Risk of venous thromboembolism due to antipsychotic drug therapy

Antipsychotics and Risks of Cardiovascular and Cerebrovascular Diseases and Mortality in Dwelling Community Older Adults

This study aims to investigate the effect of antipsychotic agents on cardiovascular and cerebrovascular diseases (CVD/CEV) and mortality risks in the older population living in a community. A cohort of 42,650 new users of antipsychotic agents was built using Quebec healthcare databases (1998-2011). The outcomes were CVD/CEV and mortality incidence in 5 years of follow-up in the total cohort, sub-cohort of patients with no schizophrenia/dementia, sub-cohort with schizophrenia, and sub-cohort with dementia. Comparisons were made between the new users who continued the treatment (adherent level ≥ 60%) vs. those ceasing treatment (adherence level < 60%) using inverse probability of treatment weighting and Cox models. Comparing high adherence vs. low levels, CVD/CEV risk was increased by 36% in the sub-cohort with schizophrenia for atypical antipsychotic users and by 25% in the sub-cohort with dementia for typical antipsychotic users. An increasing mortality risk of 2- to 3-fold was linked with the typical antipsychotic use in all cohorts except the sub-cohort with schizophrenia; in addition, mortality risk is linked with the use of high vs. low doses. Antipsychotics were not linked with CVD/CEV risk, except for atypical antipsychotics in patients with schizophrenia and typical antipsychotics in patients with dementia. The mortality risk was linked with the use of typical antipsychotics and the dose used.

Psychopharmacological Considerations for Gender-Affirming Hormone Therapy

ABSTRACT

The field of transgender health has grown exponentially since the early 2010s. While this increased visibility has not been without controversy, there is growing acknowledgement of the needs of transgender, nonbinary, and gender expansive (TNG) patients and the health disparities they experience compared to the cisgender population. There is also increased interest among clinicians and trainees in providing gender-affirming care in all medical specialties. This is particularly relevant in psychiatry as mental health disparities in TNG patients have been well-documented. TNG patients experience significant minority stress and higher rates of psychiatric illness, self-harm, suicidality, and psychiatric hospitalization compared to their cisgender peers. In this review, we will cover potential interactions and side effects relevant to psychiatric medication management for the three most common medication classes prescribed as part of gender-affirming hormone therapy (GAHT): gonadotropin-releasing hormone receptor agonists, estradiol, and testosterone. Although no studies directly examining the efficacy of psychiatric medications or their interactions with GAHT for TNG patients have been published yet, we have synthesized the existing literature from both cisgender and TNG patients to shed light on health care disparities seen in TNG patients. Since clinicians' lack of comfort and familiarity with gender-affirming care contributes significantly to these disparities, we hope this narrative review will help psychiatric prescribers provide TNG patients with the same quality of care that cisgender patients receive.

Recognition of Strokes in the ICU: A Narrative Review

Despite the remarkable progress in acute treatment for stroke, in-hospital stroke is still devastating. The mortality and neurological sequelae are worse in patients with in-hospital stroke than in those with community-onset stroke. The leading cause of this tragic situation is the delay in emergent treatment. To achieve better outcomes, early stroke recognition and immediate treatment are crucial. In general, in-hospital stroke is initially witnessed by non-neurologists, but it is sometimes challenging for non-neurologists to diagnose a patient's state as a stroke and respond quickly. Therefore, understanding the risk and characteristics of in-hospital stroke would be helpful for early recognition. First, we need to know "the epicenter of in-hospital stroke". Critically ill patients and patients who undergo surgery or procedures are admitted to the intensive care unit, and they are potentially at high risk for stroke. Moreover, since they are often sedated and intubated, evaluating their neurological status concisely is difficult. The limited evidence demonstrated that the intensive care unit is the most common place for in-hospital strokes. This paper presents a review of the literature and clarifies the causes and risks of stroke in the intensive care unit.

Antipsychotic use and Risk of Venous Thromboembolism: A Meta-Analysis

OBJECTIVE

This study aimed to evaluate the association between antipsychotic drugs (APs) and the risk of venous thromboembolism (VTE).

METHODS

We searched Pubmed, Embase, and the Cochrane Library from inception to August 15, 2019 for case-control studies and cohort studies that explored the association between APs and VTE. Two researchers independently screened the literature, extracted the data and evaluated the bias risk included in the study. Meta-analysis was carried out by using STATA 13.0.

RESULTS

1,468 studies were identified through database search, and 22 studies were finally included (14 case-control studies and 8 cohort studies). Overall, the APs usage was associated with increased risk of VTE and pulmonary embolism (PE) with no publication bias. Both the first-generation APs (FGAs) and second-generation APs (SGAs) can increased the risk of VTE. The low-potency FGAs lead to a higher risk of VTE than high-potency FGAs. The risk of PE and VTE in younger patients was about 3-fold higher compared with elderly.

CONCLUSION

This review demonstrates that APs usage can increase the risk of VTE. Young people are at a higher risk of VTE than elderly when taking APs.

