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

What is the current scope of research assessing patients' and clinicians' perspectives on clozapine treatment? A comprehensive scoping review

OBJECTIVES

Clozapine is continuously underused. The existing systematic reviews addressing barriers to clozapine prescribing primarily focus on clinical staff's attitudes and perceived barriers to prescribing. However, a preliminary literature search revealed additional literature on the subject not previously included in systematic reviews, including literature on patient perspectives. A scoping review is warranted to map the scope of primary studies on patients' and/or clinicians' perspectives on clozapine treatment and to identify gaps in research.

DESIGN

A scoping review was designed and reported in accordance with established guidelines for scoping reviews.

DATA SOURCES

The electronic databases Cochrane Library, CINAHL, Web of Science, PsycINFO, MEDLINE, EMBASE, Google Scholar and two grey literature databases were searched. Furthermore, citation tracking of selected studies was undertaken.

ELIGIBILITY CRITERIA

We included primary, empirical studies reporting clinicians' and/or patients' perspectives on clozapine treatment. No limitation was set for the year of publication or type of primary study.

DATA EXTRACTION AND SYNTHESIS

Two researchers independently screened for studies, extracted the data and coded the content. Findings were summarised visually and narratively.

RESULTS

146 studies were included. Most studies reported on patients' or clinicians' perspectives on active clozapine treatment or on clinicians' perspectives on barriers to clozapine initiation in general. Three gaps in research were identified: (1) clozapine-eligible, yet clozapine-naïve, patients' attitudes towards clozapine commencement, (2) clinicians' reasons for clozapine withholding and perceived facilitators of clozapine treatment in specific patient-cases and (3) patient and clinician perspectives on clozapine discontinuation, continuation and rechallenge in specific patient cases.

CONCLUSIONS

Research on clozapine perspectives tends to repeat itself. Future studies addressing the identified gaps in evidence could provide the insights needed to optimise clozapine utilisation.

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.

Early Treatment-Resistance in First Episode Psychosis

INTRODUCTION

Approximately 30% of individuals with schizophrenia experience treatment resistance (TR), with 70% exhibiting it from the onset. Most research fails to distinguish between acquired and innate resistance, with limited data on TR in first episode psychosis (FEP). However, FEP patients with TR experience progressively worse outcomes compared to those with initial response. To further understand these findings, clinical and demographic data of FEP patients with and without TR were compared in this naturalistic study.

METHODS

Information was extracted on FEP patients who were antipsychotic-naive at the time of admission from a retrospective database on F2x diagnosed patients admitted to the LMU psychiatric clinic between 2008 and 2018. Clozapine was used at discharge as a marker of TR in the FEP cohort. A similarly antipsychotic-naïve FEP control group without clozapine at discharge, was generated by matching for gender and age. Thirty clinical and demographic variables were analyzed to identify differences.

RESULTS

Two-hundred forty antipsychotic-naive FEPs were included: 33 with clozapine at discharge (TRC group), and 207 in the control group (non-TRC). Significant differences were observed in inpatient stay duration, chlorpromazine-equivalent dosage, number of antipsychotics, and anticholinergic medication at discharge.

DISCUSSION

The findings indicate that longer inpatient stay, an increased number of antipsychotics, and possibly a more extended prodrome may serve as markers for non-clozapine TR in FEP. Further research is necessary to establish the robustness of these variables as early-stage TR markers.

Medical, Psychiatric, and Sociodemographic Predictors of Clozapine Initiation at an Academic Medical Center

Background and Hypothesis

Clozapine is an effective yet underutilized treatment for treatment-resistant schizophrenia spectrum disorders. This study aimed to identify factors affecting clozapine prescribing patterns among patients with treatment-resistant schizophrenia and schizoaffective disorder at an academic medical center.

Study Design

This retrospective combined cohort and case-control study examined demographic, socioeconomic, medical and psychiatric characteristics to determine predictors of clozapine initiation. Eligible patients had a diagnosis of schizophrenia or schizoaffective disorder with at least two prior antipsychotic trials and were admitted to a University of Utah inpatient psychiatric facility (1/2014-3/2021). Patients who did and did not receive clozapine during the index hospitalization were compared in cohort and case-control study arms.

Study Results

Twelve percent (59/477) of the cohort received clozapine during the index admission. Among the cohort (n = 477), Black patients were twice as likely to receive clozapine than White and Hispanic patients (OR 2.18, 95% CI 1.20-3.97, p = 0.008). In the case-control analysis, patients with a greater number of previous psychiatric admissions (OR 1.14, p = 0.079) and antipsychotic trials (OR 1.40, p = 0.038) had greater odds of receiving clozapine. Homelessness was identified as a predictor against clozapine use (OR 2.77, p = 0.014).

Conclusions

This is the first study to identify homelessness as a predictor against clozapine use, which raises important clinical and ethical considerations. Our findings also add to the literature on clozapine prescribing discrepancies among ethnic-minority patients. Overall, clozapine remains underutilized as the gold-standard treatment for treatment-resistant schizophrenia-spectrum disorders, reinforcing a need to improve evidence-based prescribing.

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.

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.

A qualitative study of clinicians' perspectives on reasons for delays in clozapine initiation

OBJECTIVES

To elicit mental health clinicians' views on the reasons for delayed initiation of clozapine treatment.

METHOD

Thematic analysis of transcripts from a semi-structured interview of 15 mental health clinicians.

RESULTS

Four major themes emerged from data analysis: Patient and Carer Factors, Medication factors, Protocol factors, and Prescriber factors. Patient and carer anxiety over side effects and experience of stigma, difficulties in implementing the monitoring protocol, problems with community managing of treatment, prescriber preferences and practices, and gaps in mental health services were some of the reasons identified.

