Optimizing clozapine treatment

Impact of clozapine once-daily versus multiple-daily dosing regimen on relapse in patients with treatment-resistant schizophrenia: A 1-year retrospective cohort study

RATIONALE

Clozapine, the standard treatment for treatment-resistant schizophrenia (TRS), is generally recommended in a multiple-daily dosing regimen. However, it is commonly administered once daily in clinical practice. Few studies have compared the longitudinal clinical outcomes of these two dosing regimens.

OBJECTIVE

To investigate the effect of once-daily versus multiple-daily dosing regimens of clozapine on relapse in patients with TRS.

METHODS

This retrospective cohort study included patients with TRS who commenced treatment with clozapine during hospitalization and were discharged between April 2012 and January 2022 from a tertiary psychiatric hospital in Japan. Relapse, defined as a psychiatric exacerbation requiring re-hospitalization within the first-year post-discharge, was analyzed. Multivariable Cox proportional hazards regression analysis compared the relapse risk between once-daily and multiple-daily dosing regimens. A subgroup analysis was conducted to examine the potential interactions between dosing regimen and dose category (low versus high dose).

RESULTS

Among 179 patients, 107 (59.8%) received clozapine once daily. No significant difference in the relapse risk was observed between once-daily and multiple-daily dosing regimens (adjusted hazard ratio [aHR]: 1.16; 95% confidence interval [CI]: 0.68-1.99; p = 0.58). However, in patients receiving high doses of clozapine (> 300 mg/day), multiple-daily dosing increased the relapse risk compared to once-daily dosing (aHR: 2.23; 95% CI: 1.00-4.97; p = 0.049).

CONCLUSIONS

Once-daily clozapine dosing may not be associated with an increased relapse risk. The increased relapse risk in high-dose multiple-daily dosing may be confounded by unmeasured non-adherence. Further randomized controlled trials are required to validate these findings.

Risks and benefits of clozapine and lithium co-prescribing: A systematic review and expert recommendations

OBJECTIVES

To identify the risks and benefits of clozapine‑lithium co-prescription.

METHODS

Articles published in English or French were identified with a MEDLINE, Web of Sciences and PsycINFO search, from inception through January 2023, using the term 'clozapine' in combination with 'lithium'. Data were synthesized narratively.

RESULTS

Of the 67 articles included in the review, more than half (n = 38, 56.7 %) were focused on clozapine-related blood dyscrasia. A body of evidence drawn from case reports and retrospective chart studies highlights the potential benefits of lithium prescription for clozapine-related neutropenia, since this strategy may avoid clozapine discontinuation or allow its rechallenge. The most documented adverse drug reactions (ADRs) associated with clozapine‑lithium co-prescription are neurotoxic events, which may be prevented or detected early by clinical, electroencephalographic and therapeutic drug monitoring. Causality assessment cannot be established for other reported ADRs occurring during clozapine‑lithium co-prescription. The benefits of the combined prescription on psychotic and/or mood symptoms are poorly documented.

CONCLUSION

The risks and benefits of clozapine‑lithium co-prescription require further exploration as the combination might significantly contribute to reducing underprescription or premature discontinuation of clozapine.

Chromatographic Methods for the Analysis of the Antipsychotic Drug Clozapine and Its Major Metabolites: A Review

Clozapine (CLZ), a second-generation antipsychotic, can effectively reduce schizophrenia, bipolar disorder and major depression symptoms. This review provides an overview of all reported chromatographic methods (62 references) for the quantification of CLZ and its two main metabolites, norclozapine and clozapine N-oxide in pharmaceutical formulations, biological matrices and environmental samples.

Clozapine-induced pneumonitis mimicking an atypical pneumonia

Clozapine is an antipsychotic used for treatment-resistant schizophrenia with a significant side effect profile, including agranulocytosis, myocarditis and fever. Clozapine-induced fever often occurs in the first 2 weeks of treatment and settle after a few days. We report a case of a woman in her mid-30s who developed fever and infective symptoms suggestive of an atypical pneumonia while on clozapine titration. She was on clozapine for 16 days before developing high-grade fever, dry cough, diarrhoea, headache and photophobia with a very high CRP. We performed an extensive infection workup that returned negative results except for bilateral upper lobe ground glass changes of the lungs on CT. Despite antibiotic therapy, which would cover an atypical pneumonia, her CRP remained elevated and her fever persisted. Focus was directed to clozapine-induced pneumonitis as the cause for her symptoms. Her antibiotics were ceased, and clozapine was downtitrated. With the adjustment of her clozapine dose, her fevers and associated symptoms resolved, and CRP downtrended. Her fevers did not return when clozapine was uptitrated in the community subsequently. Clozapine-induced fever or other immune-allergic reactions should be systematically considered when patients develop fever during the initiation phase of clozapine therapy. Ruling out infective causes is desirable prior to attributing fevers to clozapine especially when they are accompanied by infective symptoms and high inflammatory markers. Careful downtitration of clozapine should be considered rather than abrupt cessation in managing clozapine-induced fevers and subsequent slow uptitration could be considered.

Comparative Study of the Efficacy and Side Effects of Brand-Name and Generic Clozapine for Long-Term Maintenance Treatment Among Korean Patients With Schizophrenia: A Retrospective Naturalistic Mirror-Image Study

OBJECTIVE

Clozapine is considered the most reliable drug for treatment-resistant schizophrenia. In 2014, a generic formulation of clozapine (Clzapine) was introduced in Korea. This study was performed to provide clinical information regarding the use of clozapine and to compare efficacy and tolerability when converting from the brand-name formulation (Clozaril) to the generic formulation during longterm maintenance treatment among Korean patients with schizophrenia.

METHODS

This mirror-image study retrospectively investigated the electronic medical records of patients who had switched from Clozaril to Clzapine with a ≥1-year duration for each formulation. Clinical data were collected, including information regarding clozapine use, psychiatric hospitalization, co-medications, and blood test findings. Data before and after the switch were compared using paired t-tests.

RESULTS

Among 332 patients, the mean 1-year dosages were 233.32±149.35 mg/day for Clozaril and 217.36±136.66 mg/day for Clzapine. The mean clozapine concentration-to-dose ratios were similar before and after the switch (Clozaril, 1.33±0.68; Clzapine, 1.26±0.80). Switching from Clozaril to Clzapine resulted in no significant differences in the hospitalization rate, hospitalization duration, or laboratory findings (liver function parameters, serum cholesterol level, and serum glucose level). Equivalent doses of co-prescribed antidepressants were decreased, but concomitant medications otherwise showed no significant differences.

CONCLUSION

Clinical efficacy and tolerability appear comparable when switching to Clzapine during clozapine maintenance treatment. This study offers descriptive real-world clinical insights into clozapine maintenance treatment in Korea, thereby providing patients with more treatment options and contributing to the development of maintenance guidelines tailored to the Korean population.

Schizophrenia Patients Discharged on Clozapine Plus Long-Acting Injectable Antipsychotics From a Public Psychiatric Hospital in Taiwan, 2006-2021

BACKGROUND

Some schizophrenia patients treated with clozapine experience an inadequate response and adherence problems. The purpose of this study was to compare time to rehospitalization within 6 months in schizophrenia patients discharged on 3 clozapine regimens. Additionally, the temporal trend of prescription rate in each group was also explored.