Investigation of Clozapine and Olanzapine Reactive Metabolite Formation and Protein Binding by Liquid Chromatography-Tandem Mass Spectrometry

Drug-induced toxicity has, in many cases, been linked to oxidative metabolism resulting in the formation of reactive metabolites and subsequent covalent binding to biomolecules. Two structurally related antipsychotic drugs, clozapine (CLZ) and olanzapine (OLZ), are known to form similar nitrenium ion reactive metabolites. CLZ-derived reactive metabolites have been linked to agranulocytosis and hepatotoxicity. We have studied the oxidative metabolism of CLZ and OLZ as well as two known metabolites of CLZ, desmethyl-CLZ (DCLZ), and CLZ-N-oxide (CLZ-NO), using in vitro rat liver microsomal (RLM) incubations with glutathione (GSH) trapping of reactive metabolites and liquid chromatography-high resolution tandem mass spectrometry (LC-HRMS/MS). Reactive metabolite binding to selected standard peptides and recombinant purified human proteins was also evaluated. Bottom-up proteomics was performed using two complementary proteases, prefractionation of peptides followed by LC-HRMS/MS for elucidating modifications of target proteins. Induced RLM was selected to form reactive metabolites enzymatically to assess the complex profile of reactive metabolite structures and their binding potential to standard human proteins. Multiple oxidative metabolites and several different GSH adducts were found for CLZ and OLZ. Modification sites were characterized on human glutathione S-transferase (hGST) alpha 1 (OLZ-modified at Cys112), hGST mu 2 (OLZ at Cys115), and hGST pi (CLZ, DCLZ, CLZ-NO and OLZ at Cys170), human microsomal GST 1 (hMGST1, CLZ and OLZ at Cys50), and human serum albumin (hSA, CLZ at Cys34). Furthermore, two modified rat proteins, microsomal GST 1 (CLZ and OLZ at Cys50) and one CYP (OLZ-modified, multiple possible isoforms), from RLM background were also characterized. In addition, direct effects of the reactive metabolite modifications on proteins were observed, including differences in protease cleavage specificity, chromatographic behavior, and charge-state distributions.

Second-generation antipsychotic drugs and short-term somatic serious adverse events: a systematic review and meta-analysis

BACKGROUND

Antipsychotic drugs might cause acutely occurring, serious side-effects and thus contribute to the increased physical morbidity and mortality observed in patients with severe mental health disorders. We examined this hypothesis by doing a meta-analysis of International Conference on Harmonisation-Good Clinical Practice-defined serious adverse events occurring in placebo-controlled trials of antipsychotics.

METHODS

For this systematic review and meta-analysis, we included randomised controlled trials (RCTs) comparing second-generation antipsychotics with placebo. We searched MEDLINE, Embase, Cochrane CENTRAL, BIOSIS, PsycINFO, PubMed, ClinicalTrials.gov, and WHO International Clinical Trials Registry Platform for trials published in any language from database inception up until Jan 27, 2017. Trials were included without limitations in population (diagnostic category, age, sex, ethnicity), dosing regimen, blinding status, duration, or publication year. Only psychological studies lasting less than 1 day and trials done in mainland China were excluded. We contacted pharmaceutical companies, drug regulatory authorities, and study investigators for additional data. The primary outcome was the number of patients with at least one somatic serious adverse event. We estimated minimum and maximum numbers of patients with the outcome in each study group and synthesised the results with odds ratios (ORs) in a common-effects meta-analysis. This study is registered with PROSPERO, number CRD42016033930.

FINDINGS

We identified 597 RCTs, comprising 108 664 participants, that met the inclusion criteria. 314 trials (67 642 participants) with details on individual serious adverse events available constituted the main dataset for meta-analysis. 88% of these were 13 weeks (approximately 3 months) or shorter in duration (median 6 weeks, IQR 4-9). At least one somatic serious adverse event occurred in 698 (1·63%) to 862 (2·02%) of 42 600 patients on antipsychotics, and in 343 (1·37%) to 419 (1·67%) of 25 042 patients on placebo. The odds ratios (ORs) were 1·24 (95% CI 1·08-1·42) and 1·24 (1·10-1·41) based on the minimum and maximum estimate, respectively. In predefined subgroup analyses we found evidence suggesting a larger effect in older patients (>65 years; OR 1·56, 95% CI 1·22-1·98; 1·58, 1·25-1·99) as compared with adults (18-65 years; 1·09, 0·91-1·29; 1·10, 0·95-1·28); likewise in children or adolescents (<18 years) although the evidence was more uncertain (1·49, 0·81-2·75; 1·54, 0·85-2·77). Of 597 included RCTs, 30 (5%), 358 (60%), and 209 (35%) were rated at high, moderate, or low risk of bias, respectively. τ² was zero for both analyses of the primary outcome (minimum estimate, maximum estimate). A Bayesian sensitivity analysis using external information on heterogeneity gave similar results.

INTERPRETATION

We found evidence that antipsychotics cause short-term somatic serious adverse events on top of somatic serious adverse events occurring independent of treatment. This effect appears to be mainly driven by results in older patients. Hence, clinicians should be aware that antipsychotics are potentially toxic, particularly when treating patients sharing risk factors with the older population.

FUNDING

German Ministry of Education and Research.

Antipsychotic drug use and risk of stroke and myocardial infarction: a systematic review and meta-analysis

BACKGROUND

The effect of antipsychotic (AP) drugs on risk of stroke and myocardial infarction (MI) remains unclear due to methodological limitations of, and inconsistencies across, existing studies. We aimed to systematically review studies reporting on the associations between AP drug use and stroke or MI risk, and to investigate whether associations differed among different sub-populations.

METHODS

We searched Medline, EMBASE, PsychINFO and Cochrane Library (from inception to May 28, 2017) for observational studies reporting on AP drug use and MI or stroke occurrence. We performed random-effects meta-analyses for each outcome, performing sub-groups analyses by study population - specifically general population (i.e. those not restricted to patients with a particular indication for AP drug use), people with dementia only and psychiatric illness only. Where feasible we performed subgroup analyses by AP drug class.

