Clozapine in China

A brief history of clozapine in China with a look forward

Clozapine was first manufactured in China in 1976. Clozapine is currently used not only for treatment-refractory schizophrenia (TRS), but also continues to be used in the treatment of patients with non-TRS and other mental disorders; moreover, low-dose clozapine is also used in sedative-hypnotic therapy and in combination with other drugs. There is need for studies in China using various titrations and assessing their risk for myocarditis and aspiration pneumonia. The Chinese clozapine package insert will also greatly benefit from these changes.

The occurrence of typical psychotropic drugs in the aquatic environments and their potential toxicity to aquatic organisms - A review

Psychotropic drugs (PDs) and their bioactive metabolites often persist in aquatic environments due to their typical physical properties, which made them resistant to removal by traditional wastewater treatment plants (WWTPs). Consequently, such drugs and/or their metabolites are frequently detected in both aquatic environments and organisms. Even at low concentrations, these drugs can exhibit toxic effects on non-target organisms including bony fish (zebrafish (Danio rerio) and fathead minnows) and bivalves (freshwater mussels and clams). This narrative review focuses on the quintessential representatives of three different categories of PDs-antiepileptics, antidepressants, and antipsychotics. The data regarding their concentrations occurring in the environment, patterns of distribution, the degree of enrichment in various tissues of aquatic organisms, and the toxicological effects on them are summarized. The toxicological assessments of these drugs included the evaluation of their effects on the reproductive, embryonic development, oxidative stress-related, neurobehavioral, and genetic functions in various experimental models. However, the mechanisms underlying the toxicity of PDs to aquatic organisms and their potential health risks to humans remain unclear. Most studies have focused on the effects caused by acute short-term exposure due to limitations in the experimental conditions, thus making it necessary to investigate the chronic toxic effects at concentrations that are in coherence with those occurring in the environment. Additionally, this review aims to raise awareness and stimulate further research efforts by highlighting the gaps in the understanding of the mechanisms behind PD-induced toxicity and potential health risks. Ultimately, the study underscores the importance of developing advanced remediation methods for the removal of PDs in WWTPs and encourages a broader discussion on mitigating their environmental impacts.

Respiratory aspiration during treatment with clozapine and other antipsychotics: a literature search and a pharmacovigilance study in VigiBase

INTRODUCTION

Antipsychotics (APs), during treatment or overdose, may be associated with respiratory aspiration.

AREAS COVERED

A PubMed search on September 30, 2022, provided 3 cases of respiratory aspiration during clozapine therapy and 1 case during an AP overdose. VigiBase records of respiratory aspiration associated with APs from inception until September 5, 2021, were reviewed. VigiBase, the World Health Organization's global pharmacovigilance database, uses a statistical signal for associations called the information component (IC).

EXPERT OPINION

The ICs (and IC₀₂₅) were 2.1 (and 2.0) for APs, 3.2 (and 3.0) for clozapine, 2.6 (and 2.4) for quetiapine, and 2.5 (and 2.2) for olanzapine. Cases of respiratory aspiration associated with APs included: 137 overdose/suicide cases (64 fatal) and 609 cases during treatment (385 fatal) including 333 taking clozapine (238 fatal). In logistic regression models of fatal outcomes, the odds ratios, OR, and (95% confidence intervals, CI) of significant independent variables were: a) 2.3 - 2.6 for clozapine in 3 samples of AP treatment of varying size, b) 1.9 (CI 1.0 to 3.5) for geriatric age in 284 patients on clozapine treatment, and c) 1.8 (CI 1.1 - 3.2) for antidepressant co-medication in 276 patients on non-clozapine APs. Multiple AP pharmacological mechanisms may explain respiratory aspiration.

Mn(III)-Mediated Radical Addition/Cyclization of Isocyanides with Aryl Boronic Acids/Diarylphosphine Oxides: Access to 11-Functionalized Dibenzodiazepines

A Mn(III)-mediated radical addition/cyclization reaction of isocyanides with aryl boronic acids/diarylphosphine oxides has been developed. A series of 11-arylated/-phosphorylated dibenzodiazepines were efficiently constructed in moderate to excellent yields under mild reaction conditions via imidoyl radical process. The present protocol offers novel access to functionalized seven-membered N-heterocycles.

Clozapine-associated myocarditis in the World Health Organization's pharmacovigilance database: Focus on reports from various countries

INTRODUCTION

The incidence of clozapine-associated myocarditis varies by country. These variations were explored in VigiBase, the World Health Organization's global database which has >25 million spontaneously reported adverse drug reaction (ADR) reports from 145 national drug agencies.

METHODS

On January 15, 2021, a search of VigiBase since inception focused on myocarditis in clozapine patients. The 3572 individual reports were studied using the standard VigiBase logarithmic measure of disproportionality called information component (IC). The IC measures the disproportionality between the expected and the reported rates. After duplicates were eliminated there were 3274 different patients with myocarditis studied in logistic regression models.

RESULTS

The first case was published in 1980 but since 1993 the VigiBase clozapine-myocarditis IC has been significant; moreover, currently it is very strong (IC=6.0, IC₀₀₅-IC₉₉₅=5.9-6.1) and statistically significantly different from other antipsychotics. Of the 3274 different patients with myocarditis, 43.4% were non-serious cases, 51.8% were serious but non-fatal, and 4.8% were fatal. More than half (1621/3274) of the reports came from Australia, of which 69.2% were non-serious, 27.7% serious but non-fatal, and 3.1% fatal. Asian countries contributed only 41 cases.

CONCLUSIONS

In pharmacovigilance studies, confounding factors may explain statistical associations, but the strength and robustness of these results are compatible with the hypothesis that myocarditis is definitively associated with early clozapine treatment (84% [1309/1560] and 5% [82/1560] in the first and second months). Myocarditis reports from Australia are over-represented to a major degree. Asian countries may be underreporting myocarditis to their drug agencies.

Recognition and management of clozapine adverse effects: A systematic review and qualitative synthesis

OBJECTIVE

Clozapine is substantially underutilized in most countries and clinician factors including lack of knowledge and concerns about adverse drug effects (ADEs) contribute strongly to treatment reluctance. The aim of this systematic review was to provide clinicians with a comprehensive information source regarding clozapine ADEs.

METHODS

PubMed and Embase databases were searched for English language reviews concerned with clozapine ADEs; publications identified by the automated search were manually searched for additional relevant citations. Following exclusion of redundant and irrelevant reports, pertinent information was summarized in evidence tables corresponding to each of six major ADE domains; two authors reviewed all citations for each ADE domain and summarized their content by consensus in the corresponding evidence table. This study was conducted in accordance with PRISMA principles.

