Clozapine in China: a review and preview of US/PRC collaboration

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.

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.

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.

US-China health exchange and collaboration following COVID-19

Strong US-China collaboration on health and medicine is a crucial element of the global effort against COVID-19. We review the history of health collaboration and exchanges between the public and private sectors in the USA and China, including the long-lasting collaboration between governmental public health agencies of the two countries. Academic and scientific exchanges should be reinvigorated and the increasing valuable role of non-profit foundations acknowledged. The shared interests of the two countries and the magnitude of the pandemic necessitate both countries to collaborate and cooperate. We provide recommendations to the two governments and the global health community to control the ongoing COVID-19 pandemic and prepare for future threats. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Effect of age on the relative efficacy of clozapine in schizophrenia

OBJECTIVE

Early treatment of schizophrenia improves outcomes. Clozapine appears to have unique benefit when other antipsychotic medication has failed. This systematic review and meta-analysis aims to assess clozapine's superiority over alternative antipsychotic medication and examine whether earlier use is associated with additional benefit.

METHOD

Systematic retrieval of blinded, randomized controlled trials comparing clozapine with alternative antipsychotics in adults with schizophrenia. The effect of mean age on relative clozapine response was examined using random effects meta-regression, and multiple linear regression on available patient data.

RESULTS

A total of 276 studies were retrieved. Thirty-four studies were included in the meta-analysis. Clozapine was significantly more effective than alternative antipsychotics in reducing psychotic symptoms and increasing response. However, meta-regression failed to show a more significant effect in younger patients (age on effect size (total psychotic symptoms) 0.00, P = 0.79 CI -0.03 to 0.03). Individual patient data were available for two studies, the larger of which showed a significant interaction between younger age and superiority of clozapine.

CONCLUSION

The results support clozapine's superiority over other antipsychotics. A convincing effect of age on this effect was not demonstrated, although this was suggested in one study. In view of the age of many of the included studies, and changes in reporting practice over time, new clozapine RCTs, which include age of illness onset as well as age at trial time, would be welcome in order to provide meta-analysable data for future use.

Second-generation antipsychotics and constipation: A review of the literature

Antipsychotics are the cornerstone in the management of psychotic disorders and schizophrenia. They are effective agents but also have a wide range of side effects. In the recent literature constipation as possible side effect has received little attention. A review of the literature concerning constipation associated with antipsychotics was performed. Overall constipation is a rarely studied or reported side effect of antipsychotic medication. Nevertheless constipation is a common side effect. Antipsychotic agents differ in their liability to induce constipation. Constipation can be severe and can lead to serious consequences such as paralytic ileus, bowel occlusion and death. Active screening, monitoring and treatment are recommended. Further research on incidence, prevalence, underlying mechanisms and preventive measures is required.

Amisulpride augmentation in clozapine-unresponsive schizophrenia (AMICUS): a double-blind, placebo-controlled, randomised trial of clinical effectiveness and cost-effectiveness

BACKGROUND

When treatment-refractory schizophrenia shows an insufficient response to a trial of clozapine, clinicians commonly add a second antipsychotic, despite the lack of robust evidence to justify this practice.

OBJECTIVES

The main objectives of the study were to establish the clinical effectiveness and cost-effectiveness of augmentation of clozapine medication with a second antipsychotic, amisulpride, for the management of treatment-resistant schizophrenia.

DESIGN

The study was a multicentre, double-blind, individually randomised, placebo-controlled trial with follow-up at 12 weeks.

SETTINGS

The study was set in NHS multidisciplinary teams in adult psychiatry.

PARTICIPANTS

Eligible participants were people aged 18-65 years with treatment-resistant schizophrenia unresponsive, at a criterion level of persistent symptom severity and impaired social function, to an adequate trial of clozapine monotherapy.

INTERVENTIONS

Interventions comprised clozapine augmentation over 12 weeks with amisulpride or placebo. Participants received 400 mg of amisulpride or two matching placebo capsules for the first 4 weeks, after which there was a clinical option to titrate the dosage of amisulpride up to 800 mg or four matching placebo capsules for the remaining 8 weeks.

MAIN OUTCOME MEASURES

The primary outcome measure was the proportion of 'responders', using a criterion response threshold of a 20% reduction in total score on the Positive and Negative Syndrome Scale.

RESULTS

A total of 68 participants were randomised. Compared with the participants assigned to placebo, those receiving amisulpride had a greater chance of being a responder by the 12-week follow-up (odds ratio 1.17, 95% confidence interval 0.40 to 3.42) and a greater improvement in negative symptoms, although neither finding had been present at 6-week follow-up and neither was statistically significant. Amisulpride was associated with a greater side effect burden, including cardiac side effects. Economic analyses indicated that amisulpride augmentation has the potential to be cost-effective in the short term [net saving of between £329 and £2011; no difference in quality-adjusted life-years (QALYs)] and possibly in the longer term.

LIMITATIONS

The trial under-recruited and, therefore, the power of statistical analysis to detect significant differences between the active and placebo groups was limited. The economic analyses indicated high uncertainty because of the short duration and relatively small number of participants.

CONCLUSIONS

The risk-benefit of amisulpride augmentation of clozapine for schizophrenia that has shown an insufficient response to a trial of clozapine monotherapy is worthy of further investigation in larger studies. The size and extent of the side effect burden identified for the amisulpride-clozapine combination may partly reflect the comprehensive assessment of side effects in this study. The design of future trials of such a treatment strategy should take into account that a clinical response may be not be evident within the 4- to 6-week follow-up period usually considered adequate in studies of antipsychotic treatment of acute psychotic episodes. Economic evaluation indicated the need for larger, longer-term studies to address uncertainty about the extent of savings because of amisulpride and impact on QALYs. The extent and nature of the side effect burden identified for the amisulpride-clozapine combination has implications for the nature and frequency of safety and tolerability monitoring of clozapine augmentation with a second antipsychotic in both clinical and research settings.

TRIAL REGISTRATION

EudraCT number 2010-018963-40 and Current Controlled Trials ISRCTN68824876.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 21, No. 49. See the NIHR Journals Library website for further project information.

Antipsychotic combinations for schizophrenia

BACKGROUND

Many people with schizophrenia do not achieve a satisfactory treatment response with their initial antipsychotic drug treatment. Sometimes a second antipsychotic, in combination with the first, is used in these situations.

OBJECTIVES

To examine whether:1. treatment with antipsychotic combinations is effective for schizophrenia; and2. treatment with antipsychotic combinations is safe for the same illness.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's register which is based on regular searches of CINAHL, BIOSIS, AMED, Embase, PubMed, MEDLINE, PsycINFO, and registries of clinical trials. There are no language, time, document type, or publication status limitations for inclusion of records in the register. We ran searches in September 2010, August 2012 and January 2016. We checked for additional trials in the reference lists of included trials.

SELECTION CRITERIA

We included all randomised and quasi-randomised controlled trials comparing antipsychotic combinations with antipsychotic monotherapy for the treatment of schizophrenia and/or schizophrenia-like psychoses.

DATA COLLECTION AND ANALYSIS

We independently extracted data from the included studies. We analysed dichotomous data using risk ratios (RR) and the 95% confidence intervals (CI). We analysed continuous data using mean difference (MD) with a 95% CIs. For the meta-analysis we used a random-effects model. We used GRADE to complete a 'Summary of findings' table and assessed risk of bias for included studies.

MAIN RESULTS

Sixty-two studies are included in the review, 31 of these compared clozapine monotherapy with clozapine combination. We considered the risk of bias in the included studies to be moderate to high. The majority of trials had unclear allocation concealment, method of randomisation and blinding, and were not free of selective reporting.There is some limited evidence that combination therapy is superior to monotherapy in improving clinical response (RR 0.73, 95% CI 0.63 to 0.85; participants = 2364; studies = 29, very low-quality evidence), although subgroup analyses show that the positive result was due to the studies with clozapine in both the monotherapy and combination groups (RR 0.66, 95% CI 0.53 to 0.83; participants = 1127; studies = 17). Few studies reported on rate of relapse, most likely due to the short length of the studies. Overall, a combination of antipsychotics was not superior or inferior to antipsychotic monotherapy in preventing relapse (RR 0.63, 95% CI 0.31 to 1.29; participants = 512; studies = 3, very low-quality evidence), but the pooled data showed high heterogeneity (I² = 82%). A combination of antipsychotics was not superior or inferior to antipsychotic monotherapy in reducing the number of participants discontinuing treatment early (RR 0.89, 95% CI 0.73 to 1.07; participants = 3103; studies = 43, low-quality evidence). No difference was found between treatment groups in the number of participants hospitalised (RR 0.96, 95% CI 0.36 to 2.55; participants = 202; studies = 3, low-quality evidence) . We did not find evidence of a difference between treatment groups in serious adverse events or those requiring discontinuation (RR 1.05, 95% CI 0.65 to 1.69; participants = 2398; studies = 30, very low-quality evidence). There is as lack of evidence on clinically important change in quality of life, with only four studies reporting average endpoint or change data for this outcome on three different scales, none of which showed a difference between treatment groups.

