Clozapine and Long-Term Mortality Risk in Patients With Schizophrenia: A Systematic Review and Meta-analysis of Studies Lasting 1.1-12.5 Years

INTEGRATE: international guidelines for the algorithmic treatment of schizophrenia

Schizophrenia is a mental illness involving multiple symptom domains and is often associated with substantial physical health comorbidities. Guidelines exist, but these tend to be country-specific and are often missing a concise yet comprehensive algorithmic approach. From May 1, 2023, to Jan 1, 2025, International Guidelines for Algorithmic Treatment (INTEGRATE) authors from all UN regions collaborated to develop a consensus guideline focused on the pharmacological treatment of schizophrenia. Following an umbrella review of the literature, input from expert workshops, a consensus survey, and lived experience focus groups, a consensus algorithmic guideline and associated digital tool were developed. Key recommendations include a focus on metabolic health from treatment initiation, timely assessment and management of non-response, symptom domain-specific interventions, mitigation of side-effects, and the prompt use of clozapine in cases of treatment resistance.

Current perspectives on the recognition and management of treatment-resistant schizophrenia: challenges and opportunities

INTRODUCTION

Treatment-resistant schizophrenia (TRS) significantly impacts patients with schizophrenia, leading to a high disease burden, reduced quality of life, and functional impairment. Many patients fail to respond to standard antipsychotic treatments, requiring specialized therapeutic approaches. Clozapine remains the only approved treatment for patients with TRS, demonstrating effectiveness in reducing symptoms, hospitalizations, and risk of suicide. However, its use is often delayed due to concerns about adverse events, and the need for ongoing monitoring.

AREAS COVERED

This critical perspective incorporates insights from psychiatrists in Greece and a comprehensive literature analysis that includes clinical guidelines and systematic reviews. It highlights strategies for early diagnosis and timely initiation of clozapine, while emphasizing practical challenges in its use. Recommendations emphasize reducing treatment delays and overcoming barriers such as inadequate training and hesitancy among clinicians. A comprehensive literature search was conducted on PubMed, Google Scholar, and Cochrane Library without any date restrictions to ensure a thorough review of available evidence. The initial literature search was carried out in September 2024, with a subsequent search conducted in March 2025.

EXPERT OPINION

International guidelines consistently recommend clozapine as the first-line treatment for patients with TRS; nevertheless, the authors advocate enhanced awareness to optimize use. Most adverse events can be effectively managed with proper oversight, and early initiation is crucial to improving remission rates and the quality of life of patients with TRS. There is a need for systemic improvements in clinical practice, which requires evidence-based guidance to better address treatment efficacy in this challenging patient population.

Letter to the FDA Proposing Major Changes in the US Clozapine Package Insert Supported by Clozapine Experts Worldwide. Part I: A Review of the Pharmacokinetic Literature and Proposed Changes

PURPOSE/BACKGROUND

Clozapine was approved in the United States (US) using 1989 regulations and knowledge. After 30 years, many sections of the US package insert (PI) are outdated.

METHODS

We comprehensively reviewed the literature to propose PI updates. We present the information in 2 articles. In Part I, we focus on basic pharmacology based on 407 relevant articles. Part II focuses on clinical aspects and pharmacovigilance.

FINDINGS/RESULTS

Based on more recent expectations of Food and Drug Administration regulations, we reviewed clozapine basic pharmacology including the following: 1) clearance, 2) pharmacokinetics and pharmacodynamics, and 3) monitoring tools. We identified 9 major problems in the basic pharmacological sections of the PI including the following: 1) in vivo studies indicate that clozapine is dependent on CYP1A2 for its metabolism, 2) the minor role of CYP2D6 in clozapine metabolism requires removing the PI recommendation to lower clozapine doses in CYP2D6 poor metabolizers, 3) in nontoxic concentrations CYP3A4 has a minor role in clozapine metabolism and potent CYP3A4 inhibitors lack clinically relevant effects, 4) several drug-drug interactions need to be updated based on recent literature, 5) systemic inflammation may decrease clozapine metabolism and increase the risk of clozapine intoxication, 6) obesity may decrease clozapine metabolism, 7) patients of Asian and Indigenous American ancestry need lower clozapine doses, 8) personalized titration and c-reactive protein monitoring should be considered until prospective studies are available, and 9) the half-life section needs to be modified to acknowledge that single dosing at night is frequent in the US.

IMPLICATIONS/CONCLUSIONS

An improvement in the US clozapine PI may lead to improvement in PIs worldwide.

Connecting the dots: Understanding and addressing the metabolic impact of antipsychotic and antidepressant medications

Serious mental disorders such as schizophrenia and major depression are associated with considerable morbidity and mortality, resulting in much shorter life expectancies in those affected. The discovery of antipsychotic medications ushered in improved health outcomes for people with serious mental disorders but also brought about increased morbidity due to their metabolic side effects, including obesity and diabetes mellitus. Antidepressant medications have a more favorable metabolic side effect profile, but some can still cause weight gain and hyperglycemia. In this narrative review, we discuss antipsychotic and antidepressant medications' mechanisms of action, their respective effectiveness in treating psychosis and depression, and their metabolic side effects. In addition, we present therapeutic strategies for minimizing cardiometabolic health risks in patients treated with these medications by applying a comprehensive, biopsychosocial approach.

Clozapine-induced gastrointestinal hypomotility: UK pharmacovigilance reports, 2018-2022

BACKGROUND

Clozapine-induced gastrointestinal hypomotility (CIGH) can cause constipation, which may progress to ileus, intestinal perforation and other life-threatening conditions. There were at least 527 unique cases of harmful CIGH (172 deaths) assessed by strict criteria in the UK, 1992-2017.

AIMS

To assess the impact of strengthened warnings about the risks of CIGH, such as those issued by the UK Medicines and Healthcare products Regulatory Agency (MHRA) (2017) and the US Food and Drug Administration (2020), on reports of harmful CIGH in the UK.

METHOD

We audited UK MHRA Yellow Card reports recorded as clozapine-related gastrointestinal disorders, 2018-end 2022.

RESULTS

Of 335 unique reports (36 fatal, 26 male) that met initial CIGH criteria, there were 129 (22 fatal, 18 male) that met the final CIGH inclusion criteria. Reports of non-fatal CIGH (final criteria) averaged 26 per year (15 in 2022). Deaths averaged four per year (two in 2022). Where data were available the greatest proportion of deaths occurred after 10-14 years of clozapine treatment.

CONCLUSIONS

Publicity aimed at raising awareness of the problem posed by CIGH has been associated with a reduction in harmful CIGH as reported to the UK MHRA since 2017. Continued vigilance is needed to reduce risk. Stopping smoking may pose a particular risk and should be monitored carefully.

Clozapine Efficacy and Adverse Drug Reactions Among a Nationwide Study of 1021 Australians Prescribed Clozapine: The ClozaGene Study

BACKGROUND AND HYPOTHESIS

The ClozaGene Study is a nationwide cohort of adults who have been treated with clozapine. While clozapine is indicated in the management of treatment-resistant schizophrenia, it is associated with a considerable adverse drug reaction (ADR) burden, and not all patients achieve adequate symptomatic response. The current study focuses on self-reported experiences of clozapine use and response, clozapine-associated ADRs, and mental health comorbidity.

STUDY DESIGN

A total of 1021 participants (41.0% female; aged 46.2 ± 10.6 years [range 18-66]) were recruited via a mail-out based on prescriptions for clozapine. Participants completed a self-report questionnaire.

STUDY RESULTS

Most participants (90.1%, n = 912) were living with schizophrenia while 41.5% reported a lifetime diagnosis of depression, 15.6% bipolar disorder, and 8.1% schizoaffective disorder. Clozapine was currently prescribed to 944 (92.5%) participants and 37.8% of these participants self-reported currently taking additional antipsychotic medication. Nearly 3 quarters of participants living with schizophrenia reported that clozapine helped control their schizophrenia symptoms moderately to very well. The most commonly reported ADRs were sialorrhea (80.3%), weight gain (71.0%), constipation (56.9%), and sedation (52.8%). The prevalence of clozapine cessation due to clozapine-induced myocarditis and neutropenia was 1% and 0.4%, respectively.

CONCLUSIONS

Our findings highlight the high rate of psychotic and metabolic symptoms and ADRs among adults prescribed clozapine in the general Australian population. Future genomic analyses will focus on identifying genetic variants influencing clozapine treatment response and side effects.

Clinical and Demographic Predictors of Early Clozapine Discontinuation Across Mood and Psychotic Disorders

BACKGROUND

Clozapine is effective for treatment-resistant schizophrenia and bipolar disorder but is often discontinued due to adverse effects. This study compared early clozapine discontinuation rates and reasons in patients with mood and psychotic disorders.