METHODS

Schizophrenia patients discharged from the study hospital from January 1, 2006, to December 31, 2021, (n = 3271) were included in the analysis. The type of clozapine prescribed at discharge was divided into 3 groups: clozapine plus long-acting injectable antipsychotics (clozapine + LAIs), clozapine plus other oral antipsychotics (clozapine + OAPs), and clozapine monotherapy. Survival analysis was used to compare time to rehospitalization within 6 months after discharge among the 3 groups. The temporal trend in the prescription rate of each group was analyzed using the Cochran-Armitage Trend test.

RESULTS

Patients discharged on clozapine + LAIs had a significantly longer time to rehospitalization than those on clozapine + OAPs or clozapine monotherapy. The prescription rates of clozapine + LAIs and clozapine + OAPs significantly increased over time, whereas the prescription rates of clozapine monotherapy significantly decreased.

CONCLUSIONS

Compared with the clozapine + OAPs group, the clozapine + LAIs group had a lower risk of rehospitalization and a lower dose of clozapine prescribed. Therefore, if a second antipsychotic is required for patients who are taking clozapine alone, LAIs should be considered earlier.

Association of clozapine and norclozapine levels with patient and therapy characteristics-focus on interaction with valproic acid

PURPOSE

The goal of the study was to examine clozapine (CLZ) and norclozapine (NCLZ) therapeutic drug monitoring (TDM) data and associated sources of pharmacokinetic variability, particularly the impact of valproic acid (VPA) use.

METHODS

This study included 126 patients with psychiatric disorders on mono- or co-therapy with CLZ. Patients' data during routine TDM were collected retrospectively from clinical records. The descriptive and statistical analysis was computed using IBM SPSS Statistics software (version 22, NY, USA). Multiple linear regression, based on the last observations, was used to assess correlation between demographic characteristics, life habits and co-therapy with dose-corrected serum levels (C/D) of CLZ and NCLZ, as well as CLZ/NCLZ.

RESULTS

A total of 295 CLZ concentrations were measured in 126 patients, with a mean of 275.5 ± 174.4 µg/L, while 124 NCLZ concentrations were determined in 74 patients, with a mean of 194.6 ± 149.8 µg/L. A statistically significant effect on ln-transformed CLZ C/D was confirmed for sex and smoking, whereas sex, smoking and VPA therapy were associated with ln-transformed NCLZ C/D. According to the final models, lower values of NCLZ C/D for about 45.9% can be expected in patients receiving VPA. Concomitant use of VPA was the only factor detected to contribute in CLZ/NCLZ variability.

CONCLUSION

The results of this study may help clinicians interpret TDM data and optimize CLZ dosing regimens, especially in patients concomitantly treated with VPA. Our results show that VPA primarily decreases NCLZ levels, while alteration of the parent drug is not statistically significant.

A case report-"When less is more": controlled inpatient reduction of anticholinergic burden in a patient with clozapine-resistant schizophrenia

The functional status of an individual with schizophrenia is the defining factor in their quality of life and is closely associated with cognitive abilities, which are impaired in individuals with schizophrenia and considered to be the core symptom of the disorder. The use of psychopharmacotherapy can also have a significant impact on cognitive functioning. The relationship between clozapine treatment and cognitive impairment in individuals with schizophrenia is an intricate one. While some studies have reported a positive effect of clozapine on learning and memory, other studies have found that patients treated with clozapine experienced a decline in cognitive functioning in particular areas. In particular, attention and memory have been shown to deteriorate with rising plasma levels of clozapine. This effect may be attributed to its anticholinergic effect. A reduction in the medication related to anticholinergic burden has been previously found to improve cognitive abilities. In the presented case, we describe a psychotic relapse with delirium symptoms in a patient on clozapine treatment with potentially toxic clozapine blood level. The symptoms of delirium subsided after a clozapine dose adjustment. Gradually lowering the initially very high anticholinergic burden improved the patient's cognitive functioning.

Longitudinal changes in clozapine dose in patients with treatment-resistant schizophrenia: a 5-year retrospective cohort study

This retrospective cohort study aimed to investigate the longitudinal changes in clozapine dose over a 5-year period in patients with treatment-resistant schizophrenia (TRS). Patients with TRS who were administered clozapine at a hospital between April 2012 and December 2016 and continued treatment with clozapine for at least 1 year were included. Clozapine doses were compared at the dose-fixation point, defined as when the same regimen of clozapine had been continued for 8 weeks or longer, and the post-dose-fixation phase, at 12, 36 and 60 months after clozapine initiation. We included 103 patients and found no significant differences in clozapine dose between the dose-fixation point and post-dose-fixation phase. Approximately half of the patients were categorized into an unchanged group at 12 months after clozapine initiation, whereas approximately 40% of patients were categorized into either the decreased or increased group at 60 months. Multivariable regression analysis revealed that the change in clozapine dose between the dose-fixation point and 60 months after clozapine initiation was negatively associated with clozapine dose at the dose-fixation point. On average, the clozapine dose was unchanged during long-term treatment in patients with TRS, although the dose was decreased or increased in approximately 40% of the patients.

Myocarditis in patients on long-term antipsychotics -mechanism, management and recent updates

Objective

Clozapine is the first atypical antipsychotic drug and was frequently cited as the most effective antipsychotic for treatment-resistant schizophrenia, but it is associated with a concert of significant cardiotoxic side effects. Clozapine-induced Myocarditis (CIM) is diagnosed based on the combination of clinical symptoms, laboratory investigations, radiological findings, and sometimes biopsy. The literature on CIM management and clinical consensus on the best course of action is mixed.

Methodology

An all-language literature search on Medline, Cochrane, Embase, and Google Scholar until April 2022. The following search strings and Medical Subject Heading (MeSH) terms were used: "CIM," "clozapine," "cardiotoxicity," and "myocarditis." We explored the literature on CIM for its pathophysiology, diagnosis, monitoring, and management.

Results

The clinical features of CIM may be highly variable, ranging from asymptomatic disease to fulminant heart failure, and cessation of medication was the mainstay treatment of CIM, followed by supportive therapy. Other antipsychotics have also been linked with cardiotoxic side effects.

Conclusion

Despite being the most effective antipsychotic, clozapine is associated with a cardiotoxic side effect. Current literature suggests that these antipsychotic-related cardiotoxic events impact the treatment selection for schizophrenia and other psychotic disorders, and they must be kept in mind while designing new treatment protocols in the future.

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.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

Clozapine ADEs rarely require discontinuation.

Factors predicting serum clozapine levels in Middle Eastern patients: an observational study

BACKGROUND

Despite its superiority over other drugs for psychosis, clozapine remains underused and is associated with many clinical challenges, including difficulties in predicting therapeutic serum levels (350-600 ng/mL). We found no large or recent study that investigated the determinants of serum clozapine levels in Middle Eastern patients. Therefore, we investigated the association between clozapine dose and serum level, and the clinical predictors of the clozapine serum level, in Middle Eastern patients.

METHODS

This cross-sectional study included 94 patients of Middle Eastern ethnicity who attended the Clozapine Clinic in King Saud University Medical City in Riyadh, Saudi Arabia. We used a single measure of the serum clozapine level, which was collected 12 h after the last oral dose of clozapine under steady-state conditions.

