Cardiovascular adverse effects of antipsychotic drugs

Cardiovascular effects of antipsychotics

There is great concern over cardiovascular disease in the schizophrenic population owing to the high incidence of cardiovascular mortality. Increased cardiovascular mortality is related to lifestyle choices (e.g., smoking and sedentary lifestyle) and a high prevalence of comorbid medical conditions, including dyslipidemia, the metabolic syndrome and Type 2 diabetes. One factor that increases cardiovascular risk is the medications used to treat the core features of schizophrenia. Adverse cardiovascular effects of antipsychotic treatment have been recognized for many decades, especially tachycardia, orthostatic hypotension and rare instances of sudden death; but, since 2000, there has been a significant shift in the focus of risk perception. The older antipsychotic literature is replete with papers primarily concerned with the physiological consequences of muscarinic cholinergic antagonism, alpha(1)-adrenergic antagonism or receptors associated with cardiac conduction, but the current literature recognizes that, for most antipsychotic-exposed patients, the more significant cardiovascular burden of treatment is mediated by metabolic adverse effects such as weight gain, dyslipidemia and diabetes mellitus. The purpose of this review is to examine the cardiovascular risks of treatment with antipsychotic medications, elucidating relevant mechanisms and differences between various agents, especially for metabolic adverse effects seen with atypical antipsychotics.

Monitoring technology for the elderly patient

In view of the current demographic change in the aging population and its impact on changing the health system towards community care, this review focuses on monitoring technology for elderly patients. In particular, the focus is on wearable monitoring technology and its integration into telehealth systems. In review of the available commercial wearable monitoring technologies, their form factor, sensing methods and application for the purpose of monitoring elderly patients for ongoing care are discussed. At the same time, advances in research regarding how to overcome the limitations of commercial wearable monitoring devices are reviewed. Issues of usability, functionality, human interaction and social factors, and ethical considerations in the application of wearable monitoring and telehealth technologies for elderly patients are outlined. Some of the initiatives taken to address these issues are also discussed and some suggestions are made. Finally, the review looks at the anticipated benefits of the application of wearable monitoring and telehealth technologies from an elderly patient, clinician or carer and healthcare system point of view. Expert opinion of what strategies need to be used to enhance the use and uptake of these technologies and what future directions are anticipated are expressed. In conclusion, available wearable monitoring technologies and its integration into teleheath systems are currently limited for application on elderly patients. There are many issues of standardization, design and ethical considerations that need to be addressed before advances can be made with these technologies so that these patients can be remotely monitored and provided with a better quality of care.

A naturalistic comparison study of the efficacy and safety of intramuscular olanzapine, intramuscular haloperidol, and intramuscular levomepromazine in acute agitated patients with schizophrenia

OBJECTIVE

This study was a comparative investigation of the clinical efficacy and safety of intramuscular (IM) olanzapine, IM haloperidol, and IM levomepromazine in acute agitated patients with schizophrenia.

METHODS

The subjects were 122 inpatients. Their clinical symptoms were assessed using Positive and Negative Syndrome Scale Excited Component (PANSS-EC), PANSS, and Agitation-Calmness Evaluation Scale, and their safety were assessed using the Abnormal Involuntary Movement Scale, Barnes Akathisia Rating Scale (BARS), and Drug-induced Extrapyramidal Symptoms Scale (DIEPSS).

RESULTS

The mean changes from baseline on the PANSS-EC, Agitation-Calmness Evaluation Scale, Abnormal Involuntary Movement Scale, BARS, and DIEPSS scores were significantly better in both IM olanzapine and IM levomepromazine than in IM haloperidol. Of these, the mean changes from baseline on the BARS and DIEPSS scores were significantly better in IM olanzapine than in IM levomepromazine. The mean change from baseline on the PANSS positive score was significantly better in both IM olanzapine and IM haloperidol than in IM levomepromazine.

CONCLUSIONS

The results of this study suggest the possibility that the anti-agitation effects of IM olanzapine and IM levomepromazine are more rapid than those of IM haloperidol. No worsening of EPS was observed. Our results also suggest that compared with IM levomepromazine, IM olanzapine is safer and affords greater improvement in symptoms.

A naturalistic comparison of the efficacy and safety of intramuscular olanzapine and intramuscular haloperidol in agitated elderly patients with schizophrenia

OBJECTIVE

This study was a comparative investigation of the clinical efficacy and safety of intramuscular (IM) olanzapine and IM haloperidol in agitated elderly patients with schizophrenia at 2 hours postdose.

METHODS

The subjects were 23 inpatients who had been diagnosed with schizophrenia according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV). Their clinical symptoms were assessed using Positive and Negative Syndrome Scale Excited Component (PANSS-EC), PANSS and Agitation Calmness Evaluation Scale (ACES), and their safety were assessed using the Abnormal Involuntary Movement Scale (AIMS), Barnes Akathisia Rating Scale (BARS), Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS) and laboratory tests.

RESULTS

The mean reduction from baseline on the PANSS-EC total score, the PANSS total score and the ACES score were significantly greater in the IM olanzapine injection group than in the IM haloperidol injection group. The mean changes from baseline on the AIMS score, the BARS score and the DIEPSS total score were significantly better in the IM olanzapine injection group than in the IM haloperidol injection group. No serious adverse events such as paralytic ileus, diabetic ketoacidosis, neuroleptic malignant syndrome or tardive dyskinesia occurred between the two groups.

CONCLUSION

The results of this study suggest the possibility that agitated elderly patients may result in superior efficacy and safety after IM olanzapine without serious adverse events in comparison with IM haloperidol.