RESULTS

Primary and secondary searches identified a total of 305 unique reports, of which 152 were included in the qualitative synthesis. Most clozapine ADEs emerge within 3 months, and almost all appear within 6 months, after initiation. Notable exceptions are weight gain, diabetic ketoacidosis (DKA), severe clozapine-induced gastrointestinal hypomotility (CIGH), clozapine-induced cardiomyopathy (CICM), seizures, and clozapine-induced neutropenia (CIN). Most clozapine ADEs subside gradually or respond to dose reduction; those that prompt discontinuation generally do not preclude rechallenge. Rechallenge is generally inadvisable for clozapine-induced myocarditis (CIM), CICM, and clozapine-induced agranulocytosis (CIA). Clozapine plasma levels >600-1000 μg/L appear more likely to cause certain ADEs (e.g., seizures) and, although there is no clear toxicity threshold, risk/benefit ratios are generally unfavorable above 1000 μg/L.

CONCLUSION

Clozapine ADEs rarely require discontinuation.

Pro-inflammatory cytokine levels are elevated in female patients with schizophrenia treated with clozapine

RATIONALE AND OBJECTIVE

In this study, we hypothesized that the chronic use of clozapine affects cytokine expression and has a greater effect on female patients than on male patients. The aims of this study were to detect (1) whether serum cytokine levels were altered in patients with chronic schizophrenia after clozapine treatment compared with age- and sex-matched healthy controls, (2) whether there was a gender difference in serum cytokine levels after clozapine treatment, and (3) whether there was a correlation between serum cytokine levels and clozapine daily dosage in patients with schizophrenia.

METHODS

Forty-nine inpatients with schizophrenia treated with clozapine and fifty-three sex- and age-matched healthy controls were recruited. The patients' psychiatric symptoms were measured by the Positive and Negative Syndrome Scale (PANSS). Blood samples from both patients and healthy controls were collected. Serum IL-1β, IL-2, IL-6, IL-17, IFN-γ, and TNF-α levels were measured in duplicate by sandwich enzyme-linked immunosorbent assay.

RESULTS

We found that chronic clozapine treatment in patients with schizophrenia resulted in the abnormal expression of serum cytokines, such as IL-2, IL-6, IL-17, and TNF-α, compared with the healthy controls. In addition, there was a gender difference in the abnormal expression of cytokines between male and female patients with schizophrenia. In the female group, IL-2 serum levels were lower than those in the male group. Interestingly, there was a positive correlation between serum IL-2 levels and the daily clozapine dosage in female patients with schizophrenia.

CONCLUSION

Findings from our study have shown clear evidence that clozapine had a greater effect on immune function in female patients with schizophrenia.

Environmentally relevant concentrations of clozapine induced lipotoxicity and gut microbiota dysbiosis in Chinese rare minnow (Gobiocypris rarus)

Clozapine (CLZ) is a neuroactive pharmaceutical that is frequently detected in aquatic environments. Although the cardiotoxicity, developmental toxicity, and neurotoxicity of CLZ in aquatic non-target organisms have been reported, its lipotoxicity and underlying mechanism are unknown. Therefore, in this study, 2-month-old Chinese rare minnows were exposed to 0, 0.1, 1, and 10 μg/L CLZ for 90 days. Overt dyslipidemia was observed after CLZ exposure, whereas the body weights of females significantly increased after CLZ exposure (p < 0.05). In addition, obvious hepatocyte vacuolization and hepatic lipid droplet accumulation were observed at all treatment groups (p < 0.05). The activities of sterol regulatory element binding proteins 1 (SREBP1) and fatty acid synthase (FAS) were significantly upregulated at the 1 and 10 μg/L CLZ treatment groups (p < 0.05). Moreover, evident cell boundary disintegration of the intestinal villi and increasing mucus secretion were observed at all treatment groups (p < 0.05). Furthermore, the diversity of the gut microbiota increased, whereas the relative abundances of Proteobacteria, Firmicutes and Bacteroidetes significantly increased after CLZ exposure (p < 0.05). Furthermore, significantly increased bacterial secondary bile acid biosynthesis activity in Chinese rare minnows was observed after 1 μg/L CLZ exposure (p < 0.05). Therefore, our findings confirmed that CLZ induced lipotoxicity by stimulating SREBP1 and affecting the bacterial secondary bile acid biosynthesis activity in Chinese rare minnows.

Drug-Induced Idiosyncratic Agranulocytosis - Infrequent but Dangerous

Drug-induced agranulocytosis is a life-threatening side effect that usually manifests as a severe form of neutropenia associated with fever or signs of sepsis. It can occur as a problem in the context of therapy with a wide variety of drug classes. Numerous drugs are capable of triggering the rare idiosyncratic form of agranulocytosis, which, unlike agranulocytosis induced by cytotoxic drugs in cancer chemotherapy, is characterised by “bizzare” type B or hypersensitivity reactions, poor predictability and a mainly low incidence. The idiosyncratic reactions are thought to be initiated by chemically reactive drugs or reactive metabolites that react with proteins and may subsequently elicit an immune response, particularly directed against neutrophils and their precursors. Cells or organs that exhibit specific metabolic and biotransformation activity are therefore frequently affected. In this review, we provide an update on the understanding of drug-induced idiosyncratic agranulocytosis. Using important triggering drugs as examples, we will summarise and discuss the chemical, the biotransformation-related, the mechanistic and the therapeutic basis of this clinically relevant and undesirable side effect.

Patterns of antipsychotic prescriptions in patients with schizophrenia in China: A national survey

INTRODUCTION

To investigate the patterns and correlates of antipsychotic prescriptions among recently discharged inpatients with schizophrenia in China.

METHODS

The study included discharged patients from 41 tertiary psychiatric hospitals in 29 provinces between March 19-30, 2019. A total of 1032 inpatients with schizophrenia were included. Socio-demographic and clinical data were retrieved from medical records upon discharge.

RESULTS

Patients received a total of 13 unique antipsychotic medications, which included 9 s-generation antipsychotics (SGAs) and 4 first-generation antipsychotics (FGAs). The utilization rates of SGAs and FGAs were 98.8 % and 6.1 % respectively. The three most commonly antipsychotic medications were risperidone (35.1 %), olanzapine (31.3 %), and clozapine (24.6 %). The mean chlorpromazine equivalent dose was 452.12 ± 230.74 mg/day. The utilization rate of mood stabilizers was 18.9 %, 8.8 % for antidepressants, 20.3 % for sleep improvers, and 9.9 % for anticholinergics. More than two fifths patients (43.1 %) received two or more antipsychotic medications. Predictors of antipsychotic polypharmacy included younger age, residing in Central or West China, a longer duration of illness, a history of prior hospitalizations, and having agitated behavior during the hospitalization.

