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

Secondary effects of antipsychotics: women at greater risk than men

CONTEXT

The health burden of antipsychotic medication is well known, but the disproportionate effect on women as compared with men is underappreciated.

OBJECTIVE

The goal of this article is preventive--to better inform clinicians so that the risks to women and to their offspring can be diminished.

METHOD

All PubMed sources in which the search term gender (or sex) was linked to a side effect of antipsychotic medication were reviewed.

RESULT

There is general agreement in the literature on women's increased susceptibility to weight gain, diabetes, and specific cardiovascular risks of antipsychotics, with less consensus on malignancy risks and risks to the fetus. Cardiovascular death, to which men are more susceptible than women, is disproportionately increased in women by the use of antipsychotics. Sedating antipsychotics raise the risk of embolic phenomena during pregnancy, and postpartum. Prolactin-elevating drugs suppress gonadal hormone secretion and may enhance autoimmune proclivity.

CONCLUSIONS

Clinicians need to be aware of the differential harm that women (and their offspring) can incur from the side effects of antipsychotics.

P wave and QT changes among inpatients with schizophrenia after parenteral ziprasidone administration

OBJECTIVE

Although ziprasidone has been reported to cause ventricular arrhythmias, there have been no studies regarding the influence of ziprasidone on atrial conduction. Intraatrial and interatrial conduction time prolongation and inhomogeneous propagation of sinus impulses are indicated by P wave changes on surface electrocardiography. We aimed to evaluate proneness to atrial fibrillation after intramuscular ziprasidone in drug-free inpatients with schizophrenia.

METHODS

We evaluated 11 eligible inpatients who were drug free for at least 4 weeks with a primary diagnosis of schizophrenia disorder and 11 healthy controls who were hospital staff members. Electrocardiography was performed at baseline and 1.5-2h after ziprasidone injection. A 12-lead surface electrocardiogram was obtained from each subject in the supine position at a paper speed of 50mm/s and 2mV/cm.

RESULTS

The changes between baseline and the period after parenteral ziprasidone administration in P-wave duration, P-wave dispersion, QTc, QTc(max), QTc(min), and QT dispersion variables were significant (p>0.05). The initial P-wave dispersion was significantly longer in patients than in healthy controls (p<0.05). There were no correlations between electrocardiography parameters and clinical severity scores or demographic variables in either group.

CONCLUSION

Intramuscular ziprasidone administration does not seem to influence atrial and ventricular electrical conduction in drug-free inpatients with schizophrenia. However, schizophrenia might affect atrial conduction resulting in atrial fibrillation, which may be a cause of some complications in inpatients with this schizophrenia.

Collation, assessment and analysis of literature in vitro data on hERG receptor blocking potency for subsequent modeling of drugs' cardiotoxic properties

The assessment of the torsadogenic potency of a new chemical entity is a crucial issue during lead optimization and the drug development process. It is required by the regulatory agencies during the registration process. In recent years, there has been a considerable interest in developing in silico models, which allow prediction of drug-hERG channel interaction at the early stage of a drug development process. The main mechanism underlying an acquired QT syndrome and a potentially fatal arrhythmia called torsades de pointes is the inhibition of potassium channel encoded by hERG (the human ether-a-go-go-related gene). The concentration producing half-maximal block of the hERG potassium current (IC(50)) is a surrogate marker for proarrhythmic properties of compounds and is considered a test for cardiac safety of drugs or drug candidates. The IC(50) values, obtained from data collected during electrophysiological studies, are highly dependent on experimental conditions (i.e. model, temperature, voltage protocol). For the in silico models' quality and performance, the data quality and consistency is a crucial issue. Therefore the main objective of our work was to collect and assess the hERG IC(50) data available in accessible scientific literature to provide a high-quality data set for further studies.

Drug-induced torsades de pointes: data mining of the public version of the FDA Adverse Event Reporting System (AERS)

AIMS

To investigate spontaneous reports of TdP present in the public version of the FDA Adverse Event Reporting System (AERS) in the light of what is already known on their TdP-liability.

METHODS

Reports of TdP from January 2004 through December 2007 were retrieved from the public version of the AERS database. All reports were selected from REACTION files and the relevant suspected and/or interacting drugs were identified from DRUG files. Qualitative analysis was performed by the case/non-case method. Cases were represented by TdP reports, whereas non-cases were all reports of adverse drug reactions other than TdP. Quantitative analysis was assessed by calculating the crude and adjusted reporting odds ratio (ROR), as a measure of disproportionality, with the 95% confidence interval.

RESULTS

Reports of TdP were 1665 over a 4-year period, involving 376 active substances. Thirty-five drugs with at least 10 reports were identified: amiodarone and methadone were associated with the highest number of cases (113 and 83 respectively) and most of the other reports were ascribable to antibacterials, antidepressants and antipsychotics; remarkable differences in number of cases and ROR were present among agents within each therapeutic class. A disproportionate reporting was also observed for other compounds such as donepezil, famotidine and mitoxantrone.

CONCLUSIONS

Large spontaneous reporting databases represent an important source for signal detection of rare adverse drug reactions (ADR), such as TdP. The number of reports associated to donepezil, famotidine and mitoxantrone could be considered unexpected on the basis of current evidence and needs further investigations on their true TdP-liability.

[Differences between men and women in side effects of second-generation antipsychotics]

In this review we investigate whether sex differences exist for side effects of second-generation antipsychotics. Results are based on a MEDLINE search for the years 1974 through 2005. Even if pharmacokinetics differ between females and males, significantly higher plasma levels for women have been demonstrated only for olanzapine and clozapine. Hyperprolactinaemia is mainly induced by treatment with risperidone and amisulpride, and there is evidence for more pronounced prolactin levels in females. Most studies reviewed indicate that clozapine and olanzapine are associated with more body weight gain, once more especially in female patients. Furthermore, the few published studies indicate that metabolic syndrome is more frequent in females and there are likely no gender-specific differences between the new antipsychotic medications concerning frequency and degree of acute or chronic movement disturbance. The risk of QT prolongation with torsades de pointes arrhythmia is again higher in females. In conclusion, there is some evidence of sex differences in the side effects of second-generation antipsychotics. For better understanding of the basic mechanisms in sex differences, future studies with a primary focus on this topic are required. More specific data will help to determine how these differences shall affect clinical management.