RESULTS

From 7008 articles, we included 29 relevant observational studies, 19 on stroke and 10 on MI. Results of cohort studies that included a general population indicated a more than two-fold increased risk of stroke, albeit with substantial heterogeneity (pooled HR 2.31, 95% CI 1.13, 4.74, I² = 83.2%). However, the risk among patients with dementia was much lower, with no heterogeneity (pooled HR 1.16, 95% CI 1.00, 1.33, I² = 0%) and there was no clear association among studies of psychiatric populations (pooled HR 1.44, 95% CI 0.90, 2.30; substantial heterogeneity [I² = 78.8])). Associations generally persisted when stratifying by AP class, but few studies reported on first generation AP drugs. We found no association between AP drug use and MI risk (pooled HR for cohort studies: 1.29, 95% CI 0.88, 1.90 and case-control studies: 1.07, 95% CI 0.94, 1.23), but substantial methodological and statistical heterogeneity among a relatively small number of studies limits firm conclusions.

CONCLUSIONS

AP drug use may be associated with an increased risk of stroke, but there is no clear evidence that this risk is further elevated in patients with dementia. Further studies are need to clarify the effect of AP drug use on MI and stroke risk in different sub-populations and should control for confounding by indication and stratify by AP drug class.

Excited catatonia in a patient with fatal pulmonary embolism and a successful treatment strategy

BACKGROUND

Patients with psychiatric disorders in critical condition are difficult to treat. In this study, we report on a patient with underlying schizoaffective disorder who developed catatonia, cardiac arrest, and pulmonary embolism, as well as a successful treatment strategy.

CASE PRESENTATION

The inpatient is a 41-year-old morbidly obese male with schizoaffective disorder whose clozapine dosage was titrated from 100 mg to 175 mg due to auditory hallucination and agitation. The patient abruptly developed acute cardiopulmonary symptoms associated with an elevated troponin-I level. He was transferred to a cardiac intensive care unit, where he remained for 3 days. He was also found to have excited catatonic symptoms, and the lorazepam-diazepam protocol was initiated to quickly relieve the catatonia. Once the coronary angiogram was read as normal, the patient was transferred back to the psychiatric ward. However, the patient then suffered from in-hospital cardiac arrest. He was resuscitated and again transferred to the medical intensive care unit. Computed tomography confirmed the diagnosis of a pulmonary embolism. The patient was treated with Rivaroxaban 30 mg/d for the first 21 days, followed by 20 mg daily for 3 months. To control his severe and refractory psychotic symptoms, the patient was re-prescribed clozapine. During the 15-month follow-up period, the patient demonstrated a fair response and tolerability to clozapine 150 mg without symptoms relapse and no thromboembolic event.

CONCLUSION

This report can serve to remind psychiatrists and physicians to be aware of fatal conditions in patients with psychiatric diseases and physical illnesses.

Antipsychotic drugs and the risk of recurrent venous thromboembolism: A prospective cohort study

BACKGROUND

Numerous studies have suggested that antipsychotic drugs are associated with an increased risk for a first episode of venous thromboembolism (VTE). However, after anticoagulation discontinuation, the impact of antipsychotic drugs on the risk of recurrent VTE (rVTE) remains unknown.

OBJECTIVE

To estimate the risk of rVTE in association with antipsychotic drugs.

METHODS

Between May 2000 and December 2012, we included all consecutive patients with a first unprovoked symptomatic VTE and who discontinued anticoagulation. During follow-up, exposure to antipsychotic drugs was systematically assessed.

RESULTS

A total of 736 patients with a first unprovoked symptomatic VTE were followed-up during a median period of 27.0 months (interquartile range (IQR) 6.2-60.0). Patients' median age was 66.0 years (IQR 49.0-76.0), 404 (54.9%) were men, and 61 (8.3%) were exposed to antipsychotics during follow-up. The incidence rate of r VTE was 12.1% person-year (95% CI 7.2-20.5) in antipsychotics users compared with 8.3% person-year (95% CI 7.1-9.8) in non-users (p = 0.20). Multivariate analysis showed a significant increased risk of recurrence associated with antipsychotic exposure (adjusted hazard ratio 1.9, 95% CI 1.1-3.3).

CONCLUSIONS

In this cohort study, exposure to antipsychotic drugs was found to be associated with an increased risk of rVTE among patients with a previous first unprovoked symptomatic VTE and who discontinued anticoagulation. Larger studies are needed to confirm and further explore this association.

Venous thromboembolism following initiation of atypical antipsychotics in two geriatric patients

Background

Although not formally highlighted as a risk factor in current practice guidelines, several observational studies have reported a possible association between antipsychotic use and development of venous thromboembolism (VTE). However, it is unclear to what extent the risk is elevated.

Case Report

Described are 2 cases of VTE following recent initiation of second-generation antipsychotics in elderly patients. Ms A was a 65-year-old woman with newly diagnosed bipolar I disorder who was hospitalized for acute mania and psychosis. She was treated with risperidone along with traditional mood stabilizers and developed a pulmonary embolism shortly after treatment initiation. Ms B was a 77-year-old woman with newly diagnosed bipolar I disorder who was hospitalized for depression and psychosis. She was treated with quetiapine and electroconvulsive therapy and developed a pulmonary embolism and deep vein thrombosis within 2 months of starting treatment. Risk assessment tools were not able to definitively predict the VTEs that developed in our patients.