CONCLUSION

Education and support to patients and carers, a modified monitoring protocol, establishing clozapine clinics, improved early intervention services, and upskilling of clinicians can promote early clozapine initiation.

Non-prescribing of clozapine for outpatients with schizophrenia in real-world settings: The clinicians' perspectives

Clozapine is the gold standard for treating treatment-resistant schizophrenia although continuously underutilized. Previous surveys of clinicians have found that some of the most frequently cited barriers to clozapine prescribing are related to the blood-monitoring requirements. However, these surveys tend to explore general perspectives and may not reflect the true impact of different barriers in real-world outpatient settings. This study aimed to explore this issue. First, by surveying the clinicians responsible for the treatment of 39 clozapine-eligible, yet clozapine-naive, outpatients with schizophrenia. Then, based on the survey results, explanatory interviews with the participating psychiatrists were conducted and analyzed thematically. The most frequently cited reason for non-prescribing of clozapine was the expected non-compliance with blood-monitoring requirements; however, overall stability and/or severe mental illness was chosen as the most important reason in most patient-cases. The qualitative analysis highlighted the combined impact of standard clinical practice, personal experiences, and organizational constraints on clozapine utility.

A systematic review of clozapine-associated inflammation and related monitoring

Clozapine is an effective antipsychotic medication used for treatment-resistant schizophrenia. However, it is underutilized due to rigorous hematologic monitoring requirements and many adverse drug reactions. Publications have highlighted the occurrence of inflammatory reactions, some life-threatening, particularly during the early stages of clozapine treatment. Although guidelines have suggested monitoring for inflammatory processes during clozapine initiation, screening in clinical practice is not universal. This systematic review aimed to investigate the relationship between clozapine and inflammation and assess the importance of monitoring for inflammatory reactions. A comprehensive literature search yielded 6915 unique publication records after removal of duplicates. After a rigorous screening process, 75 publications were included in the review, which focused on three main aspects: (i) the impact of clozapine on inflammatory markers, (ii) monitoring cardiac and other organ function during clozapine-associated inflammatory processes, and (iii) monitoring non-specific signs and symptoms of inflammation. Elevated levels of C-reactive protein (CRP) and several proinflammatory cytokines have been observed in association with clozapine treatment. However, the practicality of measuring specific markers in clinical practice remains uncertain. Current evidence supports monitoring CRP levels during the first 4-8 weeks of treatment, especially to facilitate myocarditis screening. Further research is needed to establish clinically relevant CRP thresholds for intervention. The implementation of monitoring protocols during the early phase of clozapine treatment may mitigate adverse reactions and allow for continued use of clozapine. Future studies should also explore the association between clozapine-associated inflammation and pneumonia, as well as investigate the impact of inflammation on clozapine metabolism to predict the need for dose adjustment. These endeavors may facilitate the development and implementation of evidence-based guidelines for the monitoring of clozapine-associated inflammation.

Outcomes 1 year after a first episode of psychosis in migrants to the Republic of Ireland

BACKGROUND

Migration is a robust risk factor for developing a psychotic disorder, yet there is a paucity of research on the outcomes of migrants who develop a psychotic disorder. Identifying sub-groups within FEP cohorts who have a poorer outcome, could assist in the development and delivery of more targeted interventions.

AIMS

There is a paucity of research on the outcomes of migrants who develop a psychotic disorder. This study aimed to evaluate a broad range of outcomes for those with a FEP who migrated to the Republic of Ireland, including: (i) symptomatic; (ii) functional; (iii) hospitalisation and (iv) engagement with psychosocial services.

METHODS

All individuals with a FEP aged 18 to 65 who presented between 01.02.2006 and 01.07.2014 were included. Structured and validated instruments were used to measure positive, negative, depressive symptoms and insight.

RESULTS

Of the 573 individuals with a FEP, 22.3% were first-generation migrants and 63.4% (n = 363) were followed up at 1 year. At this time, 72.4% of migrants were in remission of positive psychotic symptoms compared to 78.5% of the Irish born (OR = 0.84, 95% CI [0.50-1.41], p = .51). In relation to negative symptoms, 60.5% of migrants were in remission compared to 67.2% of the Irish born (OR = 0.75, 95% CI [0.44-1.27], p = .283). There was no difference in the severity of positive, negative or depressive symptoms between groups and there was a trend for the Irish born to have better insight (p = .056). The functional outcomes were similar across groups. One third of migrants were admitted to hospital compared to 28.7% of the Irish born (OR = 1.24, 95% CI [0.73-2.13], p = .426). Just over half of both groups attended CBT and 46.2% of caregivers for migrants attended the psychoeducation programme, compared to 39.7% for the Irish born (OR = 1.30, 95% CI [0.79-2.16], p = .306).

CONCLUSIONS

These findings demonstrate that migrants have broadly similar outcomes to the native-born populations, however there is still considerable scope for the outcomes for all individuals affected by psychotic disorders to be improved.

[Safety aspects during treatment with clozapine: : Adverse effects, titration, and therapeutic drug monitoring - a narrative review]

BACKGROUND

According to current guidelines, clozapine should be used as a third step in treatment resistant schizophrenia (TRS). In everyday clinical practice, however, it is frequently used at a much later stage, which leads to a significant deterioration of prognosis. The first part of this narrative overview focuses on the most frequent side effects of clozapine, on the relevance of slow titration, and on specific aspects of therapeutic drug monitoring (TDM).