AUTHORS' CONCLUSIONS

Currently, most evidence regarding the use of antipsychotic combinations comes from short-term trials, limiting the assessment of long-term efficacy and safety. We found very low-quality evidence that a combination of antipsychotics may improve the clinical response. We also found low-quality evidence that a combination of antipsychotics is may make no difference at preventing participants from leaving the study early, preventing relapse and/or causing more serious adverse events than monotherapy.

Clozapine combined with different antipsychotic drugs for treatment-resistant schizophrenia

BACKGROUND

Between 40% and 70% of people with treatment-resistant schizophrenia do not respond to clozapine, despite adequate blood levels. For these people, a number of treatment strategies have emerged, including the prescription of a second anti-psychotic drug in combination with clozapine.

OBJECTIVES

To determine the clinical effects of various clozapine combination strategies with antipsychotic drugs in people with treatment-resistant schizophrenia both in terms of efficacy and tolerability.

SEARCH METHODS

We searched the Cochrane Schizophrenia Group's Study-Based Register of Trials (to 28 August 2015) and MEDLINE (November 2008). We checked the reference lists of all identified randomised controlled trials (RCT). For the first version of the review, we also contacted pharmaceutical companies to identify further trials.

SELECTION CRITERIA

We included only RCTs recruiting people of both sexes, aged 18 years or more, with a diagnosis of treatment-resistant schizophrenia (or related disorders) and comparing clozapine plus another antipsychotic drug with clozapine plus a different antipsychotic drug.

DATA COLLECTION AND ANALYSIS

We extracted data independently. For dichotomous data, we calculated risk ratios (RRs) and 95% confidence intervals (CI) on an intention-to-treat basis using a random-effects meta-analysis. For continuous data, we calculated mean differences (MD) and 95% CIs. We used GRADE to create 'Summary of findings' tables and assessed risk of bias for included studies.

MAIN RESULTS

We identified two further studies with 169 participants that met our inclusion criteria. This review now includes five studies with 309 participants. The quality of evidence was low, and, due to the high degree of heterogeneity between studies, we were unable to undertake a formal meta-analysis to increase the statistical power.For this update, we specified seven main outcomes of interest: clinical response in mental state (clinically significant response, mean score/change in mental state), clinical response in global state (mean score/change in global state), weight gain, leaving the study early (acceptability of treatment), service utilisation outcomes (hospital days or admissions to hospital) and quality of life.We found some significant differences between clozapine combination strategies for global and mental state (clinically significant response and change), and there were data for leaving the study early and weight gain. We found no data for service utilisation and quality of life. Clozapine plus aripiprazole versus clozapine plus haloperidolThere was no long-term significant difference between aripiprazole and haloperidol combination strategies in change of mental state (1 RCT, n = 105, MD 0.90, 95% CI -4.38 to 6.18, low quality evidence). There were no adverse effect data for weight gain but there was a benefit of aripiprazole for adverse effects measured by the LUNSERS at 12 weeks (1 RCT, n = 105, MD -4.90, 95% CI -8.48 to -1.32) and 24 weeks (1 RCT, n = 105, MD -4.90, 95% CI -8.25 to -1.55), but not 52 weeks (1 RCT, n = 105, MD -4.80, 95% CI -9.79 to 0.19). Similar numbers of participants from each group left the study early (1 RCT, n = 106, RR 1.27, 95% CI 0.72 to 2.22, very low quality evidence). Clozapine plus amisulpride versus clozapine plus quetiapine One study showed a significant benefit of amisulpride over quetiapine in the short term, for both change in global state (Clinical Global Impression (CGI): 1 RCT, n = 50, MD -0.90, 95% CI -1.38 to -0.42, very low quality evidence) and mental state (Brief Psychiatric Rating Scale (BPRS): 1 RCT, n = 50, MD -4.00, 95% CI -5.86 to -2.14, low quality evidence). Similar numbers of participants from each group left the study early (1 RCT, n = 56, RR 0.20, 95% CI 0.02 to 1.60, very low quality evidence) Clozapine plus risperidone versus clozapine plus sulpirideThere was no difference between risperidone and sulpiride for clinically significant response, defined by the study as 20% to 50% reduction in Positive and Negative Syndrome Scale (PANSS) (1 RCT, n = 60, RR 0.82, 95% CI 0.40 to 1.68, very low quality evidence). There were similar equivocal results for weight gain (1 RCT, n = 60, RR 0.40, 95% CI 0.08 to 1.90, very low quality evidence) and mental state (PANSS total: 1 RCT, n = 60, MD -2.28, 95% CI -7.41 to 2.85, very low quality evidence). No-one left the study early. Clozapine plus risperidone versus clozapine plus ziprasidoneThere was no difference between risperidone and ziprasidone for clinically significant response (1 RCT, n = 24, RR 0.80, 95% CI 0.28 to 2.27, very low quality evidence), change in global state CGI-II score (1 RCT, n = 22, MD -0.30, 95% CI -0.82 to 0.22, very low quality evidence), change in PANSS total score (1 RCT, n = 16, MD 1.00, 95% CI -7.91 to 9.91, very low quality evidence) or leaving the study early (1 RCT, n = 24, RR 1.60, 95% CI 0.73 to 3.49, very low quality evidence). Clozapine plus ziprasidone versus clozapine plus quetiapineOne study found, in the medium term, a superior effect for ziprasidone combination compared with quetiapine combination for clinically significant response in mental state (> 50% reduction PANSS: 1 RCT, n = 63, RR 0.54, 95% CI 0.35 to 0.81, low quality evidence), global state (CGI - Severity score: 1 RCT, n = 60, MD -0.70, 95% CI -1.18 to -0.22, low quality evidence) and mental state (PANSS total score: 1 RCT, n = 60, MD -12.30, 95% CI -22.43 to -2.17, low quality evidence). There was no effect for leaving the study early (1 RCT, n = 63, RR 0.52, CI 0.05 to 5.41, very low quality evidence).

AUTHORS' CONCLUSIONS

The reliability of results from this review is limited, evidence is of low or very low quality. Furthermore, due to the limited number of included studies, we were unable to undertake formal meta-analyses. As a consequence, any conclusions drawn from these findings are based on single, small-sized RCTs with high risk of type II error. Properly conducted and adequately powered RCTs are required. Future trialists should seek to measure patient-important outcomes such as quality of life, as well as clinical response and adverse effects.

Reintroduction of Clozapine After Perforation of the Large Intestine—A Case Report and Review of the Literature

OBJECTIVE

To report on a patient who was successfully rechallenged with clozapine after perforation of the large intestine and pulmonary embolism postoperatively, and provide a literature review on clozapine rechallenge.

CASE SUMMARY

A 46-year-old Japanese man with treatment-resistant schizophrenia developed constipation and slight abdominal discomfort while taking clozapine 275 mg/day. He developed appendicitis, leading to perforation of the large intestine. During the postsurgery period, a partial embolism of the pulmonary artery was revealed. The patient's constipation was relieved when clozapine was discontinued, but other antipsychotics failed to control his delusions well. After thorough discussion, it was decided to rechallenge with clozapine. The low dose of clozapine 200 mg/day was tolerable for his delusion, and his constipation was managed with laxatives and exercises until 8 months after the accident.

DISCUSSION

Clozapine is a gold standard medication in treatment-resistant schizophrenia but is associated with various adverse effects, some of which are life-threatening. Reintroduction of clozapine after severe adverse drug effects when other medications are not effective almost always poses a clinical dilemma for mental health professionals. A PubMed search (to January 25, 2013) using the key words clozapine and rechallenge found 50 articles. There were only sporadic positive case reports regarding the rechallenge after clozapine-related serious gastrointestinal problems.

CONCLUSIONS

From the currently available evidence, most psychiatrists appear to avoid reintroduction of clozapine. However, the evidence is too weak to draw a definitive conclusion about reintroduction of this drug. Reintroduction of clozapine after initial adverse effects in patients with treatment-resistant schizophrenia may warrant case-by-case judgment, but needs to be further investigated.

Antipsychotic polypharmacy in psychotic disorders: a critical review of neurobiology, efficacy, tolerability and cost effectiveness

OBJECTIVE

The purpose of this study was to review the scientific evidence for neurobiological rationale, efficacy, tolerability and cost effectiveness of antipsychotic polypharmacy (APP).

DATA SOURCES

A systematic literature search of Medline, Embase, Ovid and the Cochrane Database of Systematic Reviews until April 2012 was carried out.

RESULTS

Theories behind APP have only modest pre-clinical and clinical evidence. We found limited statistical evidence supporting modest efficacy of APP in patients with psychotic symptoms refractory to clozapine. APP is associated with increased mortality, metabolic syndrome, decreased cognitive functioning, high dose prescription and non-adherence. It brings up extra costs, lacking evidence for cost-effectiveness.