A naturalistic comparison of the efficacy and safety of intramuscular olanzapine and intramuscular levomepromazine in agitated elderly patients with schizophrenia

BACKGROUND

There have not been any reports in Japan clarifying the efficacy and safety of intramuscular (IM) olanzapine and IM levomepromazine in agitated elderly patients with schizophrenia. This study was a comparative investigation of the clinical efficacy and safety of IM olanzapine and IM levomepromazine in agitated elderly patients with schizophrenia at 2 hours post-dose.

METHODS

The subjects were 52 inpatients who were diagnosed with schizophrenia according to the Diagnostic and Statistical Manual of Mental Disorders (DSM)-IV. Their clinical symptoms were assessed using the Positive and Negative Syndrome Scale Excited Component (PANSS-EC), PANSS, and Agitation Calmness Evaluation Scale (ACES), and their safety was assessed using the Abnormal Involuntary Movement Scale (AIMS), Barnes Akathisia Rating Scale (BARS), Drug-Induced Extrapyramidal Symptoms Scale (DIEPSS), and glucose test.

RESULTS

The PANSS-EC total score, the ACES score, and the glucose level significantly decreased from baseline in both the IM olanzapine group and the levomepromazine injection group; however, no between-group differences were observed. Mean change from baseline in the PANSS total score, positive score, the BARS score, and the DIEPSS total score was significantly greater in the IM olanzapine injection group compared with the levomepromazine injection group.

CONCLUSION

The results of this study suggest that agitated elderly patients rapidly respond to IM olanzapine and IM levomepromazine treatment. Furthermore, these results suggest that IM olanzapine is safer than IM levomepromazine and causes greater improvement in positive symptoms.

Prevalence of QTc interval changes in acute psychiatric care: a cross-sectional study

INTRODUCTION

In a case series we examined the prevalence and incidence of QT changes during a 1-week interval in hospitalized patients in a general psychiatry ward during a 6-month period.

METHOD

This cross-sectional study was done on electrocardiographic QT interval of patients admitted to the Psychiatric Department of Taleghani Hospital during a 6-month period excluding subjects with underlying cause of QT prolongation.

RESULTS

Admission and follow-up electrocardiograms of 27 men and 47 women were studied, there was significant QT prolongation during hospitalization (P value 0.001) in approximately 30% of subjects, irrespective of type of administered medication.

CONCLUSION

Pro-arrhythmic changes as reflected in QTc prolongation and QTc dispersion in electrocardiograms are common in patients admitted in psychiatric wards irrespective of type of therapy and should be screened and followed by serial electrocardiograms to minimize untoward cardiac outcomes.

Echocardiographic monitoring for clozapine cardiac toxicity: lessons from real-world experience

OBJECTIVE

We aimed to identify the baseline prevalence of cardiac dysfunction in patients commencing clozapine, assess adherence with echocardiographic monitoring recommendations, and evaluate the utility and cost of echocardiographic monitoring for the development of clozapine-associated myocarditis and cardiomyopathy.

METHODS

A retrospective longitudinal cohort study was undertaken of 159 consecutive patients from a major tertiary centre commencing clozapine in the period January 2002 to July 2009.

RESULTS

Some 73% of patients had a baseline study, and 11% had a six-month follow-up study. Nine patients had abnormal left ventricular function at baseline. Myocarditis was identified in three patients, with all cases occurring within the first month of treatment and suspected on clinical grounds before an echocardiogram was performed. One case of possible cardiomyopathy was identified. The cost of echocardiographic screening in the first year of treatment was estimated at $AUD 209,356 per case of cardiomyopathy detected.

CONCLUSION

The prevalence of cardiac dysfunction in patients commencing clozapine is high, and there are challenges in adhering with the recommended protocol for monitoring. Routine echocardiography is not useful in the detection of clozapine-associated myocarditis. Although cardiomyopathy may be identified, it is rare and associated with significant cost. Recommendations for routine echocardiographic monitoring should be re-examined.

Drug attrition during pre-clinical and clinical development: understanding and managing drug-induced cardiotoxicity

Cardiovascular toxicity remains a major cause of concern during preclinical and clinical development as well as contributing to post-approval withdrawal of medicines. This issue is particularly relevant for anticancer drugs where, the significant improvement in the life expectancies of patients has dramatically extended the use and duration of drug therapies. Nevertheless, cardiotoxicity is also observed with other classes of drugs, including antibiotics, antidepressants, and antipsychotics. This article summarizes the clinical manifestations of drug-induced cardiotoxicity by various cancer chemotherapies and novel drugs for the treatment of other diseases. Furthermore, it presents on overview of biomarker and imaging techniques for the detection of drug-induced cardiotoxicity. Guidelines for the management of patients exposed to drugs with cardiotoxic potential are presented as well as a checklist for collecting information when a safety signal is observed in clinical trials to more effectively assess the risk of cardiotoxicity and manage patient safety.

Pharmacokinetics, Tolerability, and Safety of Aripiprazole following Multiple Oral Dosing in Normal Healthy Volunteers

Two 14-day, placebo-controlled, double-blind studies evaluated the fasting pharmacokinetics, safety, and tolerability of aripiprazole, a new antipsychotic, in healthy male subjects. In Study 1, 37 subjects were randomized to aripiprazole 5 mg, 10 mg, 15 mg, 20 mg, or placebo once daily. In Study 2, 11 subjects were randomized to aripiprazole, titrated from 10 to 30 mg/day, or placebo. Aripiprazole had linear pharmacokinetics over 5 to 30 mg/day, which were described by a two-compartment open model, with first-order absorption. In Study 1, mean elimination half-life ranged from 47 to 68 hours with aripiprazole, with apparent systemic clearance (CL/F) of approximately 3.45 L/h. In Study 2, mean elimination half-life was 59 hours (CL/F approximately 4.0 L/h). Adverse events were generally mild to moderate, were transient in nature, and commonly occurred within the first 3 days of dosing. Clinical laboratory assessments, electrocardiogram, electroencephalogram, and prolactin levels showed no clinically significant changes during the studies.

