A systematic review of clozapine induced cardiomyopathy

When, Why and How to Re-challenge Clozapine in Schizophrenia Following Myocarditis

Clozapine-induced myocarditis (CIM) is among the most important adverse events limiting the use of clozapine as the most effective treatment for schizophrenia. CIM necessitates the immediate termination of clozapine, often resulting in its permanent discontinuation with considerable detrimental effects on patients' psychopathology and long-term outcome. Consequently, a clozapine re-challenge after CIM is increasingly regarded as a viable alternative, with published reports indicating a success rate of approximately 60%. However, published cases of re-challenges after CIM remain limited. Here, we provide a narrative review of the current state of research regarding the epidemiology, pathophysiology, risk factors, diagnosis and clinical management of CIM as well as a synthesis of current recommendations for re-challenging patients after CIM. This includes a step-by-step guide for this crucial procedure based on the current evidence regarding the pathophysiology and risk factors for CIM. Slow dose titration regimes and addressing risk factors including concomitant valproate and olanzapine are crucial both to prevent CIM and to ensure a safe and successful re-challenge. Furthermore, we discuss the utility of C-reactive protein, troponin, N-terminal-pro hormone and brain natriuretic peptide, therapeutic drug-monitoring and cardiac magnetic resonance imaging for CIM screening and diagnosis as well as for post-CIM re-challenges.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Clozapine metabolism and cardiotoxicity: A prospective longitudinal study

BACKGROUND

Clozapine-induced myocarditis and cardiomyopathy are difficult to detect clinically and may be fatal if not detected early. The current/routine biomarkers for clozapine-induced myocarditis are non-specific indicators of inflammation (C-reactive protein) or cardiomyocyte damage (troponins I and T) that lack sensitivity, and for which changes often arise too late to be clinically useful.

METHODS

The Clozapine Safety Study was a prospective, longitudinal, observational study to determine what, if any, the plasma concentrations of clozapine, N-desmethylclozapine, and clozapine-N-oxide in patients contribute to cardiotoxicity. Samples were collected and analysed using liquid chromatography mass spectrometry over a 41-month period from patients in the Auckland District Health Board.

RESULTS

Sixty-seven patients were included. Six patients were diagnosed with myocarditis; none were diagnosed with cardiomyopathy in the study period. In patients not undergoing dose titration, clozapine biotransformation may shift to the N-oxide pathway rather than the N-desmethyl pathway with increasing dose. During dose titration, the timeframe in which myocarditis occurs, the rate of increase in the plasma concentration of clozapine-N-oxide, as well as the ratio of N-oxidation relative to N-desmethylation, were significantly higher in patients diagnosed with myocarditis.

CONCLUSIONS

The assessment of clozapine-N-oxide formation, and N-oxidation relative to N-desmethylation ratios during treatment, may help identify a biomarker to aid the early detection of patients at risk of developing clozapine-induced cardiotoxicity.

CYP-catalysed cycling of clozapine and clozapine-N-oxide promotes the generation of reactive oxygen species in vitro

Clozapine is an effective atypical antipsychotic indicated for treatment-resistant schizophrenia, but is under-prescribed due to the risk of severe adverse drug reactions such as myocarditis.A mechanistic understanding of clozapine cardiotoxicity remains elusive.This study aimed to investigate the contribution of selected CYP isoforms to cycling between clozapine and its major circulating metabolites, N-desmethylclozapine and clozapine-N-oxide, with the potential for reactive species production.CYP supersome™-based in vitro techniques were utilised to quantify specific enzyme activity associated with clozapine, clozapine-N-oxide and N-desmethylclozapine metabolism.The formation of reactive species within each incubation were quantified, and known intermediates detected.CYP3A4 predominately catalysed clozapine-N-oxide formation from clozapine and was associated with concentration-dependent reactive species production, whereas isoforms favouring the N-desmethylclozapine pathway (CYP2C19 and CYP1A2) did not produce reactive species.Extrahepatic isoforms CYP2J2 and CYP1B1 were also associated with the formation of clozapine-N-oxide and N-desmethylclozapine but did not favour one metabolic pathway over another.Unique to this investigation is that various CYP isoforms catalyse clozapine-N-oxide reduction to clozapine.This process was associated with the concentration-dependent formation of reactive species with CYP3A4, CYP1B1 and CYP1A1 that did not correlate with known reactive intermediates, implicating metabolite cycling and reactive oxygen species in the mechanism of clozapine-induced toxicity.

[Safety aspects during treatment with clozapine. : Monitoring and rechallenge - a narrative review]

BACKGROUND

Due to its unique efficacy in treatment-resistant schizophrenia, discontinuation of treatment with clozapine is frequently associated with a significant worsening of symptoms, but also with an increased risk of suicide. Based on the literature, this review aims at summarizing different monitoring recommendations in order to be able to continue this therapy despite the occurrence of side effects. In addition, we provide recommendations when rechallenge of a previously stopped treatment with clozapine can be considered and when a definite discontinuation must take place.

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 of Psychiatry, Psychotherapy and Psychosomatics were searched for relevant literature, the last query dating from April 28th, 2023.

RESULTS

If agranulocytosis or cardiomyopathy develops, treatment with clozapine must be discontinued and should not be resumed thereafter. In contrast, treatment with clozapine which had to be discontinued due to myocarditis or prolongation of the QTc interval may be continued if left ventricular function is normal or after normalization of the QTc interval. Other side effects are usually not absolute contraindications for rechallenge but often require the adjunctive use of additional pharmacologic and non-pharmacologic measures.

CONCLUSION

Taking into consideration various monitoring recommendations, cessation of treatment with clozapine can often be prevented or treatment with clozapine that has been discontinued due to side effects can be resumed.