MATERIAL AND METHODS

Medline, the Guideline for the use of clozapine 2013 of the Netherlands Clozapine Collaboration Group, and the S3 Guideline for Schizophrenia of the German Association for Psychiatry, Psychotherapy and Psychosomatics were searched for relevant literature, the last query dating from April 28th, 2023.

RESULTS

Despite its unique efficacy clozapine is underused in clinical practice and prescription varies between and within countries. Next to hematological, metabolic, and vegetative side effects, clozapine induced inflammation manifesting in the form of pneumonia or myocarditis, which is mainly associated with rapid titration, represents a major clinical challenge with CRP monitoring being of particular relevance. In this context, it also has to be noted that sex, smoking behavior, and ethnic origin impact clozapine metabolism, thus requiring personalized dosing.

CONCLUSION

Slow titration when possible, TDM, and CYP diagnostics when appropriate increase patient safety during treatment with clozapine and thus the likelihood of early prescription of this compound in TRS.

Early Non-Response to Antipsychotic Treatment in Schizophrenia: A Systematic Review and Meta-Analysis of Evidence-Based Management Options

BACKGROUND

Early non-response is a well-established prognostic marker but evidence-based and consistent recommendations to manage it are limited. The aim of this systematic review and meta-analysis was to generate evidence-based strategies for the management of schizophrenia patients with early non-response to 2 weeks of antipsychotic treatment.

METHODS

We conducted a systematic review and meta-analysis of randomized trials comparing antipsychotic dose escalation, switch, augmentation and continuation in individuals with study-defined early antipsychotic treatment non-response. Eligibility criteria were (1) clinical trials of primary psychosis treating for at least 2 weeks with antipsychotic monotherapy with study-defined operationalized criteria for early non-response; and (2) randomization to at least two of the following treatment strategies: dose escalation, switch, augmentation, or treatment continuation. Information sources were Pubmed, PsycINFO, and EMBASE, and risk of bias was assessed using Jadad scores. Results were synthesized using random-effects meta-analysis, comparing each intervention with treatment continuation for total symptom change as the primary outcome, generating standardized mean differences (SMDs) and 95% confidence intervals (CIs). Studies meeting the selection criteria but providing insufficient data for a meta-analysis were presented separately.

RESULTS

We screened 454 records by 1 August 2022, of which 12 individual datasets met the inclusion criteria, representing 947 research participants. Of those studies, five provided data to include in the meta-analysis (four with early non-response at 2 weeks, one at 3 weeks). Early non-response was defined within a timeline of 2 weeks in eight datasets, with the remaining datasets ranging between 3 and 4 weeks. The rates of early non-response ranged between 72.0 and 24.1%, and the endpoint ranged within 4-24 weeks post randomization. Quality was good (i.e., Jadad score of ≥3) in 8 of the 12 datasets. Overall, three studies compared antipsychotic switch versus continuation and two compared antipsychotic switch versus augmentation, in both cases without significant pooled between-group differences for total symptom severity (n = 149, SMD 0.18, 95% CI -0.14 to 0.5). Individually, two relatively large studies for antipsychotic switch versus continuation found small advantages for switching antipsychotics for total symptom severity (n = 149, SMD -0.49, 95% CI -1.05 to -0.06). One relatively large study found an advantage for dose escalation, although this finding has not been replicated and was not included in the meta-analysis. None of the alternatives included antipsychotic switch to clozapine.

CONCLUSIONS

Despite robust accuracy of early antipsychotic non-response predicting ultimate response, the evidence for treatment strategies that should be used for early non-response after 2-3 weeks is limited. While meta-analytic findings were non-significant, some individual studies suggest advantages of antipsychotic switch or dose escalation. Therefore, any conclusions should be interpreted carefully, given the insufficient high-quality evidence.

Lost in Translation: Challenges in the Diagnosis and Treatment of Early-Onset Schizophrenia

Early-onset schizophrenia (EOS) is a heterogeneous condition that has a serious, insidious clinical course and poor long-term mental health outcomes. The clinical presentations are highly complex due to the overlapping symptomatology with other illnesses, which contributes to a delay in the diagnosis. The objective of the review is to study if an earlier age of onset (AAO) of EOS has poor clinical outcomes, the diagnostic challenges of EOS, and effective treatment strategies. The review provides a comprehensive literature search of 5966 articles and summarizes 126 selected for empirical evidence to methodically consider challenges in diagnosing and treating EOS for practicing clinicians. The risk factors of EOS are unique but have been shared with many other neuropsychiatric illnesses. Most of the risk factors, including genetics and obstetric complications, are nonmodifiable. The role of early diagnosis in reducing the duration of untreated psychosis (DUP) remains critical to reducing overall morbidity. Many specific issues contribute to the risk and clinical outcomes. Therefore, issues around diagnostic ambiguity, treatment resistance, nonadherence, and rehospitalizations further extend the DUP. There is hesitancy to initiate clozapine early, even though the empirical evidence strongly supports its use. There is a growing body of research that suggests the use of long-acting injectables to address nonadherence, and these measures are largely underutilized in acute settings. The clinical presentations of EOS are complex. In addition to the presence of specific risk factors, patients with an early onset of illness are also at a higher risk for treatment resistance. While there is a need to develop tools for early diagnosis, established evidence-based measures to address nonadherence, psychoeducation, and resistance must be incorporated into the treatment planning.