A thorough QTc study of 3 doses of iloperidone including metabolic inhibition via CYP2D6 and/or CYP3A4 and a comparison to quetiapine and ziprasidone

The potential for iloperidone, a D2/5-HT2A antipsychotic, to affect the heart rate-corrected QT interval (QTc) was assessed in the absence and presence of metabolic inhibitors in a randomized, open-label, multicenter study. QT interval prolongation by medications, including both conventional and atypical antipsychotic drugs, can predispose patients to cardiac arrhythmias and result in sudden death. Adults with schizophrenia or schizoaffective disorder and normal electrocardiograms at baseline (N = 188) were randomized 1:1:1:1:1 to iloperidone, 8 mg twice daily (BID), 12 mg BID, 24 mg once daily (QD); quetiapine, 375 mg BID; or ziprasidone, 80 mg BID during period 1 (no metabolic inhibitors present). Iloperidone BID produced mean changes in QTc Fridericia correction (QTcF) interval (8.5-9.0 milliseconds [ms]) similar to those produced by ziprasidone (9.6 ms) and higher than those produced by quetiapine (1.3 ms). Iloperidone, 24 mg QD, produced a mean QTcF change of 15.4 ms. Coadministration of metabolic inhibitors with iloperidone during periods 2 (paroxetine) and 3 (paroxetine and ketoconazole) resulted in greater increases in the QTc interval. Increased QTc was observed in individuals with specific cytochrome P450 2D6 polymorphisms. Up to 10% of patients on iloperidone experienced QTc intervals of 60 ms or longer in the presence of metabolic inhibition and QD dosing. However, no patients experienced QTc changes of clinical concern (QTc ≥ 500 ms). The most common adverse events with iloperidone were headache, anxiety, and dyspepsia. The only cardiovascular adverse events with iloperidone were non-concentration-dependent tachycardia that was mild in most patients and did not lead to further sequelae. Pharmacogenetics and recommendations are discussed.

A randomized, double-blind, placebo-controlled study of rapid-acting intramuscular olanzapine in Japanese patients for schizophrenia with acute agitation

BACKGROUND

Olanzapine rapid-acting intramuscular (IM) injection is an atypical antipsychotic drug already used overseas and recently approved in Japan. The objective of this study was to confirm the efficacy of rapid-acting IM olanzapine 10 mg was greater than IM placebo in patients with exacerbation of schizophrenia with acute psychotic agitation by comparing changes from baseline to 2 hours after the first IM injection, as measured by the Positive and Negative Syndrome Scale-Excited Component (PANSS-EC) total score.

METHODS

We conducted a placebo-controlled, randomized, double-blind, parallel-group study in Japanese patients diagnosed with schizophrenia according to the diagnostic criteria specified in the DSM-IV-TR. Patients were randomized to 2 treatment groups: IM olanzapine (10 mg) or IM placebo. The primary efficacy outcome was the change in PANSS-EC from baseline to 2 hours after the first IM injection. Treatment groups were compared with an analysis of variance model which included treatment and site as factors. During the 24-hour treatment period, safety was assessed by clinical examination and laboratory investigations, electrocardiograms, extrapyramidal symptoms scales, and recording spontaneously reported adverse events.

RESULTS

Of the 91 randomized patients, 90 patients (45 IM olanzapine-group; 45 IM placebo-group) were in the full analysis set. The mean change of PANSS-EC total score from baseline to 2 hours after the first IM injection (mean±standard deviation) was -9.2±4.5 for the IM olanzapine group and -2.8±5.6 for the IM placebo group. The difference between treatment groups was statistically significant (p<.001). There were no deaths, serious adverse events, treatment-emergent adverse events (TEAEs) leading to discontinuation, severe TEAEs, or instances of oversedation in this study. There were no statistically significant differences between treatment groups in the proportion of patients with potentially clinically significant changes in laboratory tests, vital signs (blood pressure and pulse rate), electrocardiograms, and treatment-emergent extrapyramidal symptoms.

CONCLUSION

The efficacy of IM olanzapine 10 mg in patients with exacerbation of schizophrenia with acute psychotic agitation was greater than IM placebo in the primary efficacy measure, PANSS-EC. Intramuscular olanzapine 10 mg was shown to be generally safe and tolerable, and could be a new option for treatment of schizophrenia in Japan.

TRIAL REGISTRATION

NCT00970281.

Safety and tolerability of antipsychotic polypharmacy

INTRODUCTION

Antipsychotic polypharmacy (APP), the concomitant use of ≥ 2 antipsychotics, is common in clinical practice. Prior reviews have focused on the efficacy of APP, but no systematic review exists regarding the safety and tolerability of this practice.

AREAS COVERED

A systematic review of adverse effects associated with APP was conducted to prepare this review; case series with ≥ 2 patients, chart reviews, naturalistic, database, cohort and randomized studies that reported on the association between APP in general or specific APP combinations and global or specific adverse effect were included. Methodological limitations of available studies are discussed and recommendations for clinicians and future research are provided.

EXPERT OPINION

Across mostly small and uncontrolled studies, APP has been associated with increased global side effect burden, rates of Parkinsonian side effects, anticholinergic use, hyperprolactinemia, sexual dysfunction, hypersalivation, sedation/somnolence, cognitive impairment and diabetes. Effects on akathisia and mortality were inconclusive. Although some combinations, particularly aripiprazole augmentation of an agent with greater side effect burden, may reduce weight gain, dyslipidemia, hyperprolactinemia and sexual dysfunction, APP should remain a last-resort treatment option after monotherapy, switching and non-antipsychotic combinations have failed. More data are needed to further inform the individualized risk-benefit evaluation of APP.