CONCLUSION

Antipsychotic polypharmacy in China is common on inpatients settings. The proportion of antipsychotic polypharmacy in China is higher than in many other countries, despite limited data to support the efficacy of many combinations. Clozapine remains one of most commonly prescribed antipsychotics in China, either as a monotherapy or combination therapy.

Clozapine-associated myocarditis in the World Health Organization's pharmacovigilance database: Focus on reports from various countries

INTRODUCTION

The incidence of clozapine-associated myocarditis varies by country. These variations were explored in VigiBase, the World Health Organization's global database which has >25 million spontaneously reported adverse drug reaction (ADR) reports from 145 national drug agencies.

METHODS

On January 15, 2021, a search of VigiBase since inception focused on myocarditis in clozapine patients. The 3572 individual reports were studied using the standard VigiBase logarithmic measure of disproportionality called information component (IC). The IC measures the disproportionality between the expected and the reported rates. After duplicates were eliminated there were 3274 different patients with myocarditis studied in logistic regression models.

RESULTS

The first case was published in 1980 but since 1993 the VigiBase clozapine-myocarditis IC has been significant; moreover, currently it is very strong (IC=6.0, IC005-IC995=5.9-6.1) and statistically significantly different from other antipsychotics. Of the 3274 different patients with myocarditis, 43.4% were non-serious cases, 51.8% were serious but non-fatal, and 4.8% were fatal. More than half (1621/3274) of the reports came from Australia, of which 69.2% were non-serious, 27.7% serious but non-fatal, and 3.1% fatal. Asian countries contributed only 41 cases.

CONCLUSIONS

In pharmacovigilance studies, confounding factors may explain statistical associations, but the strength and robustness of these results are compatible with the hypothesis that myocarditis is definitively associated with early clozapine treatment (84% [1309/1560] and 5% [82/1560] in the first and second months). Myocarditis reports from Australia are over-represented to a major degree. Asian countries may be underreporting myocarditis to their drug agencies.

Genetic risk of clozapine-induced leukopenia and neutropenia: a genome-wide association study

BACKGROUND

Clozapine is considered to be the most effective antipsychotic medication for schizophrenia. However, it is associated with several adverse effects such as leukopenia, and the underlying mechanism has not yet been fully elucidated. The authors performed a genome-wide association study (GWAS) in a Chinese population to identify genetic markers for clozapine-induced leukopenia (CIL) and clozapine-induced neutropenia (CIN).

METHODS

A total of 1879 patients (225 CIL cases, including 43 CIN cases, and 1,654 controls) of Chinese descent were included. Data from common and rare single nucleotide polymorphisms (SNPs) were tested for association. The authors also performed a trans-ancestry meta-analysis with GWAS results of European individuals from the Clozapine-Induced Agranulocytosis Consortium (CIAC).

RESULTS

The authors identified several novel loci reaching the threshold of genome-wide significance level (P < 5 × 10^-8). Three novel loci were associated with CIL while six were associated with CIN, and two T cell related genes (TRAC and TRAT1) were implicated. The authors also observed that one locus with evidence close to genome-wide significance (P = 5.08 × 10^-8) was near the HLA-B gene in the major histocompatibility complex region in the trans-ancestry meta-analysis.

CONCLUSIONS

The associations provide novel and valuable understanding of the genetic and immune causes of CIL and CIN, which is useful for improving clinical management of clozapine related treatment for schizophrenia. Causal variants and related underlying molecular mechanisms need to be understood in future developments.

A COMMENTARY ON IMPROVING CLOZAPINE ACCESSIBILITY AND REDUCING TREATMENT COST

Clozapine is vastly underutilized in the United States and many other countries. The most commonly cited reason for this is the requirement for frequent blood monitoring, which continues for the duration of treatment. Despite the notoriety clozapine achieved early in its development, accumulated evidence has demonstrated that close blood monitoring beyond the first year of treatment yields minimal safety benefits. Many health care systems have relaxed clozapine blood monitoring requirements during the COVID-19 pandemic for practical reasons, and this presents an opportunity to implement permanent, long overdue changes in mandated monitoring that reflect what has been learned about the real risk for blood dyscrasias with clozapine.

Clozapine-induced agranulocytosis

Wider use of clozapine, one of the most effective antipshychotic drugs, is precluded by its propensity to cause agranulocytosis. Currently, clozapine is used for treatment-resistant schizophrenia, with mandatory blood count monitoring for the duration of treatment. Agranulocytosis occurs in up to 0.8% of patients and presents a significant medical challenge, despite decreasing mortality rates. In this paper, we review the epidemiology of clozapine-induced agranulocytosis (CLIA), advances in identifying genetic risk factors, and the preventive measures to reduce the risk of CLIA. We discuss the pathogenesis of CLIA, which, despite receiving considerable scientific attention, has not been fully elucidated. Finally, we address the clinical management and suggest the approach to clozapine re-challenge in patients with a previous episode of neutropenia. With a significant proportion of clozapine recipients in Western hemisphere being Black, we comment on the importance of recognizing benign ethnic neutropenia as a potential impediment to clozapine administration. This review aims to aid haematologists and psychiatrists to jointly manage neutropenia and agranulocytosis caused by clozapine.

Predictors of outcome in early onset schizophrenia: a 10-year follow-up study

BACKGROUND

Younger age at onset is generally thought to be a predictor of poor outcome in Early Onset Schizophrenia (EOS), but there is a paucity of epidemiological data supporting this belief. This study aims to describe long-term outcomes and predictors of patient functioning in EOS, with a focus on the effect of age at onset.

METHODS

We consecutively enrolled 118 EOS patients who were hospitalized in 2006. Mean age at baseline was 13.3 ± 2.3 years. Sixty-five subjects were successfully interviewed. Mean length of follow up was 10.4 ± 0.3 years. Baseline data were collected from inpatient medical records, while follow up was conducted primarily through telephone interviews of patient relatives. WHODAS 2.0 was used to measure global functioning at follow up. Outcomes included education, employment, marriage status, physical health, subsequent diagnoses and treatment, and patient functioning. Univariate and multivariate regression models were used to assess predictors of outcome, while propensity scores were used to adjust for confounding in analyzing the effect of age at onset on functional outcome.