CONCLUSIONS

Pre-clinical studies underpinning neurobiological hypotheses in APP are lacking. Evidence supporting efficacy of APP is limited with modest beneficial clinical relevance. APP is associated with several serious adverse effects and increased health costs. In the absence of more convincing pre-clinical support and clinical evidence we advise adherence to existing guidelines and limiting combinations of antipsychotics (in consideration with other pharmacotherapeutic, somatic and psychotherapeutic options) to patients with clozapine-refractory psychosis in well-evaluated individual trials that might need 10 weeks or more.

A quantitative review of the profile and time course of symptom change in schizophrenia treated with clozapine

Contemporary analyses demonstrate an early response to antipsychotic treatment in non-refractory schizophrenia. The profile of response to clozapine is unknown. We used meta-analytic and statistical procedures to examine the response profile to clozapine. We identified 19 unique, randomized, double-blind controlled clinical trials with suitable time course data, representing 1745 subjects. Individual subject data were available for 419 subjects, obtained from two industry-sponsored trials. Symptom severity scores from the BPRS or the PANSS were entered into regression analyses to estimate linear and quadratic coefficients of the rate of change of symptom severity over 4 weeks. Both linear and quadratic regression coefficients for clozapine, and for comparator antipsychotics differed significantly from zero (p ≤ 0.001), indicating early response profiles. Compared with other antipsychotic arms, for clozapine the treatment response was greater (d = -0.578, p = 0.021), and the linear coefficient was steeper (d = -0.502, p = 0.042); the quadratic coefficients indicating attenuation did not differ. Analyses of 6-week data and individual subject data from non-refractory and refractory trials were consistent with the primary findings. Somewhat surprisingly, clozapine shows an early response profile, similar in pattern but somewhat larger in magnitude than other antipsychotic drugs.

World Federation of Societies of Biological Psychiatry (WFSBP) Guidelines for Biological Treatment of Schizophrenia, part 1: update 2012 on the acute treatment of schizophrenia and the management of treatment resistance

These updated guidelines are based on a first edition of the World Federation of Societies of Biological Psychiatry Guidelines for Biological Treatment of Schizophrenia published in 2005. For this 2012 revision, all available publications pertaining to the biological treatment of schizophrenia were reviewed systematically to allow for an evidence-based update. These guidelines provide evidence-based practice recommendations that are clinically and scientifically meaningful and these guidelines are intended to be used by all physicians diagnosing and treating people suffering from schizophrenia. Based on the first version of these guidelines, a systematic review of the MEDLINE/PUBMED database and the Cochrane Library, in addition to data extraction from national treatment guidelines, has been performed for this update. The identified literature was evaluated with respect to the strength of evidence for its efficacy and then categorised into six levels of evidence (A-F; Bandelow et al. 2008b, World J Biol Psychiatry 9:242). This first part of the updated guidelines covers the general descriptions of antipsychotics and their side effects, the biological treatment of acute schizophrenia and the management of treatment-resistant schizophrenia.

Clozapine resistance: augmentation strategies

BACKGROUND

Clozapine (CLZ) is not effective in more than 50% of treatment-resistant schizophrenic patients. In these cases, several pharmacological strategies are used in clinical practice, with different levels of evidence for both safety and efficacy.

OBJECTIVES

In the present paper we critically reviewed literature data regarding the efficacy and safety of adjunctive agents in CLZ-resistant schizophrenics. The following classes of agents were considered: 1) antipsychotics, 2) antidepressants, 3) mood stabilizers, 4) other agents (e.g. fatty acid supplement and glutamatergic agents), 5) electroconvulsive therapy (ECT). For lamotrigine and risperidone sufficient data were available to perform a meta-analysis.

METHODS

A Medline literature search covering a 20-year period was performed. For the meta-analysis, data were entered and analyzed with the Cochrane Collaboration Review Manager Software (RevMan version 5).

RESULTS

62 pertinent studies were identified, including 1556 schizophrenic or schizoaffective patients. Among treatments investigated, there is evidence for CLZ augmentation with 1) amisulpride and aripiprazole, 2) mirtazapine and 3) ethyl eicosapentaenoic acid (E-EPA). Although promising, ECT augmentation needs further validation. The meta-analyses did not support either the use of risperidone or lamotrigine as CLZ adjunct.

CONCLUSION

Overall, there is scarce evidence of efficacy and safety as regards adjunctive strategies for CLZ-resistant patients. However, several limitations do not allow to draw any definitive conclusion; among these we underline the small sample size of clinical trials, the variable definitions of CLZ resistance, the heterogeneity of outcome measures and methodological designs.

Augmentation of clozapine with a second antipsychotic - a meta-analysis

OBJECTIVE

To examine using meta-analysis the effect of adding a second antipsychotic to established clozapine monotherapy.

METHOD

A literature search was conducted in April 2011, and randomised placebo-controlled double-blind studies were identified. We performed a meta-analysis of efficacy (as standardised mean difference) and tolerability (withdrawals from trials) and a regression analysis of duration of study versus effect size. We also examined publication bias using funnel-plot analysis.

RESULTS

Overall, 14 studies were included (734 subjects). Individual study numbers ranged from 10 to 207 (mean 52.6, median 40). Augmentation of clozapine with a second antipsychotic conferred a small benefit over placebo (effect size -0.239 (95% CI: -0.452, -0.026); P = 0.028). Meta-regression of the effect of length of treatment on effect size showed no relationship (P = 0.254). The risk of discontinuing antipsychotic augmentation was no greater than the risk of discontinuing placebo (RR = 1.20, 95% CI 0.80-1.82). There was no evidence of publication bias.

CONCLUSION

Augmentation with a second antipsychotic is modestly beneficial in patients not responding fully to clozapine. Tolerability seems not to be adversely affected, at least in the short term. Longer studies do not appear to increase the probability of showing positive effects for augmentation.

Pimozide augmentation of clozapine inpatients with schizophrenia and schizoaffective disorder unresponsive to clozapine monotherapy

Despite its superior efficacy, clozapine is helpful in only a subset of patients with schizophrenia unresponsive to other antipsychotics. This lack of complete success has prompted the frequent use of various clozapine combination strategies despite a paucity of evidence from randomized controlled trials supporting their efficacy. Pimozide, a diphenylbutylpiperidine, possesses pharmacological and clinical properties distinct from other typical antipsychotics. An open-label trial of pimozide adjunctive treatment to clozapine provided promising pilot data in support of a larger controlled trial. Therefore, we conducted a double-blind, placebo-controlled, parallel-designed 12-week trial of pimozide adjunctive treatment added to ongoing optimal clozapine treatment in 53 patients with schizophrenia and schizoaffective disorder partially or completely unresponsive to clozapine monotherapy. An average dose of 6.48 mg/day of pimozide was found to be no better than placebo in combination with clozapine at reducing Positive and Negative Syndrome Scale total, positive, negative, and general psychopathology scores. There is no suggestion from this rigorously conducted trial to suggest that pimozide is an effective augmenting agent if an optimal clozapine trial is ineffective. However, given the lack of evidence to guide clinicians and patients when clozapine does not work well, more controlled trials of innovative strategies are warranted.

Prevalence and severity of antipsychotic related constipation in patients with schizophrenia: a retrospective descriptive study

Background

Antipsychotic are the cornerstone in the treatment of schizophrenia. They also have a number of side-effects. Constipation is thought to be common, and a potential serious side-effect, which has received little attention in recent literature.

Method

We performed a retrospective study in consecutively admitted patients, between 2007 and 2009 and treated with antipsychotic medication, linking different electronic patient data to evaluate the prevalence and severity of constipation in patients with schizophrenia under routine treatment conditions.

Results

Over a period of 22 months 36.3% of patients (99) received at least once a pharmacological treatment for constipation. On average medication for constipation was prescribed for 273 days. Severe cases (N = 50), non-responsive to initial treatment, got a plain x-ray of the abdomen. In 68.4% fecal impaction was found.

Conclusion

A high prevalence of constipation, often severe and needing medical interventions, was confirmed during the study period. Early detection, monitoring over treatment and early intervention of constipation could prevent serious consequences such as ileus.

Explicit versus implicit review to explore combination antipsychotic prescribing

OBJECTIVE

To use structured implicit review following large-scale explicit audit of antipsychotic polyprescribing to: (1) determine the true rate of antipsychotic polytherapy that deviated from best practice for schizophrenia treatment; and (2) assess whether explicit antipsychotic polytherapy criterion was appropriate for identifying patients at risk for medication problems and assessing quality of care.