Conclusion

The association between antipsychotic medication and VTE has shown the highest risk with atypical antipsychotics, high dosages, and initiation within the past 3 months. Risk assessment tools may assist in assessing the risk of VTE in patients on antipsychotic therapy, although patients who are deemed by these tools to have minimal risk can still develop a VTE. Discussing VTE risk with patients when considering antipsychotic usage may help clinicians and patients safely determine the most appropriate treatment for their psychiatric illnesses while mitigating potential adverse effects.

Venous Thromboembolism During Treatment with Antipsychotics: A Review of Current Evidence

This article summarises the current evidence on the risk of venous thromboembolism (VTE) with the use of antipsychotics. An increasing number of observational studies indicate an elevated risk of VTE in antipsychotic drug users. Although the use of certain antipsychotics has been associated with VTE, current data can neither conclusively verify differences in occurrence rates of VTE between first- and second-generation antipsychotics or between individual compounds, nor identify which antipsychotic drugs have the lowest risk of VTE. The biological mechanisms involved in the pathogenesis of this adverse drug reaction are still to be clarified but hypotheses such as drug-induced sedation, obesity, increased levels of antiphospholipid antibodies, enhanced platelet aggregation, hyperhomocysteinaemia and hyperprolactinaemia have been suggested. Risk factors associated with the underlying psychiatric disorder may at least partly explain the increased risk. Physicians should be aware of this potentially serious and even sometimes fatal adverse drug reaction and should consider discontinuing or switching the antipsychotic treatment in patients experiencing a VTE. Even though supporting evidence is limited, prophylactic antithrombotic treatment should be considered in risk situations for VTE.

The impact of antipsychotics as a risk factor for thromboembolism

Patients with schizophrenia are predisposed toward developing cardiovascular disease. Although neuroleptics affect the cardiovascular system, it is also important to consider the consequences of the disease itself such as lower physical activity due to living on disability pension, inadequate nutrition, and/or nicotine addiction, being more common among patients with schizophrenia versus the general population. All these factors combined lead to an increased risk of death caused by cardiovascular conditions in schizophrenic patients. Individuals receiving typical antipsychotic drugs have been reported to have elevated concentrations of antiphospholipid antibodies, including anticoagulants and anticardiolipin antibodies. The presence of both antibodies is associated with an increased risk for thromboembolism. It is also likely that mental illness is accompanied by increased procoagulant activity. Patients with acute psychosis have been shown to have a statistically significant increase in the concentrations of D-dimer, P-selectin, and in the expression of platelet glycoprotein IIb/IIIa receptors. Learning about causes and mechanisms of venous thromboembolism could help to reduce or neutralize the adverse effects of antipsychotic treatment and facilitate the identification of appropriate markers necessary to monitor changes and provide preventive care against hazardous and potentially fatal complications such as deep venous thrombosis and pulmonary embolism. Before atypical neuroleptic treatment is administered to hospitalized patients, all possible risk factors for thromboembolism should be considered to allow the application of lower risk drugs. Also, other preventive measures should be taken into account, including hydration, compression stockings, regular exercise of lower extremities, and low-molecular-weight heparin injections.

Platelet haemostatic function in psychiatric disorders: Effects of antidepressants and antipsychotic drugs

Objectives Platelets, the smallest anucleated blood cells, play an essential role in the first step of complex haemostatic process. This review presents the haemostatic function of blood platelets related to their activation in psychiatric disorders (schizophrenia, depression), the role of antipsychotic and antidepressant medication, and introduces the mechanisms by which activated platelets may be involved in the pathophysiology of these disorders. Methods Platelets are interesting and easily accessible blood cells to study biochemical pathways related to schizophrenia and other psychiatric disorders, and their complex activation process might be useful as a diagnostic peripheral marker for studying psychiatric disorders and haemostatic complications. Results The excessive activation of platelets observed in patients with depression and schizophrenia is involved in cardiovascular diseases, stroke and increased risk of thrombotic complications that may be major causes of morbidity and mortality of patients. The use of antidepressants or antipsychotic drugs in depression and schizophrenia treatment is often associated with haematological side effects such as bleeding, venous thromboembolism and impaired platelet function. Conclusions Understanding the role of platelet activation in psychiatric disorders such as schizophrenia or depression and medication may improve therapies in the future.

Antipsychotic Use Among Adult Outpatients and Venous Thromboembolic Disease: A Retrospective Cohort Study

BACKGROUND

Treatment with antipsychotic (AP) agents is associated with incident thromboembolic events. However, the underpinnings of this association remain unknown. We sought to evaluate the effect of AP agents-categorized by their metabolic/sedative and hyperprolactinemia adverse effect profile-on the risk of venous thromboembolic disease during long-term follow-up.

METHODS

A retrospective cohort study of adult patients initiating AP treatment for the first time was conducted. Primary outcome was defined as the time to venous thromboembolism (VTE) (either deep venous thrombosis or acute pulmonary embolism). Antipsychotic agents were categorized by their risk (high vs low) of either drug-induced (a) sedation/metabolic adverse event or (b) hyperprolactinemia. We used a propensity score-adjusted Cox proportional hazards model to control for confounding.

FINDINGS

One thousand eight patients (mean age, 72.4 y) were followed for a median of 36 months. Incident VTE occurred in 6.25% of patients, corresponding to an incidence rate of 184 cases per 10,000 person-years. We found no difference in the hazard of VTE during follow-up between high- and low-risk groups (hazard ratio, 1.23 [95% confidence interval, 0.74-2.04] for drug-induced sedation/metabolic adverse event risk categories, and hazard ratio 0.81 [95% confidence interval, 0.50-1.35] for high versus low hyperprolactinemia risk).