What are the barriers and facilitators of clozapine use in early psychosis? A survey of UK early intervention clinicians

Clozapine is the most effective medication for treatment-resistant psychosis, but evidence points to substantial underuse, especially within early intervention psychosis (EIP) services. We explored clinicians' views on perceived barriers and facilitators to offering patients clozapine within EIP services. A cross-sectional survey was distributed electronically to clinicians practising in EIP services across England. A mixed methods approach was used to assess barriers to clozapine, and attitudes and opinions concerning clozapine underutilisation. Based on the barriers identified in the literature, clinicians were asked to rate each one (scale:1-7) based on importance, with a higher score indicating higher importance. Clinicians were also asked open-ended questions on barriers to clozapine and how access can be improved in EIP services. Quantitative data were analysed using descriptive and inferential statistics, and qualitative responses were analysed thematically. One hundred and nineteen EIP clinicians from 35 services in England completed the survey. In total, 37% (n = 45) of clinicians perceived that clozapine was under-prescribed in their EIP service. The most important barrier to utilising clozapine were patient concerns with side effects, followed by monitoring requirements and clinician concerns with side effects. Thematic analysis identified 17 perceived barriers, which were grouped into three major themes: administrative (5 subthemes), clinician-related (6 subthemes), and patient-related (6 subthemes). Perceived facilitators to improving clozapine use were greater training, improved resources, and optimised monitoring. The main barriers to clozapine in EIP services, as identified by clinicians, are patient concerns regarding side effects and monitoring requirements. Identified facilitators for improved clozapine use include clinician training, improved resources, guidelines, and point-of-care testing.

Dopamine supersensitivity psychosis and delay of clozapine treatment in patients with treatment-resistant schizophrenia

Both the underutilization of clozapine and treatment resistance of patients to clozapine are serious problems worldwide. Identifying clinical markers predicting response to clozapine would help clinicians more effectively utilize clozapine treatment. The present study retrospectively assessed dopamine supersensitivity psychosis (DSP) in addition to other measures such as age at disease onset and delay of clozapine introduction for a total of 47 treatment-resistant schizophrenia (TRS) patients. The response to clozapine was judged with CGI-C at 1 and 2 years from clozapine introduction. Results revealed that the DSP group tended to have a longer delay between designation of TRS and introduction of clozapine and continued to have slightly more severe psychopathology after treatment with clozapine, showing only slight improvement. The logistic regression analysis showed that the age at disease onset was the only significant indicator, predicting responsiveness to clozapine: patients with an onset age <20 years had a significantly better response to clozapine than patients with an onset age ≥20 years. The present study suggests that DSP might be related to a longer delay in clozapine introduction and the persistence of refractory symptoms despite clozapine treatment, whereas early age of disease onset might be related to a better response to clozapine.

Antipsychotic prescribing practices for outpatients with schizophrenia and reasons for non-clozapine treatment - Data from a Danish quality assessment audit

BACKGROUND

Clozapine is the gold standard for treating treatment-resistant schizophrenia (TRS) although widely underutilised. Both organisational, patient- and clinician related reasons for the underutilisation have been reported, however, the clinical impact of either in real-world settings is not fully elucidated.

AIM

This audit aimed to evaluate the local antipsychotic (AP) prescribing practices for outpatients with schizophrenia and to assess the spectrum and prevalence of journalised reasons for non-clozapine treatment amongst eligible outpatients.

METHODS

Data on demographics, current and former AP treatments, as well as documented reasons for non-clozapine treatment, was extracted through chart audit.

RESULTS

Of the 668 affiliated outpatients with schizophrenia, 43% were treated with AP polytherapy (APP) and 19.6% with clozapine. The most prevalent reason for clozapine discontinuation was related to side effects whereas the most prevalent reason for refusal or omission of clozapine treatment was related to the associated monitoring regimen.

CONCLUSIONS

This audit showed that APP prescribing is a highly prevalent practice in our services when treating outpatients with schizophrenia and that clozapine is underutilised in a 'last resort' manner. The blood-monitoring regimen associated with clozapine treatment was found to be an important factor in the underutilisation. It seemed, however, that the monitoring constituted a barrier for different reasons, requiring different approaches to remedy. Future studies, directly involving both patients and clinicians in the identification and management of the most clinically relevant barriers and their corresponding facilitators, are warranted.

Genetic determinants associated with response to clozapine in schizophrenia: an umbrella review

OBJECTIVE

Clozapine response varies widely from person to person, which may be due to inter-individual genetic variability. This umbrella review aims to summarize the current evidence on associations between pharmacodynamic genes and response to clozapine treatment.

METHODS

Following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis methodology, a systematic literature search was conducted in the PubMed and EMBASE databases from inception to November 2021 to identify systematic reviews and meta-analyses of studies that examined genetic determinants of clozapine response. The quality of the reviews was assessed with the AMSTAR-2 tool.

RESULTS

From a total of 128 records, 10 studies representing nine systematic reviews and one meta-analysis met our inclusion criteria. The overall quality of the included studies was poor. All systematic reviews concluded that the results of primary studies were largely negative or conflicting. Most evidence was found for an association with clozapine response and rs6313 and rs6314 within HTR2A and rs1062613 within HTR3A in the serotonergic system.

CONCLUSIONS

Conclusive evidence for associations between genetic variants and clozapine response is still lacking. Hypothesis-generating genetic studies in large, well-characterized study populations are urgently needed to obtain more consistent and clinically informative results. Future studies may also include multi-omics approaches to identify novel genetic determinants associated with clozapine response.

