Sudden cardiac death and antipsychotics. Part 1: Risk factors and mechanisms

Dietary saturated fat and heart disease: a narrative review

The American Heart Association (AHA) recently published a meta-analysis that confirmed their 60-year-old recommendation to limit saturated fat (SFA, saturated fatty acid) and replace it with polyunsaturated fat to reduce the risk of heart disease based on the strength of 4 Core Trials. To assess the evidence for this recommendation, meta-analyses on the effect of SFA consumption on heart disease outcomes were reviewed. Nineteen meta-analyses addressing this topic were identified: 9 observational studies and 10 randomized controlled trials. Meta-analyses of observational studies found no association between SFA intake and heart disease, while meta-analyses of randomized controlled trials were inconsistent but tended to show a lack of an association. The inconsistency seems to have been mediated by the differing clinical trials included. For example, the AHA meta-analysis only included 4 trials (the Core Trials), and those trials contained design and methodological flaws and did not meet all the predefined inclusion criteria. The AHA stance regarding the strength of the evidence for the recommendation to limit SFAs for heart disease prevention may be overstated and in need of reevaluation.

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.

LEARNING OBJECTIVES

After reading this article you will be able to: •

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.

Rapid tranquillisation: the science and advice

‘Rapid tranquillisation’ refers to the use of medication to calm highly agitated individuals experiencing mental disorder who have not responded to non-pharmacological approaches. Commonly it is the initial stage in the treatment of severe and enduring illness. Using medication in this way requires particularly robust evidence of efficacy and the management of side-effects. This article attempts to integrate current understanding of the neurochemical mechanisms of underlying illness and drug actions with therapeutic interventions. It distinguishes arousal from agitation, and effects on sedation from tranquillisation. It reviews critically the practice of rapid tranquillisation in the light of new evidence, changes in the NICE guidelines and British National Formulary recommendations and a national audit (POMH-UK). Broader aspects of management, known as ‘restrictive practices’ (such as control and restraint and seclusion), psychological support of team members, incident reporting, risk assessment, monitoring and medico-legal aspects are not covered.

LEARNING OBJECTIVES

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DECLARATION OF INTEREST

None.

Mechanisms Underlying the Actions of Antidepressant and Antipsychotic Drugs That Cause Sudden Cardiac Arrest

A number of antipsychotic and antidepressant drugs are known to increase the risk of ventricular arrhythmias and sudden cardiac death. Based largely on a concern over the development of life-threatening arrhythmias, a number of antipsychotic drugs have been temporarily or permanently withdrawn from the market or their use restricted. While many antidepressants and antipsychotics have been linked to QT prolongation and the development of torsade de pointes arrhythmias, some have been associated with a Brugada syndrome phenotype and the development of polymorphic ventricular arrhythmias. This article examines the arrhythmic liability of antipsychotic and antidepressant drugs capable of inducing long QT and/or Brugada syndrome phenotypes. The goal of this article is to provide an update on the ionic and cellular mechanisms thought to be involved in, and the genetic and environmental factors that predispose to, the development of cardiac arrhythmias and sudden cardiac death among patients taking antidepressant and antipsychotic drugs that are in clinical use.

Management of acute agitation in psychosis: an evidence-based approach in the USA

Agitation in psychiatric settings, particularly in psychosis, presents a staggering challenge for clinicians, who must both manage the patient's acute symptoms and simultaneously make an accurate diagnosis. Too often, the management of the former confounds the latter. Patients are very often sedated medically, which masks their underlying condition, rendering accurate diagnosis delayed and inherently difficult. Significant data are available regarding both pharmacological and non-pharmacological interventions for agitation that maximise symptom control while minimising confounding side-effects. In this article, a review of the historical evolution of agitation management in psychotic illness is presented, followed by an evidence-based clinical guideline for managing agitation in psychosis in the USA.