Magnitude of QT prolongation associated with a higher risk of Torsades de Pointes

PURPOSE

Drug induced Torsades de Pointes (TdP) is a major concern for new drugs seeking regulatory approval. Prolongation of QT intervals greater than 60 millisecond or to longer than 500 millisecond in an individual patient has been considered to be associated with a higher risk. The purpose of this study is to identify values inferred from a population that predict a stronger potential for TdP.

METHODS

Prolongation data of 30 non-antiarrhythmic QT prolonging drugs were analysed. Depending on how strong the drugs were associated with TdP, they were categorized as strong or borderline torsadogens. The differences in mean QTc increases between the two groups were compared and cut-off values that distinguished strong from borderline drugs were searched for.

RESULTS

The average QTc increase of 19.3 millisecond of strong torsadogens was significantly greater than the 8.0 millisecond of borderline torsadogens. Prolongation greater than 12 millisecond in the context of monotherapy or 25 millisecond in the presence of metabolic inhibition and an upper bound of 95% confidence interval (CI) for the mean QTc increase greater than 14 millisecond in monotherapy or 30.1 millisecond in combination therapy with metabolic inhibitors favoured a stronger association with TdP.

CONCLUSIONS

Drugs strongly associated with TdP have greater QTc increases than those with less concern. Several cut-off values have been noted to distinguish between them. These values may be helpful for evaluation of TdP risk for future QT prolonging drugs.

The QTc interval and its dispersion in patients receiving two atypical antipsychotics

OBJECTIVE

Treatment with atypical antipsychotics may prolong the rate-corrected Q-T interval (QTc) on electrocardiogram and increase the risk of dangerous ventricular arrhythmias. Polytherapy with atypical antipsychotics is becoming common, but the effect of this practice on the QTc has not been explored in detail.

METHODS

Among 364 adults treated with atypical antipsychotics randomly selected from consecutive admissions to a single hospital, electrocardiograms with measurable Q-T intervals in at least six leads were available for 38 of 49 patients receiving polytherapy with two atypical antipsychotics. Daily chlorpromazine equivalent, QTc duration and QTc dispersion were assessed in this group and in 73 closely matched patients receiving atypical antipsychotic monotherapy.

RESULTS

The daily chlorpromazine equivalent of atypical antipsychotics was significantly greater in the polytherapy group (525.2 vs. 244.7 mg, P = 0.0003). Polytherapy and monotherapy patients were similar with regard to QTc duration, QTc dispersion and proportion of patients with gender-adjusted QTc prolongation (7.9% vs. 9.6%). The QTc duration had only a modest correlation with the total antipsychotic dose (P = 0.064). The presence of hypokalemia (3.0-3.5 mEq/l) was not associated with longer QTc intervals.

CONCLUSIONS

The common practice of polytherapy with two atypical antipsychotics does not seem to lead to significant QTc prolongation compared to monotherapy.

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.

The Phenothiazine Drugs Inhibit hERG Potassium Channels

Cardiovascular adverse effects from phenothiazine drugs are common. The most serious consequences of treatment, arrhythmias and sudden death, are probably rare and most likely to be caused primarily by blockade of cardiac potassium channels such as the human ether-a-go-go-related gene (hERG) channel, which plays a central role in arrhythmogenesis. This phenomenon has been previously reported to occur with a few phenothiazine drugs. However, phenothiazine drugs are composed of pharmacologically and structurally diverse groups. The effects of many of the phenothiazine drugs on hERG channels expressed in mammalian cell lines remain unknown. Therefore, we investigated the effects of four distinct phenothiazine drugs (thioridazine, chlorpromazine, trifluoperazine, and perphenazine) on hERG channel expressed in chinese hamster ovary (CHO) cells. HERG channels were expressed in CHO cells, and ion currents were measured using the patch-clamp technique. Thioridazine, perphenazine, trifluoperazine, and chlorpromazine blocked hERG potassium channels with the following IC(50) values: IC(50) values were 224 +/- 42 nM for thioridazine, 1003 +/- 71 nM for perphenazine, 1406 +/- 124 nM for trifluoperazine, and 1561 +/- 281 nM for chloropromazine. Inhibition of hERG channels by thioridazine was characterized by significant changes in voltage dependence, the value of V(1/2), the half-maximal activation potential, and shift into negative potential, that is, the amount of block was greater at more positive potential. No significant changes were noted in other drugs.

Delusional disorder, somatic type treated with aripiprazole--mirtazapine combination

Delusional disorder, somatic type (DDST) is a rare psychiatric disorder and the treatment is mostly based on observations, due to the lack of well-organized studies. Initially, antipsychotics and especially pimozide were considered to be the pharmacological approach of choice but, subsequently, tryciclic anti-depressants and selective serotonin re-uptake inhibitors (SSRIs) were also suggested to be effective, implicating the serotonergic system in the pathophysiology of the disorder. We present the case of a female with DDST, who responded to aripiprazole-mirtazapine combination, a finding that is in accordance with the initial approach of this disorder as a part of the schizophrenic spectrum, but also supports the hypothesis of serotonin dysfunction in DDST.

[The issue of mortality in schizophrenia]

First and second generation antipsychotic drugs have led to major therapeutic advances in the field of schizophrenia. Since the 50ties, they have enable schizophrenic patients to be treated as out-patients, contributing to the birth of a modern psychiatry. However, several therapeutic targets have not yet been reached. This paper will focus on mortality of schizophrenic patients, mortality due to suicide or mortality due to somatic conditions. In the future, therapeutic research in the field of psychotropic drugs should focus not only on improving efficacy on psychic targets and a better profile of tolerance, but also on improvement of mortality of schizophrenic patients treated with antipsychotics, which should decrease.