Psychiatric patient and anaesthesia

Many patients with psychiatric illnesses are prescribed long-term drug treatment, and the anaesthesiologist must be aware of potential interactions with anaesthetic agents. Psychotropic drugs often given in combination with each other or with other non-psychiatric drugs generally exert profound effects on the central and peripheral neurotransmitter and ionic mechanisms. Hence, prior intake of these drugs is an important consideration in the management of the patient about to undergo anaesthesia and surgery. This article highlights the effects of anaesthetics on patients taking antipsychotics, tricyclic antidepressants, monoamine oxidase inhibitors and lithium carbonate. The risk that should be considered in the perioperative period are the extent of surgery, the patient's physical state, anaesthesia, the direct and indirect effects of psychotropics, risk of withdrawal symptoms and risk of psychiatric recurrence and relapse.

Risk of serious cardiac events in older adults using antipsychotic agents

BACKGROUND

Antipsychotic agents can lead to severe cardiovascular adverse events due to multiple mechanisms involving electrophysiologic and metabolic effects. Few epidemiologic studies have evaluated the risk of serious cardiovascular-related events in typical and atypical antipsychotic users.

OBJECTIVE

The purpose of this study was to compare the risk of serious cardiac events in older adults taking typical antipsychotics with those taking atypical antipsychotics.

METHODS

Prescription and medical information were derived from the IMS LifeLink Health Plan Claims database. The study involved a retrospective cohort of older adults (≥50 years) taking atypical or typical antipsychotics from July 1, 2000, to December 31, 2007. The primary outcome measure was hospitalization or emergency room visit due to serious cardiac events, including thromboembolism, myocardial infarction, cardiac arrest, and ventricular arrhythmias within 1 year after the index date. The 2 groups were matched on a propensity score to minimize the baseline differences between the groups. Survival analysis was conducted on the matched cohort to assess the risk of serious cardiovascular events in typical versus atypical users.

RESULTS

A total of 5580 patients were selected in each antipsychotic users group after propensity score matching. Serious cardiac events were found in 666 (11.9 %) atypical antipsychotic users and 698 (12.4%) typical antipsychotic users. Survival analysis revealed that typical antipsychotic users were at increased risk of serious cardiovascular events compared with atypical antipsychotic users (hazard ratio = 1.21; 95% CI, 1.04-1.40) after controlling for other factors.

CONCLUSIONS

Moderate increases in risk of serious cardiac events are associated with older adults using typical antipsychotic agents compared with atypical users. Health care professionals should carefully evaluate the benefit/risk ratio of antipsychotic agents before prescribing these agents to a vulnerable population.

Cardiovascular aspects of antipsychotics

PURPOSE OF REVIEW

Schizophrenia is associated with increased mortality and reduced life expectancy, with cardiovascular disease being the most frequent cause of death. Antipsychotics have detrimental effects on different risk factors for cardiovascular disease. This review will focus on the relationship between antipsychotic treatment and cardiovascular disease.

RECENT FINDINGS

The increased overall mortality and mortality from cardiovascular disease in schizophrenia are now well documented. Patients with schizophrenia are at risk of receiving less optimal treatment for cardiovascular disease. Patients with schizophrenia are at high risk of metabolic syndrome, a cluster of risk factors for cardiovascular disease. Some antipsychotics, in particular, clozapine and olanzapine, frequently cause weight gain, dyslipidemia and diabetes mellitus. Antipsychotics differ in their effects on body weight, lipids and glucose regulation. However, the long-term effects of these differences between individual antipsychotics on overall mortality and cardiovascular mortality are not well established.

SUMMARY

More research is needed to better understand the relationship between schizophrenia, antipsychotic treatment and cardiovascular disease. More effective treatment strategies need to be developed to reduce the burden of cardiovascular disease in schizophrenia.

Potential adverse interaction of human cardiac calsequestrin

Calsequestrin (CASQ) is a major Ca(2+) storage protein within the sarcoplasmic reticulum (SR) of both cardiac and skeletal muscles. CASQ reportedly acts as a Ca(2+) buffer and Ca(2+)-channel regulator through its unique Ca(2+)-dependent oligomerization, maintaining the free Ca(2+) concentration at a low level (0.5-1mM) and the stability of SR Ca(2+) releases. Our approach, employing isothermal titration calorimetry and light scattering in parallel, has provided valuable information about the affinity of human cardiac CASQ (hCASQ2) for a variety of drugs, which have been associated with heart- or muscle-related side effects. Those strongly binding drugs included phenothiazines, anthracyclines and Ca(2+) channel blockers, such as trifluoperazine, thioridazine, doxorubicin, daunorubicin, amlodipine and verapamil, having an average affinity of ~18 μM. They exhibit an inhibitory effect on in vitro Ca(2+)-dependent polymerization of hCASQ2 in a manner proportional to their binding affinity. Therefore accumulation of such drugs in the SR could significantly hinder the Ca(2+)-buffering capacity of the SR and/or the regulation of the Ca(2+) channel, RyR2. These effects could result in serious cardiac problems in people who have genetically impaired hCASQ2, defects in other E-C coupling components or problems with metabolism and clearance of those drugs.

Feasibility, efficacy, and safety of antipsychotics for intensive care unit delirium: the MIND randomized, placebo-controlled trial

OBJECTIVE

To demonstrate the feasibility of a placebo-controlled trial of antipsychotics for delirium in the intensive care unit and to test the hypothesis that antipsychotics would improve days alive without delirium or coma.

DESIGN

Randomized, double-blind, placebo-controlled trial.

SETTING

Six tertiary care medical centers in the US.

PATIENTS

One hundred one mechanically ventilated medical and surgical intensive care unit patients.