Clozapine-induced eosinophilia: A case report

Schizophrenia is a chronic neuropsychiatric illness defined by the appearance of positive, and negative symptoms and/or cognitive impairment. Antipsychotic drugs are predominantly used in the treatment of psychotic disorders, but not all patients with schizophrenia respond to every antipsychotic medication. Clozapine is one of the best atypical antipsychotics and is highly effective in treating treatment-resistant schizophrenia. Evidence suggests that clozapine appears to be effective in lowering the risk of suicide, extrapyramidal side effects, and relapse in patients with schizophrenia. Per contra, clozapine is not the first-line treatment due to its unalterable aftereffects such as agranulocytosis, metabolic syndrome, seizures, and rarely, eosinophilia. Eosinophilia can be life-threatening. Eosinophils infiltrate different tissues and cause inflammation in multiple organs causing end-organ damage. The current study aimed to report the incidence of eosinophilia associated with clozapine use in patients with schizophrenia. Literature on clozapine-induced eosinophilia is relatively scarce. Understanding the progression and management of clozapine-induced eosinophilia and its end-organ effects is imperative. While there is insufficient data about the guidelines in the management of clozapine-induced eosinophilia, this study contributes to understanding the patterns of the disease progression with clozapine dosage. A case study was done on a patient with schizophrenia and autistic spectrum disorder who was on clozapine. Data on how eosinophil levels varied with clozapine dosing was analyzed and documented. The evidence of clozapine dosage affecting eosinophil and C-reactive protein levels in this patient was summarized in a table and a narrative review.

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.

Clozapine-induced Myocarditis: Pathophysiologic Mechanisms and Implications for Therapeutic Approaches

Clozapine, a superior treatment for treatment-resistant schizophrenia can cause potentially life-threatening myocarditis and dilated cardiomyopathy. While the occurrence of this condition is well known, its molecular mechanisms are unclear and may be multifactorial. Putative mechanisms warrant an in-depth review not only from the perspective of toxicity but also for understanding the molecular mechanisms of the adverse cardiac effects of clozapine and the development of novel therapeutic approaches. Clozapine-induced cardiac toxicity encompasses a diverse set of pathways, including (i) immune modulation and proinflammatory processes encompassing an IgEmediated (type I hypersensitivity) response and perhaps a cytokine release syndrome (ii) catecholaminergic activation (iii) induction of free radicals and oxidative stress (iv) activation of cardiomyocyte cell death pathways, including apoptosis, ischemia through impairment in coronary blood flow via changes in endothelial production of NO and vasoconstriction induced by norepinephrine as well as other factors released from cardiac mast cells. (v) In addition, an extensive examination of the effects of clozapine on non-cardiac cellular proteins demonstrates that clozapine can impair enzymes involved in cellular metabolism, such as pyruvate kinase, mitochondrial malate dehydrogenase, and other proteins, including α-enolase, triosephosphate isomerase and cofilin, which might explain clozapine-induced reductions in myocardial energy generation for cell viability as well as contractile function. Pharmacologic antagonism of these cellular protein effects may lead to the development of strategies to antagonize the cardiac damage induced by clozapine.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Early Manifestation of Clozapine-Induced Cardiotoxicity: Detection, Pathophysiology, and Management

Schizoaffective disorder, bipolar type is a chronic mental health disorder that may manifest as mania. Clozapine is effective in treating acute mania and in achieving mood stabilization. However, on rare occasions, the use of clozapine has been associated with cardiotoxicity. Here, we present a case of a 31-year-old man who at baseline is known to have schizoaffective disorder, bipolar type, and cannabis dependence and was admitted to our hospital with a psychotic relapse. He was treated with clozapine, uptitrated to a maximum daily dose of 200mg twice daily by day 10. Thereafter he became febrile and experienced malaise, myalgias, and chest pain. He was noted on electrocardiogram to have sinus tachycardia without ischemic changes. In this context, he had a troponin leak, increased white blood cell count, serologies and cultures were negative and chest x-ray revealed no acute disease of the chest. Due to the suspicion of clozapine-induced cardiotoxicity, a transthoracic echocardiogram was done, which revealed mildly depressed left ventricular (LV) systolic function without pericardial effusion. Thereafter, clozapine was withdrawn and switched to lithium. Additionally, the cardioselective, metoprolol tartrate was initiated. Within 36-48 hours, he had resolution of symptoms and remained cardiovascularly stable. Clozapine uncommonly causes cardiotoxicity and early features may be non-specific. Awareness of this and recognizing early features aids in reducing the associated cardiovascular morbidity and mortality.

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.

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.

Risk factors for clozapine-induced myocarditis and cardiomyopathy: A systematic review and meta-analysis

OBJECTIVE

Clozapine is the most effective medication for treatment-refractory schizophrenia, but it is associated with severe cardiac adverse events including myocarditis and cardiomyopathy. To aid treatment decision-making for clinicians, patients and their carers, we conducted a systematic review and meta-analysis to identify potential risk factors for clozapine-induced myocarditis and cardiomyopathy.

METHODS

A systematic search was conducted of PubMed, Embase, CINAHL, Web of Science, Cochrane and PsycInfo for studies reporting myocarditis and cardiomyopathy among people on clozapine and potential risk factors. We calculated pooled effect sizes on risk factors using a random-effects meta-analytic model. Risk of publication bias was assessed using the Newcastle-Ottawa scale.

RESULTS

Seven studies met the inclusion criteria, of which six studies had quantitative data included in the meta-analysis. The odds of clozapine-induced myocarditis increased with concurrent sodium valproate use (k = 6, n = 903, pooled OR 3.58, 95% CI 1.81-7.06), but were not significantly greater with the use of quetiapine, lithium or selective serotonin reuptake inhibitors. Our qualitative review identified conflicting results reported for increasing age and higher clozapine dose as risk factors for myocarditis. No other factors, including genetic risk, sex, ethnicity, smoking, alcohol, substance abuse or cardiometabolic disease, were associated with greater odds of myocarditis. No risk factors for cardiomyopathy were identified in the literature.