RESULTS

Of the 65 subjects where follow-up data were available, 3 were deceased at follow up. Five (8%) discontinued treatment. Diagnostic stability was 76%. Nearly a quarter (24%) were using clozapine at follow up. In male and female patients, 61 and 55% respectively were overweight, while 29 and 32% respectively were obese. Sixteen (26%) were economically self-sufficient, while 34 (55%) were unemployed. Thirteen (21%) patients had ever been married. The median WHODAS score was 15 (IQR 2 to 35), roughly corresponding to the 78th percentile on population norms. Extroverted personality (p = 0.01), suspicious personality (p = 0.02), and high level of education (p = 0.001) predicted better functioning. Age of onset was not associated with function in either the univariate model (p = 0.24), full model (p = 0.17) or the final risk factor model (p = 0.11), nor after using propensity scores to further adjust for confounders.

CONCLUSION

The long-term functional outcome of EOS is more optimistic than generally believed. Age at disease onset does not predict long-term functional outcome in EOS populations.

Implementing a clozapine supply service in Australian community pharmacies: barriers and facilitators

BACKGROUND

Clozapine is the most effective antipsychotic for treatment-resistant schizophrenia, although serious adverse effects such as agranulocytosis and cardiomyopathy limit its use. In July 2015, Australian regulations changed to allow community-based prescribing and supply of clozapine for maintenance therapy. However, there is currently no information on the rate of clozapine services available in Australian community pharmacies, or the factors that influence a pharmacist's decision to provide, or not provide, a clozapine service, particularly from the perspective of those pharmacists who do not offer this service. This study investigated Australian community pharmacies providing a clozapine supply service and the barriers to, and facilitators of, implementing this service.

METHODS

This mixed method exploratory study was conducted in two stages: (1) a brief online survey of community pharmacists Australia-wide; and (2) semi-structured telephone interviews. The survey was conducted between November 2017-January 2018; results were analysed via descriptive statistics. Survey respondents who did not provide a clozapine service were eligible to participate in a telephone interview exploring barriers and facilitators. Interviews were undertaken between December 2017-January 2018 and data analysed thematically.

RESULTS

A total of 265 pharmacists completed the survey; 51.3% (n = 136) provided a clozapine service. Consumer demand was a key facilitator (n = 18/247; 66.1%) and the main barrier to implementing a clozapine service was a perceived lack of need (n = 70/122; 57.4%). Twelve survey respondents were interviewed; while most participants acknowledged that supplying clozapine in community pharmacies would benefit consumers due to convenience, the lack of training and support led to difficulties in service implementation.

CONCLUSIONS

Although regulatory changes aimed to improve access to clozapine, it is unclear if they have been successful, or to what degree. Community pharmacists were positive about supplying clozapine in the community but identified a need for training and support to raise awareness of the service so that eligible clozapine consumers can be transitioned to community-based care. Further research is needed about the perceptions of clozapine consumers to determine whether the regulatory changes have resulted in positive outcomes for their independence and quality of life.

Clozapine Metabolism in East Asians and Caucasians: A Pilot Exploration of the Prevalence of Poor Metabolizers and a Systematic Review

PURPOSE/BACKGROUND

In clozapine therapeutic drug monitoring (TDM) studies, Chinese reached the same concentrations using half the dosage Caucasians use. Defining clozapine poor metabolizers (PMs) requires stratification by ethnicity, smoking, and sex.

METHODS/PROCEDURES

After sex and smoking stratification in 129 Chinese inpatients (mean, 8.8 TDM samples per patient), we explored the association between the total concentration-dose (C/D) ratio and CYP1A2 (*1C, *1F, and *7) and CYP2C19 alleles (*2 and *3). A systematic literature review identified 22 clozapine TDM prior studies (13 in Caucasians and 7 in East Asians).

FINDINGS/RESULTS

In our Chinese sample, the mean total clozapine C/D ratio (ng/mL per mg/d) was 1.96 for 22 male smokers, 2.07 for 5 female smokers, 2.47 for 36 male nonsmokers, and 2.95 for 66 female nonsmokers. CYP1A2 *1C had no significant effects, and CYP1A2 *1F had small effects. Five clozapine PMs (4%) needed low clozapine doses of 75 to 115 mg/d to get therapeutic concentrations. Using the same methodology in a published Italian sample, we found 5 PMs (3.3% of 152). In the systematic review, the clozapine C/D ratio (ng/mL per mg/d) was higher when comparing: (1) weighted mean values of 1.57 in 876 East Asians versus 1.07 in 1147 Caucasians and (2) ranks of 8 East Asians versus 13 Caucasian samples (P < 0.001).

IMPLICATIONS/CONCLUSIONS

Future TDM studies need to further explore the frequency of clozapine PMs after sex and smoking stratification in East Asian and Caucasian patients. Compared with Caucasians, East Asians appear to have a clinically relevant decrease in clozapine clearance.

Delays and barriers to the commencement of clozapine in eligible people with a psychotic disorder: A literature review

AIM

While the majority of individuals with a first episode of psychosis (FEP) achieve symptomatic remission with the appropriate treatment, there is a small but significant proportion who do not achieve remission of symptoms despite adequate treatment with at least two antipsychotic medications (termed treatment resistance). Clozapine is indicated in individuals who fulfil the criteria for treatment-resistant schizophrenia, however, despite it being the most effective antipsychotic medication, there can be delays in the commencement of clozapine in eligible patients.

METHODS

A systematic search was performed to identify articles reporting either the time taken to commence clozapine (or delays) in eligible individuals or articles reporting barriers to the commencement of clozapine. The initial search generated 5588 articles and of these, 18 were eligible.

RESULTS

13 studies described delays in commencing clozapine and five studies reported on the barriers to the commencement of clozapine. The duration of delay from when an individual was deemed eligible for clozapine treatment to the time of clozapine commencement ranged from 19.3 weeks to 5.5 years. In addition, the duration of illness prior to clozapine initiation ranged from 1.1 to 9.7 years. It was found that some clinicians were more inclined to prescribe antipsychotic polypharmacy or doses higher than recommended than to prescribe clozapine.

CONCLUSIONS

Delays in commencing clozapine have been consistently demonstrated. Early intervention for psychosis services are the ideal settings to identify individuals with persistent positive psychotic symptoms and commence clozapine if indicated.

The Effect of Body Weight Changes on Total Plasma Clozapine Concentrations Determined by Applying a Statistical Model to the Data From a Double-Blind Trial

PURPOSE/BACKGROUND

Some therapeutic drug monitoring studies suggest that increased weight is associated with small increases in clozapine concentrations. The goal of this study was to reanalyze a US double-blind study using a sophisticated statistical model to test whether weight gains from baseline or increases in percentage of body fat from baseline, computed from a published equation, are associated with increased total plasma clozapine concentrations after controlling for the effects of smoking and sex.

METHODS/PROCEDURES

Using data from a multidosage randomized double-blind US clozapine trial previously published, a random intercept linear model of steady-state total plasma clozapine concentrations was fitted to 424 concentrations from 47 patients.