Epidemiologic features of antipsychotic prescribing to children and adolescents in primary care in the United Kingdom

OBJECTIVE

The goal was to investigate the epidemiologic features of antipsychotic prescribing to children and adolescents in general practice in the United Kingdom.

METHODS

A total of 384 participating general practices from the United Kingdom General Practice Research Database were used to identify patients 0 to 18 years of age who were prescribed > or = 1 antipsychotic medication between January 1, 1992, and December 31, 2005. Annual age-specific prevalences and incidences of antipsychotic prescribing were calculated.

RESULTS

The overall prevalence of use of all antipsychotics increased from 1992 (0.39 users per 1000 patient-years) to 2005 (0.77 users per 1000 patient-years). The prescribing prevalence for patients 7 to 12 years of age almost tripled between 1992 (0.23 users per 1000 patient-years) and 2005 (0.61 users per 1000 patient-years). Atypical antipsychotic prescribing increased 60-fold from 1994 (0.01 users per 1000 patient-years) to 2005 (0.61 users per 1000 patient-years). However, typical antipsychotic prescribing decreased significantly from 2000 (0.44 users per 1000 patient-years) to 2005 (0.18 users per 1000 patient-years). The incidences for typical and atypical antipsychotics showed trends similar to those of the respective prevalences. However, the overall incidence (number of new starters) for all antipsychotics was relatively stable between 1992 and 2005, which suggests that patients remain on treatment longer.

CONCLUSIONS

The overall prevalence of antipsychotics almost doubled between 1992 and 2005; however, the rate of increase was much lower than the reported figures in the United States. The prescribing of atypical antipsychotic drugs has increased despite the lack of conclusive evidence showing their superiority over older conventional antipsychotics. Additional investigation is required to evaluate their efficacy and safety in children and adolescents.

Cardiotoxic effects of antihistamines: from basics to clinics (...and back)

Drug-induced arrhythmias, particularly those caused by a prolonged QT interval, have become a critical safety issue for compound selection during development by pharmaceutical companies and for health care regulators. The last two decades have witnessed enormous progress in the definition of the clinical conditions that facilitate the occurrence of such serious adverse effects, of its molecular basis, and in the preclinical strategies aimed at early identification of the cardiotoxic liability of compounds undergoing investigation or already used in the clinic. Moreover, despite the fact that acquired factors play an obvious role in drug-induced arrhythmias, it has become evident that the disease is often manifested upon the interaction of strong environmental stressors with specific genetic determinants of the affected individuals; in that sense, few examples can illustrate the existing interaction between acquired and genetic factors in disease manifestation better than drug-induced arrhythmogenesis. Progress in this field has been mainly driven by a strong interaction among various disciplines, including medicinal chemistry, pharmacology, electrophysiology, molecular genetics, and clinical cardiology; such an interdisciplinary approach has often generated unexpected discoveries of great clinical value, allowing clinicians to drive drug selection toward compounds of proven efficacy and safety. Historically, studies on antihistamines have paved the way for much of our current understanding of the mechanisms and problems associated with QT prolongation and drug-induced arrhythmogenesis; therefore, in this perspective, we will attempt to summarize how basic research studies have helped the interpretation of clinically relevant phenomena (from basics to clinics...) and how this information has prompted new emphasis in preclinical studies aimed at predicting the cardiotoxic potential of compounds (...and back). The current availability of several strategies provided with great predictive potential, together with an increased awareness of physicians, pharmaceutical industries, and health care regulators to this potentially serious cardiovascular side effect, has significantly decreased the risk associated with drug-induced arrhythmias caused by drugs newly introduced into the market; nevertheless, given the large number of cases of QT prolongation still occurring during treatment with a wide variety of congeners, it seems appropriate to review the issue of the cardiotoxic actions of antihistamines, as a better comprehension of the underlying mechanisms and risk factors is likely to contribute to the improvement of the risk/benefit ratio for pharmacological treatment in several therapeutic areas.

Adverse effects of antipsychotics as outcome measures

BACKGROUND

Antipsychotic drugs are associated with adverse effects that can lead to poor medication adherence, stigma, distress and impaired quality of life.

AIMS

To review the use of adverse effects of antipsychotic drugs as outcome measures, with a particular emphasis on methodological issues.

METHOD

Review of data on adverse effects from sources including randomised controlled trials (RCTs), post-marketing surveillance and naturalistic studies.

RESULTS

All have advantages and disadvantages and the best overview comes from considering all sources of data together. Adverse effects are inconsistently reported, hampering cross-study comparisons. Many outcome measures lack clinical meaning. In both naturalistic studies and RCTs adverse effects often account for less treatment discontinuation than lack of efficacy.

CONCLUSIONS

Standardisation in the reporting of adverse effects is needed. Patients' subjective experience of medication should be given more consideration. Total discontinuation rates provide a useful global outcome measure that incorporates tolerability and efficacy as well as patient and clinician viewpoints. Patients should be informed of common side-effects prior to treatment and monitored for their occurrence during treatment.

Effect of risperidone on serum lipids and cerebrovascular mortality among elderly dementia patients with associated behavioral disturbances

Background. Concern exists about safety of risperidone in glucose and lipid metabolism as well as cerebrovascular mortality. Our aim is to evaluate the safety of low-dose risperidone in elderly dementia patients with associated behavioral disturbances on glucose, serum lipids and cerebrovascular mortality. Material and methods. Thirty-one patients entered the study. Fasting glucose, total cholesterol, LDL, HDL, BMI, waist circumference, and triglycerides were measured at baseline and after 3 months. Mortality was reported after 6 months of starting the study. Risk factors for cerebrovascular disease were reported. A control group with 30 subjects was included. Results. Eighteen women and 13 men were included. Mean age was 80.6 years. After analyzing the different variables no significant differences between baseline and after 3 months of follow-up were found. During the study seven (22.58%) patients died, one from stroke. The most frequent associated cerebrovascular risk factors were smoking history, valvular heart disease and atrial fibrillation. Conclusion. In our study, low-dose risperidone administered in patients with behavioral symptoms associated dementia does not affect significantly the lipid profile, fasting glucose, BMI or waist circumference and is not associated with an increased risk for cerebrovascular mortality.