A Guideline and Checklist for Initiating and Managing Clozapine Treatment in Patients with Treatment-Resistant Schizophrenia

Treatment-resistant schizophrenia (TRS) will affect about one in three patients with schizophrenia. Clozapine is the only treatment approved for TRS, and patients should be treated as soon as possible to improve their chances of achieving remission. Despite its effectiveness, concern over side effects, monitoring requirements, and inexperience with prescribing often result in long delays that can expose patients to unnecessary risks and compromise their chances of achieving favorable long-term outcomes. We critically reviewed the literature on clozapine use in TRS, focusing on guidelines, systematic reviews, and algorithms to identify strategies for improving clozapine safety and tolerability. Based on this, we have provided an overview of strategies to support early initiation of clozapine in patients with TRS based on the latest evidence and our clinical experience, and have summarized the key elements in a practical, evidence-based checklist for identifying and managing patients with TRS, with the aim of increasing confidence in prescribing and monitoring clozapine therapy.

Quality prescribing in early psychosis: key pharmacotherapy principles

OBJECTIVE

To present a practical, easy-to-implement clinical framework designed to support evidence-based quality prescribing for people with early psychosis.

METHOD

Identification and explanation of key principles relating to evidence-based pharmacotherapy for people with early psychosis. These were derived from the literature, practice guidelines and clinical experience.

RESULTS

Key principles include (1) medication choice informed by adverse effects; (2) metabolic monitoring at baseline and at regular intervals; (3) comprehensive and regular medication risk-benefit assessment and psychoeducation; (4) early consideration of long-acting injectable formulations (preferably driven by informed patient choice); (5) identification and treatment of comorbid mood disorders and (6) early consideration of clozapine when treatment refractory criteria are met.

CONCLUSIONS

Current prescribing practices do not align with the well-established evidence for quality pharmacotherapy in early psychosis. Adopting evidence-based prescribing practices for people with early psychosis will improve outcomes.

Patients' Experiences of Clozapine for Treatment-Resistant Schizophrenia: A Systematic Review

Background

Clozapine is the most effective antipsychotic for patients with treatment-resistant schizophrenia (TRS), however, it remains widely under-utilized in clinical practice. To date, relatively little attention has been given to patients' experience of clozapine. By synthesizing the existing literature, we sought to determine the experiences of patients with TRS treated with clozapine.

Methods

A systematic review was conducted on Embase, Medline, PsychInfo, and PubMed databases for studies from 1956 to 2021. English language studies and those based on adult patients prescribed clozapine for TRS were included.

Results

Thirteen studies were included with a total of 1487 patients and a narrative synthesis was performed. Overall, most patients reported positive experiences of clozapine, with generally high levels of satisfaction, alongside symptom improvement and preference over previous medications. Negative experiences of clozapine were less common, but when mentioned, focused on blood tests and common side effects, including hypersalivation and weight gain.

Conclusions

This is the first systematic review exploring patients' subjective experiences of clozapine for TRS. Findings suggest that patients generally have a favorable experience when being treated with clozapine. However, conclusions are limited by the risk of bias, particularly survivorship bias. High-quality longitudinal studies exploring patients' experiences of clozapine are indicated for the future.

Early intervention services, patterns of prescription and rates of discontinuation of antipsychotic treatment in first-episode psychosis

AIMS

Non-compliance is still an important problem in psychotic patients. Although antipsychotic (AP) treatment leads to a decrease in psychotic relapses, there are no clear recommendations about how long treatment should be maintained after first-episode psychosis (FEP) and no indication of the rates and causes of treatment withdrawal in this group.

METHODS

We evaluated a large sample of patients with FEP for 2 years to compare the time to all-cause treatment discontinuation of AP drugs and the time to the first relapse. We collected the sociodemographic and psychopathological characteristics of the sample. The number of relapses was also recorded.

RESULTS

A total of 310 FEP patients were assessed across seven early intervention teams (mean age = 30.2 years; SD = 11.2). The most prevalent diagnosis at baseline was psychotic disorder not otherwise specified (36.1%), and the most commonly used APs were risperidone (26.5%) and olanzapine (18.7%). A lack of efficacy was the most frequent reason for the withdrawal of the first AP prescribed, followed by non-compliance. There were no differences in the relapse rates between different APs. Patients treated with long-acting injectable (LAI) APs presented less disengagement from services than patients treated with oral APs.

CONCLUSIONS

Although there were no differences between the different APs in terms of relapse rates, LAIs had higher retention rates than oral APs in early intervention services. Compliance is still an important issue in Psychiatry, so clinicians should use different strategies to encourage it, such as the use of LAI treatments.

Clozapine prescribing barriers in the management of treatment-resistant schizophrenia: A systematic review

BACKGROUND

Treatment-resistant schizophrenia is prevalent and difficult to manage, as patients fail multiple antipsychotic trials before being considered as treatment-resistant. Currently clozapine is the only Food and Drug Administration-approved pharmacotherapy for treatment-resistant schizophrenia but remains under-prescribed. The purpose of this study is to investigate recent literature on clozapine in order to identify barriers to prescribing clozapine and categorize the recommended solutions.

METHODS

We conducted a systematic review following Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Using free text and the medical subject headings, we searched MEDLINE/PubMed electronic bibliographic database from 2017 until 2020. Eligible studies included peer-reviewed English language articles with multiple methodologies aiming to identify clozapine barriers in treatment-resistant schizophrenia. We used search terms combining clozapine AND treatment OR treatment-resistant schizophrenia AND barriers AND prescribing OR prescription OR prescriber. We merged search results in a citation manager software, removed duplicates, and screened the remaining articles based on the study eligibility criteria.