INTERVENTION

Patients were randomly assigned to receive haloperidol or ziprasidone or placebo every 6 hrs for up to 14 days. Twice each day, frequency of study drug administration was adjusted according to delirium status, level of sedation, and side effects.

MEASUREMENTS AND MAIN OUTCOMES

The primary end point was the number of days patients were alive without delirium or coma. During the 21-day study period, patients in the haloperidol group spent a similar number days alive without delirium or coma (median [interquartile range], 14.0 [6.0-18.0] days) as did patients in the ziprasidone (15.0 [9.1-18.0] days) and placebo groups (12.5 [1.2-17.2] days; p = 0.66). No differences were found in secondary clinical outcomes, including ventilator-free days (p = .25), hospital length of stay (p = .68), and mortality (p = .81). Ten (29%) patients in the haloperidol group reported symptoms consistent with akathisia, compared with six (20%) patients in the ziprasidone group and seven (19%) patients in the placebo group (p = .60), and a global measure of extrapyramidal symptoms was similar between treatment groups (p = .46).

CONCLUSIONS

A randomized, placebo-controlled trial of antipsychotics for delirium in mechanically ventilated intensive care unit patients is feasible. Treatment with antipsychotics in this limited pilot trial did not improve the number of days alive without delirium or coma, nor did it increase adverse outcomes. Thus, a large trial is needed to determine whether use of antipsychotics for intensive care unit delirium is appropriate.

Trifluoperazine: a rynodine receptor agonist

Trifluoperazine (TFP), a phenothiazine, is a commonly used antipsychotic drug whose therapeutic effects are attributed to its central anti-adrenergic and anti-dopaminergic actions. However, TFP is also a calmodulin (CaM) antagonist and alters the Ca(2+) binding properties of calsequestrin (CSQ). The CaM and CSQ proteins are known modulators of sarcoplasmic reticulum (SR) Ca(2+) release in ventricular myocytes. We explored TFP actions on cardiac SR Ca(2+) release in cells and single type-2 ryanodine receptor (RyR2) channel activity in bilayers. In intact and permeabilized ventricular myocytes, TFP produced an initial activation of RyR2-mediated SR Ca(2+) release and over time depleted SR Ca(2+) content. At the single channel level, TFP or nortryptiline (NRT; a tricyclic antidepressant also known to modify CSQ Ca(2+) binding) increased the open probability (Po) of CSQ-free channels with an EC(50) of 5.2 microM or 8.9 microM (respectively). This Po increase was due to elevated open event frequency at low drug concentrations while longer mean open events sustained Po at higher drug concentrations. Activation of RyR2 by TFP occurred in the presence or absence of CaM. TFP may also inhibit SR Ca uptake as well as increase RyR2 opening. Our results suggest TFP and NRT can alter RyR2 function by interacting with the channel protein directly, independent of its actions on CSQ or CaM. This direct action may contribute to the clinical adverse cardiac side effects associated with these drugs.

Atypical antipsychotic drugs and the risk of sudden cardiac death

BACKGROUND

Users of typical antipsychotic drugs have an increased risk of serious ventricular arrhythmias and sudden cardiac death. However, less is known regarding the cardiac safety of the atypical antipsychotic drugs, which have largely replaced the older agents in clinical practice.

METHODS

We calculated the adjusted incidence of sudden cardiac death among current users of antipsychotic drugs in a retrospective cohort study of Medicaid enrollees in Tennessee. The primary analysis included 44,218 and 46,089 baseline users of single typical and atypical drugs, respectively, and 186,600 matched nonusers of antipsychotic drugs. To assess residual confounding related to factors associated with the use of antipsychotic drugs, we performed a secondary analysis of users of antipsychotic drugs who had no baseline diagnosis of schizophrenia or related psychoses and with whom nonusers were matched according to propensity score (i.e., the predicted probability that they would be users of antipsychotic drugs).

RESULTS

Current users of typical and of atypical antipsychotic drugs had higher rates of sudden cardiac death than did nonusers of antipsychotic drugs, with adjusted incidence-rate ratios of 1.99 (95% confidence interval [CI], 1.68 to 2.34) and 2.26 (95% CI, 1.88 to 2.72), respectively. The incidence-rate ratio for users of atypical antipsychotic drugs as compared with users of typical antipsychotic drugs was 1.14 (95% CI, 0.93 to 1.39). Former users of antipsychotic drugs had no significantly increased risk (incidence-rate ratio, 1.13; 95% CI, 0.98 to 1.30). For both classes of drugs, the risk for current users increased significantly with an increasing dose. Among users of typical antipsychotic drugs, the incidence-rate ratios increased from 1.31 (95% CI, 0.97 to 1.77) for those taking low doses to 2.42 (95% CI, 1.91 to 3.06) for those taking high doses (P<0.001). Among users of atypical agents, the incidence-rate ratios increased from 1.59 (95% CI, 1 .03 to 2.46) for those taking low doses to 2.86 (95% CI, 2.25 to 3.65) for those taking high doses (P=0.01). The findings were similar in the cohort that was matched for propensity score.

CONCLUSIONS

Current users of typical and of atypical antipsychotic drugs had a similar, dose-related increased risk of sudden cardiac death.

Cerebellar ataxia in youths at risk for bipolar disorder

OBJECTIVE

Structural, biochemical, and functional cerebellar abnormalities occur in individuals with or at-risk for developing bipolar disorder (BD), but the clinical implications of these abnormalities are unknown. The present study examined cerebellar function in youths who were at familial risk for BD by comparing ataxia battery scores of youths with a bipolar parent to those of healthy youths.