METHODS

Data from all individuals with mood or psychotic disorders who initiated clozapine for the first time at the inpatient psychiatric unit of Mayo Clinic, Rochester, Minnesota, between 2014 and 2022 were retrospectively analyzed. Early clozapine discontinuation, defined as discontinuation within 90 days of initiation, was the primary outcome. Cox proportional hazards regression was used to assess factors associated with discontinuation.

RESULTS

Of 83 patients (mood group n = 37, psychosis group n = 46), those in the mood group were older ( P = 0.022) and more likely to be nonsmokers ( P = 0.034). The overall 90-day clozapine discontinuation rate was 45.7%. Early discontinuation was significantly higher in the mood group than in the psychosis group (hazard ratio = 2.41, 95% confidence interval = 1.26-4.64, P = 0.008). Other factors associated with early discontinuation were female sex ( P = 0.033), older age ( P = 0.026), and nonsmoking ( P = 0.001). In multivariable analysis, smoking status was the only factor significantly inversely associated with early clozapine discontinuation (hazard ratio = 0.47, 95% confidence interval = 0.22-0.99, P = 0.048), while diagnostic group, sex, and age did not show significant associations (all P > 0.05). Discontinuations were primarily due to adverse drug reactions in both groups.

CONCLUSIONS

Nearly half of the patients discontinued clozapine early, with higher rates in the mood group. Studies should further explore potential pharmacodynamic and pharmacokinetic factors associated with discontinuation, including the influence of smoking. Careful monitoring and personalized management of side effects are crucial for optimizing clozapine therapy and improving treatment outcomes.

Comparative effectiveness of antipsychotic treatment strategies for relapse prevention in first-episode schizophrenia in Finland: a population-based cohort study

BACKGROUND

The best pharmacological treatment practices for relapse prevention in patients with first-episode schizophrenia are unclear. We aimed to assess different treatment strategies used before and after the first relapse, and their associations with subsequent relapse risk.

METHODS

In this population-based cohort study, we enrolled individuals (aged ≤45 years) with first-episode schizophrenia who were hospitalised and subsequently relapsed between 1996 and 2014 from the nationwide Finnish Hospital Discharge Register. Individuals who had not been taking antipsychotics within the year preceeding initial hospitalisation and who had a relapse within 5 years of discharge were included in the analyses. Treatment strategies were assessed during the 30 days before hospitalisation for the first relapse and 30 days after discharge and were categorised as either long-acting injectable, clozapine, non-clozapine oral antipsychotic monotherapy, non-clozapine oral antipsychotic polypharmacy, and antipsychotic non-use. Adjusted hazard ratios (aHRs) of the risk of second relapse based on treatment type were analysed with Cox regression models for 2 years after the first relapse, or until death or end of data linkage (Dec 31, 2017). People with lived experience of schizophrenia were not involved in the research and writing process.

FINDINGS

Between Jan 31, 1996 and Dec 31, 2017, 3000 individuals had their first psychosis relapse and were eligible for analysis. Mean age was 30·0 years (SD 7·6), 1069 (35·6%) of patients were women and 1931 (64·4%) men. No ethnicity data were available. 2148 (71·7%) had a second relapse within 2 years. Before first relapse, most individuals were either not using antipsychotics (n=1366 [45·5%]), or were using non-clozapine oral antipsychotic monotherapy (n=973 [32·4%]). Compared with continuing the same treatment strategy used before the first relapse, switching to clozapine was associated with the lowest risk of second relapse compared with continuing any non-clozapine oral antipsychotic monotherapy (aHR 0·66, 95% CI 0·49-0·89; relapse rate 73·2% with oral non-clozapine antipsychotic monotherapy continuation vs 57·1% with switch to clozapine). Switching to another non-clozapine oral antipsychotic monotherapy (0·99, 0·76-1·28) was approximately as unhelpful in preventing the next relapse as switching to antipsychotic non-use (1·07, 0·80-1·42).

INTERPRETATION

In patients with first-episode schizophrenia having their first psychosis relapse despite use of non-clozapine oral antipsychotics, continuation with the same antipsychotic modality or switch to another non-clozapine oral antipsychotic did not show evidence of being beneficial in relapse prevention, suggesting that clozapine should be started instead. This finding, together with existing knowledge of decreased risk of mortality associated with clozapine, challenges current treatment guidelines that recommend clozapine as a third-line treatment, resulting in treatment practices characterised by long delays to clozapine initiation.

FUNDING

Sigrid Jusélius Foundation.

Identifying and managing treatment resistance early with the integration of a clozapine clinic within an early intervention for psychosis service

BACKGROUND

Despite being the most effective antipsychotic medication for treatment-resistant psychosis, clozapine is often under-utilized with long delays to initiation.

AIMS

This study aimed to determine whether the integration of a clozapine clinic within an early intervention for psychosis service resulted in a change in the rate and time to initiation of clozapine, the number of trials of different antipsychotic medications prior to clozapine, community initiation and discontinuation rates.

METHODS

A clozapine clinic was established in the Early Psychosis Prevention and Intervention Centre in Melbourne. This was a pre- and post-evaluation study design. The 'clozapine clinic' cohort included those who commenced on clozapine from 01 January 2016 to 30 June 2018.

RESULTS

Prior to the clozapine clinic, 24 young people commenced clozapine over the 30-month period compared to 36 in the clozapine clinic cohort (RR = 1.30, 95% CI: 0.75-2.28, p = .32). In the pre-clozapine clinic cohort, 4.6% of all those with a first episode of psychosis were commenced on clozapine compared to 6% in the clozapine clinic cohort. Prior to the clozapine clinic, the median time to the commencement of clozapine was 72 weeks (IQR: 38, 87), compared to 53.5 weeks (IQR: 38, 81.5) in the clozapine clinic (Z = -0.86, p = .393). The mean number of different antipsychotic medications prior to commencing clozapine remained stable at 3.2 (SD ± 1.1) in both cohorts (t = -0.20, p = .841). There was a lower rate of discontinuation in the clozapine clinic (43.5% vs. 14.7%, HR = 0.30, 95% CI: 0.09-0.98, p = .046).

CONCLUSIONS

While this study was underpowered and there are limitations to the naturalistic study design, the findings lend support to the integration of a clozapine clinic within early intervention for psychosis services.

Clozapine as a mood stabiliser for schizoaffective disorder: Effectiveness during a three-month follow-up

Clozapine has shown signs of effectiveness in treating symptoms of schizoaffective disorder, although little research has been carried out to specifically assess this question. The objective of this current work was to analyse the mood-stabilising effectiveness and tolerability of clozapine in patients with schizoaffective disorder. This was a prospective, longitudinal, and quasi-experimental trial with three months of follow-up in patients with refractory schizoaffective disorder (PANSS score exceeding 80). Clinical response was evaluated through monthly visits using the YMRS, MADRS, CDSS, CGI-S and UKU. Twenty-seven participants (63% men, 37% women) with a mean age of 32.56 years were included. Clozapine significantly reduced the symptoms of mania, as measured by the YMRS (pre-treatment: 16.19, post-treatment: 0.67; p < 0.01) as well as the symptoms of depression, quantified with the CDSS (pre-treatment: 6.11, post-treatment: 0.67; p < 0.01), MADRS (pre-treatment: 9.56, post-treatment: 1.07; p < 0.01), and CGI-S (pre-treatment: 4.74, post-treatment: 1.15; p < 0.01). The prescription of clozapine significantly reduced the average daily dose of neuroleptics, measured in mg of chlorpromazine (pre-treatment: 1253.55, post-treatment: 742.59; p < 0.01) and hypnosedatives, measured in mg of diazepam (pre-treatment: 33.88, post-treatment: 5.74; p < 0.05) required in these patients. Patient-perceived tolerability, measured with the UKU, also improved during follow-up (pre-treatment: 12.89, post-treatment: 8.14; p < 0.01). The efficacy of clozapine was significant for the affective symptoms of schizoaffective disorder, thereby improving patient tolerability and permitting reductions in the other medications the patients used.

