Sudden cardiac death with clozapine and sertraline combination

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.

Optimizing antidepressant and clozapine co-prescription in clinical practice: A systematic review and expert recommendations

OBJECTIVES

To synthesize the information relevant for clinical practice on clozapine-antidepressant co-prescription concerning pharmacokinetic drug-drug interactions (DDI), adverse drug reactions (ADRs) associated with the co-prescription, antidepressant add-on for clozapine-resistant symptoms and antidepressant add-on for clozapine-induced ADRs.

METHODS

Articles were identified with MEDLINE, Web of Sciences and PsycINFO search from inception through April 2023. Data were synthesized narratively.

RESULTS

ADRs are most often induced by the co-prescription of antidepressants that inhibit CYP enzymes (fluvoxamine, fluoxetine, paroxetine). Fluvoxamine add-on is hazardous because of its potent inhibition of clozapine metabolism and has few indications (lowering daily number of clozapine tablets, reducing norclozapine-induced metabolic disturbances and other dose-dependent clozapine-induced ADRs). ADR frequency may be reduced by therapeutic drug monitoring and knowledge of other factors impacting clozapine metabolism (pneumonia, inflammation, smoking, etc.). Improvement of negative symptoms is the most documented beneficial effect of antidepressant add-on for clozapine-resistant psychotic symptoms. The add-on antidepressant should be chosen according to its safety profile regarding DDI with clozapine: antidepressants inhibiting clozapine metabolism or increasing the anticholinergic load should be avoided. Other indications of antidepressant add-on (affective or obsessive compulsive symptoms, sialorrhea, and enuresis) are poorly documented.

CONCLUSION

Antidepressant add-on to clozapine is associated with potential benefits in clozapine users as this strategy may contribute to reduce the burden of clozapine-resistant symptoms or of clozapine-induced ADRs. Further studies are needed to determine whether antidepressant add-on can reduce the risk of clozapine discontinuation.

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.

Analysis of the effect of the antidepressant sertraline on the length of QT interval in patients with depression and alcohol dependence

Introduction and Aim: Depression in psychiatry covers a large area of mental pathology and it is one of the most complex problems of modern medicine with broad implications for the health of the individual and the society as a whole. Depression is also a frequent companion of alcohol addiction. The aim of this study was to investigate the effect of the antidepressant drug sertraline on the length of QT interval in depressed patients with alcohol dependence. Patients and methods: This research included male patients (older than 18 years of age) suffering from alcohol addiction, who were also diagnosed with depression, that is, depressive disorder, at the beginning of hospitalisation, on the basis of DSM-IV (Diagnostic and statistical manual of mental disorders) criterion and positive Hamilton Rating Scale for Depression (HRSD). The study included 49 patients treated with antidepressant sertraline for 20 days. In our study, the global QTc interval (12 leads) was determined automatically by applying ECG device of the producer and type "Schiller Cardiovit AT-1", which uses "SCHILLER ECG Measurement and Interpretation Software for Children and Adult ECGs". Measured/empirical values of data were statistically processed in SPSS 16.0 programme package for Windows. Methods of descriptive statistics and methods of statistic testing of hypotheses were used. Results: In our study, in spite of the vulnerability of patients due to the heart damage and the liver dysfunction arising from alcohol consumption, as well as altered patients' drugs metabolism, no elongation of QTc interval resulting from the application of sertraline was established (p = 0.735). The average prolongation of QTc interval of 1.633 ms was observed (95% CI = 8.005 ms, 11.270 ms). Conclusion: Our study does not indicate that the antidepressant drug sertraline has a statistically significant effect on the prolongation of the QT interval of depressed patients with alcohol dependence.