CONCLUSION

Concurrent use of sodium valproate increases the odds of clozapine-induced myocarditis. Thus, clinicians should consider the temporary cessation of sodium valproate during the initial titration phase of clozapine.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Clinical Utility and Safety of Slower-than-Recommended Titration of Clozapine for Treatment-Resistant Schizophrenia: a Retrospective Cohort Study

Slow titration of clozapine is recommended given the risk of serious adverse effects. However, the utility and safety of slower-than-recommended titration of clozapine remain unclear. Consequently, we aimed to investigate the clinical utility and safety of slower-than-recommended titration of clozapine for treatment-resistant schizophrenia. We conducted a retrospective chart review of 152 inpatients with treatment-resistant schizophrenia who had been newly started on clozapine in a tertiary psychiatric public hospital between April 2012 and March 2018. The primary outcome was clozapine continuation for the first 18 weeks. We performed multivariate logistic regression to identify the association between the rate of clozapine dose titration and clozapine continuation for the first 18 weeks. Among the 152 inpatients, 122 (80%) could continue clozapine for the first 18 weeks. There was no significant association between the rate of clozapine dose titration and clozapine continuation for the first 18 weeks (adjusted odds ratio 1.23; 95% CI 0.29-5.26; p = 0.78). Our findings indicate that slower-than-recommended titration of clozapine may not improve toward clozapine continuation for the first 18 weeks. Therefore, it may not be a beneficial option in terms of safe clozapine continuation when starting clozapine for treatment-resistant schizophrenia.

"My Heart Said It's Swollen": A Rare Case of Clozapine-Induced Myocarditis in a Schizophrenic Patient

Clozapine is a Food and Drug Administration-approved, second-generation antipsychotic used to treat treatment-resistant schizophrenia. Known for its benefits in reducing extrapyramidal symptoms typically seen with antipsychotics, this drug carries a risk of agranulocytosis and, to a lesser-known extent, myocarditis. A 49-year-old patient, who was initially admitted to psychiatry with a primary diagnosis of schizophrenia, was started on clozapine. After three weeks of being on clozapine, the patient developed fevers and was admitted under internal medicine for further workup of presumed systemic inflammatory response syndrome due to noninfectious etiology. The patient was also asymptomatic. He was subsequently found to have elevated cardiac markers and C-reactive protein levels as well as decreased left ventricular ejection fraction and findings consistent with myocarditis using echocardiography. Clozapine was discontinued and the patient was transferred to the cardiology service for guideline-directed medical management of myocarditis and heart failure with reduced ejection fraction. The overall mechanism of clozapine cardiotoxicity is not well understood. Proposed hypotheses include IgE-mediated acute hypersensitivity and cardiac myocyte damage via the release of proinflammatory cytokines. However, when suspecting myocarditis after initiating clozapine, continuous monitoring and cessation of the medication are crucial in preventing permanent damage to the myocardium. Given the cardiac risk of medication and potential lethality of myocarditis via progression to heart failure, it is important to observe physical examination findings as well as symptoms of the condition when initiating a patient on clozapine.

Incidence and investigation of potential risk-factors for clozapine-associated myocarditis and cardiomyopathy in a New Zealand cohort

Clozapine is a uniquely effective antipsychotic indicated for treatment-resistant schizophrenia. However, its use is underutilised and often delayed for years due to potential adverse reactions including myocarditis and cardiomyopathy. The purpose of this study was to conduct a retrospective review of the clinical records of patients initiating clozapine in the Auckland District Health Board (ADHB) region to determine the incidence of clozapine-associated myocarditis and cardiomyopathy and to identify potential risk factors associated with these cardiotoxicities. The incidence of clozapine-associated myocarditis and cardiomyopathy over a two-year period in the ADHB region was 3.8% and 1.3% respectively.

An evaluation of the variation and underuse of clozapine in the United Kingdom

BACKGROUND

Clozapine is the only licensed treatment for treatment refractory schizophrenia. Despite this, it remains grossly underused relative to the prevalence of refractory schizophrenia. The extent of underuse and the degree of regional variation in prescribing in the United Kingdom is unknown. It is also unclear, how the UK compares with other European countries in rates of clozapine prescribing.

METHODS

We obtained data relating to all clozapine prescribing in the UK from the relevant clozapine registries. We examined regional variation in clozapine use across England, corrected for the known prevalence of severe mental illness (SMI). We also compared the UK rate of clozapine use per 100,000 population to that described in other European countries.

FINDINGS

There is substantial variation in clozapine prescribing across different regions of England and only about a third of potentially eligible patients were prescribed the drug in the UK. Clozapine prescribing rate in the UK was lower than in several European countries.

INTERPRETATION

There is clear regional inequity in access to the most effective treatment in refractory schizophrenia in England. Strategies to increase clozapine use, by overcoming both real and perceived barriers, are urgently necessary to reduce treatment inequity for patients with refractory schizophrenia.

Clozapine-Associated Myocarditis: A Protocol for Monitoring Upon Clozapine Initiation and Recommendations for How to Conduct a Clozapine Rechallenge

BACKGROUND

Clozapine is the only medication with Food and Drug Administration approval for treatment-resistant schizophrenia. However, it is underutilized in the United States because of several life-threatening adverse effects, including clozapine-associated myocarditis (CAM), and a limited understanding of how to manage these complications. To date, recommendations for rechallenging patients with CAM that incorporate the cardiac literature or cardioprotective medications have not been developed.

FINDINGS

In this article, we outline a protocol developed with cardiologists and guided by the cardiac literature that provides direction on how to monitor for the initial development of CAM and how to rechallenge patients with CAM. Furthermore, we present 2 successful cases of clozapine rechallenge that were managed using this protocol.

CONCLUSIONS

In both cases, the patients showed marked improvement in their psychiatric symptoms and functioning, demonstrating the importance of considering rechallenge in patients after CAM.