Clozapine and Pneumonia: Synthesizing the Link by Reviewing Existing Reports-A Systematic Review and Meta-Analysis

Background and Objectives: Clozapine is a highly effective antipsychotic used for treating treatment-refractory psychotic and mood disorders. However, clozapine also has a serious risk of side effects leading to mortality, particularly its potentiated risk of leading to pneumonia. This review aims to overview the demographic and health-related risk factors leading to pneumonia to better inform risk assessment for clozapine users and to summarise current theories on the mechanisms for clozapine-associated pneumonia. This paper will highlight the need to prioritise pneumococcal vaccination in this population group. Materials and Method: We conducted a literary search of five online databases conforming to PRISMA. Our review includes all peer-reviewed papers with original data that discuss clozapine and pneumonia and excludes case reports. Baseline information of participants, pneumonia-related information and information regarding risk factors and mechanisms causing pneumonia were also extracted. Results: Clozapine was found to have an increased risk of pneumonia compared to other antipsychotic medications. Factors included comorbidities, higher clozapine dosages, and concurrent use of other antipsychotic medications. Key mechanisms for clozapine-associated pneumonia include clozapine-induced hyper sedation, sialorrhea and neutropoenia. Conclusions: While clozapine improves overall mortality for patients, our review confirms clozapine has the highest risk of pneumonia of all antipsychotics. The review also highlights the prevalent underuse of pneumococcal vaccines among clozapine users and the urgent need to increase uptake.

Rare but elevated incidence of hematological malignancy after clozapine use in schizophrenia: A population cohort study

BACKGROUND

Clozapine is widely regarded as a highly efficacious psychotropic drug that is largely underused worldwide. Recent disproportionality analyses and nationwide case-control studies suggested a potential association between clozapine use and hematological malignancy (HM). Nevertheless, the absolute rate difference is not well-established due to the absence of analytic cohort studies. The clinical significance of such a potential risk remains unclear.

METHODS AND FINDINGS

We extracted data from a territory-wide public healthcare database from January 2001 to August 2022 in Hong Kong to conduct a retrospective cohort study of anonymized patients aged 18+ years with a diagnosis of schizophrenia who used clozapine or olanzapine (drug comparator with highly similar chemical structure and pharmacological mechanisms) for 90+ days, with at least 2 prior other antipsychotic use records within both groups. Weighted by inverse probability of treatment (IPTW) based on propensity scores, Poisson regression was used to estimate the incidence rate ratio (IRR) of HM between clozapine and olanzapine users. The absolute rate difference was also estimated. In total, 9,965 patients with a median follow-up period of 6.99 years (25th to 75th percentile: 4.45 to 10.32 years) were included, among which 834 were clozapine users. After IPTW, the demographic and clinical characteristics of clozapine users were comparable to those of olanzapine users. Clozapine users had a significant weighted IRR of 2.22 (95% confidence interval (CI) [1.52, 3.34]; p < 0.001) for HM compared to olanzapine users. The absolute rate difference was estimated at 57.40 (95% CI [33.24, 81.55]) per 100,000 person-years. Findings were consistent across subgroups by age and sex. Sensitivity analyses all supported the robustness of the results and showed good specificity to HM but no other cancers. The main limitation of this observational study is the potential residual confounding effects that could have arisen from the lack of randomization in clozapine or olanzapine use.

CONCLUSIONS

Absolute rate difference in HM incidence associated with clozapine is small despite a 2-fold elevated rate. Given the rarity of HM and existing blood monitoring requirements, more restrictive indication for clozapine or special warnings may not be necessary.

Second Generation Antipsychotics and Cardiovascular Adverse Effects: Developing Evidence-Based Recommendations for Primary Care Medicine

Background

Second-generation antipsychotic medications (SGAs) are often used by primary care physicians (PCPs) to treat multiple psychiatric diagnoses. SGAs have been connected to a number of adverse effects, including cardiovascular disease. Currently, there are no published evidence-based recommendations addressing SGAs and cardiotoxicity that are directed toward PCPs. This project aims to fill this gap.

Methods

Relevant search terms related to SGAs and cardiovascular disease were identified and then used to search databases (PubMed, PubMed Central, and AccessMedicine). Research studies obtained from the searches were narrowed to include systematic reviews and meta-analyses. The Assessment of Multiple Systematic Reviews-2 (AMSTAR-2) tool was utilized by 2 investigators to evaluate the quality of the research independently. Research rated by both investigators to be of high and moderate quality using the AMSTAR-2 system was employed to develop recommendations for PCPs when using SGAs with their patients.

Results

Seven systematic reviews and meta-analyses were found to be of high or moderate quality by AMSTAR-2 evaluations. The studies identified associations between SGAs and a number of adverse cardiac conditions, including corrected QT interval (QTc) prolongation, arrhythmias, myocardial infarction, tachycardia, and other cardio-metabolic associated morbidities.

Conclusion

Our project indicated that cardiovascular risks can be associated with SGAs and that screening and monitoring for cardiac toxicities are indicated when treating patients with this class of medications. These risks, however, do not appear to override benefits in most patients. Furthermore, it appears that when using SGAs, methods of risk reduction can be applied effectively in the primary care setting.

Antipsychotic prescribing practices and their association with rehospitalization in a forensic psychiatric sample

While there is extensive literature examining the effectiveness of antipsychotic prescribing to patients with schizophrenia spectrum or other psychotic disorders in general psychiatric services, there is a dearth of studies examining antipsychotic prescribing practices and their effectiveness in forensic psychiatric services. Forensic psychiatric patients have unique challenges often due to their high-profile offences, public scrutiny, and legal requirements. This longitudinal, retrospective study aimed to examine antipsychotic prescribing and rehospitalization rates in a forensic psychiatric sample, along with relevant socio-demographic, clinical, and forensic characteristics. All patients had a psychotic illness and were prescribed antipsychotic medication. The sample included 153 patients, of which the majority were male (85.6%), Caucasian (71.2%), middle aged (30s to 50s), had schizophrenia or schizoaffective disorder (76.5%), had a substance use disorder (62.1%), and had a most serious index offence against the person (80.4%). Atypical antipsychotics accounted for the majority of antipsychotic prescriptions (75.9%) and the sample had an antipsychotic polypharmacy rate of 39.9%. The sample was divided into four primary antipsychotic formulation types, which were oral (34.0%), injection (39.2%), clozapine (19.0%), and subtherapeutic (7.8%). Regarding rehospitalization, 52.9% of the sample was rehospitalized, with the average number of rehospitalizations being 1.2 (SD = 1.7) and proportion of the follow up period rehospitalized being 16.4% (SD = 27.7%). Patients prescribed clozapine had numerically lower rates of rehospitalization than those prescribed oral and injection formulation types, but it was not statistically significant. With a 19.0% prescription rate, clozapine may be underutilized in this sample. Further research is needed to demonstrate the potential benefits of clozapine regarding rehospitalization in forensic psychiatric patients, as has already been done in general psychiatry. Advancing treatment of the high-profile forensic population can reduce stigma toward people with mental illness and criminal justice involvement.

Predictors and shared traits of longevity within 1 year before death in patients with schizophrenia receiving long-term care: 3-year retrospective cross-sectional study

BACKGROUND

Research on schizophrenia and life expectancy has mainly focused on premature mortality.

AIMS

This study investigates factors associated with longevity in patients with schizophrenia receiving long-term care and identifies shared traits among these individuals.

METHOD

A retrospective cross-sectional study analysing the clinical records of 138 patients with schizophrenia who died between 2015 and 2017 in a psychiatric long-term care facility was conducted. Longevity was defined by life tables drawn from the national health database. Variables were compared between longevity and control groups to determine predictors of longer lifespans. Cluster analysis was employed to identify shared traits among individuals with longevity. Causes of death by age were compared.

RESULTS

In the long-term care setting, of the 138 participants, 45 were in the longevity group. This group had more males, lower antipsychotic doses, but more mobility issues. Significant predictors of longevity included older age at onset, longer length of stay, lower activities of daily living scores and a hypertension diagnosis. Cluster analysis revealed two patterns, suggesting that poorer health indicators did not necessarily lead to shorter lives. Fatalities caused by pneumonia were associated with a higher age, compared to those from cancer and choking.

CONCLUSIONS

Addressing modifiable risk factors enhances life expectancy in patients with schizophrenia, especially for males, while the age at onset may play a significant role. An integrated long-term care model with close monitoring and timely provision of mental and general healthcare may help extend lifespans. Further research is needed to balance long-term residential care and community-based care for elderly patients with schizophrenia.

Risk factors, prevention and treatment of weight gain associated with the use of antidepressants and antipsychotics: a state-of-the-art clinical review

INTRODUCTION

People with severe mental illness have poor cardiometabolic health. Commonly used antidepressants and antipsychotics frequently lead to weight gain, which may further contribute to adverse cardiovascular outcomes.

AREAS COVERED

We searched MEDLINE up to April 2023 for umbrella reviews, (network-)meta-analyses, trials and cohort studies on risk factors, prevention and treatment strategies of weight gain associated with antidepressants/antipsychotics. We developed 10 clinical recommendations.