Sudden cardiac death and antipsychotics Part 2: Monitoring and prevention

Cardiac safety of antipsychotic drugs continues to be a concern for both typical and atypical antipsychotics. Risk appears greatest in those with pre-existing cardiac disease but many patients may have occult cardiovascular disease. In addition, several drugs appear to increase the likelihood of diabetes and weight gain, which may have an additive adverse effect. On the basis of risk of sudden cardiac death and risk of QTc prolongation we suggest considering antipsychotics in two categories – higher and lower risk. Of most concern is the use of large cumulative doses of antipsychotics that are sometimes given inadvertently by different prescribers. Clinicians need to be aware how to read an ECG, and how to monitor physical parameters and interpret the significance of QTc prolongation in relation to antipsychotic prescribing. We suggest provisional guidance on antipsychotic monitoring in relation to cardiac safety but acknowledge that future studies will help clarify which antipsychotic drugs and which concomitant risk factors are most important for those with and without established cardiac disease.

Use of psychotropic medication in seven English psychiatric intensive care units

Aims and method

To describe the psychotropic medication given to 332 patients admitted consecutively to seven English psychiatric intensive care units (PICUs) by prospective, multicentre case-note analysis.

Results

Overall, 104 (32%) patients received rapid tranquillisation or zuclopenthixol acetate by intramuscular injection; 72 (23%) received more than one regular antipsychotic drug simultaneously. It was reported that 20 patients received high-dose antipsychotic medication, which was probably an underestimate. The use of these interventions varied significantly between different units.

Clinical implications

Potentially risky treatments such as forcible intramuscular medication are a standard part of PICU activity. Further work is needed to clarify the reasons behind the differences in prescribing practices between different PICUs.

A new clinical guideline to improve sedation safety in patients transferred under the Mental Health Act from remote parts of Western Australia

OBJECTIVE

Clinicians dealing with referrals under the Mental Health Act in rural and remote parts of Australia face the difficult task of providing safe sedation whilst transferring the patient to an appropriate authorized facility. This paper reviews the efforts to overcome these challenges in the remote north-west of Australia.

METHODS

Senior medical staff undertook a review of sedation practice in the region. A search was made of the medical literature to determine whether evidence based treatment may exist elsewhere and this information was used in conjunction with consensus opinion to devise a new guideline.

RESULTS

Scant literature exists in the field of sedation and aeronautical evacuation of patients with acute mental health presentations in remote areas. Issues and challenges were identified and a new clinical guideline based on local expert consensus of good practice was developed.

CONCLUSIONS

Standardizing the approach to managing agitated patients who are transferred under the Mental Health Act is essential in order to mitigate medical morbidity that may arise from sedation related complications. The sedation guideline developed by our service has been well received by staff, seems practical and feasible to implement and has the potential to reduce sedation related morbidity.

The comparative efficacy of intramuscular antipsychotics for the management of acute agitation

OBJECTIVE

To review the current role and comparative efficacy of short-acting intramuscular (IM) antipsychotics in the management of acute agitation, in current clinical practice.

METHOD

The efficacy and tolerability of IM antipsychotics in the management of acute agitation in current clinical practice were reviewed in the Medline, PubMed, Cinahl Plus, Scopus-v.4 and PsycInfo databases.

RESULTS

The comparative efficacy of the rapidly-acting IM atypical antipsychotics (olanzapine, ziprasidone and aripiprazole) is similar to that of the typical antipsychotic, haloperidol. IM olanzapine and ziprasidone were associated with fewer extrapyramidal side-effects and had similar cardiac tolerability to IM haloperidol.

CONCLUSIONS

Further studies are required in the ongoing development of contemporary, evidence-based clinical guidelines in acute agitation, including head-to-head comparisons of currently utilized IM atypical antipsychotics, sequential treatment or combinations of medications.

Off-licence prescribing and regulation in psychiatry: current challenges require a new model of governance

The growing worldwide use of pharmaceuticals is managed in some countries by a regulatory system which sharply divides legal use into licensed and unlicensed categories. We examine how for the range of psychotropics this simultaneously restricts the possible benefits to patients, prescribers and producers in some domains, while failing to manage the risks in others. A more flexible system, which shares at an earlier stage experience and evidence on benefits and risks in patients, previously marginalized on the grounds of age, diagnosis or comorbidity, would aid the development of safer, more effective 'real-world prescribing'. Practical recommendations are made for a new model of research and prescribing governance, to enable more effective repurposing of these treatments.