A Working Hypothesis Regarding Identical Pathomechanisms between Clinical Efficacy and Adverse Reaction of Clozapine via the Activation of Connexin43

Clozapine (CLZ) is an approved antipsychotic agent for the medication of treatment-resistant schizophrenia but is also well known as one of the most toxic antipsychotics. Recently, the World Health Organization’s (WHO) global database (VigiBase) reported the relative lethality of severe adverse reactions of CLZ. Agranulocytosis is the most famous adverse CLZ reaction but is of lesser lethality compared with the other adverse drug reactions of CLZ. Unexpectedly, VigiBase indicated that the prevalence and relative lethality of pneumonia, cardiotoxicity, and seizures associated with CLZ were more serious than that of agranulocytosis. Therefore, haematological monitoring in CLZ patients monitoring system provided success in the prevention of lethal adverse events from CLZ-induced agranulocytosis. Hereafter, psychiatrists must amend the CLZ patients monitoring system to protect patients with treatment-resistant schizophrenia from severe adverse CLZ reactions, such as pneumonia, cardiotoxicity, and seizures, according to the clinical evidence and pathophysiology. In this review, we discuss the mechanisms of clinical efficacy and the adverse reactions of CLZ based on the accumulating pharmacodynamic findings of CLZ, including tripartite synaptic transmission, and we propose suggestions for amending the monitoring and medication of adverse CLZ reactions associated with pneumonia, cardiotoxicity, and seizures.

Potentially Inappropriate Prescriptions in Heart Failure with Reduced Ejection Fraction (PIP-HFrEF)

Heart failure (HF) is a chronic debilitating and potentially life-threatening condition. Heart Failure patients are usually at high risk of polypharmacy and consequently, potentially inappropriate prescribing leading to poor clinical outcomes. Based on the published literature, a comprehensive HF-specific prescribing review tool is compiled to avoid medications that may cause HF or harm HF patients and to optimize the prescribing practice of HF guideline-directed medical therapies. Recommendations are made in line with the last versions of ESC guidelines, ESC position papers, scientific evidence, and experts' opinions.

Echocardiographic Changes with Positive Airway Pressure Therapy in Obesity Hypoventilation Syndrome. Long-Term Pickwick Randomized Controlled Clinical Trial

Rationale: Obesity hypoventilation syndrome (OHS) has been associated with cardiac dysfunction. However, randomized trials assessing the impact of long-term noninvasive ventilation (NIV) or continuous positive airway pressure (CPAP) on cardiac structure and function assessed by echocardiography are lacking.Objectives: In a prespecified secondary analysis of the largest multicenter randomized controlled trial of OHS (Pickwick Project; N = 221 patients with OHS and coexistent severe obstructive sleep apnea), we compared the effectiveness of three years of NIV and CPAP on structural and functional echocardiographic changes.Methods: At baseline and annually during three sequential years, patients underwent transthoracic two-dimensional and Doppler echocardiography. Echocardiographers at each site were blinded to the treatment allocation. Statistical analysis was performed using a linear mixed-effects model with a treatment group and repeated measures interaction to determine the differential effect between CPAP and NIV.Measurements and Main Results: A total of 196 patients were analyzed: 102 were treated with CPAP and 94 were treated with NIV. Systolic pulmonary artery pressure decreased from 40.5 ± 1.47 mm Hg at baseline to 35.3 ± 1.33 mm Hg at three years with CPAP, and from 41.5 ± 1.56 mm Hg to 35.5 ± 1.42 with NIV (P < 0.0001 for longitudinal intragroup changes for both treatment arms). However, there were no significant differences between groups. NIV and CPAP therapies similarly improved left ventricular diastolic dysfunction and reduced left atrial diameter. Both NIV and CPAP improved respiratory function and dyspnea.Conclusions: In patients with OHS who have concomitant severe obstructive sleep apnea, long-term treatment with NIV and CPAP led to similar degrees of improvement in pulmonary hypertension and left ventricular diastolic dysfunction.Clinical trial registered with www.clinicaltrials.gov (NCT01405976).

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.

Clozapine associated cardiotoxicity: Issues, challenges and way forward

OBJECTIVE

To review the published literature on clozapine associated cardiotoxicity (CACT), summarize diagnostic features, and evaluate monitoring procedures for safe clozapine re-challenge.

RESULTS

Clozapine-associated Myocarditis (CAM) - Incidence of early myocarditis (≤2 months) is infrequent but serious. Clinical diagnosis is confounded by variability in presentation and non-specificity of symptoms. Re-challenge considerations include clozapine impact on symptomatic severity and associated disability and risk of suicidality. Re-challenging is recommended only after full clinical resolution of myocarditis and cardiac function impairment, under closely controlled conditions, starting at very low dosage, extremely slow titration and frequent assays of lab and cardio biomarkers. Clozapine associated cardiomyopathy (CAC) -develops later but mortality has been reported at 12.5-24.0%. Re-challenge is generally not recommended due to paucity of outcome data. Monitoring Cardiac Toxicity: Plausible steps include closer clinical monitoring, repeated assays of biomarkers, and echocardiographic studies, and cardiac MRI changes with unremarkable findings of cardiac dysfunction with echocardiography. Subclinical clozapine associated cardiotoxicity is more prevalent than CAM and CAC. Diagnosis is often challenging due to non specific presentation. Active monitoring is recommended. Rechallenging is feasible but should be done under close monitoring conditions. A protocol is proposed based on literature review and clinical experience in order to reduce the risk of CACT.

CONCLUSION

Clozapine-associated myocarditis and cardiomyopathy may have been underreported worldwide. Identification of subclinical cardiotoxic effects can improve outcomes by earlier recognition before clinical manifestations of cardiac impairments. A pragmatic close clinical monitoring protocol including cardiac biomarkers aimed at timely detection of cardiac toxicity, in the initial phase of treatment is proposed.