Cardiovascular Disease in Clozapine-Treated Patients: Evidence, Mechanisms and Management

Myocarditis occurs in about 3% of those initiated on clozapine but monitoring reduces the risk of serious outcome. Cardiomyopathy may develop after myocarditis, or from prolonged tachycardia. Monitoring using echocardiography is not deemed cost effective. Tachycardia, orthostatic hypotension and reduced heart rate variability are a group of clozapine-related adverse effects associated with autonomic dysfunction and may have serious consequences in the long term. Elevated heart rate and poor heart rate variability can be treated with a β-blocker or a non-dihydropyridine calcium channel blocker, while orthostatic hypotension can be alleviated by increased fluid intake and abdominal binding, but may require pharmacological intervention. Adequate correction for heart rate may show that clozapine does not prolong the QT interval. Other cardiovascular effects, pulmonary embolism, metabolic syndrome, sudden cardiac death and particularly the excessive mortality from cardiovascular disease events may be more strongly associated with the combination of mental illness, lifestyle factors and poor treatment of cardiovascular disease and its risk factors than with clozapine treatment. In view of the efficacy of clozapine and the evidence of reduced mortality relative to other antipsychotics, clozapine should be prescribed when indicated and recipients should be enrolled in lifestyle programmes to increase exercise and improve diet, and referred for diagnosis and treatment of cardiovascular disease and its risk factors.

Current and potential pharmacological and psychosocial interventions for anxiety symptoms and disorders in patients with schizophrenia: structured review

OBJECTIVE

Between 30% and 62% of patients with schizophrenia present with co-morbid anxiety disorders that are associated with increased overall burden. Our aim was to summarize current and potential interventions for anxiety in schizophrenia.

DESIGN

Structured review, summarizing pharmacological and psychosocial interventions used to reduce anxiety in schizophrenia and psychosis.

RESULTS

Antipsychotics have been shown to reduce anxiety, increase anxiety, or have no effect. These may be augmented with another antipsychotic, anxiolytic, or antidepressant. Novel agents, such as L-theanine, pregabalin, and cycloserine, show promise in attenuating anxiety in schizophrenia. Psychosocial therapies have been developed to reduce the distress of schizophrenia. Cognitive behavioural therapy (CBT) has shown that benefit and refinements in the therapy have been successful, for example, for managing worry in schizophrenia. CBT usually involves more than 16 sessions, as short courses of CBT do not attenuate the presentation of anxiety in schizophrenia. To address time and cost, the development of manualized CBT to address anxiety in schizophrenia is being developed.

CONCLUSIONS

The presence of coexisting anxiety symptoms and co-morbid anxiety disorders should be ascertained when assessing patients with schizophrenia or other psychoses as a range of pharmacological and psychosocial treatments are available.

Cardiac Toxicity in Selective Serotonin Reuptake Inhibitor Users

Several classes of recreational and prescription drugs have been associated with an increased risk of cardiovascular disease and the occurrence of arrhythmias, which may be involved in sudden deaths in chronic users even at therapeutic doses. The study presented herein focuses on pathological changes involving the heart, which may be caused by selective serotonin reuptake inhibitor use and their possible role in the occurrence of sudden cardiac death. A total of 40 cases were included in the study and were divided evenly into 2 groups: 20 cases of patients treated with selective serotonin reuptake inhibitors and 20 cases of sudden deaths involving patients void of any drug treatment. The first group included 16 patients treated with citalopram and 4 with sertraline. Autopsies, histology, biochemistry, and toxicology were performed in all cases. Pathological changes in selective serotonin reuptake inhibitor users consisted of various degrees of interstitial and perivascular fibrosis as well as a small degree of perineural fibrosis within the myocardium of the left ventricle. Within the limits of the small number of investigated cases, the results of this study seem to confirm former observations on this topic, suggesting that selective serotonin reuptake inhibitors may play a potential, causative role in the pathogenesis of sudden deaths in chronic users even at therapeutic concentrations.