FINDINGS/RESULTS

After adjusting for sex and smoking, (1) a 1-kg gain in body weight during clozapine treatment was significantly associated with a 1.4% increase in total plasma clozapine concentrations (95% confidence interval = 0.55 to 2.3) and (2) a 1-point increase in percentage of body fat during clozapine treatment was significantly associated with a 5.4% increase in total clozapine concentration (2.5 to 8.3) in females and 1.4% (-1.1 to 4.0) in males.

IMPLICATIONS/CONCLUSIONS

As hypothesized, weight increases during clozapine treatment, which probably reflect increases in fat tissue, were associated with increases in total plasma concentrations. Pending further replication in other samples, it seems likely that clozapine may deposit in body fat and that this may decrease clozapine clearance. This change may be small in most patients but may be clinically relevant in females with major gains in body fat.

Prevalence, risk factors and clinical characteristics of osteoporosis in Chinese inpatients with schizophrenia

Patients with schizophrenia have a high prevalence of developing osteoporosis and osteoporosis-related fractures. We examined the prevalence of osteoporosis and its clinical correlates in Chinese patients with schizophrenia, which is not well-studied. A total of 199 inpatients (males/females=132/67; average age: 54.5±11.1years) and 107 healthy controls (males/females=22/85; average age: 41.7±11.9years) were recruited. Bone mineral density (BMD) was measured by ultrasonography of the calcaneus. The prevalence of osteoporosis and low BMD (osteoporosis and osteopenia) was 23.1% and 65.3% for the patient group, versus 7.5% and 39.3% for the control group (both p<0.001). Further, the average BMD T-score in patients was significantly lower than in controls (p<0.05). There was gender difference in the prevalence of low BMD conditions for the patients (males: 56.1% versus females: 76.1%; p<0.01) as well as the BMD T-score (p<0.001). Several risk factors correlated with the osteoporosis classification in the patient group: older age (58.9±11.2years vs. 53.3±11.0years), lower weight (63.7±12.2kg vs. 70.4±15.2kg) and body mass index (BMI) (22.8±4.1kg/m² vs. 24.2±4.7kg/m²; all p<0.01) than those without osteoporosis. Stepwise multiple logistic regression analysis indicated that age, weight and BMI remained significantly associated with osteoporosis. In addition, correlation analysis showed significant correlations between BMD T-score and the following parameters: gender, age and drug type (clozapine versus non-clozapine) (Bonferroni corrected p's<0.05). Our results suggest a higher prevalence of osteoporosis and osteopenia in Chinese schizophrenic inpatients, with both the expected risk factors of gender and age, as well as drug type.

Clozapine users in Australia: their characteristics and experiences of care based on data from the 2010 National Survey of High Impact Psychosis

AIMS

Clozapine is the most effective medication for treatment refractory schizophrenia. However, descriptions of the mental health and comorbidity profile and care experiences of people on clozapine in routine clinical settings are scarce. Using data from the 2010 Australian Survey of High Impact Psychosis, we aimed to examine the proportion of people using clozapine, and to compare clozapine users with other antipsychotic users on demographic, mental health, adverse drug reaction, polypharmacy and treatment satisfaction variables.

METHODS

Data describing 1049 people with a diagnosis of schizophrenia or schizoaffective disorder, who reported taking any antipsychotic medication in the previous 4 weeks, were drawn from a representative Australian survey of people with psychotic disorders in contact with mental health services in the previous 12 months. We compared participants taking clozapine (n = 257, 22.4%) with those taking other antipsychotic medications, on a range of demographic, clinical and treatment-related indicators.

RESULTS

One quarter of participants were on clozapine. Of participants with a chronic course of illness, only one third were on clozapine. After adjusting for diagnosis and illness chronicity, participants taking clozapine had significantly lower odds of current alcohol, cannabis and other drug use despite similar lifetime odds. Metabolic syndrome and diabetes were more common among people taking clozapine; chronic pain was less common. Psychotropic polypharmacy did not differ between groups.

CONCLUSIONS

Consistent with international evidence of clozapine underutilisation, a large number of participants with chronic illness and high symptom burden were not taking clozapine. The lower probabilities of current substance use and chronic pain among clozapine users warrant further study.

The prevalence, risk factors and clinical correlates of obesity in Chinese patients with schizophrenia

Obesity is a common comorbidity in schizophrenia. Few studies have addressed obesity in Chinese schizophrenia patients. The aims of this current study were to evaluate the prevalence, risk factors and clinical correlates of obesity in Chinese patients with schizophrenia. A total of 206 patients were recruited from a hospital in Beijing. Their clinical and anthropometric data together with plasma glucose and lipid parameters were collected. Positive and Negative Syndrome Scale (PANSS) was rated for all patients. Overall, 43 (20.9%) patients were obese and 67 (32.5%) were overweight. The obese patients had significantly higher glucose levels, triglyceride levels than non-obese patients. Females and patients with type 2 diabetes mellitus had increased risk for obesity. Correlation analysis showed that BMI was associated with sex, education levels, negative symptoms, total PANSS score, triglyceride levels and type 2 diabetes mellitus. Further stepwise regression analysis showed that sex, type 2 diabetes, education level, triglyceride and amount of smoking/day were significant predictors for obesity. Our study showed that the prevalence of obesity in Chinese patients with schizophrenia is higher than that in the general population. Some demographic and clinical variables are risk factors for obesity in schizophrenia.

More than 25 years of genetic studies of clozapine-induced agranulocytosis

Clozapine is one of the most effective atypical antipsychotic drugs prescribed to patients with treatment-resistant schizophrenia. Approximately 1% of patients experience potential life-threatening adverse effects in the form of agranulocytosis, greatly hindering its applicability in clinical practice. The etiology of clozapine-induced agranulocytosis (CIA) remains unclear, but is thought to be a heritable trait. We reviewed the genetic studies of CIA published thus far. One recurrent finding from early candidate gene study to more recent genome-wide analysis is that of the involvement of human leukocyte antigen locus. We conclude that CIA is most likely a complex, polygenic trait, which may hamper efforts to the development of a genetic predictor test with clinical relevance. To decipher the genetic architecture of CIA, it is necessary to apply more rigorous standards of phenotyping and study much larger sample sizes.