CONCLUSIONS

These results suggest that the risk of thromboembolic events in older adults who started AP treatment for the first time does not seem to be related to these drugs' risk of either sedation/metabolic adverse events or hyperprolactinemia. However, VTE remains a common problem in this subgroup of patients.

Venous Thromboembolism Following Dantrolene Treatment for Neuroleptic Malignant Syndrome

Neuroleptic malignant syndrome (NMS) is one of the most severe iatrogenic emergencies in clinical service. The symptoms including sudden consciousness change, critical temperature elevation and electrolytes imbalance followed by mutli-organ system failure were common in NMS. In addition to aggressive interventions with intravenous fluid resuscitation and antipyretics, several antidotes have been suggested to prevent further progression of the muscle damage. Dantrolene has been reported to be one of the most effective treatments for NMS. However, the adverse effects of dantrolene treatment for NMS have not yet been evaluated thoroughly. Here we report a young male patient with bipolar I disorder who developed NMS after rapid tranquilization with haloperidol. Dantrolene was given intravenously for the treatment of NMS. However, fever accompanied with local tenderness, hardness with clear border and swelling with heat over the patient’s left forearm occurred on the sixth day of dantrolene treatment. Venous thromboembolism (VTE) over intravenous indwelling site at the patient’s forearm was noted and confirmed by Doppler ultrasound. The patient’s VTE recovered after heparin and warfarin thrombolytic therapy. To our knowledge, this is the first case report demonstrating the possible relationship between dantrolene use and VTE in a patient with antipsychotic treatment. Although the causal relationship and the underlying pathogenesis require further studies, dantrolene should be used with caution for patients with NMS.

Drug-Induced Thrombophilic or Prothrombotic States: An Underestimated Clinical Problem That Involves Both Legal and Illegal Compounds

Vascular thrombosis, both arterial and venous, is a condition associated with significant morbidity and mortality. There are multiple risk factors for thrombosis, both congenital and acquired, and in the majority of cases, these risk factors are not modifiable. Over the past 2 decades, multiple drugs (both illegal and legal) have been associated with increased risk of thrombosis. However, due to limited scientific literature regarding the prothrombotic tendencies of these drugs, there is a concomitant limited understanding of the pathophysiology of drug-induced thrombosis. As drugs are one of the few modifiable risk factors for thrombosis, further study and dissemination of knowledge regarding drug-associated and drug-induced thrombosis are essential and have the potential to lead to decreased future incidence of thrombosis. The mechanisms at the basis of the thrombophilic activity of these drugs are variable and sometimes still ill recognized. Increased levels of clotting factors, reduction in coagulation natural inhibitors, decreased fibrinolysis, activated clotting factors, increased blood viscosity, endothelial damage, and increased platelet number and activation are the most frequent causes. Arterial steal or coronary arteries no flow has also been implicated. In some cases due to the intake of several drugs, more than one mechanism is present in a given patient. The purpose of the present review is to analyze all the drugs demonstrated to be potentially thrombotic. It is hoped that a prudent use or nonuse of these drugs might result in a reduction of thrombosis-associated diseases.

Antipsychotic drug exposure and risk of pulmonary embolism: a population-based, nested case-control study

BACKGROUND

Only three observational studies investigated whether exposure to antipsychotics is associated with an increased risk of pulmonary embolism, with conflicting results. This study was therefore carried out to establish the risk of pulmonary embolism associated with antipsychotic drugs, and to ascertain the risk associated with first- and second-generation antipsychotic drugs, and with exposure to individual drugs.

METHODS

We identified 84,253 adult individuals who began antipsychotic treatment in a large Italian health care system. Cases were all cohort members who were hospitalized for non-fatal or fatal pulmonary embolism during follow-up. Up to 20 controls for each case were extracted from the study cohort using incidence density sampling and matched by age at cohort entry and gender. Each individual was classified as current, recent or past antipsychotic user. The occurrence non-fatal or fatal pulmonary embolism was the outcome of interest.

RESULTS

Compared to past use, current antipsychotic use more than double the risk of pulmonary embolism (odds ratio 2.31, 95% confidence interval 1.16 to 4.59), while recent use did not increase the risk. Both conventional and atypical antipsychotic exposure was associated with an increase in risk, and the concomitant use of both classes increased the risk of four times (odds ratio 4.21, 95% confidence interval 1.53 to 11.59).

CONCLUSIONS

Adding the results of this case-control study to a recent meta-analysis of three observational studies substantially changed the overall estimate, which now indicates that antipsychotic exposure significantly increases the risk of pulmonary embolism.

Venous thromboembolism prophylaxis in mental healthcare: do the benefits outweigh the risks?

Venous thromboembolism is an important cause of morbidity and mortality. In recent years, growing awareness has led to the development of strategies to prevent venous thromboembolism in individuals admitted to hospital who are deemed to be at high risk. However, there remains a considerable degree of uncertainty over whether these strategies are of overall benefit and there are few published studies on people who are admitted to psychiatric hospitals. In this editorial I review current clinical practice and areas of uncertainty with respect to venous thromboembolism prophylaxis and its implementation in mental healthcare settings.

Global hypercoagulability in patients with schizophrenia receiving long-term antipsychotic therapy

BACKGROUND

Patients with schizophrenia are at increased risk of venous thromboembolism. The mechanisms underlying this association are poorly understood.

AIMS

We investigated whether there is a global hypercoagulable state in patients with schizophrenia utilising the overall haemostatic potential (OHP) assay which assesses overall coagulation potential (OCP), haemostatic potential (OHP) and fibrinolytic potential (OFP).