RESULTS

The average clozapine dose and serum level were 400 mg/daily and 705 ng/mL, respectively. The majority of patients (59.8%) had serum levels higher than 600 ng/mL. Clozapine dose and serum level were positively correlated (rs [94] = 0.32, p = 0.002). We generated a predictive model of the serum clozapine level, which revealed that the daily dose, smoking status, use of fluvoxamine or lamotrigine, and body mass index (BMI) predicted 43.6% of the variance in the serum level (p < 0.001). Using this model, we calculated that patients with a BMI of 25 kg/m2 would require a clozapine dose between 50 to 275 mg/daily if they were non-smokers, and a dose of 200 to 450 mg/daily if they were smokers, in order to reach a serum clozapine level between 350 to 600 ng/mL. Patients with higher BMI and those receiving fluvoxamine would require lower doses.

CONCLUSIONS

This was a naturalistic study of the clozapine dose-level relationship and the clinical predictors of the serum clozapine level in a sample of Middle Eastern patients. The ratios of clozapine level to dose in our patients more closely resembled those reported in Asian samples than in European samples. These findings do not reduce the value of individualised therapeutic drug monitoring, but may assist clinicians when prescribing clozapine to Middle Eastern patients. Further psychopharmacological studies are needed on this demographic population.

Antipsychotic medication for women with schizophrenia spectrum disorders

There are significant differences between men and women in the efficacy and tolerability of antipsychotic drugs. Here, we provide a comprehensive overview of what is currently known about the pharmacokinetics and pharmacodynamics of antipsychotics in women with schizophrenia spectrum disorders (SSDs) and translate these insights into considerations for clinical practice. Slower drug absorption, metabolism and excretion in women all lead to higher plasma levels, which increase the risk for side-effects. Moreover, women reach higher dopamine receptor occupancy compared to men at similar serum levels, since oestrogens increase dopamine sensitivity. As current treatment guidelines are based on studies predominantly conducted in men, women are likely to be overmedicated by default. The risk of overmedicating generally increases when sex hormone levels are high (e.g. during ovulation and gestation), whereas higher doses may be required during low-hormonal phases (e.g. during menstruation and menopause). For premenopausal women, with the exceptions of quetiapine and lurasidone, doses of antipsychotics should be lower with largest adjustments required for olanzapine. Clinicians should be wary of side-effects that are particularly harmful in women, such as hyperprolactinaemia which can cause oestrogen deficiency and metabolic symptoms that may cause cardiovascular diseases. Given the protective effects of oestrogens on the course of SSD, oestrogen replacement therapy should be considered for postmenopausal patients, who are more vulnerable to side-effects and yet require higher dosages of most antipsychotics to reach similar efficacy. In conclusion, there is a need for tailored, female-specific prescription guidelines, which take into account adjustments required across different phases of life.

Clozapine resistant schizophrenia: Newer avenues of management

About 40%-70% of the patients with treatment-resistant schizophrenia have a poor response to adequate treatment with clozapine. The impact of clozapine-resistant schizophrenia (CRS) is even greater than that of treatment resistance in terms of severe and persistent symptoms, relapses and hospitalizations, poorer quality of life, and healthcare costs. Such serious consequences often compel clinicians to try different augmentation strategies to enhance the inadequate clozapine response in CRS. Unfortunately, a large body of evidence has shown that antipsychotics, antidepressants, mood stabilizers, electroconvulsive therapy, and cognitive-behavioural therapy are mostly ineffective in augmenting clozapine response. When beneficial effects of augmentation have been found, they are usually small and of doubtful clinical significance or based on low-quality evidence. Therefore, newer treatment approaches that go beyond the evidence are needed. The options proposed include developing a clinical consensus about the augmentation strategies that are most likely to be effective and using them sequentially in patients with CRS. Secondly, newer approaches such as augmentation with long-acting antipsychotic injections or multi-component psychosocial interventions could be considered. Lastly, perhaps the most effective way to deal with CRS would be to optimize clozapine treatment, which might prevent clozapine resistance from developing. Personalized dosing, adequate treatment durations, management of side effects and non-adherence, collaboration with patients and caregivers, and addressing clinician barriers to clozapine use are the principal ways of ensuring optimal clozapine treatment. At present, these three options could the best way to manage CRS until research provides more firm directions about the effective options for augmenting clozapine response.

Augmentation of Antipsychotic Medications with Low-Dose Clozapine in Treatment-Resistant Schizophrenia-Case Reports and Discussion

Treatment resistance in schizophrenia is often encountered in clinical practice, with clozapine usually recommended as the appropriate therapy. However, where clozapine proves ineffective or cannot be tolerated due to side effects, treatment options are limited. In patients within forensic mental health services, residual symptomatology often presents a barrier to discharge and can have lasting effects on prospects for rehabilitation as well as risk to self and others. This paper presents a review of the relevant literature and three cases of a novel approach, utilising clozapine in doses usually considered subtherapeutic, in combination with the primary antipsychotic treatment. In all three patients, it improved clinical efficacy as well as tolerability, resulting in improvement that allowed discharge from the forensic hospital.

No adverse events were observed in clozapine-treated patients on extended hematologic monitoring intervals during the coronavirus pandemic in four psychiatric centers in Japan

AIM

As an emergency measure during the coronavirus disease pandemic, the monitoring interval for clozapine use was temporarily extended beyond the regulatory requirement in Japan, which is the safest monitoring interval worldwide. In this study, we aimed to explore the effect of this measure on patients undergoing clozapine treatment.

METHODS

This retrospective chart review study included patients with treatment-resistant schizophrenia (TRS) who were undergoing clozapine treatment at four psychiatric institutions in Japan. Demographic characteristics and clinical information of these patients were collected on April 27, 2020, when Japanese psychiatrists were virtually allowed to prescribe clozapine beyond the regulatory requirement. Furthermore, information of adverse events related to the emergency measure was collected and analyzed.

RESULTS

Of the 41 patients with TRS included in this study, 19 patients underwent extended hematological monitoring during clozapine treatment. No psychiatric or hematological adverse events were observed in the patients during the extended monitoring interval.

CONCLUSION

This study suggested that there were few adverse events of clozapine-treated patients related to emergency measures in Japan. However, hematological monitoring intervals during clozapine treatment have been emergently extended worldwide; hence, it is necessary to verify the results of these measures.

A systematic review and meta-analysis of the association between clozapine and norclozapine serum levels and peripheral adverse drug reactions

RATIONALE

Clozapine is the most effective antipsychotic for treatment-refractory schizophrenia for reducing positive psychotic symptoms. It is associated with a reduction in hospitalisation and overall mortality. In spite of this, clozapine remains underutilised due to its complex adverse drug reaction (ADR) profile.

OBJECTIVE

This systematic review aims to investigate the association of clozapine and norclozapine serum levels, and peripheral ADRs.

METHODS

Studies were searched from four electronic databases (PubMed, EMBASE, PsycINFO and CINAHL) from inception to 12 June 2020. Studies were included if they had adult patients, provided data on steady-state trough clozapine or norclozapine levels and reported on clozapine-associated ADRs. Pregnant women, case reports and series were excluded.