Left Ventricular Thrombus as a Complication of Clozapine-Induced Cardiomyopathy: A Case Report and Brief Literature Review

A 48-year-old male with history of schizoaffective disorder on clozapine presented with chest pain, dyspnea, and new left bundle branch block. He underwent coronary angiography, which revealed no atherosclerosis. The patient's workup was unrevealing for a cause for the cardiomyopathy and thus it was thought that clozapine was the offending agent. The patient was taken off clozapine and started on guideline directed heart failure therapy. During the course of hospitalization, he was also discovered to have a left ventricular (LV) thrombus for which he received anticoagulation. To our knowledge, this is the first case report of clozapine-induced cardiomyopathy complicated by a LV thrombus.

Metabolic syndrome and obesity among users of second generation antipsychotics: A global challenge for modern psychopharmacology

Second generation antipsychotics (SGAs), such as clozapine, olanzapine, risperidone and quetiapine, are among the most effective therapies to stabilize symptoms schizophrenia (SZ) spectrum disorders. In fact, clozapine, olanzapine and risperidone have improved the quality of life of billions SZ patients worldwide. Based on the broad spectrum of efficacy and low risk of extrapyramidal symptoms displayed by SGAs, some regulatory agencies approved the use of SGAs in non-schizophrenic adults, children and adolescents suffering from a range of neuropsychiatric disorders. However, increasing number of reports have shown that SGAs are strongly associated with accelerated weight gain, insulin resistance, diabetes, dyslipidemia, and increased cardiovascular risk. These metabolic alterations can develop in as short as six months after the initiation of pharmacotherapy, which is now a controversial fact in public disclosure. Although the percentage of schizophrenic patients, the main target group of SGAs, is estimated in only 1% of the population, during the past ten years there was an exponential increase in the number of SGAs users, including millions of non-SZ patients. The scientific bases of SGAs metabolic side effects are not yet elucidated, but the evidence shows that the activation of transcriptional factor SRBP1c, the D1/D2 dopamine, GABA2 and 5HT neurotransmitions are implicated in the SGAs cardiovascular toxicity. Polypharmacological interventions are either non- or modestly effective in maintaining low cardiovascular risk in SGAs users. In this review we critically discuss the clinical and molecular evidence on metabolic alterations induced by SGAs, the evidence on the efficacy of classical antidiabetic drugs and the emerging concept of antidiabetic polyphenols as potential coadjutants in SGA-induced metabolic disorders.

A systematic review of clozapine induced cardiomyopathy

BACKGROUND

Clozapine is a unique anti-psychotic medication that is most effective in the treatment of refractory schizophrenia and reducing suicidality. Cardiomyopathy is among the side effects of this medication that limits its use. There are a number of case reports, case series and expert opinion papers discussing clozapine induced cardiomyopathy, but there is no evidence-based review of the subject to guide clinicians.

METHODS

We undertook a systematic review of the literature on cardiomyopathy associated with clozapine. The primary systemic search was in MEDLINE but EMBASE, PsycINFO, and Cochrane were searched and manufacturers of clozapine were contacted for cases. Articles were then individually reviewed to find additional reports.

RESULTS

We identified 17 articles detailing 26 individual cases and 11 additional articles without individual case data. The mean age at time of diagnosis was 33.5 years. The mean dose of clozapine on presentation was 360 mg. Symptoms developed at an average of 14.4 months after initiating clozapine. The clinical presentation was generally consistent with heart failure: including shortness of breath (60%) and palpitations (36%). Echocardiography at presentation showed dilated cardiomyopathy in 39% of cases and was not specified in other cases.

CONCLUSION

There should be a low threshold in performing echocardiography in suspected cases of clozapine induced cardiomyopathy. Clozapine should be withheld in the setting of cardiomyopathy without other explanation. There is limited data on the safety of drug re-challenge in clozapine induced cardiomyopathy. Re-challenge may be considered in carefully selected cases but close monitoring and frequent echocardiography are required.

