, Wanfang, and VIP Information/Chinese Scientific Journals Database. We pooled data on response rates, chance of withdrawal due to adverse events, probability of adverse events, and odds of withdrawal for any reason.

RESULTS

Fifty randomized controlled trials were identified. The response rate for paliperidone ER was significantly higher than that of other pooled SGAs (risk ratio [RR] 0.83, 95% confidence interval [CI] 0.72-0.96) and ziprasidone (RR 0.57, 95% CI 0.39-0.82). Paliperidone ER significantly reduced the chance of withdrawal due to adverse events and the chance of any adverse events compared with other pooled SGAs (RR 0.32, 95% CI 0.17-0.58 and RR 0.88, 95% CI 0.79-0.97) and risperidone (RR 0.31, 95% CI 0.14-0.67 and RR 0.70, 95% CI 0.57-0.86). The incidence of extrapyramidal symptoms on paliperidone ER was comparable with other pooled SGAs (RR 0.94, 95% CI 0.66-1.35) and significantly lower than that of risperidone (RR 0.56, 0.41-0.77) but higher than that of olanzapine (RR 1.88, 95% CI 1.05-3.36). Paliperidone ER was superior to other pooled SGAs (RR 0.32, 95% CI 0.21-0.49 and RR 0.50, 95% CI 0.35-0.72) and olanzapine (RR 0.23, 95% CI 0.15-0.33 and RR 0.33, 95% CI 0.23-0.47) as far as weight gain and somnolence were concerned. Further, prolactin-related adverse events caused by paliperidone ER were comparable with other pooled SGAs (RR 1.30, 95% CI 0.73-2.33), but outnumbered those caused by olanzapine (RR 7.53, 95% CI 2.05-27.71).

CONCLUSION

Paliperidone ER is efficacious, safe, and well accepted when compared with other pooled SGAs for the treatment of Chinese patients with schizophrenia.

Aminotransferase levels as a prospective predictor for the development of metabolic syndrome in patients with schizophrenia

RATIONALE

Increased levels of alanine aminotransferase (ALT) are a biomarker for metabolic syndrome (MetS), but this relationship remains unproven in patients with schizophrenia.

OBJECTIVE

We assessed the relationship between aminotransferase levels and MetS in patients with schizophrenia.

METHOD

This pooled analysis from two open-label prospective studies included 342 patients with schizophrenia who did not meet criteria for MetS at baseline. The development of MetS was assessed at weeks 12 and 24.

RESULTS

MetS developed in 19.1 % of patients during the 24-week follow-up period. ALT levels were significantly associated with incident MetS: for each sex-specific standard deviation increase in log ALT, the odds ratio (OR) of MetS was 1.357 (p = .006) after adjusting for age, sex, duration of illness, smoking, and previous use of antipsychotics. This result remained significant after adjusting for interim weight changes. Compared with patients in the lowest quartile, the OR of MetS in those in the highest quartile within the normal range of ALT levels was 4.276 (p = .024). However, this association was significant only in male patients. Using a cutoff value of 23.0 U/L, sensitivity and specificity were 70.6 and 68.3 %, respectively, in male patients whose ALT levels were in the normal range.

CONCLUSIONS

A prospective association between ALT levels and MetS highlights the value of ALT levels, even mild ALT elevations within the normal range, as a predictor of the MetS risk in male patients. Baseline liver function tests and monitoring should be obtained during antipsychotic treatment to identify the risk for MetS.

Olanzapine in Chinese patients with schizophrenia or bipolar disorder: a systematic literature review

BACKGROUND

Despite the burden of schizophrenia and bipolar disorder in the Chinese population, country-specific data to guide practitioners regarding antipsychotic therapy are lacking. The primary aim of this systematic review was to examine evidence of the efficacy, effectiveness, and safety of olanzapine in Chinese populations.

METHODS

A systematic literature search was conducted using databases covering international and Chinese core journals using search terms related to schizophrenia and bipolar disorder, specified countries (People's Republic of China, Hong Kong, Taiwan), and olanzapine treatment. Following initial screening, inclusion and exclusion criteria were applied to the search results to identify relevant studies from which data were extracted.