EXPERT OPINION

To prevent, manage, and treat antidepressant/antipsychotic-related weight gain, we recommend i) assessing risk factors for obesity before treatment, ii) monitoring metabolic health at baseline and regularly during follow-up, iii) offering lifestyle interventions including regular exercise and healthy diet based on patient preference to optimize motivation, iv) considering first-line psychotherapy for mild-moderate depression and anxiety disorders, v)choosing medications based on medications' and patient's weight gain risk, vi) choosing medications based on acute vs long-term treatment, vii) using effective, tolerated medications, viii) switching to less weight-inducing antipsychotics/antidepressants where possible, ix) using early weight gain as a predictor of further weight gain to inform the timing of intervention/switch options, and x) considering adding metformin or glucagon-like peptide-1 receptor agonists, or topiramate(second-line due to potential adverse cognitive effects) to antipsychotics, or aripiprazole to clozapine or olanzapine.

High Burden of Ileus and Pneumonia in Clozapine-Treated Individuals With Schizophrenia: A Finnish 25-Year Follow-Up Register Study

OBJECTIVE

The authors used longitudinal biobank data with up to 25 years of follow-up on over 2,600 clozapine users to derive reliable estimates of the real-world burden of clozapine adverse drug events (ADEs).

METHODS

A total of 2,659 participants in the FinnGen biobank project had a schizophrenia diagnosis and clozapine purchases with longitudinal electronic health record follow-up for up to 25 years after clozapine initiation. Diseases and health-related events enriched during clozapine use were identified, adjusting for disease severity. The incidence and recurrence of ADEs over years of clozapine use, their effect on clozapine discontinuation and deaths, and their pharmacogenetics were studied.

RESULTS

Median follow-up time after clozapine initiation was 12.7 years. Across 2,157 diseases and health-related events, 27 were enriched during clozapine use, falling into five disease categories: gastrointestinal hypomotility, seizures, pneumonia, other acute respiratory tract infections, and tachycardia, along with a heterogeneous group including neutropenia and type 2 diabetes, among others. Cumulative incidence estimates for ileus (severe gastrointestinal hypomotility) and pneumonia were 5.3% and 29.5%, respectively, 20 years after clozapine initiation. Both events were significantly associated with increased mortality among clozapine users (ileus: odds ratio=4.5; pneumonia: odds ratio=2.8). Decreased genotype-predicted CYP2C19 and CYP1A2 activities were associated with higher pneumonia risk.

CONCLUSIONS

Clozapine-induced ileus and pneumonia were notably more frequent than has previously been reported and were associated with increased mortality. Two CYP genes influenced pneumonia risk. Pneumonia and ileus call for improved utilization of available preventive measures.

Second Opinions for Diagnoses of Psychotic Disorders: Delivering Stage-Specific Recommendations

OBJECTIVE

The impact of obtaining second-opinion consultations on diagnoses of schizophrenia spectrum disorders was evaluated.

METHODS

A retrospective chart review was conducted for 177 patients referred to a psychosis consultation service at an academic medical center from January 1, 2017, to October 1, 2023; these consultations aimed to clarify a diagnosis of psychosis. Diagnoses made before and after consultations were compared, and treatment recommendations resulting from the consultation visit were summarized.

RESULTS

Among patients without a preconsultation diagnosis of schizophrenia, 28% (N=28 of 100) received a postconsultation diagnosis of schizophrenia. Among 62 patients with a postconsultation diagnosis of treatment-resistant schizophrenia (TRS), 56% (N=35) received this diagnosis only after consultation. Nearly all of these patients were advised to begin taking clozapine, and electroconvulsive therapy was less commonly recommended.

CONCLUSIONS

Expert consultation facilitates timely identification and optimal treatment of schizophrenia and its more severe subtype, TRS.

Developing a validated methodology for identifying clozapine treatment periods in electronic health records

BACKGROUND

Clozapine is the only recommended antipsychotic medication for individuals diagnosed with treatment-resistant schizophrenia. Unfortunately, its wider use is hindered by several possible adverse effects, some of which are rare but potentially life threatening. As such, there is a growing interest in studying clozapine use and safety in routinely collected healthcare data. However, previous attempts to characterise clozapine treatment have had low accuracy.

AIM

To develop a methodology for identifying clozapine treatment dates by combining several data sources and implement this on a large clinical database.

METHODS

Non-identifiable electronic health records from a large mental health provider in London and a linked database from a national clozapine blood monitoring service were used to obtain information regarding patients' clozapine treatment status, blood tests and pharmacy dispensing records. A rule-based algorithm was developed to determine the dates of starting and stopping treatment based on these data, and more than 10% of the outcomes were validated by manual review of de-identified case note text.

RESULTS

A total of 3,212 possible clozapine treatment periods were identified, of which 425 (13.2%) were excluded due to insufficient data to verify clozapine administration. Of the 2,787 treatments remaining, 1,902 (68.2%) had an identified start-date. On evaluation, the algorithm identified treatments with 96.4% accuracy; start dates were 96.2% accurate within 15 days, and end dates were 85.1% accurate within 30 days.

CONCLUSIONS

The algorithm produced a reliable database of clozapine treatment periods. Beyond underpinning future observational clozapine studies, we envisage it will facilitate similar implementations on additional large clinical databases worldwide.

Time for a change to clozapine haematological monitoring

OBJECTIVES

This paper critiques the haematological monitoring guidelines for clozapine. It describes the history of clozapine, as well as the pathophysiology and epidemiology of clozapine-induced neutropenia (CIN) and agranulocytosis (CIA). The paper appraises the extant literature on mandatory clozapine haematological monitoring.

CONCLUSION

Contemporary Australian protocols for clozapine haematological monitoring are not consistent with the current evidence base. CIN and CIA are rare occurrences, and the associated risk of death is low. Potential modifications to existing guidelines include changing neutrophil thresholds for patients with benign ethnic neutropenia and reducing the frequency or removing haematological monitoring after two years of clozapine treatment.

Overcoming clozapine's adverse events: a narrative review of systematic reviews and meta-analyses

INTRODUCTION

Clozapine is the gold standard treatment for treatment-resistant schizophrenia, however adverse events remain a clinical challenge.

AREAS COVERED

This review presents a narrative synthesis of systematic reviews and meta-analyses that have reported the onset, incidence, prevalence, and management of clozapine's adverse events. We conducted a systematic literature search using PubMed, Embase, PsycINFO, OvidMEDLINE, CINAHL, and the Cochrane Database of Systematic Reviews from inception to April 2024.

EXPERT OPINION

Effective management of clozapine's adverse events necessitates multi-faceted, individualized, and shared-decision strategies. Despite a lack of high-quality systematic evidence, expert inter-disciplinary solutions are provided to help address a critical need for clinical guidance. This 35-year update offers an evidence-based framework to assist clinicians, patients, and caregivers navigate the adverse events associated with clozapine therapy.

Clozapine use in the first two years after first-episode psychosis in a real-world clinical sample

BACKGROUND

Approximately 20-30% of patients with schizophrenia fail to respond to antipsychotic treatment and are considered treatment resistant (TR). Although clozapine is the treatment of choice in these patients, in real-world clinical settings, clinicians often delay clozapine initiation, especially in first-episode psychosis (FEP).

AIM

The main aim of this study was to describe prescription patterns for clozapine in a sample of patients diagnosed with FEP and receiving specialized treatment at a university hospital. More specifically, we aimed to determine the following: (1) the proportion of patients who received clozapine within two years of disease onset, (2) baseline predictors of clozapine use, (3) time from starting the first antipsychotic to clozapine initiation, (4) concomitant medications, and (5) clozapine-related adverse effects.

METHODS

All patients admitted to a specialized FEP treatment unit at our hospital between April 2013 and July 2020 were included and followed for two years. The following variables were assessed: baseline sociodemographic characteristics; medications prescribed during follow-up; clozapine-related adverse effects; and baseline predictors of clozapine use. We classified the sample into three groups: clozapine users, clozapine-eligible, and non-treatment resistant (TR).

RESULTS

A total of 255 patients were consecutively included. Of these, 20 (7.8%) received clozapine, 57 (22.4%) were clozapine-eligible, and 178 (69.8%) were non-TR. The only significant variable associated with clozapine use at baseline was the Global Assessment of Functioning (GAF) score (R2=0.09, B=-0.07; OR=0.94; 95% CI: 0.88-0.99; p=0.019). The median time to clozapine initiation was 55.0 (93.3) days. The most common side effect was sedation.

CONCLUSIONS

A significant proportion (30.2%) of patients in this cohort were treatment resistant and eligible for clozapine. However, only 7.8% of the sample received clozapine, indicating that this medication was underprescribed. A lower baseline GAF score was associated with clozapine use within two years, suggesting that it could be used to facilitate the early identification of patients who will need treatment with clozapine, which could in turn improve treatment outcomes.