METHODS

Antipsychotic prescribing was reviewed for outpatients in four public health services in Auckland, New Zealand on 31 October 2004 (T1). Schizophrenia patients in one service (n = 794) prescribed antipsychotic polytherapy (n = 84, 10.6%) were followed up 10 months later (T2). Historical medication summaries were prepared for those remaining on polytherapy, including diagnosis, clinical problems and treatment plan. Criteria for structured implicit review and rating form for quality of antipsychotic management were piloted. All medication summaries were independently rated by two reviewers, and a third independent rater reviewed summaries where disagreement was found.

RESULTS

Forty-nine patients remained on long-term polytherapy at T2 (6.2% of original population). All but two cases included a second-generation antipsychotic. At T2, average polytherapy duration was 35.8 months, and average antipsychotic dose was 699 mg day(-1) chlorpromazine equivalents. Two raters achieved agreement for 24/49 summaries, and the remaining 25 were rated independently by a third reviewer. Consensus agreement of antipsychotic management (by two raters) was reached for 44/49 cases (89.8%). Polytherapy was rated 'well-justified' in 32.7%, 'some justification' in 10.2% and 'lacked justification' in 46.9% cases. The final rate of polytherapy deviating from best practice reduced from 10.6% to 3.5% when short-term polytherapy was excluded, and details of the clinical situation and care plan were included in implicit review.

CONCLUSIONS

Audit of prescribing in routine practice using explicit guideline-based criteria may be a useful baseline performance indicator. It does not provide an accurate measurement of quality of care because it overestimates the deviation rate from good practice. It may also identify complex patients at risk for poor treatment outcomes who may benefit from structured treatment review.

Morning pseudoneutropenia during clozapine treatment

Clozapine, an atypical antipsychotic drug, is associated with a high risk of neutropenia and agranulocytosis, necessitating the immediate discontinuation of the drug. We report the case of a patient who developed clozapine-induced neutropenia. Assessments revealed a pronounced diurnal variation in the number of circulating neutrophils (1200-1900/mm(3) in the morning and 2200-2700/mm(3) in the afternoon). Due to these circadian changes, we decided to continue clozapine treatment.

Augmentation of clozapine with a second antipsychotic--a meta-analysis of randomized, placebo-controlled studies

OBJECTIVE

Inadequate response to clozapine treatment is frequently encountered in practice and augmentation strategies have been developed in an attempt to improve response. Aims of the study were to evaluate the therapeutic effect of adding an antipsychotic drug to clozapine treatment.

METHOD

Meta-analysis of randomized, placebo-controlled studies of antipsychotic augmentation of clozapine treatment.

RESULTS

Ten studies (including 522 subjects) met inclusion criteria. Antipsychotic augmentation showed significant benefit over the addition of placebo on only one outcome measure examined [mean effect size for rating scale score (BPRS/PANSS) -0.180, 95% CI -0.356 to -0.004]. Antipsychotic augmentation showed no advantage on withdrawals from trials (risk ratio 1.261, 95% CI 0.679-2.345) or on CGI scores (effect size -0.661, 95% CI -1.475 to 0.151). Duration of study was not associated with outcome (P = 0.95). There was no evidence of publication bias.

CONCLUSION

In studies lasting up to 16 weeks, the addition of an antipsychotic to clozapine treatment has marginal therapeutic benefit. Longer and larger trials are necessary to demonstrate the precise therapeutic utility of antipsychotic co-therapy with clozapine.

Antipsychotic combinations vs monotherapy in schizophrenia: a meta-analysis of randomized controlled trials

CONTEXT

Despite lacking evidence for its safety and efficacy, antipsychotic cotreatment is common in schizophrenia.

OBJECTIVE

To evaluate therapeutic and adverse effects of antipsychotic cotreatment vs monotherapy in schizophrenia.

DATA SOURCES

Cochrane Schizophrenia Group register and hand searches of relevant journals/conference proceedings.

STUDY SELECTION

Randomized controlled trials comparing antipsychotic monotherapy to cotreatment with a second antipsychotic.

DATA EXTRACTION AND ANALYSIS

Two authors independently extracted data. For homogenous dichotomous data, we calculated random effects, relative risk (RR), 95% confidence intervals (CIs), and numbers needed to treat (NNT). For continuous data, weighted mean differences were calculated.

RESULTS

In 19 studies (1229 patients) with 28 monotherapy and 19 cotreatment arms, antipsychotic cotreatment was superior to monotherapy regarding 2 a priori defined coprimary outcomes: less study-specific defined inefficacy (N = 22, n = 1202, RR = 0.76, CI = 0.63-0.90, P = .002, NNT = 7, CI = 4-17, P = .0008, I(2) = 78.9%) and all-cause discontinuation (N = 20, n = 1052, RR = 0.65, CI = 0.54-0.78, P < .00001). Results were consistent using Clinical Global Impressions thresholds of less than much (P = .006) and less than minimally (P = .01) improved. Specific psychopathology and adverse event data were insufficient to yield meaningful results. In sensitivity analyses, 5 efficacy moderators emerged: concurrent polypharmacy initiation, clozapine combinations, trial duration >10 weeks, Chinese trials, and second-generation + first-generation antipsychotics. In a meta-regression, similar dose combinations, second-generation + first-generation antipsychotics and concurrent polypharmacy initiation remained significant.

CONCLUSIONS

In certain clinical situations, antipsychotic cotreatment may be superior to monotherapy. However, the database is subject to possible publication bias and too heterogeneous to derive firm clinical recommendations, underscoring the need for future research.

Clozapine versus typical neuroleptic medication for schizophrenia

BACKGROUND

Long-term drug treatment of schizophrenia with typical antipsychotics has limitations: 25 to 33% of patients have illnesses that are treatment-resistant. Clozapine is an antipsychotic drug, which is claimed to have superior efficacy and to cause fewer motor adverse effects than typical drugs for people with treatment-resistant illnesses. Clozapine carries a significant risk of serious blood disorders, which necessitates mandatory weekly blood monitoring at least during the first months of treatment.

OBJECTIVES

To evaluate the effects of clozapine compared with typical antipsychotic drugs in people with schizophrenia.

SEARCH STRATEGY

For the current update of this review (March 2006) we searched the Cochrane Schizophrenia Group Trials Register.

SELECTION CRITERIA

All relevant randomised clinical trials (RCTs).

DATA COLLECTION AND ANALYSIS

We extracted data independently. For dichotomous data we calculated relative risks (RR) and their 95% confidence intervals (CI) on an intention-to-treat basis, based on a fixed-effect model. We calculated numbers needed to treat/harm (NNT/NNH) where appropriate. For continuous data, we calculated weighted mean differences (WMD) again based on a fixed-effect model.

MAIN RESULTS

We have included 42 trials (3950 participants) in this review. Twenty-eight of the included studies are less than 13 weeks in duration, and, overall, trials were at significant risk of bias. We found no significant difference in the effects of clozapine and typical neuroleptic drugs for broad outcomes such as mortality, ability to work or suitability for discharge at the end of the study. Clinical improvements were seen more frequently in those taking clozapine (n=1119, 14 RCTs, RR 0.72 CI 0.7 to 0.8, NNT 6 CI 5 to 8). Also, participants given clozapine had fewer relapses than those on typical antipsychotic drugs (n=1303, RR 0.62 CI 0.5 to 0.8, NNT 21 CI 15 to 49). BPRS scores showed a greater reduction of symptoms in clozapine-treated patients, (n=1145, 16 RCTs, WMD -4.22 CI -5.4 to -3.1), although the data were heterogeneous (Chi(2) 0.0001, I(2) 66%). Short-term data from the SANS negative symptom scores favoured clozapine (n=196, 5 RCTs, WMD -5.92 CI -7.8 to -4.1). We found clozapine to be more acceptable in long-term treatment than conventional antipsychotic drugs (n=982, 16 RCTs, RR 0.60 CI 0.5 to 0.7, NNT 15 CI 12 to 20). Blood problems occurred more frequently in participants receiving clozapine (3.2%) compared with those given typical antipsychotics (0%) (n=1031, 13 RCTs, RR 7.09 CI 2.0 to 25.6). Clozapine participants experienced more drowsiness, hypersalivation, or temperature increase, than those given conventional neuroleptics. However, clozapine patients experienced fewer motor adverse effects (n=1433, 18 RCTs, RR 0.58 CI 0.5 to 0.7, NNT 5 CI 4 to 6).The clinical effects of clozapine were more pronounced in participants resistant to typical neuroleptics in terms of clinical improvement (n=370, 4 RCTs, RR 0.71 CI 0.6 to 0.8, NNT 4 CI 3 to 6) and symptom reduction. Thirty-four per cent of treatment-resistant participants had a clinical improvement with clozapine treatment.