Sertraline-induced ventricular tachycardia

Sertraline is a selective serotonin reuptake inhibitor, which is a commonly used drug for major depressive disorder. Most frequently reported adverse effects of sertraline in patients receiving 50-150 mg/d are dry mouth, headache, diarrhea, nausea, vomiting, sweating, and dizziness. We hereby report one of the few cases of sertraline-induced ventricular tachycardia, which has been for the first time objectively assessed by the Naranjo scale. We therefore urge the primary care physicians and the cardiologists to keep sertraline as a possible precipitating factor for evaluation of ventricular tachycardia.

A comparison of the risk of QT prolongation among SSRIs

OBJECTIVE

To report QT prolongation potential in selective serotonin reuptake inhibitors (SSRIs) in order to advise clinicians on safe use of SSRIs other than citalopram in light of citalopram warnings.

DATA SOURCES

Primary literature and case reports were identified through a systematic search. Data from drug manufacturers, package inserts, and the ArizonaCERT database were also utilized.

STUDY SELECTION AND DATA EXTRACTION

English-language studies and case reports were included.

DATA SYNTHESIS

Studies demonstrate possible dose-related clinically significant QT prolongation with escitalopram. Fluoxetine, fluvoxamine, and sertraline at traditional doses demonstrate a lack of clinically significant increases in QTc in the majority of studies. Further, paroxetine monotherapy shows a lack of clinically significant QTc prolongation in all studies. However, case reports or reporting tools still link these SSRIs with QTc prolongation. Fluoxetine, escitalopram, and sertraline used in post-acute coronary syndrome patients did not demonstrate risk of QTc prolongation.

CONCLUSION

For clinicians who choose not to use citalopram due to recent Food and Drug Administration (FDA) recommendations, other antidepressants within this class may be considered. When citalopram is not utilized based on risk factors for TdP, use of escitalopram is not likely the safest alternative. Based on current literature, fluoxetine, fluvoxamine, and sertraline appear to have similar, low risk for QT prolongation, and paroxetine appears to have the lowest risk. However, there are significant limitations in interpreting the studies, including varying definitions of significant QT prolongation. Therefore, choice of an alternative SSRI should be based on individual risk factors for arrhythmias and other patient-specific factors.

Wide spectrum of inhibitory effects of sertraline on cardiac ion channels

Sertraline is a commonly used antidepressant of the selective serotonin reuptake inhibitors (SSRIs) class. In these experiments, we have used the whole cell patch clamp technique to examine the effects of sertraline on the major cardiac ion channels expressed in HEK293 cells and the native voltage-gated Ca(2+) channels in rat ventricular myocytes. According to the results, sertraline is a potent blocker of cardiac K(+) channels, such as hERG, I(Ks) and I(K1). The rank order of inhibitory potency was hERG >I(K1)> I(Ks) with IC(50) values of 0.7, 10.5, and 15.2 µM, respectively. In addition to K(+) channels, sertraline also inhibited I(Na) and I(Ca), and the IC(50) values are 6.1 and 2.6 µM, respectively. Modification of these ion channels by sertraline could induce changes of the cardiac action potential duration and QT interval, and might result in cardiac arrhythmia.

The effects of aripiprazole on electrocardiography in children with pervasive developmental disorders

OBJECTIVES

Psychotropic medications, including the atypical antipsychotics, have historically been scrutinized for cardiac effects and risk of sudden death. Aripiprazole is an atypical antipsychotic approved for pediatric use in schizophrenia, bipolar I disorder, and autistic disorder. Adult studies have evaluated aripiprazole's effects on electrocardiograms, but no pediatric studies have been published to date.

METHODS

Electrocardiographic data were collected from children and adolescents participating in a 14-week, prospective, open-label study (n=25) of aripiprazole for irritability in pervasive developmental disorder not otherwise specified and Asperger's disorder. A 12-lead electrocardiogram was obtained at the baseline and end point visits. The electrocardiograms were evaluated for abnormal findings, and the PR, QRS, QT(c), and RR intervals were recorded. The QT interval was corrected using Bazett's, United States Food and Drug Administration (FDA) Pharmacology Division, and Fridericia's formulas.