[Cardiological monitoring of antipsychotic-treated patients: evaluation and evolution of a hospital protocol]

INTRODUCTION

Following the Agence Française de Sécurité Sanitaire des Produits de Santé (Afssaps) (French Health Authority) recommendations in 2001, which impose the rigorous follow-up (electrocardiogram [ECG] and ionogram) of patients treated with antipsychotics (AP), a monitoring protocol was elaborated and set up in the Caen psychiatric hospital in April 2002. Protocol evaluation compared with fixed aims was performed after two years' follow-up.

AIM OF THE STUDY

This protocol had to answer a triple aim: better identification of patients at risk, ensure in-treatment monitoring, be simple and adapted to daily practice.

INCLUSION CRITERIA

A systematic admission check-up (S0) which includes cardiological and biological controls and after one and six months' treatment control (S1 and S6) were recommended. The major risk factors (RF) researched were long QT interval, bradycardia and hypokaliemia.

RESULTS

The initial monitoring was conducted in 601 patients (that only corresponded to 17% of hospital admission active files during the considered period). Means delays before obtaining an ECG were three times those obtained existing biological check-ups (11 days versus three days after date of admission). Systematic and integrated characterisation controls on admission were not respected. We noted that two-third of patients admitted during this period were hospitalized for only five days, although the mean time to obtain an ECG is of 11 days. This delay (approximately one week) between ECG and biological check-up is not compatible with a complete patient RF evaluation. Respectively, 83 and 68 patients were controlled under treatment at S1 and S6. Only half of the patients were controlled at the one-month (S1) and 16% at the six-months' theoretical dates (S6). These delays are inappropriate, notably with regard to the mean time of hospitalisation (15-17 days). The incidence of major RF was higher in treated (71%) than in non-treated patients. Major RF presence at S0 was not systematically associated with an AP treatment contraindication. The excessive delay before the first ECG could partially explain why this initial check-up was not able to detect a pretreatment contraindication. On the other hand, AP treated patients who presented at least one major RF at S0 were more frequently monitored at S1 than patients who did not (26% versus 13%, p=0.05). Among the 168 patients treated with AP or other drugs prolonging the QT interval at risk, 33 had at least one follow-up. This risk population was not better controlled than the initial cohort.

DISCUSSION

Protocol evaluation is essential to improve its interest and feasibility. If systematic characterisation is simple, its application in practice is very difficult. The second version of the protocol presented here proposes to substitute the systematic ECG characterisation with the classification on admission of patients in "risk groups" that will condition the subsequent monitoring. Risk groups are identified into two RF types: those which are not related to AP treatment and those which are therapeutic attitude is adapted according to initial QTcorrigé (QTc), its progression between S0 and S (seven days) and kaliemia.

Adverse effects of atypical antipsychotics : differential risk and clinical implications

Antipsychotic drugs can be of great benefit in a range of psychiatric disorders, including schizophrenia and bipolar disorder, but all are associated with a wide range of potential adverse effects. These can impair quality of life, cause stigma, lead to poor adherence with medication, cause physical morbidity and, in extreme cases, be fatal. A comprehensive overview of tolerability requires a review of all available data, including randomised controlled trials (RCTs), observational studies and postmarketing surveillance studies. Assessing the relative tolerability of atypical antipsychotics is hampered by the paucity of RCTs that compare these drugs head-to-head, and limited and inconsistent reporting of adverse effect data that makes cross-study comparisons difficult. Despite methodological problems in assessment and interpretation of tolerability data, important differences exist between the atypical antipsychotics in the relative risk of acute extrapyramidal symptoms (highest risk: higher doses of risperidone), hyperglycaemia and dyslipidaemia (highest risk: clozapine and olanzapine), hyperprolactinaemia (highest risk: amisulpride and risperidone), prolongation of heart rate-corrected QT interval (QTc) [highest risk: ziprasidone and sertindole] and weight gain (highest risk: clozapine and olanzapine). Sedation, antimuscarinic symptoms, postural hypotension, agranulocytosis and seizures are more common with clozapine than with other atypical antipsychotics. The variation in their tolerability suggests that it is misleading to regard the atypical antipsychotics as a uniform drug class, and also means that the term 'atypical antipsychotic' has only limited usefulness. Differences between the atypical agents in terms of efficacy and pharmacodynamic profiles also support this view. As tolerability differs between specific conventional and atypical drugs, we conclude that broad statements comparing the relative risk of specific adverse effects between 'atypical' and 'conventional' antipsychotics are largely meaningless; rather, comparisons should be made between specific atypical and specific conventional drugs. Adverse effects are usually dose dependent and can be influenced by patient characteristics, including age and gender. These confounding factors should be considered in clinical practice and in the interpretation of research data. Selection of an antipsychotic should be on an individual patient basis. Patients should be involved in prescribing decisions and this should involve discussion about adverse effects.