RESULTS

A total of 489 publications were retrieved and 61 studies were identified for inclusion. Most studies were related to schizophrenia (n=54), with six studies related to bipolar disorder and one study related to both conditions. The quality of study methods and reporting in international journals was noticeably better than in Chinese language journals. Most studies included relatively small patient populations and were of short duration. The efficacy of olanzapine in Chinese populations was confirmed by multiple comparative and noncomparative studies that found statistically significant reductions in symptom measures in studies conducted for ≥6 weeks (schizophrenia) or ≥3 weeks (bipolar disorder). Findings related to effectiveness (treatment discontinuation, quality of life, and neurocognitive improvements) were generally consistent with those observed in non-Chinese populations. No new safety signals specific for Chinese populations were raised for olanzapine.

CONCLUSION

Chinese and non-Chinese populations with schizophrenia or bipolar disorder treated with olanzapine display broadly similar responses. Differences between these populations, especially in relation to the relative efficacy of olanzapine versus other antipsychotics, may warrant further investigation via studies incorporating both populations. Use of local data to provide evidence for practice guidelines should be encouraged, and may promote ongoing improvements in the quality of research and study reporting.

The effects of novel and newly approved antipsychotics on serum prolactin levels: a comprehensive review

Since the 1970s, clinicians have increasingly become more familiar with hyperprolactinemia (HPRL) as a common adverse effect of antipsychotic medication, which remains the cornerstone of pharmacological treatment for patients with schizophrenia. Although treatment with second-generation antipsychotics (SGAs) as a group is, compared with use of the first-generation antipsychotics, associated with lower prolactin (PRL) plasma levels, the detailed effects on plasma PRL levels for each of these compounds in reports often remain incomplete or inaccurate. Moreover, at this moment, no review has been published about the effect of the newly approved antipsychotics asenapine, iloperidone and lurasidone on PRL levels. The objective of this review is to describe PRL physiology; PRL measurement; diagnosis, causes, consequences and mechanisms of HPRL; incidence figures of (new-onset) HPRL with SGAs and newly approved antipsychotics in adolescent and adult patients; and revisit lingering questions regarding this hormone. A literature search, using the MEDLINE database (1966-December 2013), was conducted to identify relevant publications to report on the state of the art of HPRL and to summarize the available evidence with respect to the propensity of the SGAs and the newly approved antipsychotics to elevate PRL levels. Our review shows that although HPRL usually is defined as a sustained level of PRL above the laboratory upper limit of normal, limit values show some degree of variability in clinical reports, making the interpretation and comparison of data across studies difficult. Moreover, many reports do not provide much or any data detailing the measurement of PRL. Although the highest rates of HPRL are consistently reported in association with amisulpride, risperidone and paliperidone, while aripiprazole and quetiapine have the most favorable profile with respect to this outcome, all SGAs can induce PRL elevations, especially at the beginning of treatment, and have the potential to cause new-onset HPRL. Considering the PRL-elevating propensity of the newly approved antipsychotics, evidence seems to indicate these agents have a PRL profile comparable to that of clozapine (asenapine and iloperidone), ziprasidone and olanzapine (lurasidone). PRL elevations with antipsychotic medication generally are dose dependant. However, antipsychotics having a high potential for PRL elevation (amisulpride, risperidone and paliperidone) can have a profound impact on PRL levels even at relatively low doses, while PRL levels with antipsychotics having a minimal effect on PRL, in most cases, can remain unchanged (quetiapine) or reduce (aripiprazole) over all dosages. Although tolerance and decreases in PRL values after long-term administration of PRL-elevating antipsychotics can occur, the elevations, in most cases, remain above the upper limit of normal. PRL profiles of antipsychotics in children and adolescents seem to be the same as in adults. The hyperprolactinemic effects of antipsychotic medication are mostly correlated with their affinity for dopamine D2 receptors at the level of the anterior pituitary lactotrophs (and probably other neurotransmitter mechanisms) and their blood-brain barrier penetrating capability. Even though antipsychotics are the most common cause of pharmacologically induced HPRL, recent research has shown that HPRL can be pre-existing in a substantial portion of antipsychotic-naïve patients with first-episode psychosis or at-risk mental state.

Metabolic syndrome in patients taking clozapine: prevalence and influence of catechol-O-methyltransferase genotype

RATIONALE

Metabolic syndrome (MetS) has consistently been identified as an adverse effect of long-term treatment with atypical antipsychotics (AAPs) such as clozapine. Elevated serum homocysteine concentration has been found to act as an independent risk factor for MetS, and catechol-O-methyltransferase (COMT) catalyzes the homocysteine metabolism. We accordingly hypothesized that COMT dysregulation may confer the susceptibility to MetS induced by AAPs, potentially in a gender-specific manner, because the interaction effects of COMT and gender have been consistently reported.