RESULTS

We retrieved 123 studies, however, only 10 articles exclusively met the study inclusion criteria for full text review. These studies represented 20 countries; 6 were exclusively conducted in the US. The top barriers delineated by the studies include: providers' lack of knowledge and training (n = 7), concern about side effects (n = 8), and poor adherence (n = 7). All studies described more than 1 barrier. Other barriers included prescriber-perceived barriers (n = 4), administrative barriers (n = 5), and other healthcare systems-related barriers (n = 3). Top recommendations to overcome clozapine prescription barriers included improving prescriber clozapine education/training, utilizing interdisciplinary teams and providing integrated care via clozapine clinics, and simplifying blood test monitoring.

CONCLUSION

Clozapine remains under-prescribed for patients with treatment-resistant schizophrenia due to multiple barriers related to the individual prescriber, system of care, and technology. It is recommended that by improving prescriber knowledge and training, use of integrated care, and use of technology that can enable continuous, real-time blood test monitoring, these barriers may be overcome.

Patients' and psychiatrists' perspectives on clozapine treatment-a scoping review protocol

INTRODUCTION

The atypical antipsychotic clozapine has shown superior efficacy compared with other antipsychotics and is the gold standard for treating otherwise treatment resistant schizophrenia. However, multiple studies have found that clozapine is underutilised in most parts of the world. A few reviews of literature addressing barriers to clozapine prescribing have been conducted. While there is some variation in the literature included in these reviews, a common feature of the studies included is that they primarily focus on clinical staff's attitudes and perceived barriers for prescribing. Studies of patient perspectives are only sparsely included. A preliminary literature search revealed though, that additional literature on the subject exists, including literature on patient perspectives. It is therefore difficult to conclude if the formerly synthesised literature is representative of current evidence or if the topic has been adequately investigated to inform clinical practice. A scoping review is warranted in order to map and synthesise primary literature on patients' and psychiatrists' perspectives on clozapine treatment, and to identify gaps for future research.

METHODS AND ANALYSIS

The electronic databases Cochrane Library, CINAHL, Web of Science, Psychinfo, MEDLINE and EMBASE will be searched for relevant publications, supplied with searches of Google scholar, The Networked Digital Library of Theses and Dissertations and OpenGrey. Citation tracking of selected studies will furthermore be undertaken. Two researchers will independently screen and extract data. Data will be collated to provide a descriptive summary of the literature, along with a qualitative content analysis of key findings. Identified gaps in research will be accompanied by recommendations for future investigations.

ETHICS AND DISSEMINATION

Findings will be disseminated through a peer-reviewed journal and conference presentations. The scoping review does not require ethics approval.

Efficacy and safety of clozapine in psychotic disorders-a systematic quantitative meta-review

A recent increase in the literature regarding the evidence base for clozapine has made it increasingly difficult for clinicians to judge "best evidence" for clozapine use. As such, we aimed at elucidating the state-of-the-art for clozapine with regard to efficacy, effectiveness, tolerability, and management of clozapine and clozapine-related adverse events in neuropsychiatric disorders. We conducted a systematic PRISMA-conforming quantitative meta-review of available meta-analytic evidence regarding clozapine use. Primary outcome effect sizes were extracted and transformed into relative risk ratios (RR) and standardized mean differences (SMD). The methodological quality of meta-analyses was assessed using the AMSTAR-2 checklist. Of the 112 meta-analyses included in our review, 61 (54.5%) had an overall high methodological quality according to AMSTAR-2. Clozapine appears to have superior effects on positive, negative, and overall symptoms and relapse rates in schizophrenia (treatment-resistant and non-treatment-resistant subpopulations) compared to first-generation antipsychotics (FGAs) and to pooled FGAs/second-generation antipsychotics (SGAs) in treatment-resistant schizophrenia (TRS). Despite an unfavorable metabolic and hematological adverse-event profile compared to other antipsychotics, hospitalization, mortality and all-cause discontinuation (ACD) rates of clozapine surprisingly show a pattern of superiority. Our meta-review outlines the superior overall efficacy of clozapine compared to FGAs and most other SGAs in schizophrenia and suggests beneficial efficacy outcomes in bipolar disorder and Parkinson's disease psychosis (PDP). More clinical studies and subsequent meta-analyses are needed beyond the application of clozapine in schizophrenia-spectrum disorders and future studies should be directed into multidimensional clozapine side-effect management to foster evidence and to inform future guidelines.

Cost and health impacts of adherence to the National Institute for Health and Care Excellence schizophrenia guideline recommendations

BACKGROUND

Discrepancies between the National Institute for Health and Care Excellence (NICE) schizophrenia guideline recommendations and current clinical practice in the UK have been reported.

AIMS

We aim to assess whether it is cost-effective to improve adherence to the NICE schizophrenia guideline recommendations, compared with current practice.

METHOD

A previously developed whole-disease model for schizophrenia, using the discrete event simulation method, was adapted to assess the cost and health impacts of adherence to the NICE recommendations. Three scenarios to improve adherence to the clinical guidelines were modelled: universal provision of cognitive-behavioural therapy for patients at clinical high risk of psychosis, universal provision of family intervention for patients with first-episode psychosis and prompt provision of clozapine for patients with treatment-resistant schizophrenia. The primary outcomes were lifetime costs and quality-adjusted life-years gained.

RESULTS

The results suggest full adherence to the guideline recommendations would decrease cost and improve quality-adjusted life-years. Based on the NICE willingness-to-pay threshold of £20 000-£30 000 per quality-adjusted life-year gained, prompt provision of clozapine for patients with treatment-resistant schizophrenia results in the greatest net monetary benefit, followed by universal provision of cognitive-behavioural therapy for patients at clinical high risk of psychosis, and universal provision of family intervention for patients with first-episode psychosis.