Current schizophrenia drugs: efficacy and side effects

Over the course of the past decade, the acceptance of several second-generation antipsychotics (SGAs) as effective medication for the treatment of schizophrenia has led to some changes. SGAs have a lower risk of inducing extrapyramidal side effects and tardive dyskinesia compared with first-generation antipsychotics, and have been said to be more successful in long-term treatment and tolerability. They also significantly improve the quality of life of schizophrenic patients. However, during treatment with SGAs other adverse effects can occur, such as weight gain, metabolic changes, sexual dysfunction and QTc-prolongation, significantly affecting the patient's physical health. Consequently, these side effects might be the reason that a high proportion of patients discontinue treatment with SGAs. Thus, from the authors' view, optimising individualised treatment implies increasing the efficacy of current schizophrenia drugs. This can be achieved by finding clinical or pharmacogenetic predictors for the most appropriate drug or drug combination, and by improving side-effect management in combination with non-pharmacological interventions in order to increase patients' quality of life and treatment compliance, possibly resulting in a better long-term outcome.

Factors affecting outcome in schizophrenia and their relevance for psychopharmacological treatment

A major focus of current treatment research in schizophrenia is the determinants of long-term outcome, including functional outcome and general medical well being, rather than just specific domains of psychopathology such as positive and negative symptoms, mood symptoms, and cognitive impairment. This focus does not negate the importance of the latter issues but sees them as factors contributing to long-term outcome to variable extents. A long-term treatment focus facilitates a more clinically relevant assessment of benefits versus risks of available treatments. For instance, atypical antipsychotic drugs as a group have clear advantages for several important domains of efficacy that may influence long-term outcome, but are also more expensive over the long term. Use of some agents may also result in deleterious physical health consequences as well as large additional costs over the long term owing to metabolic adverse effects. The present paper focuses on several key issues in schizophrenia which are important determinants of long-term outcome in schizophrenia, or influence choice of antipsychotic drugs, or both, including: (i) duration of untreated psychosis; (ii) impact of relapse on long-term outcome; (iii) limited efficacy for specific domains of psychopathology of current treatments; (iv) mortality owing to suicide; and (v) mortality owing to other causes (e.g. cardiovascular disease).

Current concepts in the mechanisms and management of drug-induced QT prolongation and torsade de pointes

Drug-induced long QT syndrome is characterized by a prolonged corrected QT interval (QTc) and increased risk of a polymorphic ventricular tachycardia known as torsade de pointes (TdP). We review mechanisms, predispositions, culprit agents, and management of this potentially fatal phenomenon. Virtually all drugs that prolong QTc block the rapid component of the delayed rectifier current (I(kr)). Some drugs prolong QTc in a dose-dependent manner, others do so at any dose. Most patients that develop drug-induced TdP have underlying risk factors. Female sex is the most common. Implicated drugs include class 1A and III antiarrhythmics, macrolide antibiotics, pentamidine, antimalarials, antipsychotics, arsenic trioxide, and methadone. Treatment for TdP includes immediate defibrillation for hemodynamic instability and intravenous magnesium sulfate. Potassium levels should be maintained in the high normal range, and all QT prolonging agents must be promptly discontinued.

Cardiovascular effects of high dose venlafaxine XL in patients with major depressive disorder

OBJECTIVE

To assess cardiovascular safety profile of high dose Venlafaxine XL in patients with major depression.

METHOD

Effects of high dose venlafaxine (mean 346.15 mg;) on the cardiovascular system in 37 patients with major depressive disorder were evaluated: BP, ECG (PR, QT, QRSD and QTc intervals) and heart rate.

RESULTS

12.5% of patients developed hypertension after starting treatment with venlafaxine. There was an association between heart rate and the dose of venlafaxine although not statistically significant. There was no association between dose of venlafaxine and PR, QT, QRSD and QTc intervals. One patient on 300 mg who was hypertensive and on other medications that may prolong QTc, had mildly prolonged QTc. However this was not clinically significant.

CONCLUSION

This study of subjects on high dose venlafaxine (mean 346.15 mg; range 225-525 mg) did not demonstrate any clinical or statistically significant effects on electrocardiogram (ECG) parameters including PR, QT, QRSD and QTc interval.

QT interval and dispersion in very young children treated with antipsychotic drugs: a retrospective chart review

OBJECTIVES AND BACKGROUND

QT dispersion (QTd) is a measure of interlead variations of the surface 12-lead electrocardiogram (ECG). Increased QTd, found in various cardiac diseases, reflects cardiac instability and risk for lethal cardiac arrhythmias. Research suggests a link between psychotropic treatment, ECG abnormalities (QT prolongation), and increased sudden cardiac mortality rates. Reports of sudden death in children treated with psychotropic drugs have raised concerns about cardiovascular monitoring and risk stratification. QTd analysis has not been investigated in very young children treated with antipsychotic drugs. In the present retrospective chart review study, we calculated QT interval, QTd, and their rate-corrected values in very young children treated with antipsychotics.

METHODS

The charts of 12 children (ages 5.8 +/- 0.98 yr; 4 girls, 8 boys) were examined before initiation of antipsychotic treatment [risperidone (n = 7), clotinapine (n = 1), and propericiazine (n = 4)] and during the maintenance period after achieving a positive clinical response. Three children were concomitantly maintained on methylphenidate. QT interval, QTd, and their rate-corrected values were calculated.

RESULTS

QT interval, QTd, and their rate-corrected values were all within normal values both before and after successful drug treatment.

CONCLUSIONS

This preliminary, naturalistic, small-scale study suggests that antipsychotic treatment, with or without methylphenidate, in very young children is not commonly associated with significant alterations of QT interval and dispersion, suggesting the relative safety of these agents in this unique age group.

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.

Second-generation antipsychotics: is there evidence for sex differences in pharmacokinetic and adverse effect profiles?