AUTHORS' CONCLUSIONS

Clozapine may be more effective in reducing symptoms of schizophrenia, producing clinically meaningful improvements and postponing relapse, than typical antipsychotic drugs - but data are weak and prone to bias. Participants were more satisfied with clozapine treatment than with typical neuroleptic treatment. The clinical effect of clozapine, however, is, at least in the short term, not reflected in measures of global functioning such as ability to leave the hospital and maintain an occupation. The short-term benefits of clozapine have to be weighed against the risk of adverse effects. Within the context of trials, the potentially dangerous white blood cell decline seems to be more frequent in children and adolescents and in the elderly than in young adults or people of middle-age.The existing trials have largely neglected to assess the views of participants and their families on clozapine. More community-based long-term randomised trials are needed to evaluate the efficacy of clozapine on global and social functioning as trials in special groups such as people with learning disabilities.

Effectiveness of antipsychotic polypharmacy for patients with treatment refractory schizophrenia: an open-label trial of olanzapine plus risperidone for those who failed to respond to a sequential treatment with olanzapine, quetiapine and risperidone

OBJECTIVE

To evaluate the effectiveness of antipsychotic polypharmacy in a methodologically sound manner.

METHODS

In this open-label study, 17 patients with treatment-refractory schizophrenia, who failed to respond to a sequential monotherapy with olanzapine, quetiapine and risperidone, were subsequently treated with a combination therapy with olanzapine plus risperidone for at least 8 weeks.

RESULTS

Seven responded according to the primary endpoint defined as the post-treatment Brief Psychiatric Rating Scale being less than 70% of the pretreatment values, and they were classified as such an average of 10 weeks after the initiation of polypharmacy. Two of them were successful in a later conversion to monotherapy. None dropped out prematurely. Four (out of 13 inpatients) got better enough to be discharged from the hospital, while six patients did not show any response. The Global Assessment of Functioning score improved from 37.1 to 53.0 in responders (mean maximum dose: olanzapine 12.9 mg; risperidone 3.14 mg), while it showed non-significant changes among others (mean maximum dose: olanzapine 14.5 mg; risperidone 5.50 mg). Body weight, prolactin, and total cholesterol increased significantly.

CONCLUSIONS

Antipsychotic polypharmacy might be sometimes helpful for difficult populations but at the cost of adverse effects. More studies of antipsychotic combination therapy versus clozapine, augmentation strategies or tenacious longer- term monotherapy are warranted for refractory schizophrenia.

Adding or switching antipsychotic medications in treatment-refractory schizophrenia

OBJECTIVE

This study compared patients with schizophrenia whose antipsychotic medications were switched to manage treatment-resistant positive psychotic symptoms with those for whom another antipsychotic was added. Psychiatrists' characteristics and perceptions of effectiveness of the medication change on clinical outcomes were also reported.

METHODS

Psychiatrists participating in a nationally representative mailed survey (N=209) reported on the clinical features, management, and response to the change in antipsychotic medication (added versus switched) of one adult patient with treatment-refractory schizophrenia under their care for at least one year.

RESULTS

Thirty-three percent of patients were treated with an added antipsychotic medication. Compared with patients whose antipsychotic medications were switched, those with an added antipsychotic medication were more likely to be female, to have received care from the same psychiatrist for more than two years, and to have been recently prescribed an antidepressant. Compared with psychiatrists who switched antipsychotic prescriptions, those who added an antipsychotic reported that the change was less likely to reduce positive symptoms, improve functioning, and prevent hospitalization. Psychiatrists who added rather than switched antipsychotics reported more frequent attendance at educational programs sponsored by a pharmaceutical company.

CONCLUSIONS

Consistent with other lines of research and practice guideline recommendations, psychiatrists perceive antipsychotic polypharmacy to be a generally ineffective strategy for treatment-resistant positive psychotic symptoms. In light of these findings, efforts to identify and implement more effective evidence-based pharmacologic approaches should be undertaken.

Adding or switching antipsychotic medications in treatment-refractory schizophrenia

OBJECTIVE

This study compared patients with schizophrenia whose antipsychotic medications were switched to manage treatment-resistant positive psychotic symptoms with those for whom another antipsychotic was added. Psychiatrists' characteristics and perceptions of effectiveness of the medication change on clinical outcomes were also reported.

METHODS

Psychiatrists participating in a nationally representative mailed survey (N=209) reported on the clinical features, management, and response to the change in antipsychotic medication (added versus switched) of one adult patient with treatment-refractory schizophrenia under their care for at least one year.

RESULTS

Thirty-three percent of patients were treated with an added antipsychotic medication. Compared with patients whose antipsychotic medications were switched, those with an added antipsychotic medication were more likely to be female, to have received care from the same psychiatrist for more than two years, and to have been recently prescribed an antidepressant. Compared with psychiatrists who switched antipsychotic prescriptions, those who added an antipsychotic reported that the change was less likely to reduce positive symptoms, improve functioning, and prevent hospitalization. Psychiatrists who added rather than switched antipsychotics reported more frequent attendance at educational programs sponsored by a pharmaceutical company.

CONCLUSIONS

Consistent with other lines of research and practice guideline recommendations, psychiatrists perceive antipsychotic polypharmacy to be a generally ineffective strategy for treatment-resistant positive psychotic symptoms. In light of these findings, efforts to identify and implement more effective evidence-based pharmacologic approaches should be undertaken.

Long-term antipsychotic polypharmacy in the VA health system: patient characteristics and treatment patterns

OBJECTIVE

Although antipsychotic polypharmacy is being prescribed with increasing frequency, few studies have described patient characteristics and treatment patterns associated with long-term use of this treatment strategy.

METHODS

By using data from the National Psychosis Registry of the Department of Veterans Affairs, 5,826 patients with schizophrenia or schizoaffective disorder who received long-term antipsychotic polypharmacy (simultaneous treatment with two or more antipsychotics for 90 or more days) during fiscal year 2000 and 39,745 patients who received long-term antipsychotic monotherapy were identified. By using multivariate regression models, patient demographic and clinical characteristics, antipsychotic dosages, and use of antiparkinson and adjunctive psychotropic medications were compared between the two groups.

RESULTS

Patients were more likely to receive antipsychotic polypharmacy if they were younger, were unmarried, had a military service-connected disability, had schizophrenia rather than schizoaffective disorder, or had greater use of inpatient and outpatient mental health services. Patients were less likely to receive antipsychotic polypharmacy if they were African American, had concurrent diagnoses of depression or substance use disorder, or had greater medical comorbidity. For most antipsychotics, dosages prescribed for patients receiving polypharmacy were the same or modestly higher than those prescribed for patients receiving monotherapy. Patients given prescriptions for polypharmacy were more likely to receive antiparkinson medications, antianxiety agents, and mood stabilizers and equally likely to receive concurrent treatment with antidepressants.

CONCLUSIONS

Long-term antipsychotic polypharmacy appears to be reserved for more severely ill patients with psychotic symptoms rather than mood symptoms. These patients may experience increased adverse effects as a result of excess antipsychotic exposure.

Augmentation with a second antipsychotic in patients with schizophrenia who partially respond to clozapine: a meta-analysis

OBJECTIVES

To conduct a meta-analysis of randomized placebo-controlled trials (RCTs) of clozapine augmentation with another antipsychotic drug in patient with schizophrenia who partially respond to clozapine and compare the results with the findings of relevant open studies.

METHODS

A systematic literature search was conducted to identify eligible RCTs. All baseline, posttreatment, and change scores in these trials were included in the meta-analysis. For change in Brief Psychiatric Rating Scale/Positive and Negative Syndrome Scale total scores, the effect size was calculated, and for the proportion of patients with a reduction in Brief Psychiatric Rating Scale/Positive and Negative Syndrome Scale scores of 20% or more, the relative risk was calculated.

RESULTS

There was a total of 166 participants in the 4 eligible RCTs. Pooling effect sizes across these studies revealed clinically important heterogeneity (I = 63.5%). Analyzing by duration accounted for the heterogeneity (I = 0%), whereas analyzing by drug did not (I = 57.5%). The 2 RCTs lasting 10 weeks or more gave an odds ratio of response to treatment of 4.41 (95% confidence interval, 1.38 to 14.07). In 8 open studies identified, the same pattern of response was seen. The main treatment-emergent side effects reported were extrapyramidal side effects and raised serum prolactin.

CONCLUSIONS

Augmentation of clozapine with another antipsychotic drug in patients with schizophrenic illness that has partially responded to clozapine is worthy of an individual clinical trial. This trial may need to be longer than the 4 to 6 weeks usually recommended for acute antipsychotic monotherapy.

A study of polypharmacy with second generation antipsychotics in patients with severe and persistent mental illness

BACKGROUND

There is a paucity of empirical support for polypharmacy with second generation (atypical) antipsychotics (SGAs), especially in understudied populations.

OBJECTIVE

To investigate the frequency, effectiveness, and safety of this practice in patients with severe and persistent mental illness who are chronically hospitalized.

METHODS

A chart review was conducted at a state psychiatric hospital in Syracuse, NY. The study subjects (N=26) were chronically hospitalized individuals with DSM-IV diagnoses of schizophrenia or schizoaffective disorder who were initially prescribed at least one SGA and then received at least one other SGA during the study period. Demographic and clinical data were collected. Baseline and 6-month assessments were compared for statistical significance (p<0.05).