Decoding Clozapine-Induced Agranulocytosis: Unraveling Interactions and Mitigation Strategies

Agranulocytosis represents a severe complication associated with the administration of clozapine. Clozapine is an antipsychotic medication that has demonstrated substantial efficacy in remediating refractory schizophrenia and various other psychiatric disorders. Nonetheless, it is crucial to monitor patients for neutropenia regularly during clozapine therapy. Therefore, this article aimed to delve into the prevalence of agranulocytosis during clozapine treatment by scrutinizing the extant literature to discern trends and correlations. This review endeavored to explore factors such as drug interactions, dose-related factors, duration of treatment, and genetic predispositions that could potentially influence the likelihood of patients developing agranulocytosis while undergoing clozapine therapy. Moreover, this review enunciates the ramifications of agranulocytosis on both patients and healthcare providers and meticulously evaluates the strategies to mitigate this risk and ensure optimal patient outcomes.

History of suicidal behavior and clozapine prescribing among people with schizophrenia in China: a cohort study

BACKGROUND

Clozapine is an off-label drug used in most countries to prevent suicide in individuals with schizophrenia. However, few studies have reported real-world prescription practices. This study aimed to explore the association between a history of suicidal behavior and clozapine prescribing during eight weeks of hospitalization for individuals with early-stage schizophrenia.

METHODS

This observational cohort study used routine health data collected from a mental health hospital in Beijing, China. The study included 1057 inpatients who had schizophrenia onset within 3 years. History of suicidal behavior was coded from reviewing medical notes according to the Columbia Suicide Severity Rating Scale. Information on antipsychotic use during hospitalization was extracted from the prescription records. Time to clozapine use was analyzed using Cox regression models adjusted for sociodemographic and clinical covariates.

RESULTS

The prevalence rates of self-harm, suicidal behavior, and suicide attempt were 12.3%, 7.5%, and 5.4%, respectively. A history of self-harm history was positively associated with clozapine uses upon admission (4.1% vs. 0.8%, exact p = 0.009). Among those who had not used clozapine and had no clozapine contraindication, A history of suicidal behavior increased the possibility of switch to clozapine within 56 days after admission (Hazard Ratio[95% CI], 6.09[2.08-17.83]) or during hospitalization (4.18[1.62-10.78]).

CONCLUSION

The use of clozapine for early-stage schizophrenia was more frequent among those with suicidal behavior than among those without suicidal behavior in China, although the drug instructions do not label its use for suicide risk.

Revealing the reporting disparity: VigiBase highlights underreporting of clozapine in other Western European countries compared to the UK

BACKGROUND

Pharmacovigilance studies indicate clozapine history is marked by adverse drug reactions (ADRs).

OBJECTIVE

In a 2021 article, the United Kingdom (UK) had >90 % of European clozapine-related fatal outcomes in VigiBase, the World Health Organization's pharmacovigilance database. Two possibly opposing hypotheses could explain this disparity: 1) fewer reported fatal outcomes in other Western European countries mainly reflect underreporting to VigiBase, and 2) the higher number of UK reports reflects higher real relative mortality.

METHODS

VigiBase reports from clozapine's introduction to December 31, 2022, were studied for ADRs and the top 10 causes of fatal outcomes. The UK was compared with 11 other top reporting Western countries (Germany, Denmark, France, Finland, Ireland, Italy, Netherlands, Norway, Spain, Sweden and Switzerland). Nine countries (except Ireland and Switzerland) were compared after controlling for population and clozapine prescriptions.

RESULTS

The UK accounted for 29 % of worldwide clozapine-related fatal outcomes, Germany 2 % and <1 % in each of the other countries. The nonspecific label "death" was the top cause in the world (46 %) and in the UK (33 %). "Pneumonia" was second in the world (8 %), the UK (12 %), Ireland (8 %) and Finland (14 %). Assuming that our corrections for population and clozapine use are correct, other countries underreported only 1-10 % of the UK clozapine fatal outcome number.

CONCLUSIONS

Different Western European countries consistently underreport to VigiBase compared to the UK, but have different reporting/publishing styles for clozapine-related ADRs/fatal outcomes. Three Scandinavian registries suggest lives are saved as clozapine use increases, but this cannot be studied in pharmacovigilance databases.

Response rates to sequential trials of antipsychotic medications according to algorithms or treatment guidelines in psychotic disorders. A systematic review and meta-analysis

BACKGROUND

There is a relative lack of research evaluating the outcomes when treatment guidelines or algorithms for psychotic disorders are followed. This systematic review and meta-analysis determined the response rates to antipsychotic medications at different stages of these algorithms and whether these response rates differ in first episode cohorts.

METHODS

Data sources: A systematic search strategy was conducted across four databases PubMed, EMBASE, PsycINFO (Ovid) and CINAHL. Studies that had sequential trials of different antipsychotic medications were included. A meta-analysis of proportions was performed using random effects models and sub-group analysis in first episode psychosis studies.

RESULTS

Of the 4078 unique articles screened, fourteen articles, from nine unique studies, were eligible and included 2522 participants. The proportion who experienced a response to any antipsychotic in the first stage of an algorithm was 0.53 (95 % C.I.:0.38,0.68) and this decreased to 0.26 (95 % C.I.:0.15,0.39) in the second stage. When clozapine was used in the third stage, the proportion that achieved a response was 0.43 (95 % C.I. 0.19, 0.69) compared to 0.26 (95 % C.I.:0.05,0.54) if a different antipsychotic was used. Four studies included 907 participants with a first episode of psychosis and the proportions that achieved a response were: 1st stage: 0.63 (95 % C.I.: 0.45, 0.79); 2nd stage: 0.34 (95 % C.I.:0.16,0.55); clozapine 3rd stage: 0.45 (95 % C.I.:0.0,0.97), different antipsychotic 3rd stage: 0.15 (95 % C.I.,0.01,0.37).

DISCUSSION

These findings support the recommendation to have a trial of clozapine after two other antipsychotic medications have been found to be ineffective.

Clozapine and its protective effect on all-cause, natural, and suicide mortality in patients with schizophrenia: A nationwide cohort study in Taiwan

AIM

Clozapine is indicated as the last-line agent for the treatment of refractory schizophrenia due to its side effects. This study included an Asian schizophrenia population and investigated the effect of clozapine on the risks of all-cause, natural, and suicide mortality.

METHODS

This study included a large-scale schizophrenia inpatient cohort derived from the National Health Insurance Research Database from January 1, 2001, to December 31, 2019 (n = 43,025). Of them, we selected those who received clozapine (clozapine cohort, n = 5800). From those who never used clozapine, we selected two individuals for each patient in the clozapine cohort by matching by age, sex, and the year of the index date (ratio: 1:2, control cohort, n = 11,583). The clozapine and nonclozapine control cohorts together were defined as the study cohort (n = 17,383). Multivariate Cox proportional-hazards regression with a time-dependent model was performed to investigate the effect of individual antipsychotic agents on mortality.

RESULTS

All individual first-generation antipsychotics were not associated with mortality risk. However, most individual second-generation antipsychotics exerted protective effects against all-cause and natural mortality. Furthermore, only clozapine and risperidone were significantly associated with a low risk of suicide mortality. Only clozapine exhibited a dose-dependent relationship with all-cause, natural, and suicide mortality.

CONCLUSIONS

This study provides robust evidence supporting the strong protective effect of clozapine on all-cause, suicide, and natural mortality risks in an Asian population. Under close monitoring, clozapine use can be advantageous in patients with schizophrenia who are at a high risk of suicide.

Current practice for clozapine-induced leukopenia in Japanese psychiatric hospitals: A nationwide survey

Clozapine is an atypical antipsychotic used for treatment-resistant schizophrenia. In Japan, its use requires management by a blood monitoring system called the Clozaril Patient Monitoring Service (CPMS) for the early detection of serious side effects such as agranulocytosis, which is extremely rare. Monitoring services vary among the clozapine suppliers in different countries. Additionally, Japanese patients can be started on clozapine treatment exclusively through an 18-week inpatient admission at a psychiatric hospital capable of coordinating with a hematologist. One reported reason for the lack of widespread clozapine use in Japan is the difficulty in establishing collaboration with hematologists when agranulocytosis/leukopenia occurs. Hence, we conducted a nationwide web-based survey of CPMS-registered psychiatric facilities in Japan to determine the status of collaboration with hematology departments. Valid responses were received from the psychiatrists responsible for prescribing clozapine at 203 of the 547 facilities (response rate: 37.1 %). The largest number of psychiatric facilities (61 %) collaborated with hematologists at another facility with a psychiatry department, while psychiatrists in 32 % of the facilities worked with hematologists at their own facilities. Most patients with clozapine-induced agranulocytosis/leukopenia could be treated with clozapine discontinuation and follow-up in psychiatric inpatient units with the assistance of a hematologist. The actual workload of hematologists was limited, and the patients might experience the burden of repeated blood sampling. This study suggests that disseminating information regarding the status of collaborations with hematologists may promote the widespread use of clozapine in Japan. SHORT COMMENT FOR TWITTER: This study suggests that most patients with clozapine-induced agranulocytosis/leukopenia could be treated with clozapine discontinuation and follow-up in psychiatric inpatient units with the assistance of a hematologist.