Six second-generation antipsychotics (SGAs), aripiprazole, clozapine, olanzapine, quetiapine, risperidone and ziprasidone, are currently US FDA approved. The aim of this review is to investigate whether sex differences exist for efficacy and adverse effects of these drugs.Sex-related differences have been shown in the pharmacokinetics of cytochrome P450 (CYP), with a higher activity in females for CYP3A4 and CYP2D6. However, even if there are pharmacokinetic differences between females and males, significantly higher plasma concentrations in women have been demonstrated only for olanzapine and clozapine. To date, sex differences in adverse effects have not been well studied, but some adverse effects such as weight gain, hyperprolactinaemia and cardiac effects are reported to be particularly problematic for women. Most of the studies reviewed indicate that clozapine and olanzapine are associated with greater bodyweight gain than the other atypical antipsychotics, and that serious adverse effects such as metabolic syndrome, which includes increased visceral adiposity, hyperglycaemia, hypertension and dyslipidaemia induced by SGAs, are more frequent in females. According to most studies, the risk for cardiac adverse effects induced by SGAs is the same in male and female patients. Although women are at a lower risk of sudden cardiac death, they have a higher risk of induced long QT syndrome from antiarrhythmic and, probably, antipsychotic drugs. The propensity of sexual dysfunctions is higher with conventional antipsychotics than with SGAs. Additionally, there is some evidence that female sexual dysfunction is associated with high prolactin levels; however, whether the degree of prolactin level elevation is different between female and male patients remains controversial. There is no evidence for sex differences for any of the SGAs to cause a higher rate of extrapyramidal symptoms, acute dystonia or any other movement disturbance. Knowledge of the risks and benefits associated with the use of SGAs during pregnancy and lactation is limited, although the direction of dose adjustments during pregnancy depends on the drug and the enzyme that is responsible for its metabolism. In general, data on sex differences were mostly obtained by posthoc analysis and, therefore, the conclusions that can be drawn are limited. For a better understanding of the basic mechanisms of sex differences, future studies with a primary focus on this topic are required. Data that are more specific will help determine the extent to which these differences will have implications for clinical management.

K201, a multi-channel blocker, inhibits clofilium-induced torsades de pointes and attenuates an increase in repolarization

K201 (JTV519) is a 1,4-benzothiazepine derivative that exhibits a strong cardioprotective action and acts as a multiple-channel blocker, including as a K+ channel blocker. An experimental model of prolongation of the QT interval and torsades de pointes can be induced in rabbits by treatment with clofilium in the presence of the alpha1-adrenoreceptor agonist methoxamine. In this study we examined the effects of K201 with and without methoxamine on the QT and QTc intervals, and determined whether K201 inhibits clofilium-induced torsades de pointes in the presence of methoxamine (15 microg/kg/min) in rabbits (n=74). Administration of K201 (0, 40, 100, 200 and 400 microg/kg/min) with and without methoxamine prolonged the QT interval in a dose-dependent manner, and torsades de pointes did not occur in any animals. However, clofilium (50 microg/kg/min) with methoxamine induced torsades de pointes in all animals (6/6). Torsades de pointes occurred at rates of 100%, 67%, 40% and 0% at K201 concentrations of 0, 50, 200 and 400 microg/kg/min, respectively, in the clofilium-infused torsades de pointes model. Therefore, 400 microg/kg/min of K201 completely inhibited clofilium-induced torsades de pointes and attenuated the increase of repolarization caused by clofilium; the inhibitory effects of K201 may be related to its pharmacological properties as an alpha1-adrenoceptor blocker. Overall, our results show that K201 causes prolongation of the QT and QTc intervals, but does not induce torsades de pointes, with and without alpha1-adrenoceptor stimulation. Furthermore, K201 inhibits clofilium-induced torsades de pointes, despite QT prolongation, suggesting that QT prolongation alone is not a proarrhythmic signal.

Cardiovascular changes associated with venlafaxine in the treatment of late-life depression

BACKGROUND

Potential cardiovascular side effects from venlafaxine-XR must be considered when prescribing this medication, especially in geriatric patients, who often present with comorbid medical conditions.

METHODS

Participants age 60 and older with a Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition diagnosis of a major depressive episode without psychotic features were treated openly with venlafaxine-XR for 12 weeks during which venlafaxine-XR was titrated based on tolerability and response according to predefined guidelines. Sitting and standing blood pressures and heart rates were measured. A 12-lead electrocardiogram was obtained at baseline and at week 12.

RESULTS

Sixty-two participants started treatment; 59 completed at least two weeks of the 12-week study. The mean final dose of venlafaxine-XR was 195.5 mg/day (standard deviation: 72.2). Twenty-four percent (95% confidence interval [CI]: 7.3%-40.7%) of initially normotensive participants and 54% (95% CI: 34.3%-74%) of those with preexisting hypertension experienced an increase in blood pressure. Twenty-nine percent (95% CI: 14.6%-43.4%) of participants developed orthostatic hypotension. Two participants experienced a clinically significant increase in QTc interval. One participant reported new-onset mild dizziness, whereas four participants reported new-onset tachycardia or palpitation. Overall, 17 unique participants (28.8%; 95% CI: 17.3%-40.4%) experienced a new-onset cardiovascular problem, potentially related to the study medication.

CONCLUSION

Overall, venlafaxine-XR was well tolerated. However, similar to previous reports, venlafaxine-XR was associated with some undesirable cardiovascular effects in some of the participants. Systematic monitoring of cardiovascular parameters during treatment with venlafaxine-XR should be strongly recommended, especially in the elderly.