Sudden cardiac death and antipsychotic medications: literature review

The review summarises the evidence from international publications on sudden cardiac death (SCD) in psychiatric patients receiving neuroleptics. Modern SCD definitions are presented, together with the relevant epidemiological data. The pathogenesis of fatal cardiac arrhythmias, caused by cardiotoxic effects of antipsychotic medications, is discussed. Electrocardiographic changes, in particular QT interval changes, as well as risk factors of SCD and main principles of its prevention, are described in detail.

Automatic filtering and substantiation of drug safety signals

Drug safety issues pose serious health threats to the population and constitute a major cause of mortality worldwide. Due to the prominent implications to both public health and the pharmaceutical industry, it is of great importance to unravel the molecular mechanisms by which an adverse drug reaction can be potentially elicited. These mechanisms can be investigated by placing the pharmaco-epidemiologically detected adverse drug reaction in an information-rich context and by exploiting all currently available biomedical knowledge to substantiate it. We present a computational framework for the biological annotation of potential adverse drug reactions. First, the proposed framework investigates previous evidences on the drug-event association in the context of biomedical literature (signal filtering). Then, it seeks to provide a biological explanation (signal substantiation) by exploring mechanistic connections that might explain why a drug produces a specific adverse reaction. The mechanistic connections include the activity of the drug, related compounds and drug metabolites on protein targets, the association of protein targets to clinical events, and the annotation of proteins (both protein targets and proteins associated with clinical events) to biological pathways. Hence, the workflows for signal filtering and substantiation integrate modules for literature and database mining, in silico drug-target profiling, and analyses based on gene-disease networks and biological pathways. Application examples of these workflows carried out on selected cases of drug safety signals are discussed. The methodology and workflows presented offer a novel approach to explore the molecular mechanisms underlying adverse drug reactions.

Adverse drug reactions (ADRs) constitute a major cause of morbidity and mortality worldwide. Due to the relevance of ADRs for both public health and pharmaceutical industry, it is important to develop efficient ways to monitor ADRs in the population. In addition, it is also essential to comprehend why a drug produces an adverse effect. To unravel the molecular mechanisms of ADRs, it is necessary to consider the ADR in the context of current biomedical knowledge that might explain it. Nowadays there are plenty of information sources that can be exploited in order to accomplish this goal. Nevertheless, the fragmentation of information and, more importantly, the diverse knowledge domains that need to be traversed, pose challenges to the task of exploring the molecular mechanisms of ADRs. We present a novel computational framework to aid in the collection and exploration of evidences that support the causal inference of ADRs detected by mining clinical records. This framework was implemented as publicly available tools integrating state-of-the-art bioinformatics methods for the analysis of drugs, targets, biological processes and clinical events. The availability of such tools for in silico experiments will facilitate research on the mechanisms that underlie ADR, contributing to the development of safer drugs.

Cardiovascular risk assessment of atypical antipsychotic drugs in a zebrafish model

The zebrafish model has been developed and evaluated for its ability to predict the toxicity of chemicals. Zebrafish additionally serve as an excellent model for assessing drug-induced cardiotoxicity, although zebrafish and mammalian hearts differ in structure. Recently, regulatory authorities have expressed concerns about a possible relationship between antipsychotics and risk of QTc interval prolongation, serious arrhythmia and sudden cardiac death. In the current study, we performed a cardiovascular risk assessment of six atypical antipsychotic drugs in zebrafish, specifically, aripiprazole, clozapine, olanzapine, quetiapine, risperidone and ziprasidone. Visual endpoints, such as lethality, edema (the presence of heart and trunk edema), hemorrhage (clustering of a pool of blood in an area outside the normal circulation), abnormal body shape (including bent or misshapen caudal region of the larvae) and motility, were evaluated as general toxicity endpoints, and the heart beat rate calculated as the cardiovascular toxicity endpoint. The zebrafish model facilitates determination of the heart beat rate, and may thus be an attractive screening tool for cardiovascular risk assessment of atypical antipsychotic drugs to understand the variations in response to QT-prolonging drugs.