In Vitro Effects of Concomitant Use of Herbal Preparations on Cytochrome P450s Involved in Clozapine Metabolism

Herbal supplements are increasingly used in psychiatric practice. Our epidemiological study has identified several herbal preparations associated with adverse outcomes of antipsychotic therapy. In this study, we evaluated the in vitro effects of four herbal preparations—Radix Rehmanniae (RR), Fructus Schisandrae (FS), Radix Bupleuri (RB) and Fructus Gardeniae (FG)—on cytochrome P450s (CYPs) involved in the metabolism of clozapine in human liver microsomes (HLMs) and recombinant human cytochrome P450 enzymes (rCYPs). N-desmethylclozapine and clozapine N-oxide, two major metabolites of clozapine, were measured using high-performance liquid chromatography (HPLC). FG, RR and RB showed negligible inhibitory effects in both in vitro systems, with estimated half-maximal inhibitory concentrations (IC₅₀) and apparent inhibitory constant values (K_i) greater than 1 mg/mL (raw material), suggesting that minimal metabolic interaction occurs when these preparations are used concomitantly with clozapine. The FS extract affected CYP activity with varying potency; its effect on CYP 3A4-catalyzed clozapine oxidation was relatively strong (K_i: 0.11 mg/mL). Overall, the weak-to-moderate inhibitory effect of FS on in vitro clozapine metabolism indicated its potential role in herb-drug interaction in practice.

Clozapine for psychotic disorders in adults with intellectual disabilities

BACKGROUND

Psychosis is three times more common in people with an intellectual disability than in those without an intellectual disability. A low intelligence quotient (IQ) is a defining characteristic for intellectual disability and a risk factor for poor outcome in psychosis. Clozapine is recommended for treatment-resistant psychosis. The effect of psychotropic medication can be different in people with intellectual disability; for example, they may be more prone to side effects. People with an intellectual disability and psychosis form a special subgroup and we wanted to examine if there is randomised controlled trial (RCT) data in this population to support the use of clozapine.

OBJECTIVES

To determine the effects of clozapine for treating adults with a dual diagnosis of intellectual disability and psychosis.

SEARCH METHODS

We searched CENTRAL, Ovid MEDLINE, Embase and eight other databases up to December 2014. We also searched two trials registers, the Cochrane Schizophrenia Group's Register of Trials, and contacted the manufacturers of clozapine.

SELECTION CRITERIA

RCTs that assessed the effects of clozapine, at any dose, for treating adults (aged 18 years and over) with a dual diagnosis of intellectual disability and psychotic disorder, compared with placebo or another antipsychotic medication.

DATA COLLECTION AND ANALYSIS

Three review authors independently screened all titles, abstracts and any relevant full-text reports against the inclusion criteria.

MAIN RESULTS

Of the 1224 titles and abstracts screened, we shortlisted 38 full-text articles, which we subsequently excluded as they did not meet the inclusion criteria. These studies were not RCTs. Consequently, no studies are included in this Cochrane review.

AUTHORS' CONCLUSIONS

There are currently no RCTs that assess the efficacy and side effects of clozapine in people with intellectual disabilities and psychoses. Given the use of clozapine in this vulnerable population, there is an urgent need for a RCT of clozapine in people with a dual diagnosis of intellectual disability and psychosis to fill the evidence gap.

Peony-Glycyrrhiza Decoction, an Herbal Preparation, Inhibits Clozapine Metabolism via Cytochrome P450s, but Not Flavin-Containing Monooxygenase in In Vitro Models

Our previous studies have shown the therapeutic efficacy and underlying mechanisms of Peony-Glycyrrhiza Decoction (PGD), an herbal preparation, in treating antipsychotic-induced hyperprolactinemia in cultured cells, animal models, and human subjects. In the present study, we further evaluated pharmacokinetic interactions of PGD with clozapine (CLZ) in human liver microsomes (HLM), recombinantly expressed cytochrome P450s (P450s), and flavin-containing monooxygenases (FMOs). CLZ metabolites, N-demethyl-clozapine and clozapine-N-oxide, were measured. PGD, individual peony and glycyrrhiza preparations, and the two individual preparations in combination reduced production of CLZ metabolites to different extents in HLM. While the known bioactive constituents of PGD play a relatively minor role in the kinetic effects of PGD on P450 activity, PGD as a whole had a weak-to-moderate inhibitory potency toward P450s, in particular CYP1A2 and CYP3A4. FMOs are less actively involved in mediating CLZ metabolism and the PGD inhibition of CLZ. These results suggest that PGD has the capacity to suppress CLZ metabolism in the human liver microsomal system. This suppression is principally associated with the inhibition of related P450 activity but not FMOs. The present study provides in vitro evidence of herb-antipsychotic interactions.

Clozapine for treatment-resistant bipolar disorder: a systematic review

OBJECTIVE

To evaluate the efficacy and safety of clozapine for treatment-resistant bipolar disorder (TRBD).

METHODS

A systematic review of randomized controlled studies, open-label prospective studies, and retrospective studies of patients with TRBD was carried out. Interventions included clozapine monotherapy or clozapine combined with other medications. Outcome measures were efficacy and adverse drug reactions (ADRs).

RESULTS

Fifteen clinical trials with a total sample of 1,044 patients met the inclusion criteria. Clozapine monotherapy or clozapine combined with other treatments for TRBD was associated with improvement in: (i) symptoms of mania, depression, rapid cycling, and psychotic symptoms, with many patients with TRBD achieving a remission or response; (ii) the number and duration of hospitalizations, the number of psychotropic co-medications, and the number of hospital visits for somatic reasons for intentional self-harm/overdose; (iii) suicidal ideation and aggressive behavior; and (iv) social functioning. In addition, patients with TRBD showed greater clinical improvement in long-term follow-up when compared with published schizophrenia data. Sedation (12%), constipation (5.0%), sialorrhea (5.2%), weight gain (4%), and body ache/pain (2%) were the commonly reported ADRs; however, these symptoms but did not usually require drug discontinuation. The percentage of severe ADRs reported, such as leukopenia (2%), agranulocytosis (0.3%), and seizure (0.5%), appeared to be lower than those reported in the published schizophrenia literature.

CONCLUSION

The limited current evidence supports the concept that clozapine may be both an effective and a relatively safe medication for TRBD.

Association between subjective well-being and depressive symptoms in treatment-resistant schizophrenia before and after treatment with clozapine

BACKGROUND

We examined the relationship between subjective well-being and depressive symptoms in patients with treatment-resistant schizophrenia before and after treatment with clozapine to contribute to the growing body of research regarding the determinants of patients' perspective of their own well-being in schizophrenia.

METHODS

Forty patients with treatment-resistant schizophrenia were comprehensively evaluated for subjective well-being, schizophrenic symptoms, and depressive symptoms before and 8 weeks after the initiation of treatment with clozapine. Correlation analysis and Fisher's z-transformation statistics were performed.