CONCLUSIONS

Our results suggest that adherence to guideline recommendations would decrease cost and improve quality-adjusted life-years. Greater investment is needed to improve guideline adherence and therefore improve patient quality of life and realise potential cost savings.

A Synthetic Literature Review on the Management of Emerging Treatment Resistance in First Episode Psychosis: Can We Move towards Precision Intervention and Individualised Care?

Treatment resistance is prevalent in early intervention in psychosis services, and causes a significant burden for the individual. A wide range of variables are shown to contribute to treatment resistance in first episode psychosis (FEP). Heterogeneity in illness course and the complex, multidimensional nature of the concept of recovery calls for an evidence base to better inform practice at an individual level. Current gold standard treatments, adopting a ‘one-size fits all’ approach, may not be addressing the needs of many individuals. This following review will provide an update and critical appraisal of current clinical practices and methodological approaches for understanding, identifying, and managing early treatment resistance in early psychosis. Potential new treatments along with new avenues for research will be discussed. Finally, we will discuss and critique the application and translation of machine learning approaches to aid progression in this area. The move towards ‘big data’ and machine learning holds some prospect for stratifying intervention-based subgroups of individuals. Moving forward, better recognition of early treatment resistance is needed, along with greater sophistication and precision in predicting outcomes, so that effective evidence-based treatments can be appropriately tailored to the individual. Understanding the antecedents and the early trajectory of one’s illness may also be key to understanding the factors that drive illness course.

Prevalence of treatment resistance and clozapine use in early intervention services

BACKGROUND

Treatment resistance causes significant burden in psychosis. Clozapine is the only evidence-based pharmacologic intervention available for people with treatment-resistant schizophrenia; current guidelines recommend commencement after two unsuccessful trials of standard antipsychotics.

AIMS

This paper aims to explore the prevalence of treatment resistance and pathways to commencement of clozapine in UK early intervention in psychosis (EIP) services.

METHOD

Data were taken from the National Evaluation of the Development and Impact of Early Intervention Services study (N = 1027) and included demographics, medication history and psychosis symptoms measured by the Positive and Negative Syndrome Scale (PANSS) at baseline, 6 months and 12 months. Prescribing patterns and pathways to clozapine were examined. We adopted a strict criterion for treatment resistance, defined as persistent elevated positive symptoms (a PANSS positive score ≥16, equating to at least two items of at least moderate severity), across three time points.

RESULTS

A total of 143 (18.1%) participants met the definition of treatment resistance of having continuous positive symptoms over 12 months, despite treatment in EIP services. Sixty-one (7.7%) participants were treatment resistant and eligible for clozapine, having had two trials of standard antipsychotics; however, only 25 (2.4%) were prescribed clozapine over the 12-month study period. Treatment-resistant participants were more likely to be prescribed additional antipsychotic medication and polypharmacy, instead of clozapine.

CONCLUSIONS

Prevalent treatment resistance was observed in UK EIP services, but prescription of polypharmacy was much more common than clozapine. Significant delays in the commencement of clozapine may reflect a missed opportunity to promote recovery in this critical period.

Clozapine in the Time of COVID-19

Clozapine is the most effective antipsychotic for treatment resistant schizophrenia but adverse reactions to clozapine include neutropenia. The current COVID-19 pandemic may raise specific concerns for clinicians prescribing clozapine for patients who need it. We report on two actively psychotic patients with treatment resistant schizophrenia who required admission to our inner-London acute psychiatric unit during the COVID-19 pandemic and who were treated with clozapine. One was a young patient who developed COVID-19 symptoms and tested positive for the SARS-CoV-2 virus while receiving clozapine and the other was an aging man who tested negative for the SARS-CoV-2 virus but had contact with COVID-19 during initiation of clozapine treatment. Both responded to clozapine treatment and were safely discharged from hospital without any complication. These cases suggest that, in the absence of complications, exposure to COVID-19 per se and the onset of mild symptoms in those infected may not warrant withdrawal or postponement of clozapine treatment when this is indicated.

Psychosis breakthrough on antipsychotic maintenance: results from a nationwide study

BACKGROUND

There is uncertainty about the incidence of breakthrough psychosis in treatment adherent patients, and the role that factors, such as cumulative antipsychotic exposure, play in this phenomenon.

METHODS

In a nationwide cohort of individuals treated for schizophrenia-spectrum disorders in Finland between 1 January 1996 and 31 December 2015, 'Breakthrough Psychosis on Antipsychotic Maintenance Medication' (BAMM) was defined as hospitalization for psychosis despite ongoing continuous treatment with long-acting injectable antipsychotics (LAIs) or oral antipsychotics (OAPs) for ⩾8 weeks. Incidence rates, survival curves, and risk factors were presented.

RESULTS

In a cohort of 16 031 continuous LAI treatment episodes with virtually assured adherence [median duration = 441 days, interquartile range (IQR) = 155-1277], BAMM incidence was 31.5%. For 42 867 OAPs treatment episodes (median duration = 483 days, IQR = 167-1491), for whom adherence was modeled by the PRE2DUP method, BAMM incidence was 31.1%. Factors related to illness instability at treatment onset were associated with BAMM, although median time to BAMM was 291 days (IQR = 121-876) for LAIs and 344 days (IQR = 142-989) for OAPs, and 27.4% (N = 1386) of the BAMM events in the LAI, and 32.9% (N = 4378) in the OAP group occurred despite >1 year since last hospitalization at treatment onset. Cumulative antipsychotic exposure was not a consistent risk factor.