RESULTS

Of the 117 chronically hospitalized inpatients at the study center, 22.2% (N=26) received treatment regimens involving polypharmacy with SGAs. These patients as a group achieved statistically significant reductions on their scores on the Brief Psychiatric Rating Scale (34.2 +/- 11.0 compared with 25.3 +/- 11.8; p=0.016) and the Clinical Global Impressions-Improvement Scale (5.5 +/- 0.6 compared with. 5.0 +/- 0.8; p=0.016) at 6 months. There was a significant decrease in the use of prn medications (7.6 +/- 19.6 compared with 1.6 +/- 2.6; p<0.04). However, the number of patients receiving anticholinergic medications increased from 5 to 8 (p<0.04).

CONCLUSIONS

Polypharmacy with SGAs is quite frequent among chronic inpatients with severe and persistent mental illness despite a limited empirical database supporting its use. The results of our pilot study do not demonstrate the effectiveness and safety of this practice. However, methodological shortcomings may have contributed to our failure to detect a true, positive effect. Controlled studies are needed to accurately determine the risks and benefits of SGA polypharmacy.

Adjunctive Treatment With Risperidone in Clozapine-Resistant Schizophrenia

OBJECTIVES

Long-term studies show that 47% to 63% of schizophrenic patients treated with clozapine fail to respond after 12 years of treatment. Such high rates of resistance justify the growing interest in therapeutic strategies based on enhancing the effect of clozapine with other antipsychotics. The combination of clozapine and risperidone in the treatment of partial responders to clozapine has been one of those receiving most interest from research.

METHODS AND RESULTS

The present work reports the case of a 26-year-old man, diagnosed with schizophrenia who, after treatment with clozapine at appropriate doses over 12 weeks without observable response, showed a marked and sustained improvement after the addition of risperidone to the clozapine treatment. We also present a detailed review of publications related to the therapeutic combination of clozapine and risperidone in clozapine-resistant schizophrenia.

CONCLUSIONS

Despite the contradictory nature of the published data, our results are in support of other work reporting that treatment with a combination of clozapine and risperidone, apart from being well tolerated, may constitute an effective alternative in this type of patient. Nevertheless, there is a need for further, controlled studies, with larger samples, with a view to drawing definitive conclusions and making specific recommendations.

Clinical correlates of clozapine prescription for schizophrenia in China

AIMS

Few studies have investigated the prescription patterns of clozapine in outpatients with schizophrenia in China. It is an important issue due to clozapine's high efficacy and potentially fatal side effect profile. This study examined the use of clozapine and its correlates in China.

METHODS

Three hundred ninety-eight clinically stable outpatients with schizophrenia were randomly selected and interviewed in Hong Kong (HK) and Beijing (BJ). Assessment instruments included the Structured Clinical Interview for DSM-IV, Brief Psychiatric Rating Scale, Simpson and Angus Scale of Extrapyramidal Symptoms, Barnes Akathisia Rating Scale and the Hong Kong and Mainland China World Health Organization Quality of Life Schedule-Brief version. Assessments were performed by the same investigator in both sites.

RESULTS

Clozapine was prescribed to 15.6% of (n = 62) patients. There was a wide inter-site variation between HK and BJ. Use of clozapine was associated with age, age at onset, extrapyramidal side effects (EPS), having health insurance, use of depot and typical antipsychotic and anticholinergic drugs and benzodiazepines as well as history of suicidal attempts. On multiple logistic regression analysis, the number of hospitalizations, site (HK vs. BJ), use of typical antipsychotics, polypharmacy and co-prescription with anticholinergics were significantly associated with the prescription of clozapine. No significant differences were found between the clozapine and non-clozapine groups with regard to any of the quality of life domains.

CONCLUSION

A combination of economical and clinical factors, health policies and the characteristics of the treatment settings plays important roles in determining clozapine use. Clozapine appears to have little significant influence on quality of life in clinical stable Chinese patients with schizophrenia.

Antipsychotic drug use in 503 Chinese inpatients with schizophrenia

Objective. To determine current patterns of antipsychotic medication use and metabolic complications among hospitalized Chinese patients with schizophrenia. Method. A total of 503 inpatients who met ICD-10 diagnostic criteria for schizophrenia were enrolled. Demographic features and records of current treatment (medication, dose, duration of treatment) were collected through cross-sectional chart review along with biophysical parameters (body mass index and laboratory findings). Results. (1) Most patients (457/503, 90.9%) were found to receive antipsychotic monotherapy; (2) clozapine was the most common medication used (152/507, 30.2%); (3) the subset of patients treated within the course of a first episode psychosis, or with less than 5 years of illness, were more likely to be treated with second-generation antipsychotics (SGAs) than with conventional antipsychotic medications or clozapine; (4) patients treated with clozapine or conventional antipsychotics were more likely to manifest metabolism-related physical conditions than those receiving SGAs. Conclusion. Conventional antipsychotics and clozapine constitute the current mainstream of schizophrenia treatment in China where a lower percentage of patients receive SGAs other than clozapine than in developed countries. The high incidence of treatment-related metabolic complications in this population suggests that these issues are under-appreciated based on current patterns of medication use.

Long-term patient monitoring for clozapine-induced agranulocytosis and neutropenia in Korea: when is it safe to discontinue CPMS?

OBJECTIVES

This study documents the incidences of agranulocytosis and neutropenia, and the patterns of incidence of the side effects of long-term clozapine treatment in order to determine an appropriate time to stop the Clozaril Patient Monitoring System (CPMS).

METHODS

Hematological, demographic, and other data from the CPMS for 6782 patients who took clozapine for the past 11 years in the Republic of Korea has been analyzed.

RESULTS

Twenty-nine (53.7%) of fifty-four agranulocytosis cases occurred within the first 18 weeks. The cumulative incidence of agranulocytosis was 1.64% between 6 and 11 years and the crude incidence was 0.8%. Neutropenia occurred in 697 patients, and 365 (52.4%) of these cases occurred within the first 18 weeks. The cumulative incidence of neutropenia was 19.8% between 8 and 11 years, and the crude incidence was 10.3%. There were no cases of agranulocytosis or neutropenia after the 9th year of clozapine treatment.

CONCLUSIONS

The incidence of agranulocytosis in the Republic of Korea was similar to those in the rest of the world. While agranulocytosis began several years after clozapine treatment, long-term monitoring of white blood cells is necessary. We suggest that the CPMS should be stopped or less frequently after the 9th year of treatment.

Augmentation strategies of clozapine with antipsychotics in the treatment of ultraresistant schizophrenia

BACKGROUND

Approximately 40% to 70% of neuroleptic-resistant schizophrenic patients are nonresponders to clozapine. Several clozapine augmentation strategies have come into clinical practice although often without evidence-based support. Among these strategies, the combined use of clozapine with another antipsychotic has been reported for up to 35% of patients receiving clozapine.

OBJECTIVE

The purposes of the present work were to (1) review the available literature on the efficacy and safety of the clozapine augmentation with another antipsychotic using a MEDLINE search of the literature from 1978 to December 2005 and (2) to propose an operational definition of schizophrenia refractory to clozapine ("ultraresistant schizophrenia") for the implementation and homogenization of future therapeutic trials.

CONCLUSION

Case controls and open clinical trials largely dominate the literature, and there are only 4 double-blind studies of clozapine augmentation with antipsychotics. The results of these studies are somewhat discrepant. Moreover, the heterogeneity of definitions of resistance to clozapine, of outcome measures and of dose and duration of pharmacological trials is a major limitation for drawing conclusions.

Long-term combination antipsychotic treatment in VA patients with schizophrenia

Treatment guidelines consider antipsychotic monotherapy the standard of care for patients with schizophrenia. However, previous studies have reported widely varying, and sometimes high, rates of antipsychotic polypharmacy. We identified 61,257 VA patients with schizophrenia in fiscal year 2000 who had >or=90 non-institutionalized days and one or more fills of antipsychotic medications. We used criteria of increasing stringency (>or=30, >or=60, or >or=90 overlapping days' supply of antipsychotic medications) and several cross-sectional criteria from previous studies to compare the prevalence of antipsychotic polypharmacy using these definitions. We also describe specific treatment combinations among patients receiving long-term polypharmacy. The prevalence of antipsychotic polypharmacy was 20.0%, 13.1%, and 9.5% when defined by a >or=30, >or=60, or >or=90-day overlap, respectively. Cross-sectional definitions used in previous studies did not identify 32-89% of patients receiving long-term polypharmacy (>or=90 days). In addition, approximately half of patients identified by cross-sectional criteria had only short-term overlaps of antipsychotic medications. Among patients receiving long-term polypharmacy, 74% received a first- and a second-generation agent, 18% received two second-generation agents, and 6% received two first-generation agents. Definitions of polypharmacy that rely on cross-sectional data or narrow observation periods do not accurately identify patients receiving long-term treatment; in this study, only 10% of patients with schizophrenia received combination treatments for >or=90 days. The most commonly used antipsychotic combinations have little support for safety or efficacy. Further research is needed to understand the impact of these treatments on symptoms, side effects, and costs.