RESULTS

There were significant improvements in all Positive and Negative Syndrome Scale (PANSS) factor scores and Beck Depression Inventory (BDI) score over the treatment period (P<.05). Before clozapine administration, the subjective well-being score had significant negative correlations with the PANSS depression factor score (P<.05) and the BDI score (P<.05). After clozapine treatment, the subjective well-being score still had significant negative correlations with the PANSS depression factor score (P<.05) and the BDI score (P<.05) and no new associations emerged with treatment. Fisher's z-transformation statistics revealed that the correlations between the subjective well-being score and the depression score were not significantly different before and after clozapine treatment.

CONCLUSIONS

These results indicate that depressive symptoms are significantly associated with low subjective well-being in patients with treatment-resistant schizophrenia. The association was equally significant before and after treatment with clozapine, suggesting that the relationship does not change with clozapine treatment, even when depressive symptoms improve significantly, and that there may be a common pathophysiological basis for depressive symptoms and the subjective appraisal of well-being in schizophrenia.

Intramuscular ziprasidone versus haloperidol for managing agitation in Chinese patients with schizophrenia

Intramuscular (IM) antipsychotics are preferred for efficient control of agitation symptoms. Previous studies have demonstrated that IM ziprasidone is efficacious and safe for treatment of agitation in schizophrenia. However, clinicians now recognize that racial differences may contribute to altered therapeutic response and tolerability. This study compared the efficacy and tolerability of IM ziprasidone versus IM haloperidol for the management of agitation in Chinese subjects with schizophrenia. Subjects with acute schizophrenia were randomized to either ziprasidone (n = 189, 10 to 20 mg as required up to a maximum of 40 mg/d) or haloperidol (n = 187, 5 mg every 4 to 8 hours to a maximum of 20 mg/d) for 3 days. Psychiatric assessments and adverse events were assessed at baseline, 2, 4, 24, 48, and 72 hours. In the ziprasidone group, 2.1% of subjects discontinued versus 3.7% in the haloperidol group. The least squares mean change (SE) from baseline to 72 hours in Brief Psychiatry Rating Scale total score was -17.32 (0.7) for ziprasidone (n = 167) and -18.44 (0.7) for haloperidol (n = 152), with a 95% confidence interval treatment difference of -0.7 to 2.9. Fewer subjects experienced adverse events after ziprasidone (n = 54, 28.6%) than haloperidol (n = 116, 62.0%), with a notably higher incidence of extrapyramidal symptoms in the haloperidol group (n = 69, 36.9%) compared to the ziprasidone group (n = 4, 2.1%). For controlling agitation in schizophrenia in this Chinese study, ziprasidone had a favorable tolerability profile and comparable efficacy and safety compared to haloperidol.

Adherence to treatment guidelines in clinical practice: study of antipsychotic treatment prior to clozapine initiation

BACKGROUND

Clozapine is the only antipsychotic drug licensed for treatment-resistant schizophrenia but its use is often delayed. Since previous studies, national guidelines on the use of clozapine and other antipsychotics have been disseminated to clinicians.

AIMS

To determine the theoretical delay to clozapine initiation and to quantify the prior use of antipsychotic polypharmacy and high-dose antipsychotic treatment.

METHOD

Clinico-demographic data were extracted from the treatment records of all patients commencing clozapine in our centre between 2006 and 2010.

RESULTS

Complete records were available for 149 patients. The mean theoretical delay in initiating clozapine was 47.7 months (s.d. = 49.7). Before commencing clozapine, antipsychotic polypharmacy and high-dose treatment was evident in 36.2 and 34.2% of patients respectively. Theoretical delay was related to illness duration (β = 0.7, P<0.001) but did not differ by gender or ethnicity.

CONCLUSIONS

Substantial delays to clozapine initiation remain and antipsychotic polypharmacy and high doses are commonly used prior to clozapine, despite treatment guidelines.

Clozapine: balancing safety with superior antipsychotic efficacy

Clozapine is often referred to as the gold standard for the treatment of schizophrenia and yet has also been described as the most underutilized treatment for schizophrenia supported by solid evidence-based medicine. In 2008, it was used to treat only 4.4% of patients with schizophrenia in the U.S., which is ~10-20% of those with approved indications for clozapine for which there is no alternative of equal efficacy. Its use is much higher in Scandinavian countries and China. The primary indications for clozapine are: 1) treatment-resistant schizophrenia or schizoaffective disorder, defined as persistent moderate to severe delusions or hallucinations despite two or more clinical trials with other antipsychotic drugs; and, 2) patients with schizophrenia or schizoaffective disorder who are at high risk for suicide. Concerns over a number of safety considerations are responsible for much of the underutilization of clozapine: 1) agranulocytosis; 2) metabolic side effects; and, 3) myocarditis. These side effects can be detected, prevented, minimized and treated, but there will be a very small number of fatalities. Nevertheless, clozapine has been found in two large epidemiologic studies to have the lowest mortality of any antipsychotic drug, mainly due to its very large effect to reduce the risk for suicide. Other reasons for limited use of clozapine include the extra effort entailed in monitoring white blood cell counts to detect granulocytopenia or agranulocytosis and, possibly, minimal efforts to market it now that it is largely generic. Awareness of the benefits and risks of clozapine is essential for increasing the use of this lifesaving agent.

The prevalence and clinical-demographic correlates of diabetes mellitus in chronic schizophrenic patients receiving clozapine

OBJECTIVE

To examine the prevalence and correlates of diabetes in a large sample of Chinese patients with schizophrenia on long-term clozapine treatment, because this population previously has received little systematic study.

METHODS

Two hundred and six inpatients meeting Diagnostic and Statistical Manual of Mental Disorders, 4th Edition schizophrenia criteria were recruited in a cross-sectional naturalistic study, and compared with 615 healthy control subjects matched for age, sex, education, and body mass index (BMI). The patient's psychopathology was assessed using the Positive and Negative Syndrome Scale (PANSS). Diagnoses of diabetes were established through review of medical records and fasting blood glucose testing, or an oral glucose tolerance test.

RESULTS

Diabetes mellitus was more common in patients than in the normal controls (22.3% vs 6.2%) (odds ratio = 4.37, confidence interval (CI) 2.76-6.92, p < 0.001). The prevalence of diabetes increased with age across five age-groups as compared with normal controls (X(2) = 18.0, df = 4, p = 0.001). The PANSS total score and sub-scores showed no differences between the diabetic and non-diabetic groups. Logistic regression in the patients revealed significant associations between diabetes and a family history of diabetes (p < 0.001), age (p < 0.01), and BMI (p < 0.05).

CONCLUSION

Long-term clozapine treatment was associated with an increased and clinically important risk of diabetes mellitus in Chinese chronic schizophrenic patients, which is consistent with previous reports in Western populations.