OBJECTIVES

This study aimed at determining the prevalence and influence of COMT on MetS among a population undergoing long-term clozapine treatment.

METHODS

A total of 468 schizophrenia patients taking clozapine were divided into two groups, those experiencing MetS and non-MetS. We genotyped three functional variants (rs4633, rs4680, and rs4818) in COMT and measured the serum levels of fasting homocysteine, glucose, triglyceride (TG), and high-density lipoprotein cholesterol.

RESULTS

MetS was found in 202/468 (43.2 %) of all the patients, with 40.2 % prevalence (138/343) in males and 51.2 % (64/125) in females. Patients with MetS had notably higher metabolic parameters than those without MetS. The mean levels of homocysteine in patients with MetS were significantly higher than those without MetS. We found a positive association between the rs4680 polymorphism and the serum triglyceride levels (corrected P = 0.024). Further analysis revealed that the rs4680 Met allele was significantly associated with increased triglyceride levels among female patients (P = 0.009), but not among males (P = 0.07).

CONCLUSIONS

Our findings suggest a potential association between rs4680 in COMT and elevated TG levels, particularly among female patients.

The effect of reboxetine co-administration with olanzapine on metabolic and endocrine profile in schizophrenia patients

RATIONALE

We previously demonstrated that the addition of the selective norepinephrine reuptake inhibitor reboxetine attenuates olanzapine-induced weight gain. Using the same study sample, we also sought to determine whether reboxetine's weight-attenuating effect was accompanied by a beneficial effect on metabolic and endocrine parameters relevant to antipsychotic-induced weight gain and obesity.

METHOD

Blood samples at baseline and at the end of the 6-week trial were available for 54 participants who participated in previous double-blind, placebo-controlled studies of reboxetine (4 mg BID) addition to olanzapine-treated schizophrenia patients. Fasting glucose, lipid profile, insulin, leptin, cortisol, dehydroepiandrosterone (DHEA), prolactin, and thyroid-stimulating hormone (TSH) were analyzed.

RESULTS

In contrast to the olanzapine/placebo group, the olanzapine/reboxetine group exhibited a reduction in blood triglyceride (p < 0.05) and leptin (p < 0.05) levels, and elevation in cortisol (p < 0.05) and DHEA (p < 0.008) levels. No significant between-group differences were detected in the changes in cholesterol, glucose, insulin, TSH, and prolactin.

CONCLUSIONS

Reboxetine addition resulted in meaningful improvement of some metabolic and endocrine measures associated with olanzapine-induced weight gain. The potential role of reboxetine in the prevention of olanzapine-induced weight gain and cardio-metabolic morbidity merits further large-scale, long-term investigation.

Reduced serum paraoxonase 1 (PON1) activity in patients with schizophrenia treated with olanzapine but not quetiapine

BACKGROUND

Second generation antipsychotics (SGAs) are currently the most prescribed drugs in the treatment of schizophrenia. Despite their advantages, which include greater improvement in negative symptoms, cognitive function, prevention of deterioration, quality of life, and fewer extrapyramidal symptoms, the concern regarding metabolic abnormalities which might cause cardiovascular diseases during treatment with SGAs have been rising. Paraoxonase 1 (PON1) is an enzyme mostly located on high-density lipoprotein particles, and has been shown to protect or inhibit lipoprotein oxidation. Growing evidence suggests that PON1 plays a key role in the pathophysiology of atherosclerosis.

METHODS

In the present study, we measured serum PON1 activity and serum levels of total cholesterol (TC), triglyceride, high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol (LDL-C) in patients with schizophrenia, who had been treated with either olanzapine or quetiapine, and in healthy controls. Thirty five patients who had been treated with olanzapine, 29 patients who had been treated with quetiapine, and 32 age, sex, and smoking status-matched healthy control (HC) participants were enrolled. Serum PON1 activity and serum levels of TC, triglyceride, HDL-C, and LDL-C were measured.

RESULTS

Serum PON1 activity in the olanzapine group was significantly lower than that of HC and quetiapine groups. Furthermore, serum levels of TC and LDL-C in the olanzapine group were significantly higher than those of quetiapine and HC groups. Interestingly, there was a positive correlation between PON1 activity and HDL-C levels in the olanzapine group.

CONCLUSION

These findings suggest that serum PON1 activity in patients treated with olanzapine was lower than that of HC and quetiapine groups, and that PON1 may play a role in the metabolic side effects associated with olanzapine treatment. A further study to examine the relationship between serum PON1 activity and cardiovascular and metabolic side effects during treatment with SGAs will be of great interest.