METHOD

Citrated plasma was collected for OHP assays from patients with schizophrenia on long-term antipsychotic treatment and compared with healthy age- and sex-matched controls. Time courses of fibrin formation and degradation were measured by spectrophotometry (absorption of 405nm) after the addition of tissue factor and tissue plasminogen activator to plasma.

RESULTS

Ninety patients with schizophrenia (antipsychotic treatment-15.9±9.7years) and 30 controls were recruited. Patients with schizophrenia had higher rates of smoking and levels of inflammatory markers (high-sensitivity C-reactive protein and neutrophil-to-lymphocyte ratio) than controls. Whilst D-dimer, fibrinogen and platelet count did not differ between patients with schizophrenia and controls, the OCP (54.0±12.6 vs 45.9±9.1, p=0.002) and OHP (12.6±5.8 vs 7.2±3.7, p<0.001) were higher, and OFP was lower (76.6±9.8% vs 84.9±6.4%, p<0.001) in patients with schizophrenia, implying both a hypercoagulable and hypofibrinolytic state in these patients. Importantly, abnormalities in overall coagulation were independently predicted by levels of plasminogen-activator-inhibitor-1, fibrinogen, platelet count, inflammatory markers and plasma triglycerides, suggesting a multifactorial aetiology.

CONCLUSION

Patients with schizophrenia have evidence of a global hypercoagulable and hypofibrinolytic state which may contribute to their increased risk of venous thromboembolism.

Clozapine-Induced Late Agranulocytosis and Severe Neutropenia Complicated with Streptococcus pneumonia, Venous Thromboembolism, and Allergic Vasculitis in Treatment-Resistant Female Psychosis

Clozapine is a second-generation antipsychotic agent from the benzodiazepine group indicated for treatment-resistant schizophrenia and other psychotic conditions. Using clozapine earlier on once a case appears to be refractory limits both social and personal morbidity of chronic psychosis. However treatment with second-generation antipsychotics is often complicated by adverse effects. We present a case of a 33-year-old Caucasian woman with a 25-year history of refractory psychotic mania after switching to a 2-year clozapine therapy. She presented clozapine-induced absolute neutropenia, agranulocytosis, which were complicated by Streptococcus pneumonia and sepsis. Clozapine-induced thromboembolism of the common femoral and right proximal iliac vein, as well as allergic vasculitis, was diagnosed. She achieved full remission on granulocyte-colony stimulating factor and specific antibiotic treatment. Early detection of severe clozapine-induced absolute neutropenia and agranulocytosis enabled the effective treatment of two among its most severe complications. Additional evidence to the previously reported possible causal relation between clozapine and venous thromboembolism is offered. Finally, clozapine-induced allergic vasculitis is confirmed as a late adverse effect of clozapine therapy.

Rare and very rare adverse effects of clozapine

Clozapine (CLZ) is the drug of choice for the treatment of resistant schizophrenia; however, its suitable use is limited by the complex adverse effects' profile. The best-described adverse effects in the literature are represented by agranulocytosis, myocarditis, sedation, weight gain, hypotension, and drooling; nevertheless, there are other known adverse effects that psychiatrists should readily recognize and manage. This review covers the "rare" and "very rare" known adverse effects of CLZ, which have been accurately described in literature. An extensive search on the basis of predefined criteria was made using CLZ and its combination with adverse effects as keywords in electronic databases. Data show the association between the use of CLZ and uncommon adverse effects, including ischemic colitis, paralytic ileus, hematemesis, gastroesophageal reflux disease, priapism, urinary incontinence, pityriasis rosea, intertriginous erythema, pulmonary thromboembolism, pseudo-pheochromocytoma, periorbital edema, and parotitis, which are influenced by other variables including age, early diagnosis, and previous/current pharmacological therapies. Some of these adverse effects, although unpredictable, are often manageable if promptly recognized and treated. Others are serious and potentially life-threatening. However, an adequate knowledge of the drug, clinical vigilance, and rapid intervention can drastically reduce the morbidity and mortality related to CLZ treatment.

Transcriptome alterations of mitochondrial and coagulation function in schizophrenia by cortical sequencing analysis

Background

Transcriptome sequencing of brain samples provides detailed enrichment analysis of differential expression and genetic interactions for evaluation of mitochondrial and coagulation function of schizophrenia. It is implicated that schizophrenia genetic and protein interactions may give rise to biological dysfunction of energy metabolism and hemostasis. These findings may explain the biological mechanisms responsible for negative and withdraw symptoms of schizophrenia and antipsychotic-induced venous thromboembolism.

We conducted a comparison of schizophrenic candidate genes from literature reviews and constructed the schizophrenia-mediator network (SCZMN) which consists of schizophrenic candidate genes and associated mediator genes by applying differential expression analysis to BA22 RNA-Seq brain data. The network was searched against pathway databases such as PID, Reactome, HumanCyc, and Cell-Map. The candidate complexes were identified by MCL clustering using CORUM for potential pathogenesis of schizophrenia.

Results

Published BA22 RNA-Seq brain data of 9 schizophrenic patients and 9 controls samples were analyzed. The differentially expressed genes in the BA22 brain samples of schizophrenia are proposed as schizophrenia candidate marker genes (SCZCGs). The genetic interactions between mitochondrial genes and many under-expressed SCZCGs indicate the genetic predisposition of mitochondria dysfunction in schizophrenia. The biological functions of SCZCGs, as listed in the Pathway Interaction Database (PID), indicate that these genes have roles in DNA binding transcription factor, signal and cancer-related pathways, coagulation and cell cycle regulation and differentiation pathways.