RESULTS

A statistically significant correlation was found for clozapine serum levels and triglycerides (n = 70; r = 0.303, 95% CI 0.0119-0.546, p = 0.042), heart rate (n = 137; r = 0.269, 95% CI 0.0918-0.486, p = 0.035), and overall combined ADRs (n = 160; r = 0.264, 95% CI 0.110-0.405, p = 0.001), but not for absolute neutrophil count (n = 223; r = - 0.164, 95% CI - 0.529-0.253, p = 0.444) or total white cell count (n = 18; r = 0.0176, 95% CI - 0.203-0.237, p = 0.878). Interestingly, norclozapine serum levels were found to be statistically correlated to triglycerides (n = 120; r = 0.211, 95% CI 0.0305-0.378, p = 0.022), total cholesterol (n = 120; r = 0.272, 95% CI 0.0948-0.432, p = 0.003) and weight gain (n = 118; r = 0.208, 95% CI 0.0261-0.377, p = 0.025).

CONCLUSIONS

Heart rate, triglycerides and combined ADRs are significantly correlated with clozapine levels, and triglycerides, total cholesterol and weight gain with norclozapine levels. Future prospective, randomised controlled studies are needed to identify the cause-effect relationship between clozapine levels and peripheral ADRs.

Adjunctive Fluvoxamine for Schizophrenia: A Meta-analysis of Randomized Double-Blind, Placebo-Controlled Trials

BACKGROUND

This was a meta-analysis of double-blind, randomized controlled trials that examined the therapeutic effects and tolerability of adjunctive fluvoxamine versus placebo for schizophrenia.

METHODS

The Review Manager, Version 5.3, was used to analyze data.

RESULTS

Five double-blind randomized controlled trials (N = 284) covering 145 patients on adjunctive fluvoxamine and 139 patients on placebo were included in the analyses. Meta-analyses of total psychopathology, and negative, positive, and depressive symptoms did not show significant differences between the fluvoxamine and placebo groups. Two studies examined the effects of adjunctive fluvoxamine on cognitive functioning with mixed findings. Fluvoxamine was superior over placebo in lessening weight gain and metabolic abnormalities. Although fluvoxamine led to more discontinuation, no significant group differences were found regarding adverse drug reactions.

CONCLUSIONS

There was inconsistent evidence for the therapeutic effect of adjunctive fluvoxamine on cognitive functions and preliminary evidence for alleviating metabolic syndrome caused by clozapine. More studies are needed to explore further the effectiveness of adjunctive fluvoxamine for schizophrenia.

Possible pharmacogenetic factors in clozapine treatment failure: a case report

There is still much to learn about the predictors of therapeutic response in psychiatry, but progress is gradually being made and precision psychiatry is an exciting and emerging subspeciality in this field. This is critically important in the treatment of refractory psychotic disorders, where clozapine is the only evidence-based treatment but only about half the patients experience an adequate response. In this case report, we explore the possible biological mechanisms underlying treatment failure and discuss possible ways of improving clinical outcomes. Further work is required to fully understand why some patients fail to respond to the most effective treatment in refractory schizophrenia. Therapeutic drug monitoring together with early pharmacogenetic testing may offer a path for some patients with refractory psychotic symptoms unresponsive to clozapine treatment.

Clozapine: An Updated Overview of Pharmacogenetic Biomarkers, Risks, and Safety-Particularities in the Context of COVID-19

BACKGROUND

clozapine (CLZ) use is precarious due to its neurological, cardiovascular, and hematological side effects; however, it is the gold standard in therapy-resistant schizophrenia (TRS) in adults and is underused.

OBJECTIVE

to examine the most recent CLZ data on (a) side effects concerning (b) recent pharmacological mechanisms, (c) therapy benefits, and (d) the particularities of the COVID-19 pandemic.

DATA SOURCES

a search was performed in two databases (PubMed and Web of Science) using the specific keywords "clozapine" and "schizophrenia", "side effects", "agranulocytosis", "TRS", or "bipolar affective disorder (BAF)" for the last ten years.

STUDY ELIGIBILITY CRITERIA

clinical trials on adults with acute symptoms of schizophrenia or related disorders.

RESULTS

we selected 37 studies, randomized controlled trials (RCTs), and clinical case series (CCS), centered on six main topics in the search area: (a) CLZ in schizophrenia, (b) CLZ in bipolar disorder, (c) side effects during the clozapine therapy, (d) CLZ in pregnancy, (e) CLZ in early-onset schizophrenia, and (f) CLZ therapy and COVID-19 infection.

LIMITATIONS

we considered RCTs and CCS from two databases, limited to the search topics. Conclusions and implications of key findings: (a) clozapine doses should be personalized for each patient based on pharmacogenetics testing when available; the genetic vulnerability postulates predictors of adverse reactions' severity; patients with a lower genetic risk could have less frequent hematological monitoring; (b) a CLZ-associated risk of pulmonary embolism imposes prophylactic measures for venous thromboembolism; (c) convulsive episodes are not an indication for stopping treatment; the plasma concentration of clozapine is a better side effect predictor than the dosage; (d) COVID-19 infection may enhance clozapine toxicity, generating an increased risk of pneumonia. Therapy must be continued with the proper monitoring of the white blood count, and the clozapine dose decreased by half until three days after the fever breaks; psychiatrists and healthcare providers must act together.

Temporal trends in clozapine use at time of discharge among people with schizophrenia at two public psychiatric hospitals in Taiwan, 2006-2017

Clozapine treatment remains the gold standard for treatment-resistant schizophrenia. This study aimed to describe temporal trends in clozapine use at discharge among patients with schizophrenia at two of the largest public psychiatric hospitals in Taiwan over a twelve-year period. Patients with schizophrenia discharged from the two study hospitals between 2006 and 2017 (n = 24,101) were included in the analysis. Antipsychotic augmentation was defined as concomitant use of a second antipsychotic as augmentation to clozapine treatment. Changes in the rate of clozapine use and antipsychotic augmentation at discharge over time were analyzed using the Cochran-Armitage trend test. Patients discharged on clozapine had significantly longer hospital stays than other patients. The rate of clozapine use at discharge increased from 13.8% to 20.0% over time (Z = 6.88, p < .0001). Concomitant use of anticholinergic medication was more common in patients receiving antipsychotic augmentation than clozapine antipsychotic monotherapy. Among patients discharged on clozapine, the rate of augmentation with a second antipsychotic increased from 19.1% to 36.2% over time (Z = 6.58, p < .0001). Among patients receiving antipsychotic augmentation, use of another second-generation antipsychotic as the augmentation agent grew from 32.6% to 65.5% over time (Z = 8.90, p < .0001). The increase in clozapine use was accompanied by an increase in concomitant use of a second antipsychotic as augmentation during the study period. Further studies are warranted to clarify the risk/benefit of this augmentation strategy. Clozapine may still be underutilized, and educational programs are needed to promote clinical use of clozapine.

Educational needs and psychoeducation interventions in clozapine users: a narrative review

OBJECTIVE

Increasing users' knowledge about the expected benefits and risks of clozapine may contribute to the initiation and maintenance of clozapine in persons with treatment-resistant schizophrenia (TRS). The objective was to identify the educational needs of clozapine users and the interventions aimed at addressing these needs.