Sertindole: efficacy and safety in schizophrenia

Sertindole is an antipsychotic drug with affinity for dopamine D2, serotonin 5-HT2A and 5-HT2C, and alpha1-adrenoreceptors. Preclinical studies suggest that sertindole acts preferentially on limbic and cortical dopaminergic neurons and clinical trials have confirmed that sertindole is effective at a low dopamine D2 occupancy level. The active substance has a long half-life. Oral administration once daily yields highly stable plasma levels. These features may explain the clinically observed low frequency of extrapyramidal side effects, including tardive dyskinesia. In contrast to most antipsychotics, sertindole seems to be void of sedative effects. However, although not strictly proven by objective neuropsychological tests, this asset of sertindole does not add to the cognitive problems inherent in schizophrenia. Administration of sertindole is more often associated with prolongation of QTc compared with most other currently used antipsychotics. However, large cohort analyses do not suggest that all-cause mortality is higher with sertindole than with, for example, risperidone or olanzapine. The effective antipsychotic dose range of sertindole is 12-20 mg/day, with small variations among patients. The frequency of most adverse events, for example extrapyramidal symptoms and somnolence, with such a dose does not differ from placebo. Three side effects have been more common than with placebo/haloperidol in short-term studies: weight gain, rhinitis and a decreased ejaculation volume. Two head-to-head comparisons (one in treatment-resistant patients) of sertindole and risperidone showed equivalent effects on positive symptoms. For negative symptoms, one study obtained equivalent effects and one a superior effect of sertindole. Sertindole should not be used as first-line treatment for first-episode patients with schizophrenia because of the QTc prolongation. It has a side-effect profile that makes it an interesting alternative for many patients who do not respond well to the initial choice of antipsychotic drug.

Spontaneously reported fatal suspected adverse drug reactions: a 10-year survey from Sweden

PURPOSE

One of the main methods for monitoring the safety of marketed drugs is spontaneously reporting of suspected adverse drug reactions (ADRs). The objective of this study was to describe the pattern of spontaneously reported fatal adverse drug reactions (FADRs) by analysing data from the national spontaneous reporting system in Sweden.

METHODS

In Sweden it is compulsory to report all new or serious suspected ADRs to the Medical Products Agency. The information in these reports is stored in the national database SWEDIS (Swedish Drug Information System). All suspected FADRs reported to SWEDIS between 1 January 1995 and 31 December 2004 were reviewed and analysed.

RESULTS

During the study period 990 reports of FADRs were found. The main distribution of suspected FADRs was: haemorrhages (n = 603; 60.9%), blood and bone marrow dysfunction (n = 71; 7.2%), sudden death (n = 38; 3.8%) and pulmonary embolism (n = 30; 3.0%). Antithrombotic agents were the drugs most frequently implicated in the FADRs (n = 605; 61.1%). Vitamin K antagonists were reported in 453 cases (45.8%) and acetylsalicylic acid in 82 cases (8.3%). Among the fatalities with blood and bone marrow dysfunction methotrexate was the most frequently reported drug. For sudden death and pulmonary embolism, antipsychotics and oestrogen containing drugs, respectively, were most commonly reported.

CONCLUSIONS

Bleeding complications amounted more than half of all reports of FADRs and vitamin K antagonists were implicated in most of these reports. However, as spontaneous reporting systems are primarily set up for signalling purposes, the data must be interpreted with utmost care.

Myocardium distribution of sertindole and its metabolite dehydrosertindole in guinea-pigs

Sertindole, like other atypical antipsychotics, has been shown to increase the action potential duration and QT interval in a concentration dependent manner, in in vitro electrophysiological studies. However, this does not always translate into increased duration of the QT interval, increased risk of torsade de pointes or sudden death in clinical practice. The reasons for these apparent discrepancies are unclear and many studies have underscored the importance of the interpretation of in vitro electrophysiological data in the context of other pharmacodynamic (e.g. cardiac ion channels target, receptor affinity) and pharmacokinetic parameters (total plasma drug concentration and drug distribution). To address the possible relevance of the concentrations used in experimental studies, the myocardium distribution of sertindole and its metabolite was determined after single and repeated intraperitoneal administration to guinea-pigs. The data suggest that the plasma concentration appears to predict the concentration in the myocardium and that the myocardium concentrations of sertindole are 3.1 times higher than plasma concentrations. Using these data, the relevance of in vitro electrophysiological studies to clinical plasma concentrations has been appraised.

Linking pharmacovigilance with pharmacogenetics

The ability to identify individuals who are susceptible to adverse drug reactions (ADRs) has the potential to reduce the personal and population costs of drug-related morbidity. Some individuals may show an increased susceptibility to certain ADRs through genetic polymorphisms that alter their responses to various drugs. We wished to establish a methodology that would be acceptable to members of the general population and that would enable estimation of the risks that specific genetic factors confer on susceptibility to specific ADRs. Buccal swabs were selected as a minimally invasive method to obtain cells for DNA extraction. We wished to determine whether DNA of sufficient quantity and quality could be obtained to enable genotyping for two different polymorphic genes that code for enzymes that are widely involved in drug disposition. This article describes a small pilot study of methodology developed in the New Zealand Intensive Medicines Monitoring Programme (IMMP) to link prescription event monitoring (PEM) studies with pharmacogenetics. The methodology involves a nested case-control study design to investigate whether patients with genetic variants in P-glycoprotein (P-gp) and cytochrome P450 (CYP) 2C9 are more susceptible to psychiatric or visual disturbances following cyclo- oxygenase-2 inhibitor use (ADR signals identified in the IMMP database) than matched control patients taking the medication without experiencing any ADRs. It was concluded that the use of buccal swabs is acceptable to patients and provides DNA of sufficient quantity and quality for genotyping. Although no differences in the distribution of genotypes in the case and control populations were found in this small study, case-control studies investigating genetic risks for ADRs using drug cohorts from PEM studies are possible, and there are several areas where population-based studies of genetic risk factors for ADRs are needed. Examples are discussed where research in large populations is required urgently. These are: (i) genetic variations affecting P-gp function; (ii) variations affecting drugs metabolised by CYP2C9 and other polymorphic CYP enzymes; (iii) genetic variation in beta-adrenergic receptors and adverse outcomes from beta-adrenoceptor agonist therapy; and (iv) genetic variation in cardiac cell membrane potassium channels and their association with long QT syndromes and serious cardiac dysrhythmias. Such studies will help to identify factors that increase the risk of unwanted outcomes from drug therapy. They will also help to establish in what circumstances genotyping should be performed prior to commencing drug treatment and in tailoring drug treatment for individual patients.