METHODS

Trained raters administered an ataxia battery, consisting of three tasks, to children (aged 8-12 years) with at least one parent with BD type I (BDI) who themselves did not have BDI (at-risk or AR group, n = 21) and healthy comparison children (aged 8-12 years) with parents free of DSM-IV Axis I psychopathology (HC group, n = 23).

RESULTS

AR youths performed worse than HC youths on the Sharpened Romberg test (subjects standing heel-to-toe) and standing on one foot with eyes open (p < 0.02).

CONCLUSIONS

The results indicate that youths at familial risk for BD have more difficulty performing a Sharpened Romberg test than a HC group, suggesting that midline cerebellar dysfunction may be a biomarker for the future development of BD. Further studies examining the relationships among youths at risk for BD, coordination abnormalities, and cerebellar dysfunction are needed.

Adverse hospital events for mentally ill patients undergoing coronary artery bypass surgery

CONTEXT

Patients with mental disorders show higher burden of coronary heart disease, and may face special safety issues during in-hospital cardiac care.

OBJECTIVES

To compare the postoperative complication rate between patients with and without mental disorders undergoing isolated coronary artery bypass graft (CABG) surgery.

DESIGN, SETTING, AND PATIENTS

Retrospective analyses of New York state hospital claims between 1997 and 2004 (N=135,701). Complications were defined using the Agency for Healthcare Research and Quality Patient Safety Indicators (AHRQ PSI).

PRINCIPAL FINDINGS

Mental disorders were significantly associated with higher anesthesia complications (adjusted odds ratio [AOR]=6.44, p < .001), decubitus ulcer (AOR=1.42, p = .006), postoperative hip fracture (AOR = 3.29, p < .001), and overall complication rate representing nine PSIs (AOR = 1.27, p < .001).

CONCLUSIONS

Mentally ill patients undergoing CABG surgery are more likely to experience potentially preventable complications and injuries. The mechanism underlying this observation warrants further study.

Clozapine-induced myocarditis after long-term treatment: case presentation and clinical perspectives

Clozapine is the drug of choice for treatment-resistant schizophrenia. Prompted by a patient who developed reversible clozapine-induced myocarditis after long-term treatment with clozapine for several years for chronic-resistant schizophrenia, we undertook a review of the relevant literature. Concerning the myocarditis, the patient recovered rapidly by withdrawal of clozapine and with supportive management. Psychiatric stabilisation of the patient was at least possible with a combination of quetiapine (600 mg) and amisulpride (800 mg). Well-designed studies with the aim to specifically investigate treatment options after clozapine are limited and clinical possibilities are discussed in this paper. Olanzapine and combinations using non-clozapine atypical neuroleptics have partly shown improvement, whereas evidence for successful augmentation with mood stabilisers, anticonvulsants or electroconvulsive therapy in treatment-resistant schizophrenia is limited.

Orthostatic hypotensive effect of antipsychotic drugs in Wistar rats by in vivo and in vitro studies of alpha1-adrenoceptor function

RATIONALE

Many antipsychotics cause orthostatic hypotension possibly due to antagonist action on resistance vessel alpha1A-adrenoceptors (alpha1A-AR).

OBJECTIVE

We have tested this possibility by determining in Wistar rats how the orthostatic hypotensive effect of several antipsychotic drugs compares with their affinity for adrenoceptors in mesenteric small arteries (MSA with mainly alpha1A-AR) and aorta (mainly alpha1D-AR).

MATERIALS AND METHODS

Using a tilt setup, orthostatic hypotension was measured in anaesthetized rats for prazosin and the antipsychotics haloperidol, sertindole, risperidone, clozapine, ziprasidone, domperidone, olanzapine, and aripiprazole. For in vitro studies, segments of MSA and aorta were mounted on a wire myograph for isometric tension recording. Cumulative concentration-response curves were constructed to phenylephrine (PE) in the absence and presence of the drugs. Apparent affinity (pA2) was calculated by Schild analysis.

RESULTS

Prazosin antagonized tilt-induced and PE responses in both studies (threshold 4 ng/ml, pA2 9.52 MSA, 10.1 aorta). The rank order of the potency of the antipsychotics in the tilt experiments correlated (r2 = 0.69, P = 0.01) with the pA2-values in MSA: Risperidone and sertindole had the highest potency in the tilt test (threshold 159 and 97 ng/ml) and the highest apparent affinity in MSA (pA2 8.92 and 8.78), in contrast with aripiprazole and domperidone, which had the lowest in each case (threshold 4.1 and 3.0 microg/ml, pA2 7.17 and 6.99). In aorta, the pA2 values did not correlate with the in vivo potencies; in particular, sertindole had no functional affinity in aorta.

CONCLUSION

We conclude that the orthostatic hypotensive effect in rats of the antipsychotic drugs investigated is mediated through alpha1A-ARs.

Antipsychotic drug use and risk of pneumonia in elderly people

OBJECTIVES

To investigate the association between antipsychotic drug use and risk of pneumonia in elderly people.

DESIGN

A nested case-control analysis.

SETTING

Data were used from the PHARMO database, which collates information from community pharmacies and hospital discharge records.

PARTICIPANTS

A cohort of 22,944 elderly people with at least one antipsychotic prescription; 543 cases of hospital admission for pneumonia were identified. Cases were compared with four randomly selected controls matched on index date.

MEASUREMENTS

Antipsychotic drug use in the year before the index date was classified as current, recent, or past use. No prescription for an antipsychotic in the year before the index date was classified as no use. The strength of the association between use of antipsychotics and the development of pneumonia was estimated using multivariate logistic regression analysis and expressed as odds ratios (ORs) with 95% confidence intervals (CIs).