In the query-query protein-protein interaction (QQPPI) network of SCZCGs, TP53, PRKACA, STAT3 and SP1 were identified as the central "hub" genes. Mitochondrial function was modulated by dopamine inhibition of respiratory complex I activity. The genetic interaction between mitochondria function and schizophrenia may be revealed by DRD2 linked to NDUFS7 through protein-protein interactions of FLNA and ARRB2.

The biological mechanism of signaling pathway of coagulation cascade was illustrated by the PPI network of the SCZCGs and the coagulation-associated genes. The relationship between antipsychotic target genes (DRD2/3 and HTR2A) and coagulation factor genes (F3, F7 and F10) appeared to cascade the following hemostatic process implicating the bottleneck of coagulation genetic network by the bridging of actin-binding protein (FLNA).

Conclusions

It is implicated that the energy metabolism and hemostatic process have important roles in the pathogenesis for schizophrenia. The cross-talk of genetic interaction by these co-expressed genes and reached candidate genes may address the key network in disease pathology. The accuracy of candidate genes evaluated from different quantification tools could be improved by crosstalk analysis of overlapping genes in genetic networks.

Antipsychotic drug exposure and risk of venous thromboembolism: a systematic review and meta-analysis of observational studies

BACKGROUND

Venous thromboembolism (VTE) is a serious disorder that may be complicated by pulmonary embolism (PE). Case reports and observational studies published in the early 1950s suggested that antipsychotic (AP) drugs may represent a risk factor, while observational studies conducted in the last 3 decades have provided conflicting results.

OBJECTIVE

The aim was to investigate whether AP drugs increase the risk of VTE and PE, and to ascertain the risk associated with first- and second-generation AP drugs and with exposure to individual drugs.

DATA SOURCE

Relevant studies were located by searching MEDLINE, PubMed, EMBASE, PsychINFO, CINAHL and Scopus up to March 2013. Reference lists of relevant papers and previous review articles were hand searched for other relevant studies.

STUDY SELECTION

Based on the titles and abstracts of 1,386 citations, we identified 30 potentially relevant studies. Of these, 17 studies were eligible for inclusion and were included in the meta-analysis.

MAIN OUTCOMES AND MEASURES

The primary outcome measure of this meta-analysis was the occurrence of VTE or PE in individuals exposed to AP drugs in comparison with individuals unexposed or with past exposure to AP drugs.

RESULTS

Antipsychotic exposure was associated with a significant increase in risk of developing VTE [odds ratio (OR) 1.54, 95% confidence interval (CI) 1.28-1.86, 11 studies]. Exposure to APs did not significantly increase the risk of PE (OR 4.90, 95% CI 0.77-30.98, three studies), but the overall estimate was highly heterogeneous and the CI included the possibility of substantial harm. Random-effects meta-analysis on the risk of VTE associated with exposure to first- (OR 1.74, 95% CI 1.28-2.37, six studies) and second-generation (OR 2.07, 95% CI 1.74-2.52, five studies) APs revealed an increased risk. Only a few studies provided data on individual drugs, and estimates of effect were very uncertain.

CONCLUSIONS

Antipsychotic exposure in unselected patient populations may be associated with a 50% increase in the risk of developing VTE. However, between-study heterogeneity limits the confidence in this estimate. This increased risk similarly applies to first- and second-generation AP drugs.

Antipsychotic drug use and the risk of venous thromboembolism in elderly patients with dementia

The aim of this study was to investigate the association between the use of antipsychotics and the risk of venous thromboembolism (VTE) in elderly patients with dementia. Based on data from the German Pharmacoepidemiological Research Database, a nested case-control study was conducted within a cohort of 72,591 patients with dementia aged at least 65 years at cohort entry. Cases were patients with a hospitalization due to VTE. Up to 4 controls were matched to each case according to age, sex, health insurance, and calendar time of the VTE. Users of antipsychotics were classified into current or former users, and in addition, all current users were categorized as prevalent or new users. For a further analysis, we distinguished between users of either conventional or atypical antipsychotics or concurrent users of both conventional and atypical antipsychotics. Multivariate conditional logistic regression was applied to calculate odds ratios (ORs) of VTE for all user groups compared with nonusers. The case-control data set comprised 1028 VTE cases and 4109 controls. An increased risk of VTE was found for current users (OR, 1.23; 95% confidence interval [CI], 1.01-1.50) and for users of a combination of atypical and conventional antipsychotics (OR, 1.62; 95% CI, 1.15-2.27). In current users, only new use was associated with an increased risk (OR, 1.63; 95% CI, 1.10-2.40). Increased attention to clinical signs of VTE should be paid during the first 3 months of treatment with antipsychotics and in patients receiving both conventional and atypical agents, especially if other risk factors for VTE exist.

Morbidity and mortality associated with the utilization of restraints : a review of literature

Use of physical restraints remains a highly controversial topic. Even with proven efficacy in restraint usage across multiple settings, for years, investigators have debated whether or not the risks outweigh the benefits. There is a growing concern regarding restraints-related negative consequences. Although over the past two decades, with new regulations, education and training, there has been a reduction in the prevalence of restraint episodes, morbidity and mortality are still disconcerting. Given this subject remains an issue today, a more up-to-date review of available literature is warranted. This article reviews the current literature surrounding the utilization of restraints that has been published over last 10 years with particular emphasis on restraints-related adverse outcomes. The vast amount of literature during the past decade demonstrates an increased awareness in potential dangers, as well as highlights new areas of research in restraint utilization. Despite the proliferation of studies, there continues to remain a lack of evidence from prospective studies that would elucidate the dangers from theory to practice.