Adverse drug reactions and their fatal outcomes in clozapine patients in VigiBase: Comparing the top four reporting countries (US, UK, Canada and Australia)

BACKGROUND

Pharmacovigilance findings and box warnings in the clozapine package inserts have marked the history of clozapine.

OBJECTIVE

This is the largest review of clozapine adverse drug reactions (ADRs) and their associated fatal outcomes. Reports to the World Health Organization's global pharmacovigilance database, VigiBase™, were analyzed, extending from clozapine's introduction to December 31, 2022.

METHODS

The analysis focused on the top four reporting countries: United States (US), United Kingdom (UK), Canada and Australia (83 % of fatal outcomes worldwide). Attempts were made to control for population and clozapine prescription in each country.

RESULTS

Clozapine ADRs worldwide accounted for 191,557 reports, with the highest number (53,505) in "blood and lymphatic system disorder". Of the 22,596 fatal outcomes reported in clozapine patients, 9587 were from the US, 6567 from the UK, 3623 from Canada and 1484 from Australia. The top category worldwide in fatal outcomes was nonspecifically labeled "death" with 46 % (range 22-62 %). "Pneumonia" was second with 30 % (range 17-45 %). Agranulocytosis was numerically only the 35th top clozapine ADR associated with fatal outcomes. On average, 2.3 clozapine ADRs were reported per fatal outcome. Infections were associated with 24.2 % of the UK fatal outcomes (9.4 %-11.9 % in the 3 other countries).

CONCLUSIONS

The four countries appeared to report clozapine ADRs in different ways, making comparisons difficult. We estimated higher fatal outcomes in the UK and Canada after controlling for cross-sectional estimations of population and published clozapine use. This last hypothesis is limited by the lack of precise estimation of accumulated clozapine use in each country.

An expert review of clozapine in Eastern European countries: Use, regulations and pharmacovigilance

OBJECTIVES

To compare the prevalence, regulations, and pharmacovigilance practices of clozapine use in Eastern European countries (except Russia).

METHODS

Questionnaires and data from administrative databases (2016 and 2021), package inserts and national guidelines were collected from 21 co-authors from 21 countries. Reports of clozapine adverse drug reactions (ADRs) sent to the global pharmacovigilance database (VigiBase™) were analyzed from introduction to December 31, 2022.

RESULTS

Clozapine prescription among antipsychotics in 2021 varied six-fold across countries, from 2.8 % in the Czech Republic to 15.8 % in Montenegro. The utilization of antipsychotics in both 2016 and 2021 was highest in Croatia, and lowest in Serbia in 2016, and Montenegro in 2021, which had half the defined daily dose (DDD)/1000/day compared to the Croatian data. From 2016 to 2021, the prevalence of antipsychotic use increased in almost all countries; the proportion of clozapine use mainly remained unchanged. Differences were detected in hematological monitoring requirements and clozapine approved indications. Only a few national schizophrenia guidelines mention clozapine-induced myocarditis or individual titration schemes. The VigiBase search indicated major underreporting regarding clozapine and its fatal outcomes. By comparison, the United Kingdom had less than half the population of these Eastern European countries but reported to VigiBase more clozapine ADRs by 89-fold and clozapine fatal outcomes by almost 300-fold.

CONCLUSION

Clozapine is under-utilized in Eastern European countries. Introducing individualized clozapine treatment schedules may help to maximize clozapine benefits and safety. Major improvement is needed in reporting clozapine ADRs and fatal outcomes in Eastern European countries.

Variation of Clozapine Use for Treatment of Schizophrenia: Evidence from Pennsylvania Medicaid and Dually Eligible Enrollees

While clozapine is the most effective antipsychotic treatment for treatment-resistant schizophrenia, it remains underutilized across the United States, warranting a more comprehensive understanding of variation in use at the county level, as well as characterization of existing prescribing patterns. Here, we examined both Medicaid and Medicare databases to (1) characterize temporal and geographic variation in clozapine prescribing and, (2) identify patient-level characteristics associated with clozapine use. We included Medicaid and Fee for Service Medicare data in the state of Pennsylvania from January 1, 2013, through December 31, 2019. We focused on individuals with continuous enrollment, schizophrenia diagnosis, and multiple antipsychotic trials. Geographic variation was examined across counties of Pennsylvania. Regression models were constructed to determine demographic and clinical characteristics associated with clozapine use. Out of 8,255 individuals who may benefit from clozapine, 642 received treatment. We observed high medication burden, overall, including multiple antipsychotic trials. We also identified variation in clozapine use across regions in Pennsylvania with a disproportionate number of prescribers in urban areas and several counties with no identified clozapine prescribers. Finally, demographic, and clinical determinants of clozapine use were observed including less use in people identified as non-Hispanic Black, Hispanic, or with a substance use disorder. In addition, greater medical comorbidity was associated with increased clozapine use. Our work leveraged both Medicaid and Medicare data to characterize and surveil clozapine prescribing. Our findings support efforts monitor disparities and opportunities for the optimization of clozapine within municipalities to enhance clinical outcomes.

Building and Validation of an Acute Event Prediction Model for Severe Mental Disorders

Background

The global incidence of acute events in psychiatric patients is intensifying, and models to successfully predict acute events have attracted much attention.

Objective

To explore the influence factors of acute incident severe mental disorders (SMDs) and the application of Rstudio statistical software, and build and verify a nomogram prediction model.

Methods

SMDs were taken as research objects. The questionnaire survey method was adopted to collect data. Patients with acute event independent factors were screened. R software multivariable Logistic regression model was constructed and a nomogram was drawn.

Results

A total of 342 patients with SMDs were hospitalized, and the number of patients who encountered acute events was 64, which accounted for 18.70% of all patients. Statistical significances were found in many aspects (all P ˂ 0.05). Such aspects included Medication adherence, disease diagnosis, marital status, caregivers, social support and the hospitalization environment (odds ratio (OR) = 4.08, 11.62, 12.06, 10.52, 0.04 and 0.61, respectively) were independent risk factors for the acute events of patients with SMDs. The prediction model was modeled, and the AUC was 0.77 and 0.80. The calibration curve shows that the model has good calibration. The clinical decision curve shows that the model has a good clinical effect.

Conclusion

The constructed risk prediction model shows good prediction effectiveness in the acute events of patients with SMDs, which is helpful for the early detection of clinical mental health staff at high risk of acute events.

Seven decades of antipsychotic drugs: Why is the life of Australians with schizophrenia still so suboptimal?

The advent of dopamine (D2) receptor-blocking medications over 70 years ago, ushered in a new era of biological treatment for schizophrenia. However, we argue that little subsequent progress has been made in translating this into fulfilled and fulfilling lives for people with schizophrenia. This Viewpoint asks why this is the case, and suggests ways forward for capitalising on extant and emerging new treatments for psychotic disorders, to the betterment of the lives of people living with schizophrenia.

Evaluating the epidemiology of clozapine-associated neutropenia among people on clozapine across Australia and Aotearoa New Zealand: a retrospective cohort study

BACKGROUND

Clozapine is associated with the risk of serious neutropenia. However, this risk might decrease over time, meaning that indefinite absolute neutrophil count (ANC) monitoring could be unnecessary. We aimed to determine the epidemiology and timing of clozapine-associated neutropenia outcomes, to investigate variables that might contribute to the odds of neutropenia, and to determine risk of competing neutropenic events during clozapine treatment.

METHODS

We performed a retrospective analysis of the Australian and New Zealand Viatris Pharmacovigilance system (one of two monitoring databases for these two countries) between June 6, 1990, and Oct 25, 2022. Patients were excluded from analysis if they commenced clozapine before 1990, did not have a haematology test within 2 weeks of commencement date, or had no follow-up. We measured minor neutropenia (ANC 1·0-1·5 × 109 per L) and serious neutropenia (ANC <1·0 × 109 per L) leading to cessation of clozapine within 6 weeks of the neutropenic event. We determined the rates of minor and serious neutropenia and calculated odds ratios (ORs) for the likelihood of neutropenia leading to cessation. For serious neutropenia leading to cessation, we used time-to-event to calculate rolling weekly averages and to perform competing risk analysis of outcomes using Cox proportional hazards models and a Fine-Gray subdistribution hazards regression model. For the subset of data where information on previous clozapine use was available, we did an analysis for participants who did and did not have previous clozapine exposure.