RESULTS

Current use of antipsychotics was associated with an almost 60% increase in the risk of pneumonia (adjusted OR=1.6, 95% CI=1.3-2.1). The risk was highest during the first week after initiation of an antipsychotic (adjusted OR=4.5, 95% CI=2.8-7.3). Similar associations were found after exclusion of elderly people with a diagnosis of delirium. Current users of atypical agents showed a higher risk of pneumonia (adjusted OR=3.1, 95% CI=1.9-5.1) than users of conventional agents (adjusted OR=1.5, 95% CI=1.2-1.9). There was no clear dose-response relationship.

CONCLUSION

Use of antipsychotics in elderly people is associated with greater risk of pneumonia. This risk is highest shortly after the initiation of treatment, with the greatest increase in risk found for atypical antipsychotics.

Protriptyline block of the human ether-à-go-go-related gene (HERG) K+ channel

Protriptyline, a tricyclic antidepressant for psychiatric disorders, can induce prolonged QT, torsades de pointes, and sudden death. We studied the effects of protriptyline on human ether-à-go-go-related gene (HERG) channels expressed in Xenopus oocytes and HEK293 cells. Protriptyline induced a concentration-dependent decrease in current amplitudes at the end of the voltage steps and HERG tail currents. The IC(50) for protriptyline block of HERG current in Xenopus oocytes progressively decreased relative to the degree of depolarization, from 142.0 microM at -40 mV to 91.7 microM at 0 mV to 52.9 microM at +40 mV. The voltage dependence of the block could be fit with a monoexponential function, and the fractional electrical distance was estimated to be delta=0.93. The IC(50) for the protriptyline-induced blockade of HERG currents in HEK293 cells at 36 degrees C was 1.18 microM at +20 mV. Protriptyline affected channels in the activated and inactivated states, but not in the closed states. HERG blockade by protriptyline was use-dependent, exhibiting a more rapid onset and a greater steady-state block at higher frequencies of activation. Our findings suggest that inhibition of HERG currents may contribute to the arrhythmogenic side effects of protriptyline.

Cardiovascular risks of atypical antipsychotic drug treatment

Atypical antipsychotics are the treatment of choice for patients with schizophrenia. They are generally better tolerated than conventional antipsychotics since most do not cause debilitating extrapyramidal symptoms. They are associated though with an array of cardiovascular adverse events that may affect morbid-mortality of schizophrenic patients. Orthostatic hypotension, electrocardiographic changes and metabolic syndrome (MS) are the main cardiovascular effects of atypical antipsychotics. They contribute to the overall disease burden associated with schizophrenia even though the benefit risk of such treatments still is highly favourable. We aim to review the main cardiovascular side effects of new atypical oral antipsychotics, the pharmacological mechanisms involved, and to which drugs they are particularly attributed.

Atypical antipsychotics and newer antidepressants

Atypical antipsychotics and newer antidepressants are commonly prescribed medications responsible for tens of thousands of adverse drug exposures each year. The emergency medicine physician should have a basic understanding of the pharmacology and toxicity of these agents. This knowledge is crucial to providing proper care and timely management of patients presenting with adverse drug effects from exposure to atypical antipsychotics and newer antidepressants.

Clozapine-associated myocarditis: a review of 116 cases of suspected myocarditis associated with the use of clozapine in Australia during 1993-2003

BACKGROUND

Clozapine is an antipsychotic medication associated with a lower suicide rate compared with other antipsychotic agents. Clozapine is used specifically in patients for whom previous therapy was inadequate or not tolerated, and is the only antipsychotic agent associated with the development of myocarditis.

OBJECTIVE

To retrospectively review all adverse drug reaction reports voluntarily submitted to the Australian Adverse Drug Reactions Unit mentioning suspected myocarditis in clozapine-treated patients.

PATIENTS AND METHODS

We accessed all electronic database entries and case reports citing suspected myocarditis associated with clozapine therapy from January 1993 through to December 2003, inclusive.

RESULTS

116 case reports of suspected myocarditis amongst clozapine-treated patients were identified during the specified time frame (incidence between 0.7% and 1.2% of treated patients). Median patient age for these cases was 30 years (SD 11.1 years) compared with 37 years from the Clopine registry. The condition developed within a median 16 days (mean 19.8 days; SD 17.3 days) of commencing clozapine for the bulk of patients developing myocarditis within 6 months (n=93, 80.2%). For all cases with known treatment commencement and cessation dates (n=106), the condition developed within a median 17 days (mean 171.7 days, SD 530.9 days). Over nine-tenths of cases were prescribed clozapine within the dose range of 100 mg/day to 450 mg/day. Sixty patients (51.8%) recovered from their episode when reported or during follow-up reports, whereas 17 patients (14.7%) had not yet recovered: 27 patients (23.3%) had unknown outcome when reported and the remaining 12 patients (10.3%) died.

CONCLUSION

Clozapine is uncommonly but importantly related to myocarditis, often fatal or near fatal and sometimes in relatively young patients with early onset after treatment initiation. The most striking feature about this condition is the wide diversity of nonspecific symptoms that occur in afflicted patients. Additional pharmacovigilance, improved reporting systems and further investigation of mechanisms of drug-induced myocarditis and related cardiovascular conditions (such as heart failure) are clearly warranted. A case-control study would be suitable for investigation of baseline predictors.

QTc-interval abnormalities in a forensic population

BACKGROUND

Antipsychotic drugs have been linked to sudden death among psychiatric patients, with a suggestion that prolongation of the QT-interval detectable on a standard electrocardiogram may be linked to fatal cardiac arrhythmias in these circumstances. Patients in secure forensic psychiatric facilities may be particularly likely to be on high-dose antipsychotic medication, and yet, as far as the authors are aware, no study of QT-intervals among such patients has been reported.

AIM

To investigate the prevalence of QT-interval abnormalities and associated known risk factors for fatal cardiac arrhythmias in a sample of forensic patients.