RESULTS

Twenty-four subjects received both baseline and posttreatment electrocardiograms. The mean age was 8.6 years (range 5-17 years). The average final aripiprazole dose was 7.8 mg/day (range 2.5-15 mg/day). There were no significant differences noted with the PR, QRS, RR, and QT(c) intervals after aripiprazole therapy. Also, there was no significant correlation between the dose given and the percent change in the QT(c). No post-treatment QT(c) exceeded 440 ms.

CONCLUSIONS

To our knowledge, this is the first systematic evaluation of the cardiac effects of aripiprazole in children and adolescents. The results are consistent with previously published literature in adults that aripiprazole has no significant cardiac effects and can be deemed a low risk for causing sudden death. It will be important to confirm these findings in a randomized controlled trial.

Sinus arrest due to sertraline

Sertraline is a selective serotonin reuptake inhibitor with established safety for the treatment of depression. Among the common adverse effects associated with sertraline are nausea, insomnia, diarrhea, somnolence, and dizziness. Cardiac arrest had not been reported in the literature, although tachycardia was frequently seen. In this case report, a patient was presented who had adverse reactions such as nausea, dizziness, insomnia under citalopram treatment, and after his drug was changed to sertraline, developed sinus arrest on the fourth day of treatment.

Sertraline for the treatment of depression in coronary artery disease and heart failure

Depression is a common co-morbid condition in patients with cardiac disease and has been identified as an independent risk factor for increased morbidity and mortality. SSRIs are established agents for the treatment of depression and are well tolerated in patients with cardiac disease. SSRIs are a heterogeneous group of antidepressants, which apart from their common mechanism of action, differ substantially in their chemical structure, metabolism and pharmacokinetics. This article reviews experimental and clinical evidence on the safety and efficacy of the most extensively studied SSRI, sertraline, in depressed patients with coronary artery disease and heart failure. Intervention with sertraline has the potential to provide depressed patients with cardiac disease relief from their depressive symptoms, improvement in quality of life and a potential benefit in their cardiovascular risk profile.

Neonatal death following clozapine self-poisoning in late pregnancy: an unusual case report

The report presents a fatal poisoning of a neonate occurring in the final stage of gestational life and evoked by his mother, who, while 9 months pregnant, took a toxic dose of clozapine aiming at committing suicide. She was also severely poisoned, but ultimately was saved. The woman had been taking the medication due to schizophrenia and depression prior to conception, and the discontinuation of the drug in the course of pregnancy increased the risk of the woman attempting suicide. In the course of comprehensive toxicological analysis based on the developed analytical procedure with the use of LC-APCI-MS, clozapine and its two metabolites, norclozapine and clozapine-N-oxide, were determined in postmortem blood, liver and kidney in concentrations explaining the death of the neonate. The interpretation of the above-described case is complex and--apart from toxicological aspects--also involves issues associated with psychiatry, pharmacotherapy in pregnancy and medicolegal problems.

The QT interval and psychotropic medications in children: recommendations for clinicians

The use of psychotropic medications in children has increased significantly in the last few years. There have been several case reports of sudden death in children taking specific psychotropic medications. Fears that these deaths might have been caused by ventricular arrhythmias have been enhanced by reports of electrocardiographic abnormalities, including prolongation of the QTc interval, in patients taking these medications. Several factors including genetic susceptibility, pre-existing cardiac disease, abnormalities of drug clearance and concomitant use of other medications known to affect the QTc interval can increase the susceptibility of the heart to conduction abnormalities. This article discusses the potential of particular psychotropic drugs to prolong the QTc interval in children, and examines other factors that may contribute to conduction abnormalities. We aim to provide clear clinical recommendations for the prescription of these drugs and the monitoring of children taking them.

Myocarditis, pericarditis and cardiomyopathy in patients treated with clozapine

Clozapine is known to cause cardiac side-effects, including myocarditis, pericarditis and cardiomyopathy. Prompted by a case of clozapine-related pericarditis in our hospital we undertook a review of the literature for reports of myocarditis, pericarditis and cardiomyopathy occurring in patients treated with clozapine. This is the first comprehensive review of the literature on this topic.