Augmentation strategies in clozapine-resistant schizophrenia

The introduction of antipsychotics in the 1950s revolutionised the treatment of schizophrenia, but it soon became apparent that a substantial number of patients demonstrated a suboptimal response to these antipsychotics. Clozapine proved to be beneficial in patients whose symptoms were treatment resistant, but it too had limitations, with as many as 40-70% of those treated with clozapine demonstrating inadequate response to this drug as well. The availability of other 'atypical' antipsychotics offers options, but clozapine appears to remain the most effective option in treatment-resistant schizophrenia. This, of course, raises the question of what to do when clozapine is only partially effective. To address the issue of treatment in patients who have demonstrated a suboptimal response to clozapine, efforts have focused on a variety of augmentation strategies, including numerous medications and electroconvulsive therapy. The current body of evidence consists largely of data from smaller open trials and case series/reports, although data from a limited number of controlled studies are now available. Not surprisingly, the evidence drawn from the former is more supportive of augmentation strategies, although the controlled trials are not without positive findings. The available information is certainly not so overwhelming as to endorse any single augmentation approach. Indeed, it argues for more controlled data and cautions us regarding the cost-benefit ratio in adopting this strategy. Over and above the added adverse effects of another treatment, there is evidence to indicate that actual clinical worsening can occur. Without compelling evidence, clinicians must resort to guiding principles. The potential benefits of augmentation cannot be ruled out, but it should be approached with caution and in a systematic fashion. Factors compromising clozapine response should first be ruled out, and any augmentation trials should be guided by existing evidence and a treatment plan that incorporates a clear understanding of target symptoms. A means of evaluating outcome effectively needs to be in place, and the trial should be circumscribed to prevent needless polypharmacy. A priori, an endpoint needs to be established and the trial discontinued unless results firmly support added benefits.

Combination of Clozapine and Ziprasidone in Treatment-Resistant Schizophrenia

OBJECTIVES

Therapeutic options for patients with treatment-resistant schizophrenia are limited. In such patients, combined application of atypical antipsychotic drugs is an often-used strategy. The authors tested the hypothesis that the combination of ziprasidone and clozapine would lead to an improvement in this patient group.

METHODS

Nine patients with treatment-resistant schizophrenia participated in this open clinical trial and received a combination regimen of ziprasidone and clozapine. Patients had to have remained on a stable dose of clozapine for at least 6 months to ensure a reasonable opportunity to respond to clozapine monotherapy. Clinical status was evaluated at baseline, and at 3 and 6 months' follow-up using the Brief Psychiatric Rating Scale (BPRS).

RESULTS

All patients completed the 6-month combination treatment. The mental state of 7 patients (77.8%) was improved and there was a significant reduction in the mean BPRS score over the 6 months treatment. The coadministration of ziprasidone in clozapine-treated patients did not result in a corresponding increase in side effects. The combination allowed a 18% reduction of the daily clozapine dose.

CONCLUSION

The combined application of clozapine and ziprasidone follows a neurobiologic rationale and appears to be safe and well tolerated without increasing the risk of side effects.

Antipsychotic polypharmacy: is there evidence for its use?

Antipsychotic polypharmacy occurs frequently in clinical practice; however, there is a lack of controlled clinical studies testing the efficacy of the combinations used. The purpose of this literature review was to examine studies and other reports that have assessed the incremental benefits and deficits of combination antipsychotic therapy versus monotherapy. A PUBMED search covering a 26-year period from 1976 to 2002 was conducted. The search was limited to clinical trials, case series, and reports. Fifty-two reports were identified that systematically assessed the efficacy of combination therapy as opposed to monotherapy: 4 double-blind studies, 13 open-label clinical trials, and 35 case reports. Only one open-label trial and 2 case reports met the design criteria of having trials of each medication and the combination in the same patients and using some type of standardized assessment to evaluate outcome. The most frequent combination was clozapine-risperidone. Of the clinical trials, 75% (3/4) of the double-blind studies and 69% (9/13) of the open-label trials found that combination therapy was effective in reducing symptoms, while 37% (13/35) of case reports documented an overall positive outcome. Currently, the clinical practice of antipsychotic polypharmacy is not evidence-based; however, there is also no evidence against its use. Expanded systematic research to assess this clinical practice is needed.

Predictors and markers of clozapine response

RATIONALE

With other atypical antipsychotics now available, having predictors of clozapine response would be of considerable value, offering clinicians guidance in their decision as to when, and if, a trial of clozapine is warranted.

OBJECTIVES

The aim was to review existing evidence regarding identified predictors and markers of clozapine response.

METHODS

Relevant studies were identified through PUBMED searches (1975-June 2004) and cross-referencing of reviews and included studies. The data were summarized under two main categories: clinical (general, neurological, cognitive/neuropsychological, clozapine levels) and biological (biochemical, endocrine, genetic, metabolic, morphological, dopamine D2 receptor occupancy). 'Reliable' predictors/markers were defined a priori as those with support of at least two independent reports that addressed overall response, with no contradictory findings to date. 'Potential' predictors/markers had the support of a single report that addressed overall response and at least one other evaluating treatment outcome but not directly addressing response status.

RESULTS AND CONCLUSIONS

Higher baseline clinical symptoms and functioning in the previous years and low cerebrospinal homovanillic acid/5-hydroxyindoleacetic acid levels were identified as reliable. Three potential measures were identified: reduction of frontal cortex metabolic activity, reduction of caudate volume, and improvement in P50 sensory gating.

New generation antipsychotics versus low-potency conventional antipsychotics: a systematic review and meta-analysis

BACKGROUND

The clearest advantage of new generation, atypical antipsychotics is a reduced risk of extrapyramidal side-effects (EPS), compared with conventional compounds. These findings might have been biased by the use of the high-potency antipsychotic haloperidol as a comparator in most of the trials. We aimed to establish whether the new drugs induce fewer EPS than low-potency conventional antipsychotics.

METHODS

We did a meta-analysis of all randomised controlled trials in which new generation antipsychotics had been compared with low-potency (equivalent or less potent than chlorpromazine) conventional drugs. We included studies that met quality criteria A or B in the Cochrane Collaboration Handbook, and assessed quality with the Jadad scale. The primary outcome of interest was the number of patients who had at least one EPS. We used risk differences and 95% CIs as measures of effect size.

FINDINGS

We identified 31 studies with a total of 2320 participants. Of the new generation drugs, only clozapine was associated with significantly fewer EPS (RD=-0.15, 95% CI -0.26 to -0.4, p=0.008) and higher efficacy than low-potency conventional drugs. Reduced frequency of EPS seen with olanzapine was of borderline significance (-0.15, -0.31 to -0.01, p=0.07). Only one inconclusive trial of amisulpride, quetiapine, and risperidone and no investigations of ziprasidone and sertindole were identified, but some evidence indicates that zotepine and remoxipride do not lead to fewer EPS than low-potency antipsychotics. Mean doses less than 600 mg/day of chlorpromazine or its equivalent had no higher risk of EPS than new generation drugs. As a group, new generation drugs were moderately more efficacious than low-potency antipsychotics, largely irrespective of the comparator doses used.

INTERPRETATION

Optimum doses of low-potency conventional antipsychotics might not induce more EPS than new generation drugs. Potential advantages in efficacy of the new generation drugs should be a factor in clinical treatment decisions to use these rather than conventional drugs.

Antipsychotic combination therapy in schizophrenia. A review of efficacy and risks of current combinations

OBJECTIVE

To review the literature on efficacy and risks of combining antipsychotics (atypical with atypical or conventional) and suggest a rationale and strategies for future clinical trials.

METHOD

A computerized Medline search supplemented by an examination of cross-references and reviews was performed.

RESULTS

Empirical evidence for the efficacy of combining antipsychotics is too limited to draw firm conclusions. The practice of augmenting clozapine with more 'tightly bound' D2 receptor antagonists as exemplified by risperidone augmentation of clozapine has some empirical and theoretical support. The risks of augmentation strategies have not been studied systematically. No study has examined the economic impact of combination treatment.

CONCLUSION

Further trials of antipsychotic combination therapies are needed before this currently unsupported practice can be recommended. Rationales for combination treatment include a broadening of the range of receptor activity or an increase in D2 receptor occupancy with certain atypical agents. Trial methodology needs to take into account subject characteristics, duration of treatment, optimization of monotherapy comparators, and appropriate outcome measures.