FINDINGS

We included 26 630 people, with 2·6 million ANC values. Within the total cohort, 17 585 people (66%) were male, 9025 (33·9%) female, and 20 (0·1%) other gender, and the mean age was 36·1 years (SD 13·7). We did not have data on race or ethnicity. Of the 26 630 people taking clozapine, 1146 (4·3%) had minor neutropenia, 313 (1·2%) had serious neutropenia leading to cessation, and 223 (0·8%) had serious neutropenia unrelated to clozapine without cessation. In people with no previous exposure to clozapine (n=15 973), the cumulative incidence of serious neutropenia leading to cessation was 0·9% at 18 weeks and 1·4% at 2 years; the weekly incidence rate for serious neutropenia leading to cessation peaked at 9 weeks (0·128%) and fell to a rolling average weekly incidence of 0·001% by 2 years. For minor neutropenia, the cumulative incidence was 1·7% at 18 weeks and 3·5% at 2 years; the weekly incidence rate peaked at 9 weeks (0·218%) and fell to a stable rolling average of 0·01%. The median time to a serious neutropenic event leading to cessation was 17 weeks (IQR 9·96-102). Previous clozapine exposure reduced the risk of serious neutropenia leading to cessation (OR 0·19, 95% CI 0·12-0·31; p <0·0001).

INTERPRETATION

Most serious neutropenia leading to clozapine cessation occurs within 18 weeks of treatment and becomes negligible after 2 years. Weekly haematological monitoring after the first 18 weeks could be safely reduced to once every 4 weeks and ceased after 2 years unless clinically indicated. Clozapine retrial after interruption with 2 cumulative years of unremarkable testing might not require further haematological monitoring. A serious neutropenia ANC threshold of ≤1·0 × 109 per L could be used in more jurisdictions.

FUNDING

None.

Deconstructing the genetic architecture of treatment-resistant schizophrenia in East Asian ancestry

BACKGROUND

Treatment-resistant schizophrenia (TRS) affects a substantial proportion of patients who do not respond adequately to antipsychotic medications, yet the underlying biological mechanism remains poorly understood. This study investigates the link between the genetic predisposition to schizophrenia and TRS.

METHODS

857 individuals diagnosed with schizophrenia were divided into TRS (n = 142) and non-TRS (n = 715) based on well-defined TRS criteria. Polygenic risk scores (PRS) were calculated using schizophrenia genome-wide association summary statistics from East-Asian and European ancestry populations. PRS was estimated using both P-value thresholding and Bayesian framework methods. Logistic regression analyses were performed to differentiate between TRS and non-TRS individuals.

RESULTS

The schizophrenia PRS derived from the East-Asian training dataset effectively distinguished between TRS and non-TRS individuals (R2 = 0.029, p = 4.86 ×10-5, pT = 0.1, OR = 1.52, 95% CI = 1.242-1.861), with higher PRS values observed in the TRS group. Similar PRS analysis was conducted based on the European ancestry GWAS summary statistics, but we found superior prediction based on the East-Asian ancestry discovery data.

CONCLUSION

This study reveals an association between common risk variants for schizophrenia and TRS status, suggesting that the genetic burden of schizophrenia may partly contribute to treatment resistance in individuals with schizophrenia. These findings propose the potential use of genetic risk factors for early TRS identification and timely access to clozapine. However, the ancestral background of the discovery sample is crucial for successfully implementing PRS in clinical settings.

Prevention of Suicidal Behavior in Bipolar Disorder

Background

Excess mortality is a critical hallmark of bipolar disorder (BD) due to co-occurring general medical disorders and especially from suicide. It is timely to review of the status of suicide in BD and to consider the possibility of limiting suicidal risk.

Methods

We carried out a semi-systematic review of recent research reports pertaining to suicide in BD.

Findings

Suicide risk in BD is greater than with most other psychiatric disorders. Suicide rates (per 100,000/year) are approximately 11 and 4 in the adult and juvenile general populations, but over 200 in adults, and 100 among juveniles diagnosed with BD. Suicide attempt rates with BD are at least 20 times higher than in the adult general population, and over 50 times higher among juveniles. Notable suicidal risk factors in BD include: previous suicidal acts, depression, mixed-agitated-dysphoric moods, rapid mood-shifts, impulsivity, and co-occurring substance abuse. Suicide-preventing therapeutics for BD remain severely underdeveloped. Evidence favoring lithium treatment is stronger than for other measures, although encouraging findings are emerging for other treatments.

Conclusions

Suicide is a leading clinical challenge for those caring for BD patients. Improved understanding of risk and protective factors combined with knowledge and close follow-up of BD patients should limit suicidal risk. Ethically appropriate and scientifically sound studies of plausible medicinal, physical, and psychosocial treatments aimed at suicide prevention specifically for BD patients are urgently needed.Reprinted from Bipolar Disord 2021; 23:14-23, with permission from John Wiley and Sons. Copyright © 2021.

Predictors of Mortality Following a Schizophrenia Spectrum Diagnosis: Evidence From the 20-Year Follow-up of the OPUS Randomized Controlled Trial

BACKGROUND AND HYPOTHESIS

The life expectancy of patients diagnosed with schizophrenia is 10-12 years lower than in the general population and the mortality gap seems to be worsening. Many of these deaths might be avoidable. We aimed to determine mortality rates and causes of death after a first-episode psychosis, and to examine if clinical characteristics at baseline or during illness could predict mortality.

STUDY DESIGN

The OPUS study was a randomized controlled trial of 578 patients first diagnosed with schizophrenia spectrum disorders. Patients were clinically assessed after 2, 5, 10, and 20 years. Information about time and cause of death was obtained from the Danish Cause of Death Register. Hazard ratios were used to assess predictors of death.

STUDY RESULTS

In total, 82 (14.4%) participants died during 20 years of follow-up. The most common cause of death was suicide (27%). At baseline employment (HR 0.47 P = .049), psychotic disorder other than schizophrenia (HR 0.36, P = .017), and longer duration of untreated psychosis (HR 0.57 P = .042) predicted lower mortality while substance use predicted higher mortality (HR 2.56, P < .001). During follow-up, symptom remission without antipsychotic medication and recovery predicted lower mortality (HR 0.08 P = .013 and HR 0.21, P = .028) while substance use (HR 3.64 P < .001), and all chronic illnesses predicted increased risk.

CONCLUSIONS

There is an increased risk of early mortality in schizophrenia compared to the background population, and there is an urgent need for new efforts to improve the disparities in health that lead to this increased mortality.

Study on the daily dose and serum concentration of clozapine in psychiatric patients and possible influencing factors of serum concentration

BACKGROUND

Clozapine is the most effective drug for treatment-resistant schizophrenia, and the dosage and concentration of clozapine in the treatment of mental illness vary greatly in different populations and are affected by many factors.

METHODS

The serum clozapine concentration of 3734 psychiatric patients was detected, and data on daily dose, sex, age and other medical records were collected for statistical analysis.

RESULTS

The mean daily dose, mean serum concentration and mean C/D (concentration/dose) ratio of clozapine were 191.02 ± 113.47 mg/day, 326.15 ± 235.66 ng/mL and 1.94 ± 1.25 ng/mL per mg/day, respectively. There was difference in daily dose between sexes, and females had higher daily dose (p <0.01), higher serum clozapine concentrations (p < 0.01) and higher C/D ratios (p < 0.01). There were significant differences in daily dose (p < 0.001), serum drug concentration (p < 0.001) and C/D ratio (p < 0.001) among different age groups. The daily dose decreased with age (p for trend < 0.001), and the C/D ratio increased with age (p for trend < 0.001). Inpatients and outpatients had no difference in daily dose, but inpatients had higher serum concentration (p < 0.001) and C/D ratio (p < 0.001). There was no difference in daily dose among different occupations, but there were significant differences in serum concentration (p < 0.001) and C/D ratio (p < 0.001), and unemployed patients may have higher serum concentration and C/D ratio. Duration of disease, comorbidity, marital status, and psychotic type may influence the daily dose and serum concentration.

CONCLUSIONS

The effective daily dose and serum concentration of clozapine in the study area may be lower than recommended levels, and women have higher serum concentrations and slower metabolic rates. With increasing age, the daily dose decreases, and the metabolic rate slows. Inpatient status and occupation of patients may influence the serum concentration and metabolic rate of clozapine.