Clozapine-Induced Pneumonitis: A Case Report

Introduction: Clozapine is the most effective antipsychotic used for treatment resistant schizophrenia and recurrent suicidal behavior in schizophrenia or schizoaffective disorder. However, it has been underutilized due to its adverse reaction profile. Although clozapine is typically associated with neutropenia leading to increased risk of infection (i.e., pneumonia), there have been a few case reports of non-neutropenic, non-infectious drug-induced lung disease (i.e., pneumonitis). Although pneumonia and pneumonitis may have similar clinical presentation, their etiology, management, and treatment are different. Case presentation: A 53-year-old African American female with schizoaffective disorder was hospitalized for being no longer able to appropriately utilize food, clothing, and shelter. The patient developed a sepsis-like presentation during clozapine titration which resolved after treatment for presumed pneumonia and clozapine discontinuation. When clozapine was resumed due to persistent psychosis, the patient again developed a sepsis-like presentation. Clozapine was again discontinued with no other interventions and the patient's symptoms resolved. Conclusions: Drug-induced pneumonitis is a very rare adverse reaction of clozapine. Recognizing conditions that mimic sepsis may prevent patients from undergoing unnecessary laboratory testing and prevent exposure to unwarranted antibiotics.

Resolution without discontinuation: heart failure during clozapine treatment

Clozapine is an atypical antipsychotic recommended for patients with treatment-resistant schizophrenia whose illness has not responded adequately to treatment despite the sequential use of at least two different antipsychotic drugs at therapeutic doses. Unfortunately, clozapine is frequently discontinued due to both real and perceived serious, and potentially life-threatening, adverse effects, contributing to the underutilisation of the most effective treatment in refractory psychotic disorders. Here, we present the case of a 51-year-old man with treatment-resistant schizoaffective disorder, who was admitted to a locked rehabilitation unit for a clozapine rechallenge. Within 6 months after the clozapine rechallenge, he was diagnosed with heart failure likely secondary to his antipsychotic treatment. Clozapine-induced heart failure usually prompts immediate cessation of treatment. However, in this case, clozapine was continued with cardiology consultation. Ramipril and bisoprolol were initiated and the patient's cardiac condition progressively improved over time. Clozapine-induced heart failure is a serious cardiovascular complication of treatment, usually resulting in discontinuation of treatment. Although there are cases of successful rechallenge, temporary cessation of treatment can lead to severe psychotic exacerbation and non-engagement with cardiac specialists. More evidence is required for continued use of clozapine in a patient with clozapine-induced cardiac complications.

Clozapine and cardiotoxicity - A guide for psychiatrists written by cardiologists

This review discusses the rare but potentially life-threatening cardiovascular side-effects of myocarditis and dilated cardiomyopathy associated with the use of Clozapine. The clinical presentation of these conditions is non-specific, making it difficult to both risk-stratify and identify patients who develop these consequences. This review aims to examine the proposed aetiologies, diagnostic approaches and subsequent management strategies of cardiotoxicity associated with clozapine use; offering guidance to psychiatrists and general physicians. Current evidence highlights the importance of accurate diagnosis to prevent premature and unnecessary cessation of clozapine. Guidance on monitoring and reintroduction of the drug is emerging and current practice recommends a combination of regular monitoring of biomarkers and imaging to make a diagnosis of cardiotoxicity although further work is needed to establish evidence-based guidelines.

Circulating microRNA as biomarkers of clozapine-induced cardiotoxicity

Purpose: This work investigated the utility of circulating microRNA (miRNA) as biomarkers of clozapine (CLZ)-induced cardiotoxicities: serious adverse events with an unusually high incidence in Australia and New Zealand.Methods: Global plasma miRNA expression was analysed by microarray in patients taking CLZ, to investigate differential expression between CLZ-induced cardiotoxicity cases (n = 6) and matched control patients (n = 12). The results were validated by RT-qPCR using a panel of 17 miRNA, and their expression was examined in both CLZ-naïve healthy volunteers (n = 12) and an expanded cohort of CLZ-taking patients (n = 21). Temporal changes were also examined in two healthy volunteers and two CLZ-induced cardiotoxicity patients.Results: No miRNA were differentially expressed between cases of CLZ-induced cardiotoxicity and control patients. Circulating levels of several miRNA were significantly altered in CLZ-taking patients compared to healthy volunteers, with miR-16-5p, miR-25-3p, miR-92a-3p, miR-320a-3p, and miR-486-3p upregulated and miR-22-3p, miR-126-3p, and miR-142-3p downregulated in the patients. Five of these (miR-16-5p, miR-22-3p, miR-92a-3p, miR-126-3p, miR-142-3p) were stably expressed over time in both CLZ-induced cardiotoxicity patients and CLZ-naïve healthy volunteers.Conclusions: Plasma miRNA are not useful biomarkers of CLZ-induced cardiotoxicity, however patients taking CLZ have significantly altered circulating miRNA compared to healthy volunteers.

Understanding and managing cardiac side-effects of second-generation antipsychotics in the treatment of schizophrenia

Second-generation antipsychotic medications (SGAs) have advanced the treatment of schizophrenia over the past 30 years. However, a number of potentially life-threatening cardiac side-effects associated with these treatments concern and can discourage prescribers from administering these evidence-based treatments. This review provides a practical, psychiatrist-oriented understanding of the relative frequencies, mechanisms, investigations and treatments associated with these cardiac toxicities. We aim to highlight that these are relatively rare complications of an effective class of drug and to promote the advantages of early involvement of cardiologists in the psychiatric multidisciplinary team to guide the investigation and management of these conditions.

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Cardiovascular effects of psychotic illnesses and antipsychotic therapy

Mortality from cardiovascular disease is increased in people with mental health disorders in general and schizophrenia in particular. The causes are multifactorial, but it is known that antipsychotic medication can cause cardiac side-effects beyond the traditional coronary risk factors. Schizophrenia itself is a contributor to an increased risk of cardiovascular mortality via cardiac autonomic dysfunction and a higher prevalence of metabolic syndrome, both contributing to a reduced life expectancy. The pro-arrhythmic impact of traditional antipsychotics, especially via the hERG-potassium channel, has been known for several years. Newer antipsychotics have a reduced pro-arrhythmic profile but might contribute to higher cardiac death rates by worsening the metabolic profile. Clozapine-induced cardiomyopathy, which is dose independent, is a further concern and continuous monitoring of these patients is required. Prophylaxis with angiotensin-converting enzyme inhibitors is currently under review. Overall, management of cardiovascular risk within this population group must be multifaceted and nuanced to allow the most effective treatment of serious mental illness to be conducted within acceptable parameters of cardiovascular risk; some practical measures are presented for the clinical cardiologist.