Atypical antipsychotics: from potassium channels to torsade de pointes and sudden death

Syncope and sudden death are features of schizophrenia that can be attributed to ischaemic heart disease, the use of antipsychotics (because of proarrhythmia or other reasons such as pharyngeal dyskinesia) or the psychiatric disease itself. Cases have been described with most antipsychotics and have led to the withdrawal, temporary suspension from the market or restricted use of antipsychotics, such as sultopride, droperidol, sertindole or thioridazine. Reviewing the available data shows that all antipsychotics tested affect the cardiac potassium channel, with the concentration that produces 50% inhibition (IC50) ranging from 1 nmol/L (haloperidol) to 6 micromol/L (olanzapine). Experimental in vitro or in vivo electrophysiological studies have shown a dose-dependent increase in the duration of the action potential with various degrees of indicators of serious arrhythmogenicity. However, this does not always translate clinically into an increased duration of the QT interval or increased risk of torsade de pointes or sudden death in clinical trials or pharmacoepidemiological studies. In turn, QT prolongation in clinical trials does not always translate to an increased risk of torsade de pointes or sudden death. The reasons for these apparent discrepancies are unclear and could be related to insufficiently powered field studies, low plasma and tissue drug concentrations with reference to in vitro data or drug effects on other receptors or ion channels that have a protective effect. Alternatively, risks that were not apparent from preclinical or clinical data could be related to the use of the drug in high-risk patients, metabolic interactions or other factors that would only be encountered in large postmarketing populations. The assessment of cardiovascular safety, both preclinical and during premarketing clinical trials, needs to be supported by appropriately powered pharmacoepidemiology studies.

Clozapine-related myocarditis and cardiomyopathy in an Australian metropolitan psychiatric service

OBJECTIVES

Myocarditis and cardiomyopathy are rarely reported complications of clozapine treatment. The incidence of clozapine-related myocarditis has been variably reported at between 0.03% and 0.19% of initiations and cardiomyopathy has been reported even less commonly. In our Brisbane-based service, nine of 94 patients initiated on clozapine over the previous 3 years appeared to have experienced myocarditis or cardiomyopathy. The unique co-location of our service with a major cardiothoracic hospital facilitated a review of identified cases to inform decisions regarding clozapine treatment and rechallenge in this service.

METHOD

Cases were identified by survey of psychiatric and cardiac medical staff at The Prince Charles Hospital and subjected to re-evaluation by a multidiscipline consensus panel. The panel compared cases to international reports and identified the clinical features that supported a diagnosis of clozapine-related myocarditis or cardiomyopathy.

RESULTS

This process resulted in the stratification of the nine cases into the following categories of diagnostic likelihood: three highly probable, three probable, and two possible cases of clozapine-related myocarditis, and one possible case of clozapine-related cardiomyopathy. Successful clozapine rechallenge/continuation was undertaken in two patients and the panel agreed that this was a viable future option for several other patients.

CONCLUSIONS

Findings of the panel review supported the initial clinical diagnoses. This confirmed that there was an apparent high incidence of clozapine-related myocarditis within this service, for which there was no clear reason. Mechanisms underlying clozapine-related myocarditis and cardiomyopathy, as well as successful clozapine continuation and rechallenge were considered, but definitive explanations remain unknown. This review highlighted the clinician's role in post-marketing drug surveillance to guide rational management of suspected adverse drug effects.