METHOD

We systematically searched multiple electronic databases for articles: (i) exploring educational needs of clozapine users and of their relatives; and (ii) reporting educational interventions aimed at addressing these needs. Data were synthesized narratively.

RESULTS

A total of 30 articles published from 1990 to 2019 in 8 countries fulfilled our inclusion criteria. As most studies on educational needs (n = 18) were carried out in persons already taking clozapine, educational needs of TRS patients who were candidates for clozapine treatment are not well documented. Users' level of knowledge about clozapine was often poor, especially about adverse effects or interactions with other substances, with a poor retention of information delivered at treatment initiation. Among 12 studies reporting educational interventions in clozapine users, five provided quantitative outcomes. Their findings suggest that structured educational programmes may contribute to promote clozapine initiation and to improve users' knowledge about this drug.

CONCLUSION

The literature is sparse on structured educational interventions about clozapine, and only one randomized controlled trial was identified. A promising strategy emerging from this review may be staging educational interventions according to the evolving needs of persons with TRS before clozapine use, at initiation and during maintenance treatment.

Safety and acceptability of clozapine and risperidone in progressive multiple sclerosis: a phase I, randomised, blinded, placebo-controlled trial

Objective

Because clozapine and risperidone have been shown to reduce neuroinflammation in humans and mice, the Clozapine and Risperidone in Progressive Multiple Sclerosis (CRISP) trial was conducted to determine whether clozapine and risperidone are suitable for progressive multiple sclerosis (pMS).

Methods

The CRISP trial (ACTRN12616000178448) was a blinded, randomised, placebo-controlled trial with three parallel arms (n=12/arm). Participants with pMS were randomised to clozapine (100–150 mg/day), risperidone (2.0–3.5 mg/day) or placebo for 6 months. The primary outcome measures were safety (adverse events (AEs)/serious adverse events (SAE)) and acceptability (Treatment Satisfaction Questionnaire for Medication-9).

Results

An interim analysis (n=9) revealed significant differences in the time-on-trial between treatment groups and placebo (p=0.030 and 0.025, clozapine and risperidone, respectively) with all participants receiving clozapine being withdrawn during the titration period (mean dose=35±15 mg/day). Participants receiving clozapine or risperidone reported a significantly higher rate of AEs than placebo (p=0.00001) but not SAEs. Specifically, low doses of clozapine appeared to cause an acute and dose-related intoxicant effect in patients with pMS who had fairly severe chronic spastic ataxic gait and worsening over all mobility, which resolved on drug cessation.

Interpretation

The CRISP trial results suggest that patients with pMS may experience increased sensitivity to clozapine and risperidone and indicate that the dose and/or titration schedule developed for schizophrenia may not be suitable for pMS. While these findings do not negate the potential of these drugs to reduce multiple sclerosis-associated neuroinflammation, they highlight the need for further research to understand the pharmacodynamic profile and effect of clozapine and risperidone in patients with pMS.

Trial registration number

ACTRN12616000178448.

Non-ischemic Cardiomyopathy: A Rare Adverse Effect of Clozapine

Clozapine is a dibenzodiazepine antipsychotic used for treatment-resistant schizophrenia. Its association with several side effects such as agranulocytosis, seizure, and insulin resistance is well known. Cardiac side effects such as myocarditis and cardiomyopathy are less common and have been seldom reported. Here we report an unusual case of clozapine-induced nonischemic dilated cardiomyopathy. A 50-year-old female with treatment-resistant schizophrenia on clozapine presented with gradually worsening shortness of breath, productive cough, and pleuritic chest pain. She was found to have non-ischemic dilated cardiomyopathy due to clozapine use as no other causative factor was found. Clozapine was gradually tapered and then discontinued. Repeat echocardiogram in three months revealed improvement in ejection fraction. This case is unique as it outlines clozapine as a rare cause of nonischemic cardiomyopathy, as discontinuation of the drug showed improvement in symptoms and heart function.

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.

Comfort Level and Barriers to the Appropriate Use of Clozapine: a Preliminary Survey of US Psychiatric Residents

OBJECTIVE

Clozapine is the gold standard treatment for treatment-resistant schizophrenia. Prior surveys of mental health providers have identified multiple causes for underutilization of clozapine; however, no previous survey has been conducted to assess US psychiatry residents' level of comfort in prescribing clozapine.

METHODS

A survey was sent via email to program directors of Accreditation Council for Graduate Medical Education-affiliated psychiatry residency programs requesting the survey to be distributed to current residents. The survey included questions regarding demographics, clozapine-prescribing practices, comfort levels with prescription, and perceived barriers to prescription.

RESULTS

A total of 164 psychiatric residents completed the survey, 37% PGY-1 and 2 residents and 63% PGY-3 or higher. One-third of the respondents had a clozapine clinic in their program. Only 18% of the residents felt "very" comfortable in initiating clozapine and 41% felt "somewhat" comfortable. Two main reasons for not starting clozapine were (1) side effect profile (41%) and (2) limited experience and inadequate training in clozapine use (38%). More than 4/5ths of the residents (83%) responded that they would feel more comfortable in prescribing clozapine if they were trained in a clozapine clinic. Major limitation of this study has been the small sample size, lack of representativeness, and generalization.

CONCLUSIONS

Forty-one percent of the respondents did not feel comfortable with clozapine prescription. Major concerns cited included the side effect profile as well as lack of experience and training. The majority of the respondents felt that they would be more comfortable prescribing clozapine if they had the opportunity to train in a clozapine clinic.

Clozapine augmentation strategies

Clozapine is established as the gold standard for antipsychotic treatment of patients suffering from treatment-resistant schizophrenia. Over virtually 3 decades, the level of inadequate response to clozapine was found to range from 40% to 60%. A heightened interest developed in the augmentation of clozapine to try to achieve response or maximize partial response. A large variety of drug groups have been investigated. This article focuses on the meta-analyses of these trials to discover reasonable evidence-based approaches to the management of patients not responding to clozapine.

Functioning and cognitive characteristics of clozapine users referred to psychosocial rehabilitation centers: A REHABase cohort study

OBJECTIVES

To explore whether clozapine users have specific rehabilitation needs compared to users of other antipsychotics.

METHODS

The study was performed using the REHABase collecting data on persons referred to a French network of psychosocial rehabilitation centers. It was restricted to persons with schizophrenia spectrum disorder using antipsychotics. Multivariate analyses were used to compare baseline functioning and cognitive characteristics in clozapine users vs. users of other antipsychotics.

RESULTS

Of the 675 patients identified in the REHABase, one out of ten (n = 70) used clozapine. Compared to users of other antipsychotics, clozapine users had been more frequently hospitalized in psychiatry and presented less frequently with psychoactive substance use. Functional measures did not significantly differ between the two groups. Clozapine users had poorer short-term verbal memory performance than users of other antipsychotics and did not differ on executive performance.

CONCLUSION

Clozapine users may reach a recovery level comparable to that obtained in persons without treatment-resistant schizophrenia. In order to reduce the negative impact of memory deficits on the recovery process of clozapine users, it is necessary to optimize their psychotropic treatment and to promote their access to cognitive remediation programs addressing their specific needs.

Clinical determinants of fever in clozapine users and implications for treatment management: A narrative review

OBJECTIVES

To identify the clinical determinants of fever in clozapine users and their impact on management of clozapine treatment.