CONCLUSION

BAMM was relatively common even when adherence was confirmed with LAIs. Illness instability at treatment onset accounted for most cases, but relapse after years of continuous treatment was still prevalent. There was insufficient evidence to support causality between cumulative antipsychotic exposure and BAMM. Future research needs to address the role of symptom severity and neurobiology in BAMM.

Clozapine use - has practice changed?

BACKGROUND

One-third of individuals with schizophrenia have treatment-resistant illness. Of these, up to 60% will respond to clozapine treatment.

AIMS

This study retrospectively examined clozapine prescribing patterns against National Institute for Health and Care Excellence (NICE) guidelines as treatment-resistant illness emerged in a first-episode psychosis cohort.

METHODS

A total of 339 individuals with a first-episode psychosis were included in the study. Clozapine prescribing patterns were compared against the NICE guidelines and the impact of clozapine use on one index of service utilisation (hospitalisation) was assessed.

RESULTS

A total of 32 individuals (9.4%) from the cohort were prescribed clozapine. The mean time to clozapine trial was 2.1 years (SD 1.95; range 0.17-6.25). The mean number of adequate trials of antipsychotic prior to starting clozapine was 2.74 (SD 1.13; range 1-5). Following clozapine initiation, mean hospital admissions per year reduced from 2.3 to 0.3 (p=0.00). Mean hospital days pre- and post-clozapine also reduced (147 vs. 53; p=0.00). In total, 18 patients discontinued clozapine use during follow-up - 5 temporarily and 13 permanently.

CONCLUSIONS

Patients are being prescribed clozapine earlier than previously demonstrated, though delays are still evident, and many patients discontinue treatment. More work needs to be undertaken to understand and address factors which lead to its discontinuation.

How and when to use clozapine

OBJECTIVE

Clozapine is the only approved strategy for treatment-resistant schizophrenia, although it is highly underutilized. We aim to generate practical and actionable evidence-based recommendations for the use of this drug considering prescription barriers.

METHOD

Narrative review.

RESULTS

A consistent body of evidence supports the efficacy of clozapine reducing morbidity and mortality in schizophrenia. The main obstacles to its use are the lack of experience by prescribers and perceived treatment burden. Systematic screening of eligibility, utilization of available resources for consultation, developing a professional network with other stakeholders, as well as optimizing how clozapine is presented to patients is discussed. Furthermore, specific evidence-based recommendations for initiation, maintenance, and safety monitoring with clozapine are provided.

CONCLUSION

Clozapine prescription is one of the areas in psychiatry with the greatest mismatch between efficacy and utilization in clinical practice. Although multiple barriers to the use of clozapine exist, some of these may be overcome by updates of routine clinical practice.

Physical health trajectories of young people commenced on clozapine

OBJECTIVES

Clozapine is the most effective antipsychotic medication, but it has the highest propensity for metabolic side effects. A clozapine clinic was established within an early intervention for psychosis service to facilitate the timely commencement of clozapine and to manage the associated adverse effects. This study describes the changes in the weight, body mass index (BMI), waist circumference and blood pressure after 6 months in young people commenced on clozapine.

METHOD

This was a prospective cohort study of all young people, aged 15-24 years, commenced on clozapine within an early intervention service in Melbourne, Australia, between 01.04.2016 and 30.06.2018. Continuous data were analyzed with paired t-test and categorical with Wilcoxon signed-rank test.

RESULTS

Twenty-six young people received 6 months of treatment with clozapine, of whom the mean age was 19.8 years (s.d. ±3.1) and 66.7% were male. After 6 months, the mean weight gain was 5.1 kg (s.d. ±10.1 kg) and over half (53.8%) gained clinically significant weight. The proportion of young people classified as either overweight or obese rose from 69.2% to 88.5% (p = 0.006). The proportion of young people with a waist circumference above the recommended parameters increased from 57.9% to 78.9% (p = 0.008). Hypertension was present in 30%, and after 6 months, 45% had hypertension (p = 0.64). Metformin was prescribed to 34.6%, typically to those with the greatest and most rapid weight gain.

CONCLUSION

Among young people with treatment resistant psychosis, clozapine is associated with significant metabolic side effects in the early stages of commencement. More interventions aimed at attenuating this weight gain are needed.

Polypharmacy in schizophrenia

Schizophrenia is a severe mental disorder characterized by a heterogeneous symptom profile which comprises a clinical platform for widespread use of polypharmacy even though antipsychotic monotherapy is the recommended treatment regimen. This narrative review provides a summary of the current gap between evidence and practice for use of antipsychotic combination therapy in patients with schizophrenia. Antipsychotic polypharmacy is frequently prescribed instead of following international consensus of clozapine monotherapy in treatment-resistant patients. Antipsychotic-benzodiazepine combination therapy clearly has a role in the treatment of acute agitation whereas there is no evidence to support an effect on core schizophrenia symptoms when chronically prescribed. Antidepressants are typically added to antipsychotic treatment in case of persistent negative symptoms. Available evidence suggests that antidepressants may improve negative symptom control in schizophrenia. Combining an antipsychotic with an antiepileptic is not supported by any firm evidence, but individual mood stabilizers have come out positively in single trials. Generally, the evidence base for polypharmacy in schizophrenia maintenance treatment is sparse but may be warranted in certain clinical situations. Therapeutic benefits and side effects should be carefully monitored and considered to ensure a beneficial risk-benefit ratio if prescribing polypharmacy for specific clinical indications.