Determination of myocardium to plasma concentration ratios of five antipsychotic drugs: comparison with their ability to induce arrhythmia and sudden death in clinical practice

Reviewing available data shows that most of antipsychotic drugs are associated with arrhythmia and sudden death. Experimental studies have shown a HERG channel blockade, a dose-dependent increase in duration of action potential or of QT interval, with various degrees of indicators of serious arrhythmogenicity. However, it seems difficult to relate these in vitro and in vivo preclinical models to clinical findings, in part, because the relationship between concentrations used and in vivo tissue concentrations during treatment in man is not known. Consequently, we established the myocardium to plasma concentration ratios for a series of antipsychotic drugs by intraperitoneal administration of different level doses to the guinea pig. Then, we compared these values to their ability to induce arrhythmia or torsade de pointes in clinical practice. The myocardium to plasma concentration ratios were 2.2 for clozapine, 2.7 for olanzapine, 3.1 for sertindole, 4.5 for risperidone, and 6.4 for haloperidol. These data suggest that when the ratio is higher than 4, arrhythmia and sudden death may be expected. On the contrary, when the ratio is less than 3, little effect may be predicted. These results underscore the importance of interpreting HERG channel data and electrophysiological data in the context of other pharmacokinetic parameters such as myocardium to plasma distribution.

Electrical storm as initial presentation of arrhytmogenic right ventricular cardiomyopathy in an elderly woman

Arrhythmogenic right ventricular dysplasia (ARVD) is an unusual cause of electrical storm in the elderly. We report the case of a 76-year-old woman with no previous known disease who developed recurrent ventricular tachycardia and fibrillation. Postmortem examination revealed histological features of arrhythmogenic right ventricular dysplasia.

Treatment of premenstrual dysphoric disorder with luteal phase dosing of sertraline

Sertraline (Zoloft, Pfizer Inc.) is a selective serotonin re-uptake inhibitor (SSRI) which has been approved by the US FDA for the treatment of premenstrual dysphoric disorder (PMDD). PMDD is a severe form of premenstrual syndrome (PMS) which affects at least 5 - 8% of women of reproductive age. It is characterised by cyclic appearance at the late luteal phase of the menstrual cycle, and disappearance following the beginning of menses, with no symptoms during at least 1 week of the cycle - usually during the mid-follicular phase. Due to the cyclic luteal occurrence of PMDD, luteal phase dosing of SSRIs has been suggested and proven effective for sertraline as well as several other SSRIs. The clinical response of sertraline is reported to be within several days following initiation of treatment. Despite repeated cyclic discontinuation, no significant discontinuation adverse effects have been reported. In addition to its proven clinical efficacy, luteal-phase dosing may offer the advantages of minimising adverse effects of SSRIs while reducing the personal and economic burden of taking a prescription medication continuously for long periods and thus increasing compliance.

Clinical relevance and management of drug-related QT interval prolongation

Much attention recently has focused on drugs that prolong the QT interval, potentially leading to fatal cardiac dysrhythmias (e.g., torsade de pointes). We provide a detailed review of the published evidence that supports or does not support an association between drugs and their risk of QT prolongation. The mechanism of drug-induced QT prolongation is reviewed briefly, followed by an extensive evaluation of drugs associated with QT prolongation, torsade de pointes, or both. Drugs associated with QT prolongation are identified as having definite, probable, or proposed associations. The role of the clinician in the prevention and management of QT prolongation, drug-drug interactions that may occur with agents known to affect the QT interval, and the impact of this adverse effect on the regulatory process are addressed.

Fatalities associated with therapeutic use and overdose of atypical antipsychotics

Since 1989, several novel antipsychotic drugs have become available for use including clozapine, risperidone, olanzapine, quetiapine and ziprasidone. These agents represent a substantial improvement in the treatment of schizophrenia and related disorders and are considered to have a favourable adverse effect profile relative to traditional antipsychotics. Nonetheless, in rare cases, people have died as a result of taking atypical antipsychotic drugs at therapeutic and supratherapeutic doses. Toxic doses of atypical antipsychotics are highly variable: some patients have died while taking therapeutic doses and others have survived massive overdoses. Toxicity may be increased by coingestion of other agents, particularly drugs with similar metabolic pathways. Atypical antipsychotics are metabolised predominantly by cytochrome p450 (CYP) isoenzymes, particularly CYP1A2 (clozapine and olanzapine), CYP3A4 (clozapine, quetiapine and ziprasidone) and CYP2D6 (olanzapine and risperidone). Concurrent prescription of other drugs that inhibit these isoenzymes may increase the probability of adverse events in patients taking atypical antipsychotics. Deaths due to atypical antipsychotic toxicity are often related to cardiovascular complications, but pulmonary, neurological, endocrine and gastrointestinal complications have also caused fatalities. Prevention and management of atypical antipsychotic overdose are of increased clinical relevance as prescription of these drugs increases.