METHODS

Articles published in English or French identified with a MEDLINE, Web of Sciences, Cochrane Library and PsycINFO search, from inception through February 2019, using the term "clozapine" in combination with "fever" OR "hyperthermia" OR "body temperature" OR "pyrexia" OR "febrile" OR "heat" OR "thermoregulation". Information extracted for each medical condition were frequency, time to onset after initiation of clozapine treatment, characteristics of fever, associated symptoms, laboratory tests used for diagnosis, course, lethality, discontinuation of clozapine. Data were synthesized narratively.

RESULTS

Our search yielded 394 unique hits published from 1993 to 2018. We included 73 articles in the review: two meta-analyses, 14 reviews, six epidemiological studies, 11 clinical studies and 40 case reports. During clozapine initiation, fever is most frequently benign and transient but should be closely monitored as it may be the first stage of potentially life-threatening adverse drug reactions (ADR) (agranulocytosis, neuroleptic malignant syndrome myocarditis, hepatitis, pancreatitis, nephritis, colitis, etc.). Other ADR associated with fever are independent of duration of exposure to clozapine (heat stroke, pneumonia, pulmonary embolism, necrotizing colitis). If fever is due to intercurrent infection, therapeutic drug monitoring is recommended to adjust clozapine daily dosage.

CONCLUSION

Benign causes of fever are much more frequent than life-threatening ADR during clozapine treatment. Discontinuation should not be considered as automatic in the event of fever, especially during the early phase of clozapine initiation.

A Chitosan-Carbon Nanotube-Modified Microelectrode for In Situ Detection of Blood Levels of the Antipsychotic Clozapine in a Finger-Pricked Sample Volume

The antipsychotic clozapine is the most effective medication available for schizophrenia and it is the only antipsychotic with a known efficacious clinical range. However, it is dramatically underutilized due to the inability to test clozapine blood levels in finger-pricked patients' samples. This prevents obtaining immediate blood levels information, resulting in suboptimal treatment. The development of an electrochemical microsensor is presented, which enables, for the first time, clozapine detection in microliters volume whole blood. The sensor is based on a microelectrode modified with micrometer-thick biopolymer chitosan encapsulating carbon nanotubes. The developed sensor detects clozapine oxidation current, in the presence of other electroactive species in the blood, which generate overlapping electrochemical signals. Clozapine detection, characterized in whole blood from healthy volunteers, displays a sensitivity of 32 ± 3.0 µA cm^-2 µmol^-1 L and a limit-of-detection of 0.5 ± 0.03 µmol L^-1 . Finally, the developed sensor displays a reproducible electrochemical signal (0.6% relative standard deviation) and high storage stability (9.8% relative standard deviation after 8 days) in serum samples and high repeatability (9% relative standard deviation for the 5th repetition) in whole blood samples. By enabling the rapid and minimally invasive clozapine detection at the point-of-care, an optimal schizophrenia treatment is provided.

Clozapine rapid retitration in the community: an assertive approach can prevent admissions

Rapid retitration of clozapine may be necessary to reduce the known high risk of mental state destabilisation in patients who have had a 48 h treatment break. It may carry a high risk of complications, including seizures and myocarditis. We reflect on the literature on standard and rapid retitration and present a case of rapid retitration in the community. In this case, of a 54-year-old homeless man with treatment-resistant schizophrenia and polysubstance misuse, we safely retitrated clozapine in a community setting four times during a 6-month period; each retitration was completed over 4 days. We used a specific protocol based on his psychiatric history. We are now more confident in delivering clozapine retitration to other patients, thus preventing unnecessary admissions.

DECLARATION OF INTEREST

N. N. has received honoraria from Janssen Pharmaceuticals.

Prescriber and institutional barriers and facilitators of clozapine use: A systematic review

BACKGROUND

As clozapine is under-prescribed in persons with treatment-resistant schizophrenia (TRS), it is necessary to better identify the determinants of health inequalities in access to clozapine use.

OBJECTIVE

To identify mental health professionals' characteristics or attitudes and institutional characteristics facilitating or limiting clozapine prescribing.

METHOD

We systematically searched multiple electronic databases for articles reporting: (i) mental health professionals' attitudes and characteristics favoring or limiting clozapine prescribing; (ii) institutional characteristics associated with variations in clozapine prescribing; (iii) interventions aimed at enhancing clozapine prescribing. Data were synthesized narratively.

RESULTS

A total of 31 articles reporting findings of 29 studies published from 1993 to 2017 in 11 countries fulfilled our inclusion criteria. The main prescriber-related barriers to clozapine prescribing are lack of personal prescribing experience and concern with pharmacological characteristics of clozapine (blood monitoring and adverse effects). Lack of knowledge about the effectiveness of clozapine does not appear as a major determinant of under-prescription. Institutional-related characteristics favoring clozapine prescribing are prescribers' adherence to evidence-based medicine principles and learning by modelling from experienced clozapine prescribers.

CONCLUSION

Effective strategies to increase access to clozapine in persons with TRS include implementation of integrated clozapine clinics, simplification of blood monitoring, education for prescribers and contact with experienced prescribers. Programs addressing barriers in clozapine prescription need to be disseminated more broadly to ensure persons with TRS have access to evidenced based treatments such as clozapine. Inequality in access to clozapine care should be more systematically handled by mental health facilities and health regulatory agencies.

Clozapine and Psychosocial Function in Schizophrenia: A Systematic Review and Meta-Analysis

BACKGROUND

Clozapine has unique efficacy for symptoms in treatment-resistant schizophrenia; however, symptomatic remission is not necessary nor sufficient for functional improvement. No study has pooled the effect of clozapine on psychosocial function across clinical trials.

OBJECTIVE

We conducted a systematic review and meta-analysis to compare the effects of clozapine with other antipsychotics on psychosocial function, and described the predictors of functional outcome.

METHODS

We searched MEDLINE/PubMed, PsychINFO, EMBASE, CINAHL, Scopus, Web of Science, Cochrane Central Register of controlled trials and clinical trial registries till April 2018, with no language limits. Eligible studies were randomised controlled trials of clozapine vs. typical or atypical antipsychotics among adults with treatment-resistant schizophrenia. We included studies with flexible or fixed doses of antipsychotics within the therapeutic range to reflect naturalistic care. Effect sizes of studies were pooled using generic inverse variance and random-effects models and presented as standard mean differences. Study quality was assessed in accordance with the Cochrane Collaboration guideline, and subgroup analyses were carried out to identify potential moderators and methodological biases.

RESULTS

Nine studies with 1279 participants (69.7% male) were included. Clozapine showed beneficial effects on psychosocial function, but both short-term trials [n = 3; comparing 99 people taking clozapine with 97 controls (standardised mean difference = 0.04; 95% confidence interval - 0.24, 0.32; p = 0.77; I² = 0%)] and long-term trials [n = 5; comparing 415 people taking clozapine with 427 controls (standardised mean difference = 0.05; 95% confidence interval - 0.16, 0.27; p = 0.64; I² = 50%)] showed no superiority of clozapine to other antipsychotics in this regard. Only one study explored the predictors of psychosocial function. Baseline severity of illness, illicit drug use, extrapyramidal side effects, sex and cognition explained the variability in functional outcome. A range of scales measured psychosocial function, and the quality of reporting varied across trials.