METHOD

Participants had a 12-lead electrocardiogram taken at 50 mm/s. Information was collected on their age, gender, psychiatric diagnosis, history of cardiovascular, liver and kidney diseases, and smoking, on all medications and on history of seclusion over the previous 12 months. Analysis was carried out using binary logistic regression.

RESULTS

Lower rates of QT-interval abnormalities than might be expected for this population were found. It was also found that a high dose of antipsychotics was associated with QTc prolongation (Adjusted OR = 9.5, 95% CI 2.6-34.2), a result consistent with previous literature.

CONCLUSION

Forensic patients need not be at increased risk of QTc abnormality provided risk factors are properly managed. A high dose of antipsychotic medication increases the risk of QTc prolongation.

Differentiating antidepressants of the future: Efficacy and safety

There have been significant advances in the treatment of depression since the serendipitous discovery that modulating monoaminergic neurotransmission may be a pathological underpinning of the disease. Despite these advances, particularly over the last 15years with the introduction of selective serotonin and/or norepinephrine reuptake inhibitors (SNRI), there still remain multiple unmet clinical needs that would represent substantial improvements to current treatment regimens. In terms of efficacy there have been improvements in the percentage of patients achieving remission but this can still be dramatically improved and, in fact, issues still remain with relapse. Furthermore, advances are still required in terms of improving the onset of efficacy as well as addressing the large proportion of patients who remain treatment resistant. While this is not well understood, collective research in the area suggests the disease is heterogeneous in terms of the multiple parameters related to etiology, pathology and response to pharmacological agents. In addition to efficacy further therapeutic advances will also need to address such issues as cognitive impairment, pain, sexual dysfunction, nausea and emesis, weight gain and potential cardiovascular effects. With these unmet needs in mind, the next generation of antidepressants will need to differentiate themselves from the current array of therapeutics for depression. There are multiple strategies for addressing unmet needs that are currently being investigated. These range from combination monoaminergic approaches to subtype selective agents to novel targets that include mechanisms to modulate neuropeptides and excitatory amino acids (EAA). This review will discuss the many facets of differentiation and potential strategies for the development of novel antidepressants.

Blockade of HERG human K+ channel and IKr of guinea pig cardiomyocytes by prochlorperazine

Prochlorperazine, a drug for the symptomatic control of nausea, vomiting and psychiatric disorders, can induce prolonged QT, torsades de pointes and sudden death. We studied the effects of prochlorperazine on human ether-a-go-go-related gene (HERG) channels expressed in Xenopus oocytes and also in the delayed rectifier K+ current of guinea pig cardiomyocytes. Prochlorperazine induced a concentration-dependent decrease in current amplitudes at the end of the voltage steps and tail currents of HERG. The IC50 for a prochlorperazine block of HERG current in Xenopus oocytes progressively decreased relative to the degree of depolarization, from 42.1 microM at -40 mV to 37.4 microM at 0 mV to 22.6 microM at +40 mV. The block of HERG by prochlorperazine was use-dependent, exhibiting a more rapid onset and a greater steady-state block at higher frequencies of activation, while there was partial relief of the block with reduced frequencies. In guinea pig ventricular myocytes, bath applications of 0.5 and 1 muM prochlorperazine at 36 degrees C blocked rapidly activating delayed rectifier K+ current by 38.9% and 76.5%, respectively, but did not significantly block slowly activating delayed rectifier K+ current. Our findings suggest that the arrhythmogenic side effects of prochlorperazine are caused by a blockade of HERG and the rapid component of the delayed rectifier K+ current rather than by a blockade of the slow component.

Blockade of HERG human K+ channels and IKr of guinea-pig cardiomyocytes by the antipsychotic drug clozapine

Clozapine, a commonly used antipsychotic drug, can induce QT prolongation, which may lead to torsades de pointes and sudden death. To investigate the arrhythmogenic side effects of clozapine, we studied the impact of clozapine on human ether-a-go-go-related gene (HERG) channels expressed in Xenopus oocytes and HEK293 cells, and on the delayed rectifier K(+) currents of guinea-pig cardiomyocytes. Clozapine dose-dependently decreased the amplitudes of the currents at the end of voltage steps, and the tail currents of HERG. The IC(50) for the clozapine blockade of HERG currents in Xenopus oocytes progressively decreased relative to depolarization (39.9 microM at -40 mV, 28.3 microM at 0 mV and 22.9 microM at +40 mV), whereas the IC(50) for the clozapine-induced blockade of HERG currents in HEK293 cells at 36 degrees C was 2.5 microM at +20 mV. The clozapine-induced blockade of HERG currents was time dependent: the fractional current was 0.903 of the control at the beginning of the pulse, but declined to 0.412 after 4 s at a test potential of 0 mV. The clozapine-induced blockade of HERG currents was use-dependent, exhibiting more rapid onset and greater steady state blockade at higher frequencies of activation, with a partial relief of blockade observed when the frequency of activation was decreased. In guinea-pig ventricular myocytes held at 36 degrees C, treatment with 1 and 5 microM clozapine blocked the rapidly activating delayed rectifier K(+) current (I(Kr)) by 24.7 and 79.6%, respectively, but did not significantly block the slowly activating delayed rectifier K(+) current (I(Ks)). Our findings collectively suggest that blockade of HERG currents and I(Kr), but not I(Ks), may contribute to the arrhythmogenic side effects of clozapine.

Droperidol’s Effect on QT Interval

The Food and Drug Administration (FDA) issued a letter to health care providers on December 4, 2001, concerning the medication, droperidol. The purpose of the warning was to alert health care providers to the possible role of droperidol in the development of torsades de pointes (TdP) in susceptible patients. The purpose of this article is to explore the role of droperidol in the development of TdP in susceptible patients and current recommendations for the use of droperidol as an antiemetic.