Psychotropic drugs, cardiac arrhythmia, and sudden death

A variety of drugs targeted towards the central nervous system are associated with cardiac side effects, some of which are linked with reports of arrhythmia and sudden death. Some psychotropic drugs, particularly tricyclic antidepressants (TCAs) and antipsychotic agents, are correlated with iatrogenic prolongation of the QT interval of the electrocardiogram (ECG). In turn, this is associated with the arrhythmia (TdP). This review discusses the association between psychotropic agents, arrhythmia and sudden death and, focusing on TCAs and antipsychotics, considers their range of cellular actions on the heart; potentially pro-arrhythmic interactions between psychotropic and other medications are also considered. At the cellular level TCAs, such as imipramine and amitriptyline, and antipsychotics, such as thioridazine, are associated with inhibition of potassium channels encoded by In many cases this cellular action correlates with ECG changes and a risk of TdP. However, not all psychotropic agents that inhibit HERG at the cellular level are associated equally with QT prolongation in patients, and the potential for QT prolongation is not always equally correlated with TdP. Differences in risk between classes of psychotropic drugs, and between individual drugs within a class, may result from additional cellular effects of particular agents, which may influence the consequent effects of inhibition of repolarizing potassium current.

Antipsychotic-related QTc prolongation, torsade de pointes and sudden death

Sudden unexpected deaths have been reported with antipsychotic use since the early 1960s. In some cases the antipsychotic may be unrelated to death, but in others it appears to be a causal factor. Antipsychotics can cause sudden death by several mechanisms, but particular interest has centred on torsade de pointes (TdP), a polymorphic ventricular arrhythmia that can progress to ventricular fibrillation and sudden death. The QTc interval is a heart rate-corrected value that represents the time between the onset of electrical depolarisation of the ventricles and the end of repolarisation. Prolongation of the QTc interval is a surrogate marker for the ability of a drug to cause TdP. In individual patients an absolute QTc interval of >500 msec or an increase of 60 msec from baseline is regarded as indicating an increased risk of TdP. However, TdP can occur with lower QTc values or changes. Concern about a relationship between QTc prolongation, TdP and sudden death applies to a wide range of drugs and has led to the withdrawal or restricted labelling of several. Among antipsychotics available in the UK, sertindole was voluntarily suspended, droperidol was withdrawn, and restricted labelling introduced for thioridazine and pimozide. The degree of QTc prolongation is dose dependent and varies between antipsychotics reflecting their different capacity to block cardiac ion channels. Significant prolongation is not a class effect. Among currently available agents, thioridazine and ziprasidone are associated with the greatest QTc prolongation. Virtually all drugs known to cause TdP block the rapidly activating component of the delayed rectifier potassium current (I(kr)). Arrhythmias are more likely to occur if drug-induced QTc prolongation coexists with other risk factors, such as individual susceptibility, presence of congenital long QT syndromes, heart failure, bradycardia, electrolyte imbalance, overdose of a QTc prolonging drug, female sex, restraint, old age, hepatic or renal impairment, and slow metaboliser status. Pharmacodynamic and pharmacokinetic interactions can also increase the risk of arrhythmias. Further research is needed to quantify the risk of sudden death with antipsychotics. The risk should be viewed in the context of the overall risks and benefits of antipsychotic treatment. It seems prudent, where possible, to select antipsychotics that are not associated with marked QTc prolongation. If use of a QTc-prolonging drug is warranted, then measures to reduce the risk should be adopted.