Clozapine-Induced Cardiotoxicity Presenting as Sepsis: A Case Report and Literature Review

Clozapine is an atypical antipsychotic agent indicated in the treatment of medication-resistant schizophrenia. It is often reserved as a last line of treatment owing to the potential for serious and potentially life-threatening side effects, the most serious being agranulocytosis requiring close hematological monitoring and possible discontinuation of the medication from further use in the patient even when the agranulocytosis resolves. Other complications of clozapine include sedation, weight gain, elevated triglyceride levels, postural hypotension, and tachycardia. However, the potentially serious complication of myocarditis, though rare (with an incidence of 3%), may lead to cardiomyopathy as described in our present case. We present a 21-year-old patient who was started on clozapine for management of schizophrenia. He developed fever and tachycardia and was admitted to the medical unit on intravenous antibiotics for management of sepsis as he met the criteria for systemic inflammatory response syndrome. His labs revealed an elevated troponin and trending eosinophilia, which, in the context of clozapine use, raises the suspicion of clozapine cardiotoxicity. Echocardiogram showed reduced systolic function (45%). Clozapine was immediately discontinued, and his repeat echocardiogram showed normalization of his systolic function. In view of the increased prevalence of psychiatric illnesses, internists should be aware of rare but potentially life-threatening side effects.

Clozapine-induced myocarditis in an adolescent male with DiGeorge Syndrome

DiGeorge Syndrome (22q11.2 deletion syndrome) is a chromosomal disorder associated with both congenital heart malformations and schizophrenia, which is often treatment-resistant and may warrant treatment with clozapine. Clozapine-induced myocarditis (CIM) is a rare complication of clozapine therapy, with a reported incidence ranging from 0.015% to 3%. Fulminant CIM has a nonspecific presentation in both adult and pediatric populations and a mortality rate approaching 50%. Few cases of pediatric CIM have been documented in the literature. This report highlights a case of CIM in an adolescent male with DiGeorge Syndrome whose clinical course was characterized by a subtle, nonspecific presentation and resolution with supportive care.

Clozapine Pharmacogenetic Studies in Schizophrenia: Efficacy and Agranulocytosis

Clozapine is an efficacious atypical antipsychotic for treatment-refractory schizophrenia. Clinical response and appearance of adverse events vary among individual patients receiving clozapine, with genetic and non-genetic factors potentially contributing to individual variabilities. Pharmacogenetic studies investigate associations between genetic variants and drug efficacy and toxicity. To date, most pharmacogenetic studies of clozapine have been conducted through candidate gene approaches. A recent advance in technology made it possible to perform comprehensive genetic mapping underlying clinical phenotypes and outcomes, which allow novel findings beyond biological hypotheses based on current knowledge. In this paper, we will summarize the studies on clozapine pharmacogenetics that have extensively examined clinical response and agranulocytosis. While there is still limited evidence on clozapine efficacy, recent genome-wide studies provide further evidence of the involvement of the human leukocyte antigen (HLA) region in clozapine-induced agranulocytosis.

Clozapine-induced cardiomyopathy and myocarditis monitoring: A systematic review

The use of clozapine requires monitoring the absolute neutrophil count because of the risk of agranulocytosis, but other potentially fatal adverse events associated with clozapine (specifically, myocarditis and cardiomyopathy) do not have mandatory procedures. We performed a systematic review of English-language articles to synthesize an evidence-based approach for myocarditis and cardiomyopathy monitoring. Articles published from January 1988 through February 2017 were identified through a search of Ovid MEDLINE, Ovid Embase, Ovid Cochrane Database of Systematic Reviews, Web of Science, Scopus, and Google Scholar. Selected articles were required to relate to myocarditis or cardiomyopathy in humans from exposure to clozapine. A total of 144 articles were included. Recommendations varied widely. Some authors recommended baseline laboratory monitoring, with or without follow-up testing, for C-reactive protein, creatine kinase MB, and troponin. Electrocardiography was commonly recommended, and echocardiography was less commonly recommended. The expense of monitoring was a consideration. A unanimous recommendation was to stop the use of clozapine and seek a cardiovascular consultation if myocarditis or cardiomyopathy is suspected. Although there is general agreement on which tests to perform for confirming myocarditis and cardiomyopathy, preemptive screening for these clozapine-induced conditions is controversial, and cost and barriers for the use of clozapine are concerns. For asymptomatic patients receiving clozapine, testing could include baseline electrocardiography, echocardiography as part of a cardiac consultation if patients have cardiac disease or risk factors, and monitoring of C-reactive protein and troponin as indicated.

Case Report and Review of the Literature: Cardiomyopathy in a Young Woman on High-Dose Quetiapine

We describe a case of cardiomyopathy due to quetiapine. Atypical antipsychotics are known for their multiple and sometimes dangerous side effects. Various studies showed increased sudden cardiac death and sudden unexpected deaths. Quetiapine can cause tachycardia and QT prolongation, alongside a broad list of other side effects. Cardiomyopathy has been reported, but a causative relation was doubted. We report a case of a 37-year-old woman developing a cardiomyopathy under high doses of quetiapine. Symptoms and ultrasound signs largely recovered in the course of the next months after quetiapine was stopped.