CONCLUSIONS

Clozapine does not appear superior to other antipsychotics for improvement of psychosocial function. Standardisation of psychosocial function measurement is needed to improve the quality of evidence. Further exploration of the predictors of good psychosocial outcomes with clozapine treatment may improve personalisation of care.

Learned lessons from patients who take clozapine: A case study

PURPOSE

The purpose of this report is to provide clinical strategies to manage patients with schizophrenia taking clozapine.

CONCLUSIONS

Serious side effects and required blood monitoring impede the use of clozapine, despite the benefits of clozapine for managing psychiatric symptoms. Well-managed patients receiving evidence-based interventions exhibit reduced symptoms, improved functioning, and better adherence to treatment.

PRACTICE IMPLICATIONS

Preexisting medical conditions should be considered before prescribing clozapine. Ongoing education on medication and mental illness for patients and family members is essential to prepare them for adherence to management plans. Healthcare providers are responsible for monitoring the side effects of clozapine.

Clozapine-related neutropenia, myocarditis and cardiomyopathy adverse event reports in Australia 1993-2014

RATIONALE

Clozapine is the gold-standard medicine for treating refractory schizophrenia but there are some notable serious adverse events (AE). We aimed to analyse reported rates of clozapine cardiac and haematological AEs in Australia.

METHODS

Using data from the Therapeutic Goods Administration, we examined all reported clozapine AEs (1993-2014) with a specific focus on neutropenia, myocarditis and cardiomyopathy. We related AEs to clozapine-dispensing data in Queensland, scaled up to Australia.

RESULTS

There were 8561 AEs reported: neutropenia (13.7%), myocarditis (9.3%) and cardiomyopathy (3.8%). Reported rates of myocarditis and cardiomyopathy increased after 1999 following a myocarditis case series from Sydney. Cardiomyopathy AE rates have remained stable since then but myocarditis AEs have increased steadily. Neutropenia was more common in women, while cardiomyopathy and myocarditis were more common in men. There were five, 13, and two reported deaths from neutropenia, myocarditis, and cardiomyopathy, respectively.

CONCLUSIONS

The rates of serious AEs (including deaths) are low and likely an underestimate of true rates and need to be considered by clinicians in balancing the risks and benefits. Continued education on the monitoring and treatment of these AEs for consumers, carers and health professionals is essential and reporting these to the relevant national reporting agency is crucial.

Effects of adjunctive fluvoxamine on metabolic parameters and psychopathology in clozapine-treated patients with schizophrenia: A 12-week, randomized, double-blind, placebo-controlled study

OBJECTIVE

Numerous studies have demonstrated that fluvoxamine has considerable pharmacokinetic and pharmacodynamic interactions with clozapine. We conducted a 12-week, randomized, double-blind, placebo-controlled study to evaluate the effects of fluvoxamine on metabolic parameters and psychopathology in clozapine-treated patients with schizophrenia.

METHODS

We recruited 85 patients who received a DSM-IV diagnosis of schizophrenia. Eligible patients were randomized to receive fluvoxamine 50mg/day plus clozapine 100mg/day or clozapine 300mg/day. We studied metabolic parameters, psychopathology, and drug levels at baseline and 4, 8, and 12weeks after the intervention. Plasma levels of clozapine, norclozapine, clozapine N-oxide, and fluvoxamine were determined using high-performance liquid chromatography with ultraviolet detection.

RESULTS

No significant difference was observed in baseline characteristics between the two groups. Clozapine-fluvoxamine combined treatment significantly attenuated the increments in body weight, insulin resistance, and levels of insulin, glucose, and triglycerides compared with clozapine monotherapy. Both groups exhibited significant improvements in their Positive and Negative Syndrome Scale (PANSS) total and negative scores. The combined treatment group showed significant reduction in the PANSS general psychopathology scores compared with the monotherapy group. No difference was observed in the plasma clozapine level between the two groups. The monotherapy group showed higher levels of norclozapine and clozapine N-oxide than the combined group.

CONCLUSIONS

Compared with clozapine monotherapy, treatment with adjunctive fluvoxamine with clozapine for 12weeks can alleviate body weight gain and metabolic abnormalities in patients with schizophrenia, without sacrificing the clinical effect. Clinicians should interpret these findings cautiously considering the short duration of this study. The study was registered at www.clinicaltrials.gov (NCT01401491).

The association between season of birth, age at onset, and clozapine use in schizophrenia

OBJECTIVE

This study aimed to determine whether the rate of clozapine use, an indicator of refractoriness in schizophrenia, is associated with the season of birth and age at onset in patients with schizophrenia based on nationwide data.

METHODS

Patients with schizophrenia (n = 114 749) who received prescriptions for antipsychotic medication between 2008 and 2014 were retrospectively identified from the Korean National Health Insurance Service database. The study population was divided into three groups based on their age at the onset of schizophrenia (early, middle, and late onset). We assessed differences in the month of birth between patients and the general population. In addition, the cumulative clozapine use was calculated.

RESULTS

Compared to the late-onset schizophrenia group, the early- and middle-onset groups showed a higher probability of birth during the winter season. In addition, the early-onset group showed the highest cumulative clozapine use rate. In the middle-onset group, the initiation of clozapine use was significantly earlier for patients born in winter compared to those born in summer.

CONCLUSION

Our results indicate that the age at onset is an important factor in predicting the prognosis of schizophrenia patients. The season of birth also affects the prognosis, but with less robustness. Specifically, it appears that early disease onset and winter birth might be associated with poor outcomes in Korean patients with schizophrenia.

Clozapine Use in a Cohort of First-Episode Psychosis

PURPOSE/BACKGROUND

For approximately one third of individuals treated for psychosis or schizophrenia, antipsychotic medications will have little or no therapeutic benefit. Clozapine remains the sole medication approved for treatment-resistant schizophrenia, and studies have demonstrated its superior efficacy in reducing psychotic symptoms.

METHODS/PROCEDURES

Data were collected from the medical records of people who originally presented with a first-episode psychosis between 1995 and 1999 (N = 171). Data were obtained from first presentation up to December 31, 2013 or until the patient was discharged or transferred. Information on service use and physical health was gathered using a data collection template designed specifically for this audit.

FINDINGS/RESULTS

Twenty-eight (16.3%) of the cohort were prescribed clozapine. Data were available for 24 individuals. Of this clozapine subsample, the mean age at baseline was 23.11 (SD = 4.58); 82.14% (n = 23) were male; and 82.14% (n = 23) had a baseline diagnosis of schizophrenia. The mean time to first trial of clozapine was 6.7 years. The mean number of antipsychotics prescribed before clozapine trial was 4.85. After the initiation of clozapine, the mean number of hospital admissions reduced from 6.04 per year to 0.88 per year.

IMPLICATIONS/CONCLUSIONS

Nearly 1 in 5 of the original cohort was considered to have a suboptimal response to trials of antipsychotic medication. The use of clozapine for treatment-resistant schizophrenia is underutilized, and better understanding of the barriers to prescribing clozapine is necessary given the implications for patient's quality of life and hospital admission rates. Physical health data further emphasizes the importance of physical health monitoring in this vulnerable population.