The relations between socio-demographic information and negative symptoms, mental health, and quality of life: a latent profile analysis with psychotic patients in Kosovo

The current study aims to identify meaningful psychotic patients' profiles by examining certain combinations of patient's demographic and socio-economic variables (sex, age, marital status, number of children, cohabitant and level of education). Moreover, we aim to assess whether there is any significant effect of class membership (profile) on negative symptoms, health state, and quality of life among psychotic patients. A convenience sample of 103 patients (age: M = 22, SD = 1.75), was drawn from the clinical populations of Kosovo. Demographic and socio-economic data was obtained through individual interviews, meanwhile a battery of questionnaires was used to assess negative symptoms, mental health, and quality of life of patients. The 4-class solution was selected as the best fitting model and used in subsequent analyses. Results indicated a significant effect of class membership on health state, quality of life and negative symptoms. Practical implications are discussed.

Clozapine Optimization: A Delphi Consensus Guideline From the Treatment Response and Resistance in Psychosis Working Group

BACKGROUND AND HYPOTHESIS

There is limited evidence to guide the approaches to clozapine treatment. Accordingly, an international initiative was undertaken with the aim of developing consensus recommendations for the optimization of clozapine monotherapy.

STUDY DESIGN

We conducted an online Delphi survey among members of the Treatment Response and Resistance in Psychosis (TRRIP) working group comprising experts from twenty-nine countries. The threshold criterion for a consensus recommendation was ≥ 75% agreement ("agree" and "strongly agree" responses) on a question. Agreement of ≥ 50% but < 75% in a second or third Delphi round was deemed to provide guidance.

STUDY RESULTS

Forty-nine (first round), 32 (second round), and 48 (third round) of the 91 current TRRIP members participated. Expert recommendations at ≥ 75% comprised second-line treatment with clozapine in cases of persistent positive symptoms with co-occurring extrapyramidal symptoms, tardive dyskinesia, or suicidality/aggression. There was considerable disagreement on myocarditis screening parameters. The management of somatic and neuropsychiatric adverse drug reactions warrants further research for more evidence-based recommendations. Rechallenge with clozapine was recommended for eosinophilia, sinus tachycardia and fever and guidance (agreement ≥ 50%) was reached for pneumonia and thrombocytopenia.

CONCLUSIONS

Given the limited evidence available, this consensus-based series of recommendations and guidance statements supports clinical decision-making to optimize clozapine monotherapy and provides guidance for future research in treatment-resistant schizophrenia.

Evaluation of various scoring systems as predictors of the need for intensive care unit admission and other adverse outcomes among patients with acute clozapine poisoning

Acute clozapine poisoning (ACP) is frequently reported worldwide. We evaluated the efficacy of the Poison Severity Score (PSS), Acute Physiology and Chronic Health Evaluation II (APACHE II) score, Rapid Emergency Medicine Score (REMS), and Modified Early Warning Score (MEWS) as predictors for intensive care unit (ICU) admission, mechanical ventilation (MV), mortality, and length of hospital stay in patients with ACP. A retrospective cohort study was conducted using records of patients diagnosed with ACP from January 2017 to June 2022 and admitted to an Egyptian poison control center. Analyzing 156 records showed that all assessed scores were significant predictors of the studied outcomes. The PSS and APACHE II score showed the highest area under the curve (AUC) as ICU admission predictors with insignificant variations. The APACHE II score showed the best discriminatory power in predicting MV and mortality. Nevertheless, MEWS exhibited the highest odds ratio (OR) as an ICU predictor (OR = 2.39, and 95% confidence interval = 1.86-3.27) and as a mortality predictor (OR = 1.98, and 95% confidence interval = 1.16-4.41). REMS and MEWS were better predictors of length of hospital stay compared with the APACHE II score. The simpler, lab-independent nature and the comparable discrimination but higher odds ratio of MEWS compared with APACHE II score justify MEWS' superior utility as an outcome predictor in ACP. We recommend using either the APACHE II score or MEWS, depending on the availability of laboratory investigations, resources, and the case's urgency. Otherwise, the MEWS is a substantially feasible, economical, and bedside alternative outcome predictor in ACP.

Long-Term Outcome of Clozapine in Treatment-Resistant Schizophrenia

PURPOSE/BACKGROUND

The favorable effect of clozapine on psychotic symptoms in patients with treatment-resistant (TR) schizophrenia (SCZ) in short-term studies is well established. However, prospective studies of the long-term outcome of clozapine treatment on psychopathology, cognition, quality of life, and functional outcome in TR-SCZ are limited.

METHODS/PROCEDURES

Here, we have examined the long-term (mean duration of follow-up 14 years) effects of clozapine on those outcomes in a prospective, open label study in 54 TR-SCZ patients. Assessments were performed at baseline, 6 weeks, 6 months, and at the last follow-up.

FINDINGS/RESULTS

Brief Psychiatric Rating Scale (BPRS) total, positive symptoms, and anxiety/depression at the last follow-up improved significantly from baseline, as well as from the 6-month evaluation ( P < 0.0001), with a 70.5% responder rate (≥20% improvement at the last follow-up from baseline). Quality of Life Scale (QLS) total improved by 72% at the last follow-up, with 24% of patients rated as having "good" functioning compared with 0% at baseline. Suicidal thoughts/behavior was significantly reduced at the last follow-up from the baseline. No significant change in negative symptoms was found at the last follow-up in the total sample. Short-term memory function declined at the last follow-up from baseline, but there was no significant change in processing speed. The QLS total showed a significant negative correlation with BPRS positive symptoms but not with cognitive measures, or negative symptoms, at the last follow-up.

IMPLICATIONS/CONCLUSIONS

For patients with TR-SCZ, improving psychotic symptoms with clozapine seems to have a more significant impact than negative symptoms or cognition on improving psychosocial function.

Rates and Reasons for Clozapine Treatment Interruptions: Impact of the Frequency of Hematologic Monitoring and Cardiac Adverse Events

BACKGROUND

Differing rates and reasons for interruptions of clozapine treatment have been reported globally. This article evaluated the rates and reasons for clozapine therapy interruptions in Australia and explored the impact of the frequency of hematological monitoring on these parameters.

METHODS

Data of the patients who were newly commenced on clozapine at three metropolitan public mental health services in Western Australia over 11 years were retrospectively collated. The rate and reasons for clozapine therapy interruptions and their association with the frequency of hematological monitoring, age, sex, and treatment site were analyzed using parametric, nonparametric, and correlational analyses.

RESULTS

Of the 457 patients whose data were collected, 69.6% had an interruption of treatment with 41.2% of those occurring during the period of mandatory weekly hematological monitoring in the first 18 weeks. Nonadherence (57.4%) and adverse effects (28.8%) were the 2 main reasons for the treatment interruptions. Cardiac issues accounted for the majority of the interruptions (61.8%) due to specified adverse effects, and these occurred significantly more commonly within the first 18 weeks. Location, age, and sex did not predict the possibility of treatment interruptions.

CONCLUSIONS

The high rates of clozapine treatment interruption observed during the period of weekly monitoring point toward the need to address the burden of frequent hematological monitoring for patients. Disproportionately higher rates of interruption due to cardiac adverse effects observed in this study compared with research from non-Australian settings raise the possibility of geographical differences in the adverse effects leading to treatment discontinuation.

Physical and mental health status of former smokers and non-smokers patients with bipolar disorder

OBJECTIVES

Up to 70% individuals with bipolar disorder (BD) are lifetime tobacco smokers, a major modifiable risk factor for morbidity. However, quitting smoking is rarely proposed to individuals with BD, mainly because of fear of unfavorable metabolic or psychiatric changes. Evaluating the physical and mental impact of tobacco cessation is primordial. The aim of this study was to characterize the psychiatric and nonpsychiatric correlates of tobacco smoking status (never- vs. current vs. former smokers) in individuals with BD.

METHODS

3860 individuals with ascertained BD recruited in the network of Fondamental expert centers for BD between 2009 and 2020 were categorized into current, former, and never tobacco smokers. We compared the sociodemographic and clinical characteristics assessed by standard instruments (e.g., BD type, current symptoms load, and non-psychiatric morbidity-including anthropometric and biological data) of the three groups using multinomial regression logistic models. Corrections for multiple testing were applied.

RESULTS

Current smokers had higher depression, anxiety, and impulsivity levels than former and never-smokers, and also higher risk of comorbid substance use disorders with a gradient from never to former to current smokers-suggesting shared liability. Current smokers were at higher risk to have a metabolic syndrome than never-smokers, although this was only evidenced in cases, who were not using antipsychotics.

CONCLUSIONS

Tobacco smoking was associated with high morbidity level. Strikingly, as in the general population, quitting smoking seemed associated with their return to the never-smokers' levels. Our findings strongly highlight the need to spread strategies to treat tobacco addiction in the BD population.

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

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