Cardiovascular Safety of Psychiatric Agents: A Cautionary Tale

Psychiatric agents are among the most commonly prescribed medications. Despite the advent of newer generation agents, patients receiving them still experience cardiovascular (CV) side effects. However, these agents may have heterogeneous properties, calling for an individualized approach based on efficacy and also on the particular side effect profile of each specific agent. Proarrhythmic effects arising from drug-induced long-QT syndrome and consequent potentially life-threatening polymorphic ventricular arrhythmias in the form of torsade de pointes, the metabolic syndrome contributing to atherosclerosis and acute coronary syndromes, and drug-induced orthostatic hypotension raise major concerns. Of course, it is also crucial that fear of potential CV adverse effects does not deprive psychiatric patients of appropriate drug therapy. Modification of CV risk factors in psychiatric patients together with optimal management of their CV diseases and appropriate selection of psychotropic agents with greater efficacy and least CV toxicity are of paramount importance in mitigating CV risks and enhancing safety. Identifying patients at high risk of CV complications and close monitoring of all patients receiving these agents are crucial steps to prevent and manage such complications. All these issues are herein reviewed, relevant guidelines are discussed, and schemas are depicted that illustrate the interrelated connections among the psychotropic agents and their CV effects.

Safety of antipsychotics for the treatment of schizophrenia: a focus on the adverse effects of clozapine

Clozapine, a dibenzodiazepine developed in 1961, is a multireceptorial atypical antipsychotic approved for the treatment of resistant schizophrenia. Since its introduction, it has remained the drug of choice in treatment-resistant schizophrenia, despite a wide range of adverse effects, as it is a very effective drug in everyday clinical practice. However, clozapine is not considered as a top-of-the-line treatment because it may often be difficult for some patients to tolerate as some adverse effects can be particularly bothersome (i.e. sedation, weight gain, sialorrhea etc.) and it has some other potentially dangerous and life-threatening side effects (i.e. myocarditis, seizures, agranulocytosis or granulocytopenia, gastrointestinal hypomotility etc.). As poor treatment adherence in patients with resistant schizophrenia may increase the risk of a psychotic relapse, which may further lead to impaired social and cognitive functioning, psychiatric hospitalizations and increased treatment costs, clozapine adverse effects are a common reason for discontinuing this medication. Therefore, every effort should be made to monitor and minimize these adverse effects in order to improve their early detection and management. The aim of this paper is to briefly summarize and provide an update on major clozapine adverse effects, especially focusing on those that are severe and potentially life threatening, even if most of the latter are relatively uncommon.

Clozapine in Reducing Aggression and Violence in Forensic Populations

Popular media often portray people with a mental illness as being aggressive, violent, and incarcerated as a result of their behavior. Despite exaggeration in the media, risks for some aggressive behaviors are in fact higher in individuals with schizophrenia. This is often the case with influence of comorbid substance use disorders. It is essential that mental health professionals are aware of treatments that may help with attenuating and treating behaviors that contribute to violence, aggression and incarceration. This paper reviews violence and incarceration in individuals with schizophrenia as well as recommendations, guidelines and benefits for the use of clozapine in this population. Clozapine remains one of the most underutilized evidence-based medications available in the psychiatric arena in the United States. It is a viable and recommended option in the forensic population and it may be helpful on the path to recovery as well as bring substantial savings to the criminal justice system.

Clozapine-induced myocarditis

Approved in 1989 for the management of treatment-resistant schizophrenia, Clozapine is a last-line atypical antipsychotic drug used with increasing frequency. In addition to its well-known side effect of agranulocytosis, this drug also carries with it rare but serious adverse cardiovascular risk of myocarditis. We present a patient on Clozapine who was admitted to the cardiology service with chest pain, ST segment elevations and elevated troponin concerning for acute myocardial infarction. Evaluation with imaging revealed decreased left ventricular function, however, no coronary artery disease was present on catheterization; findings consistent with a diagnosis of myocarditis. Subsequent discontinuation of the patient's Clozapine and initiation of brief supportive medical therapy resulted in full recovery of systolic left ventricular function. Given the potential cardiovascular mortality risk, it is important for physicians on cardiology services caring for psychiatric patients to be aware of the presentation of symptoms, diagnostic findings and management of Clozapine induced myocarditis.

Adverse cardiac events in out-patients initiating clozapine treatment: a nationwide register-based study

OBJECTIVE

Using national Danish registers, we estimated rates of clozapine-associated cardiac adverse events. Rates of undiagnosed myocarditis were estimated by exploring causes of death after clozapine initiation.

METHOD

Through nationwide health registers, we identified all out-patients initiating antipsychotic treatment (January 1, 1996-January 1, 2015). Rates of clozapine-associated myocarditis and pericarditis within 2 months from clozapine initiation and rates of cardiomyopathy within 1-2 years from clozapine initiation were compared to rates for other antipsychotics. Mortality within 2 months from clozapine initiation was extracted.

RESULTS

Three thousand two hundred and sixty-two patients of a total 7932 patients initiated clozapine as out-patients (41.12%). One patient (0.03%) developed myocarditis, and no patients developed pericarditis within 2 months from clozapine initiation. Two (0.06%) and four patients (0.12%) developed cardiomyopathy within 1 and 2 years respectively. Rates were similar for other antipsychotics. Twenty-six patients died within 2 months from clozapine initiation. Pneumonia (23.08%) and stroke (11.54%) were the main causes of death. We estimated the maximum rate of clozapine-associated fatal myocarditis to 0.28%.

CONCLUSION

Cardiac adverse effects in Danish out-patients initiating clozapine treatment are extremely rare and these rates appear to be comparable to those observed for other antipsychotic drugs.

Hearts and Minds: Real-Life Cardiotoxicity With Clozapine in Psychosis

BACKGROUND

Schizophrenia has a 1% prevalence in the population; 30% of these patients are treatment refractory. Clozapine is the only drug licensed to treat treatment refractory psychosis, but concerns about potential adverse effects result in only a proportion of eligible patients being treated. Although a well-documented neutropenia risk is mitigated by routine blood testing, cardiac toxicity is a commonly cited reason to discontinue clozapine treatment. However, there is little data on the real-life cardiac outcomes in those receiving clozapine treatment.

METHODS

Retrospective review of electrocardiogram, echocardiogram, and clinical outcomes in 39 inpatients with treatment-refractory schizophrenia, treated with clozapine and other antipsychotic medication, referred for cardiology opinion.