CYP2C19*17 protects against metabolic complications of clozapine treatment

OBJECTIVES

Clozapine (CZ) is the most effective drug for managing treatment-resistant schizophrenic disorders. Its use has been limited due to adverse effects, which include weight gain and new-onset diabetes, but the incidence of these varies between patients.

METHODS

We investigated 187 Clozapine Clinic patients (of whom 137 consented for genotyping) for the presence of CYP2C19*17 and its association with CZ and norclozapine (NCZ) levels, and clinical outcomes.

RESULTS

Thirty-nine percent of genotyped patients were carriers of the CYP2C 19*17 polymorphism. This group demonstrated significantly higher NCZ serum levels, and significantly lower fasting glucose (5.66 ± 1.19 vs 6.72 ± 3.01 mmol/l, P = 0.009) and Hb1Ac (35.36 ± 4.78 vs 49.40 ± 20.60 mmol/mol, P = 0.006) levels compared to non-carriers of this polymorphism. CZ-treated patients with CYP2C19*17/*17 had a significantly lower prevalence of diabetes as well as a higher likelihood of clinical improvement of their schizophrenia, compared to those without this polymorphism (P = 0.012 and P = 0.031, respectively).

CONCLUSIONS

Our data suggest that CYP2C19*17 ultra-rapid-metaboliser status is a protective factor against the development of diabetes during clozapine treatment, and increases the likelihood of improvement in schizophrenia. The role of NCZ in treatment response and side effects, including metabolic syndrome, warrants further pharmacogenetic, pharmacokinetic and pharmacodynamic studies.

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

AIMS

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Role of cytokine changes in clozapine-induced fever: A cohort prospective study

AIM

Clozapine-associated fever is common but the specific cytokine changes and treatment durations that may cause fever remain unknown. We investigated the association between inflammatory cytokine changes and clozapine-induced fever in patients who were treated with clozapine.

METHODS

Forty-three patients with schizophrenia or schizoaffective disorder, diagnosed by using the Chinese Version of the Mini International Neuropsychiatric Interview, were treated with clozapine for the first time (first-time use group, n = 22) or for more than 6 months (long-term use group, n = 21). The Positive and Negative Syndrome Scale, tympanic temperature, and levels of tumor necrosis factor-α (TNF-α), interferon-γ (INF-γ), interleukin-2 (IL-2), and interleukin-6 (IL-6) were determined at baseline and weeks 1, 2, 3, 4, and 6. A multiple linear regression with generalized estimating equation methods was used to analyze the association between the changes in the cytokine levels and clozapine-induced fever in the different groups.

RESULTS

The IL-6 level changes were significantly different between the two groups (P = 0.04). In the first-time use group, the fever rate was increased (47.1%) compared with the long-term use group (5.6%, P = 0.005). Moreover, in these patients, the TNF-α, INF-γ, IL-2, and IL-6 levels were significantly (P < 0.001) different from patients who did not develop a fever. An interaction effect with the different treatment duration groups and fever development was only significant for IL-6 (P < 0.001).

CONCLUSION

Patients who were treated with clozapine for the first time have an increased rate of developing a fever, and IL-6 might have a specific role in the interaction effect between treatment duration and fever development.

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

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

Higher than recommended dosages of antipsychotics in male patients with schizophrenia are associated with increased depression but no major neurocognitive side effects: Results of a cross-sectional pilot naturalistic study

INTRODUCTION

The current small pilot naturalistic cross-sectional study assesses whether higher dosages of antipsychotics are related to a satisfactory outcome concerning symptoms of schizophrenia but also to a worse outcome in terms of adverse events and neurocognitive function.

MATERIAL AND METHODS

41 male stabilized hospitalized schizophrenic patients were assessed by PANSS, Calgary Depression Rating Scale, UKU and Simpson-Angus Scale and a battery of neurocognitive tests. Medication and dosage was prescribed according to clinical judgement of the therapist.

RESULTS

Clinical variables and adverse events did not differ between patients in the recommended vs high dosage groups. Higher dosage correlated with depressive symptoms but there was no correlation with neurocognitive measures except for impaired concentration.

DISCUSSION

Results suggest that it is possible to achieve a good clinical response in refractory patients by exceeding recommended antipsychotic dosages at the price of depression and possible mild isolated concentration deficits but not other neurocognitive or extrapyramidal adverse events. Currently clinicians prefer first-generation antipsychotics when high dosages are prescribed, but considering the more favorable adverse effects profile of newer agents, it is important to study higher dosages of these agents and to test whether they should be preferably given when high dosages are necessary.

The impact of clozapine on hospital use: a systematic review and meta-analysis

OBJECTIVE

The objective of this study was to perform a systematic review and meta-analysis of studies reporting the impact of clozapine on hospital use in people with a psychotic illness.

METHOD

PubMed, EMBASE, PsycINFO and the Cochrane Schizophrenia Group Trials Register were systematically searched from inception to 12 October 2016. We included all trials and observational studies, except case reports.

RESULTS

Thirty-seven studies were included. Clozapine significantly reduced the proportion of people hospitalised compared to control medicines (RR = 0.74; 95% CI: 0.69-0.80, P < 0.001, 22 studies, n = 44 718). There were significantly fewer bed days after clozapine treatment compared to before clozapine treatment in both controlled (MD = -34.41 days; 95% CI: -68.22 to -0.60 days, P = 0.046, n = 162) and uncontrolled studies (MD = -52.86 days; 95% CI: -79.86 days to -25.86 days, P < 0.001, n = 2917). Clozapine and control medicines had a similar time to rehospitalisation (-19.90 days; 95% CI: -62.42 to 22.63 days, P = 0.36).

CONCLUSION

Clozapine treatment reduced the number of people hospitalised and the number of bed days after treatment compared with before treatment. Clozapine has the potential to reduce acute hospital use among people with treatment refractory schizophrenia.

Enhanced disease reduction using clozapine, an atypical antipsychotic agent, and glatiramer acetate combination therapy in experimental autoimmune encephalomyelitis

BACKGROUND

Atypical antipsychotic agents (AAP) alleviate the symptoms of severe mental health disorders, such as schizophrenia, by antagonizing dopamine and serotonin receptors. Recently, AAP have also been shown to exhibit immunomodulatory properties in the central nervous system (CNS).

OBJECTIVE

Building on research which demonstrated the ability of the AAP risperidone and clozapine to modify the disease course of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS), we aimed to more fully investigate the potential of clozapine as a possible treatment for MS.

RESULTS

We report that orally administered clozapine significantly reduced the disease severity of EAE in a dose-dependent manner and was effective when administered prophylactically and therapeutically. In comparison to risperidone, quetiapine, and olanzapine, clozapine was the best at reducing disease severity. While clozapine-treated mice had only modest changes to peripheral leukocytes and cytokine responses, these animals had significantly fewer CNS-infiltrating CD4 T cells and myeloid cells. Furthermore, the CNS myeloid cells displayed a less activated phenotype in mice treated with clozapine. Finally, we found that co-administration of clozapine with glatiramer acetate enhanced disease protection compared to either treatment alone.

CONCLUSION

These studies indicate that clozapine is an effective immunomodulatory agent with the potential to treat immune-mediated diseases such as MS.