Effectiveness and costs of flupentixol compared to other first- and second-generation antipsychotics in the treatment of schizophrenia

RATIONALE

The purpose of this study is to analyse the effectiveness of flupentixol compared to other first- and second-generation antipsychotics for the treatment of schizophrenia in routine care.

METHOD

A retrospective cohort study was conducted using administrative data from four sickness funds covering 12.6 million insured. Patients discharged from hospital in 2003 with an ICD-10 diagnosis of schizophrenia were followed for 12 months. Rehospitalisation during follow-up was analysed using a hurdle regression model. Treatment costs were defined as cost of pharmaceutical and cost of inpatient care. Two thousand eight hundred ninety insured were included, of which 177 were treated with flupentixol during follow-up, while 429 and 2,284 were treated with other first-and second-generation antipsychotics, respectively.

RESULTS

Compared to patients treated with flupentixol (21.0 days), predicted hospitalisation did not differ significantly for patients treated with other first- (21.3 days, p = 0.8313) or second-generation antipsychotics (25.6 days, p = 0.4035). Predicted treatment costs for the average patient were 4,193 Euro if treated with flupentixol, 4,846 Euro if treated with other first-generation antipsychotic, and 6,523 Euro if treated with a second-generation antipsychotic. Second-generation antipsychotics showed a clear advantage over flupentixol concerning extrapyramidal symptoms co-medication.

CONCLUSION

The effectiveness of flupentixol preventing relapse in patients with schizophrenia appears to be similar to that of other first- and second-generation antipsychotics. However, the low treatment costs for patients treated with flupentixol could be explained by the small number of patients with readmissions (70 insured) and the larger share of patients treated with its depot formulation.

Increased S100B serum levels in schizophrenic patients with tardive dyskinesia: association with dyskinetic movements

Several studies show that calcium-binding protein S100B is increased in schizophrenia and may be involved in the pathogenesis of tardive dyskinesia (TD). We therefore compared serum S100B levels in normal controls (n=60), schizophrenic patients with (n=32) and without TD (n=50). Assessments included the abnormal involuntary movement scale (AIMS) and the positive and negative syndrome scale (PANSS). Serum S100B levels were measured by enzyme-linked immunosorbent assay (ELISA). The results indicated that patients with TD had higher serum S100B levels than normals and those without TD. Serum S100B levels were positively correlated with AIMS scores in patients with TD. These data suggest that increased S100B levels may be related to neuro-degeneration, associated with TD pathophysiology.

Effects of risperidone on glucose metabolism in Chinese patients with schizophrenia: a prospective study

BACKGROUND

While most of the second generation antipsychotic agents are associated with abnormal glucose metabolism, previous studies have shown that risperidone has relatively little effect upon blood glucose levels. This study aimed to explore the effect of risperidone on the glucose-regulating mechanism of patients with schizophrenia by using the oral glucose tolerance test (OGTT), measuring insulin and C-peptide levels.

METHODS

Thirty inpatients with schizophrenia taking risperidone were studied. All the patients were given a simplified OGTT at baseline and six weeks after treatment. Plasma glucose, insulin, and C-peptide concentrations were measured at fasting, then 1 and 2h after OGTT respectively. Other data, including demographic characteristics and plasma drug concentrations, were also recorded.

RESULTS

(1) There was no significant increase in the proportion of patients demonstrating abnormal plasma glucose levels compared with baseline (p=1.000, McNemar test); (2) risperidone was associated with elevated insulin concentrations (p=0.013), C-peptide levels (p=0.020), insulin/glucose ratio (p=0.020) and BMI (p<0.01); (3) no sex differences in glucose-related measures were observed.

CONCLUSION

Risperidone treatment may be associated with alterations in glucose-regulating mechanisms in patients with schizophrenia.

Psychotropic prescription practices in east Asia: looking back and peering ahead

PURPOSE OF REVIEW

The present review focuses on the pharmacoepidemiological issues of psychotropic drug use in countries within east Asia, with special emphasis on antipsychotic, antidepressant and benzodiazepine prescriptions. Pharmacogenetic studies in different ethnic groups are also reviewed.

RECENT FINDINGS

Recent studies have revealed the prevalence of antipsychotic polytherapy (defined as the use of more than one antipsychotic; up to 45.7%), less conservative antipsychotic use (defined as the use of more than 1000 mg/day chlorpromazine equivalents; up to 17.9%) and depot antipsychotic use (up to 15.3%) in different populations in east Asia. Clozapine is commonly prescribed (up to 60%) in China. There is a trend of increasing second-generation antipsychotic use in east Asian countries. Up to 67.5% of patients received newer antidepressants such as selective serotonin reuptake inhibitors. Benzodiazepine medications are used in up to 29.9% of study populations. Socioeconomic factors appear to be one of the major common factors that affect the prescription of antipsychotics and newer antidepressants. Pharmacogenetic factors associated with antipsychotic response, weight gain and extrapyramidal side effects have been examined. Treatment adherence and pharmacoeconomic factors are relatively understudied.

SUMMARY

Future studies on prescribing trends of antipsychotics and antidepressants need to focus on children, adolescent and elderly patient populations, the impact of changing prescription trends and the long-term effects on patients and their caregivers, as well as pharmacogenetic factors, which can potentially pave the way for better and more individualized prescription of psychotropic drugs in east Asia.

Pharmacotherapy for schizophrenic inpatients in East Asia--changes and challenges

OBJECTIVES

(1) to review characteristics of prescription patterns of antipsychotic medication in China, Hong Kong, Japan, Korea, Singapore and Taiwan, (2) to examine the changes of prescriptions brought about by the introduction of second generation psychotropic drugs (SGA) in East Asia, (3) to analyse factors contributing to the characteristic use of antipsychotics, and (4) to suggest ways and means to improve the prescription practice of antipsychotics in East Asia.

METHODS

Authors of this study collaborated with psychiatrists in East Asia to undertake an international survey reviewing prescription patterns of psychotropic medications in East Asia. The REAP (Research on Asian psychotropic prescription patterns) study reviewed the prescription of a large number of schizophrenic inpatients in China, Hong Kong, Japan, Korea, Singapore and Taiwan in 2001 and 2004 using a unified research protocol and questionnaire.

RESULTS

Prescription patterns of antipsychotic drugs differ greatly country by country and have recently experienced rapid changes. Our survey shows second generation antipsychotics are frequently used in East Asia. The introduction of SGA resulted in the combined use of first generation psychotropic drugs (FGA) and SGA in East Asia. These changing prescription patterns have created many challenges for psychiatrists in East Asia.