Risque cardiovasculaire des antipsychotiques, une surveillance nécessaire de l’intervalle QT

Torsades de pointes (TdP), a form of ventricular arrhythmia that can cause ventricular fibrillation and sudden death, may occur during prolongation of the QT interval. QT prolongation has recently been reported with antipsychotic drugs. Physicians should be able to obtain a corrected measurement of the QT interval. QT is measured from the beginning of the QRS complex to the end of the T wave (QTm). This value must then be corrected to take heartbeat into account. The most common formula in current use is Bazett's. In practice, a QTc interval value greater than 500 ms indicates an increased risk of TdP. Safe combinations of antipsychotic drugs have been recommended by the French drug agency (Agence française de sécurité sanitaire des produits de santé). Many other drugs, including psychotropic drugs such as tricyclic antidepressants, can prolong the QT interval. Combinations of these medications with one another, with antipsychotic medications, or with other concomitant factors, such as hypokalemia, also increase the risk. TdP is most often diagnosed only after observing QT prolongation. This underlines the need to monitor QT intervals attentively to prevent the risk of cardiac arrhythmia in patients treated with antipsychotic drugs.

An increase in late sodium current potentiates the proarrhythmic activities of low-risk QT-prolonging drugs in female rabbit hearts

Assessment of the proarrhythmic risk associated with drugs that prolong the QT interval is difficult. We hypothesized that the proarrhythmic activities of drugs with very low to moderate risk of causing torsades de pointes would be well differentiated when the late sodium current (I(NaL)) was greater than normal. The effects of selected QT-prolonging drugs on electrical activity of female rabbit isolated hearts were determined in the absence and presence of sea anemone toxin (ATX-II; an enhancer of I(NaL)). I(NaL) recorded from ventricular myocytes isolated from female rabbit hearts was slightly increased by 1 and 3 nM ATX-II (n = 13, P < 0.01). ATX-II (1 nM) prolonged the duration of the monophasic action potential (MAPD(90)) the isolated heart by of 19 +/- 3% (P < 0.001, n = 31) and shifted the concentration-response relationships for cisapride (1-30 nM), ziprasidone (0.01-3 microM), quinidine (0.1-1 microM), and moxifloxacin (0.01-1 microM) to prolong MAPD to the left by 2- to 12-fold. In contrast, the increases in MAPD(90) caused by 1 nM ATX-II and pentobarbital were only additive, and the increases in MAPD(90) caused by ATX-II and ranolazine [(+/-)-N-(2,6-dimethylphenyl)-(4[2-hydroxy-3-(2-methoxyphenoxy)propyl]-1-piperazine] were less than additive. Episodes of arrhythmic activity were commonly observed, and beat-to-beat variability of action potential duration was increased, during exposure of hearts to cisapride, ziprasidone, quinidine, and moxifloxacin but not during exposure of hearts to ranolazine or pentobarbital, in the presence of ATX-II. Thus, in the female rabbit heart, ATX-II potentiated the effects of QT-prolonging drugs to increase MAPD(90) and unmasked the proarrhythmic activities of these drugs at clinically relevant drug concentrations.

Adverse Effects of Atypical Antipsychotics in the Elderly

Use of antipsychotic medication is very common in the elderly and often an essential therapy. However, successful treatment in the elderly requires appropriate multidimensional assessment of the patient, knowledge of possible multiple co-morbidities, and awareness of the complexities of polypharmacy, age-dependent changes in pharmacokinetics and pharmacodynamics, and drug-drug interactions in this age group. Antipsychotics are known to have a number of adverse effects. New antipsychotics, such as amisulpride, clozapine, olanzapine, risperidone, quetiapine, ziprasidone, zotepine and aripiprazole, may interact with both dopamine and serotonin receptors. However, compared with conventional antipsychotics, they are less likely to cause extrapyramidal symptoms and are better tolerated in the elderly. At the same time, consistent differences between atypical antipsychotics have been demonstrated. Use of clozapine, for example, is limited by the risk of agranulocytosis, whereas this is not a disadvantage of olanzapine, risperidone, quetiapine and, more recently, ziprasidone, which are being widely used with good results in schizophrenia. However, use of the latter agents to treat the behavioural and psychological symptoms of dementia has been restricted because of recent observations of increased cardiovascular events in patients taking risperidone and olanzapine treatment. Nonetheless, careful review of the literature suggests that the available evidence does not support any causal relationship between use of risperidone or olanzapine and cardiovascular events. This article focuses on some of the main adverse effects commonly reported during administration of atypical antipsychotics to elderly patients. Such effects may be partly explained by age-related changes in pharmacokinetics and pharmacodynamics, and partly by the characteristics of the drugs themselves and their different receptor binding profiles.

World Federation of Societies of Biological Psychiatry (WFSBP) guidelines for biological treatment of schizophrenia, Part 1: acute treatment of schizophrenia

These guide lines for the biological treatment of schizophrenia were developed by an international Task Force of the World Federation of Societies of Biological Psychiatry (WFSBO). The goal during the development of these guidelines was to review systematically all available evidence pertaining to the treatment of schizophrenia, and to reach a consensus on a series of practice recommendations that are clinically and scientifically meaningful based on the available evidence. These guidelines are intended for use by all physicians seeing and treating people with schizophrenia. The data used for developing these guidelines have been extracted primarily from various national treatment guidelines and panels for schizophrenia, as well as from meta-analyses, reviews and randomised clinical trials on the efficacy of pharmacological and other biological treatment interventions identified by a search of the MEDLINE database and Cochrane Library. The identified literature was evaluated with respect to the strength of evidence for its efficacy and then categorised into four levels of evidence (A-D). This first part of the guidelines covers disease definition, classification, epidemiology and course of schizophrenia, as well as the management of the acute phase treatment. These guidelines are primarily concerned with the biological treatment (including antipsychotic medication, other pharmacological treatment options, electroconvulsive therapy, adjunctive and novel therapeutic strategies) of adults suffering from schizophrenia.