Proarrhythmic risk with antipsychotic and antidepressant drugs: implications in the elderly

The quinidine-like effects of some antidepressant drugs (particularly tricyclic antidepressants) and many antipsychotic drugs (particularly the phenothiazines) confound treatment of psychosis and depression in patients with major mental illness. This is especially true among elderly patients with existing risk factors for corrected QT (QTc) interval prolongation. We used PubMed, previously reported review articles and the extensive personal files of the authors to identify cases of subjects aged>or=60 years who developed QTc interval prolongation, polymorphic ventricular tachycardia (PVT)/torsade de pointes (TdP) and/or sudden cardiac death while taking antipsychotic or antidepressant drugs or a combination of these medications. We identified 37 patients who had taken, in total, 46 antipsychotic or antidepressant drugs. Our most striking finding was that almost four-fifths of our cases involved women. When the 14 critically ill subjects receiving haloperidol intravenously were excluded, 91.3% of our subjects were women. Almost three-quarters of our study subjects had cardiovascular disease. Intravenous administration of haloperidol in the critically ill and profoundly agitated elderly warrants particular comment. Of the 14 subjects in this category identified, six were men and eight were women. In 13 cases, the drug dose far exceeded the 2 mg necessary to produce an antipsychotic effect. These clinicians were using an agent to achieve sedation that usually requires very high doses in the critically ill and profoundly agitated elderly to achieve this effect. Inclusion criteria for our literature review required antipsychotic and/or antidepressant drug-induced QTc interval prolongation. Even so, our finding that 31 of our 37 subjects developed PVT is sobering. However, the reader should not conclude that drug-induced QTc interval prolongation is highly predictive of PVT or its TdP subtype. All of our study subjects had at least two risk factors for TdP, with age and sex being the most common. We included the rare case of a patient with congenital long QT syndrome who developed further lengthening of the QTc interval and TdP when prescribed an antidepressant drug well known to produce QTc interval prolongation. We conclude with recommendations for clinicians not expert in the specialty of cardiology to deal with the many questions raised in this review. Specifically, such clinicians treating elderly patients with antipsychotic and antidepressant drugs that may prolong the QTc interval should aggressively obtain a baseline ECG for elderly female patients with additional risk factors such as personal or family history of pre-syncope or syncope, electrolyte disturbances or cardiovascular disease. Elderly male patients are also subject to QTc interval prolongation when such risk factors are present. It is important that the clinicians themselves inspect ECGs. If the QT interval is more than half the RR interval, QTc interval prolongation is likely to be present. In such cases, a cardiology colleague interested in QTc interval issues and TdP should be asked to review the ECG. Finally, nothing in our recommendations replaces meticulous attention to US FDA guidelines in the package insert of each drug.

Sudden cardiac death secondary to antidepressant and antipsychotic drugs

A number of antipsychotic and antidepressant drugs are known to increase the risk of ventricular arrhythmias and sudden cardiac death. Based largely on a concern over QT prolongation and the development of life-threatening arrhythmias, a number of antipsychotic drugs have been temporarily or permanently withdrawn from the market or their use restricted. Some antidepressants and antipsychotics have been linked to QT prolongation and the development of Torsade de pointes arrhythmias, whereas others have been associated with a Brugada syndrome phenotype and the development of polymorphic ventricular arrhythmias. This review examines the mechanisms and predisposing factors underlying the development of cardiac arrhythmias, and sudden cardiac death, associated with antidepressant and antipsychotic drugs in clinical use.

Physical health and schizophrenia

PURPOSE OF REVIEW

Patients with schizophrenia have higher than expected rates of morbidity and mortality. It is debatable whether this is related to shared risk factors, antipsychotic medication or inherent to the condition itself. This review will describe this association and the recent advances in the field.

RECENT FINDINGS

The majority of patients with schizophrenia have at least one chronic comorbid medical condition. In the absence of systematic screening this may or may not be brought to the attention of health professionals. The cause of high rates of physical illness appears to be multifactorial involving shared vulnerability and genetic factors. Yet it is vascular risk factors and the adverse effects of prescribed medication that are most amenable to intervention. Current atypical antipsychotics may offer neurological and cognitive benefits, but there is accumulating evidence of problems with weight gain, diabetes, lipid dysregulation, metabolic syndrome and sexual side effects.

SUMMARY

The physical health of patients with schizophrenia remains a concern. Yet the quality of medical and psychiatric care of patients with comorbid physical and mental health disorders has been shown to be unsatisfactory in several areas. We suggest that clinicians routinely assess and monitor physical health needs of patients with serious mental illness.