Augmentation strategies in the treatment of schizophrenia

Use of augmenting agents in schizophrenia is a common practice in response to resistant symptoms or comorbid illness. Increasingly, clinicians are combining more than one antipsychotic agent, despite a lack of evidence from controlled studies to support this approach. A rationale can be made for adding higher-potency agents to clozapine in an attempt to optimize D2 dopamine receptor blockade, but this strategy requires further study before it should be adopted in clinical practice. Older reports have explored the use of antidepressants, mood stabilizers, and anxiolytics as augmenting agents. These agents appear to improve comorbid affective or anxiety symptoms, but earlier evidence of improvement in psychotic or negative symptoms has not been replicated consistently. Glutamatergic agents acting at the glycine coagonist site of the N-methyl-d-aspartate receptor, including glycine, d-cycloserine, and d-serine, have demonstrated impressive therapeutic effects for negative symptoms when added to conventional neuroleptic agents, but do not appear to enhance clozapine efficacy. Given the high rates of symptom persistence and disability associated with schizophrenia, the need for augmentation strategies is great, but no approach has clearly emerged as effective for a substantial portion of patients. Although certain approaches may prove helpful for individual patients, augmentation should not be used unless monotherapy has been optimized, and should not be continued long-term unless benefits are clear.

Clozapine versus typical neuroleptic medication for schizophrenia

BACKGROUND

Long-term drug treatment of schizophrenia with conventional antipsychotics has limitations: 25-33% of patients have illnesses that are treatment-resistant. Clozapine is an atypical antipsychotic drug, which is claimed to have superior efficacy and to cause fewer motor adverse effects than typical drugs for people with treatment-resistant illnesses. Clozapine carries a significant risk of serious blood disorders, which necessitates mandatory weekly blood monitoring at least during the first months of treatment.

OBJECTIVES

To evaluate the effects of clozapine for schizophrenia in comparison to typical antipsychotic drugs.

SEARCH STRATEGY

Publications in all languages were searched from the following databases: Biological Abstracts (1982-1999), The Cochrane Library CENTRAL (Issue 2, 1999), Cochrane Schizophrenia Group's Specialised Register (1999), EMbase (1980-1999), ISI Citation Index, LILACS (1982-1999), MEDLINE (1966-1999), and PsycLIT (1974-1999). Reference list screening of included papers was performed. Authors of recent trials and the manufacturer of clozapine contacted.

SELECTION CRITERIA

All randomised controlled trials comparing clozapine with typical antipsychotic drugs were included by independent assessment by at least two reviewers.

DATA COLLECTION AND ANALYSIS

Data were extracted independently by at least two reviewers. Authors of trials published since 1980 were contacted for additional and missing data. Odds ratios (OR) and 95% confidence intervals (CI) of homogeneous dichotomous data were calculated with the Peto method. A random effects model was used for heterogeneous dichotomous data. Where possible the numbers needed to treat (NNT) or needed to harm (NNH) were also calculated. Weighted or standardised means were calculated for continuous data.

MAIN RESULTS

Currently the review includes 31 studies, 26 of which are less than 13 weeks in duration. These studies include 2589 participants, most of whom were men (74%). The average age was 38 years. There was no difference in the effects of clozapine and typical neuroleptic drugs for broad outcomes such as mortality, ability to work or suitability for discharge at end of the study. Clinical improvement was seen more frequently in those taking clozapine (random effects OR 0.4 CI 0.2-0.6, NNT 6) both in the short and the long term. Also, in the short term, participants on clozapine had fewer relapses than those on typical antipsychotic drugs (OR 0.6 CI 0.4-0.8, NNT 20 CI 17-38), and this may be true for long-term treatment as well. Symptom assessment scales showed a greater reduction of symptoms in clozapine-treated patients. Clozapine treatment was more acceptable than low-potency antipsychotics such as chlorpromazine (OR 0.6 CI 0.4-0.9) but did not differ from acceptability of high-potency neuroleptics such as haloperidol (random effects OR 0.8 CI 0.4-1.5). Clozapine was more acceptable in long-term treatment than conventional antipsychotic drugs (random effects OR 0.4 CI 0.2-0.7, NNT 6 CI 3-111). Patients were more satisfied with clozapine treatment (OR 0.5 CI 0.3-0.8, NNT 12 CI 7-37), but they experienced more hypersalivation, temperature increase, and drowsiness than those given conventional neuroleptics. However, clozapine patients experience fewer motor side effects and less dry mouth. The clinical efficacy of clozapine was more pronounced in participants resistant to typical neuroleptics in terms of clinical improvement (random effects OR 0.2 CI 0.1-0.5, NNT 5 CI 4-7) and symptom reduction. Thirty-two percent of treatment resistant people had a clinical improvement with clozapine treatment.

REVIEWER'S CONCLUSIONS

This systematic review confirms that clozapine is convincingly more effective than typical antipsychotic drugs in reducing symptoms of schizophrenia, producing clinically meaningful improvements and postponing relapse. Patients were more satisfied with clozapine treatment than with typical neuroleptic treatment. (ABSTRACT TRUNCATED

Neurochemical variables in schizophrenic patients during switching from neuroleptics to clozapine

1. The study aimed to search for the effect of clozapine on the levels of the main metabolites of dopamine homovanillic acid (HVA), serotonin 5-hydroxyindoleacetic acid (5-HIAA) and norepinephrine 3-methoxy-4-hydroxyphenylglycol (MHPG) in urine as well as on plasma levels of HVA, 5-HIAA, prolactin (PRL) and cortisol. 2. Seventeen male patients diagnosed as suffering from DSM-IIIR schizophrenia completed the study. 3. The patients were switched from classical antipsychotics to clozapine. After six weeks treatment with clozapine the severity of psychopathology (total BPRS score) decreased significantly (p = 0.00004). pHVA and -5-HIAA did not change significantly. uMHPG increased significantly (p = 0.017). Both PRL and cortisol levels decreased significantly (p = 0.0002, p = 0.032 respectively). Patients with high HVA levels in both plasma and urine at baseline had a lower BPRS score at the end of treatment period (p = 0.0001, p = 0.049 respectively).

Mechanism of clozapine-induced agranulocytosis : current status of research and implications for drug development

Clozapine is an atypical antipsychotic agent that has several advantages over conventional antipsychotics, not least of which is its superior efficacy. However, the high risk of agranulocytosis (0.8% of patients) associated with clozapine therapy has resulted in restricted indications for its use.The mechanism of clozapine-induced agranulocytosis is not clear. The target cells affected are the myeloid precursors, although the mature neutrophil may also be targeted simultaneously. There is no convincing evidence of direct toxicity of the parent compound or its stable metabolites (demethyl-clozapine and clozapine N-oxide). Clozapine is also metabolised by liver microsomes, peripheral blood neutrophils and their bone marrow precursors to a chemically reactive intermediate that has been postulated to be a nitrenium ion. This toxic metabolite has been shown to covalently bind to neutrophil proteins, suggesting that it may be involved in the pathogenesis of the toxicity. However, it is not clear how toxicity is mediated. The nitrenium ion may bind to essential cellular proteins and disrupt neutrophil function or, alternatively, it may act as a hapten and initiate an immune reaction resulting in immune-mediated destruction of the neutrophil. Indirect evidence exists to support both mechanisms, although clear direct evidence is still lacking. The role of cytokines and apoptosis in the pathogenesis of the agranulocytosis is unclear.The reason why only approximately 1% of individuals who are treated with clozapine are affected by agranulocytosis has not been elucidated. Evidence exists to implicate both the major histocompatibility complex antigens and heat shock protein variants in determining individual susceptibility, although more patients of different ethnic backgrounds need to be studied.The ultimate aim of research into clozapine-induced agranulocytosis should be to either prospectively predict which individuals are going to develop agranulocytosis and/or to develop analogues that retain efficacy but are not toxic. The former is complicated by the fact that predisposition may be multifactorial, and thus prediction may require multiple tests that may be of statistical but not absolute validity. The latter depends on identifying the mechanism of toxicity and the chemical characteristics of clozapine that are responsible for the toxicity. This knowledge may allow rational design of new analogues that do not cause agranulocytosis.

Clozapine response and plasma catecholamines and their metabolites

The atypical neuroleptic clozapine has an unusual profile of clinical effects and a distinctive spectrum of pharmacological actions. Plasma measures of catecholamines and their metabolites have been used in the past to study the action of typical neuroleptics. We obtained longitudinal assessments of plasma measures of dopamine (pDA), norepinephrine (pNE), and their metabolites, homovanillic acid (pHVA) and 3-methoxy-4-hydroxyphenylglycol (pMHPG), in eight treatment-resistant or treatment-intolerant schizophrenic patients who were treated with clozapine for 12 weeks following a prolonged drug-washout period. Our findings from the study of these eight patients suggest the following: Plasma levels of HVA and possibly NE derived from the neuroleptic-free baseline period may predict response to clozapine; plasma levels of HVA and MHPG decrease during the initial weeks of treatment in responders but not in nonresponders; and plasma levels of DA and NE increase in both responders and nonresponders to clozapine.