RESULTS

Commonest reasons for referral were development of left ventricular (LV) impairment or sinus tachycardia with normal LV function. Patients were reviewed by a range of cardiologists, receiving varied interventions.Median LV ejection fraction in the clozapine group was normal (52%). Serial echocardiograms demonstrated that clozapine-treated patients with LV impairment had no change in LV ejection fraction over a 4-month follow-up. Left ventricular ejection fraction did not differ between patients treated with clozapine and other antipsychotics. However, over an 11-year follow-up period, 48% of patients had discontinued clozapine treatment.

CONCLUSIONS

This naturalistic study demonstrates that clozapine is not associated with significant cardiac mortality or morbidity. There is a real need for multidisciplinary working between specialist cardiologists and psychiatrists caring for these complex patients to facilitate optimal long-term physical and mental health outcomes.

Management of serious cardiac adverse effects of antipsychotic medications

The use of antipsychotic medications has now expanded to multiple mental health conditions beyond schizophrenia. This has increased the overall population exposure to these medications, which have been associated with both metabolic changes and adverse cardiovascular effects. QTc prolongation, torsades de pointes, sudden cardiac death, myocarditis, and cardiomyopathy are all very real concerns that clinicians face on a regular basis. One must take these risks into consideration when selecting antipsychotic therapy and also when determining whether therapeutic changes and adjustments are necessary. This review examines a number of cardiac-associated concerns, the role that antipsychotics may play in contributing to these adverse events, and suggested management interventions.

Clozapine-induced, dilated cardiomyopathy: a case report

Background

Clozapine is known to be a highly effective antipsychotic agent and additionally provides a significant reduction in suicide-risk and aggression. Clozapine-induced cardiomyopathy is a very rare but nonetheless dangerous side-effect, with an incidence of 0.02–0.1%, depending on the literature, and a mortality rate of up to 17.9%.

Case presentation

We report on the case of a 25 year-old patient, who was admitted for the evaluation of a potential electroconvulsive therapy due to persistent auditory hallucinations under clozapine. Shortly after admission he was found to be suffering from dilated cardiomyopathy, likely caused by his antipsychotic treatment.

Conclusion

Clozapine-induced cardiomyopathy should be taken into account when monitoring patients treated with this antipsychotic and regular electrocardiograms should be performed in order to detect possible alterations as soon as possible.

Heart-rate response to alpha2-adrenergic receptor antagonism by antipsychotics

PURPOSE

To explore the relationship between antipsychotic-associated antagonism of alpha₂-adrenergic receptors and resting heart rate in individuals with schizophrenia.

METHODS

Thirty-one inpatients treated with antipsychotics were included in this exploratory analysis. Antipsychotic doses were converted to haloperidol equivalents for alpha₂-adrenergic receptor antagonism. Resting heart rate was measured with the patient in the seated upright posture.

RESULTS

After controlling for confounding variables, the relationship between alpha₂-adrenergic receptor antagonism and resting heart rate demonstrated a positive linear effect (P = 0.002) as well as a nonlinear effect that accounted for an additional 14% of the variability in resting heart rate (P = 0.005).

CONCLUSION

The observed inverted-U relationship between alpha₂-adrenergic receptor antagonism and resting heart rate can possibly be attributed to an altered response of beta₁-adrenergic receptors to increased norepinephrine release. Further investigations are required to confirm this exploratory finding, taking into account additional variables that include other receptors which either directly or indirectly influence heart rate. CLINICALTRIALS.

GOV IDENTIFIER

NCT01392885.

Clozapine-induced myocarditis may be associated with rapid titration: A case report verified with autopsy

Clozapine-induced myocarditis is a poorly understood, rare, potentially fatal adverse drug reaction with absolute risks ranging from 7 to 34 per 1000 in Australia and 0.07-0.6 per 1000 in other countries. Hypersensitivity reactions have been postulated including some cases probably associated with rapid titrations. This case describes a 50-year-old African-American man with schizoaffective disorder, naïve to clozapine, who probably died from clozapine-induced myocarditis. He was started on 25 mg/day of clozapine and received 1625 mg over 14 days, prior to his death on day 15. The autopsy found predominantly lymphocytic infiltrate of the perivascular soft tissue and myocardium of the ventricles, with occasional eosinophils. Using the Liverpool ADR Causality Assessment Tool, it was deemed probable that the patient's death was secondary to myocarditis. The patient had fulminant death with no obvious changes in vital signs. Neither C-reactive protein nor troponin was measured, but it is unlikely that the results would have arrived in time to prevent the patient's death. Age, rapid titration, and concomitant use of valproate contributed to this case, which was probably an idiosyncratic adverse drug reaction associated with rapid titration. Lamotrigine-induced Stevens-Johnson syndrome also appears to be an idiosyncratic adverse drug reaction associated with rapid titration, but its incidence has been remarkably reduced since the recommended starting lamotrigine dose was reduced and corrected by the effect of inhibitors such as valproate. Similarly, clozapine-induced myocarditis incidence probably can be reduced with the use of slow titrations, including even slower titrations for patients with lower ability to metabolize clozapine, such as those taking valproate.

Clozapine re-exposure after dilated cardiomyopathy

A 63-year-old woman with diabetes type II and a history of breast cancer was treated with clozapine for her refractory schizophrenia. She developed a dilated cardiomyopathy with an ejection fraction of 25%, a life-threatening event. The cause of heart failure could be multifactorial, with clozapine, family history, chemotherapy, diabetes type II and/or lithium as possible contributing risk factors. Clozapine was discontinued and the patient was referred to a hospice. Two weeks later, her heart failure slowly improved. Subsequently, she became extremely psychotic with a severe decline in quality of life. Therefore, it was decided to restart clozapine under cardiac monitoring. The patient's psychotic symptoms improved and her heart failure status remained stable for more than a year. Thereafter, a small deterioration was seen in cardiac function. In this case, re-exposure to clozapine was successful for at least 2 years.