Risk factors for venous thromboembolism during pregnancy

BACKGROUND

Pregnant women are at an increased risk of venous thromboembolism (VTE). Risk factors for VTE among pregnant women are not sufficiently investigated.

PURPOSE

To examine pharmacological and non-pharmacological VTE risk factors during pregnancy (antepartum).

METHODS

The population comprised all pregnant women in Denmark aged 15-50 giving birth 2003-2010. Pregnancies were linked on an individual level with national registers for hospital admissions and drug dispenses from pharmacies. Risk of first occurring VTE antepartum was examined with Cox regression models.

RESULTS

Out of 299 810 pregnancies, 337 experienced a VTE, incidence rate 1.1 (95% confidence interval [CI] 1.0-1.3) per 1000 pregnancies. Being underweight (body mass index [BMI] < 18.5 kg/m(2) ) was associated with a decreased risk of VTE (hazard ratio [HR] 0.53 [CI 0.29-0.98]) compared to normal weight (18.5 ≤ BMI < 25 kg/m(2) ). Overweight (25 ≤ BMI < 30 kg/m(2) ) increased VTE risk (HR 1.30 [CI 1.01-1.67]) but obesity (BMI ≥ 30 kg/m(2) ) was insignificant (HR 1.14 [CI 0.82-1.58]). A history of VTE was highly significant (HR 72.65 [CI 51.17-103.15]). The youngest (<20 years) and oldest (≥35 years) had insignificantly increased risks (HR 1.45 [CI 0.80-2.62] and HR 1.31 [CI 0.98-1.75], respectively) compared to those aged 20-30 years. Sixteen groups of medications, including anti-infectious medications, hormones, aminosalicylic acid, insulin, and benzodiazepine derivatives, were associated with VTE.

CONCLUSION

The risk of antepartum VTE was increased in women with prior VTE. Compared to normal weight women, being underweight decreased the risk of VTE whereas being overweight increased the risk. Also, the use of several medications was associated with increased risk of VTE.

Venous thromboembolism in psychogeriatric in-patients--a study of risk assessment, incidence, and current prophylaxis prescribing

BACKGROUND

While venous thromboembolism (VTE) risk assessment and prophylaxis is well established for medical and surgical in-patients, there is a paucity of evidence, and therefore guidelines, in this area for psychogeriatric in-patients. We wished to determine VTE incidence, risk, and use of prophylaxis, in a psychogeriatric in-patient population.

METHODS

Retrospective audit of consecutive psychogeriatric patients aged 65 years and over admitted to Bankstown Hospital over a 3-year period, 2007-2009. Using an adapted VTE risk scoring system, patients were assigned as low, medium, or high VTE risk.

RESULTS

A total of 192 patients were included in the study. Mean age was 79.1 ± 7.0 years. Out of the total, 55.2% of patients had diagnosis of dementia, and 33.3% had depression. Overall, 81.8% (157/192) were assessed as low risk, and 18.2% (35/192) as medium risk. Also, 16.7% (32/192) received VTE prophylaxis. Four new VTE events occurred in medium-risk group, and one in low-risk group (p = 0.004). Overall VTE incidence was 10.5/10,000 patient-days, but 44.2 per 10,000 in medium-risk group. VTE risk score was predictive of VTE events - IRR 6.02 (95% Confidence Intervals (CI) = 1.76-20.7, p = 0.004) for every one-point increment in risk. Depression was associated with significantly higher VTE occurrence (6.3% in those with diagnosis vs. 0.8% without, p = 0.043).

CONCLUSION

Using a VTE risk scoring system adapted for psychogeriatric in-patients, those assessed to be at medium risk had a significantly increased rate of VTE. On this basis, we would recommend VTE prophylaxis be prescribed for psychogeriatric in-patients assessed to be at medium and high level of risk.

Antipsychotic drugs and venous thromboembolism

Since preliminary case reports suggesting a possible association between first generation of antipsychotics and venous thromboembolism (VTE), consistent epidemiological data is now available suggesting a moderate association between antipsychotics and VTE. However, despite several hypotheses, the underlying mechanisms remain unknown or uncertain. In addition, if the association between antipsychotics and VTE is plausible, the intensity of this risk and the dose effect relationship do not have yet been determined. Prospective data is therefore needed in order to confirm and to quantify this association. Because of the level of uncertainty, the clinical impact on the prevention and the treatment of VTE in patients with a psychiatric illness appears to be low.

Pulmonary embolism related to amisulpride treatment: a case report

Venous thromboembolism has been associated with antipsychotic drugs, but the underlying mechanisms are largely unknown. Hypotheses that have been made include body weight gain, sedation, enhanced platelet aggregation, increased levels of antiphospholipid antibodies, hyperhomocysteinemia, whereas hyperprolactinemia has recently attracted attention as a potential contributing factor. The highest risk has been demonstrated for clozapine, olanzapine, and low-potency first-generation antipsychotics; however, presently there is no data for amisulpride. In the present paper we describe a case of pulmonary embolism in a female bipolar patient, receiving treatment with amisulpride, aripiprazole, and paroxetine. Although a contribution of aripiprazole and paroxetine cannot completely be ruled out, the most probable factor underlying the thromboembolic event seems to be hyperprolactinemia, which was caused by amisulpride treatment. Increased plasma levels of prolactin should probably be taken into account during the monitoring of antipsychotic treatment as well as in future research concerning venous thromboembolism in psychiatric settings.

Review of thromboembolic prophylaxis in patients attending Cork University Hospital

BACKGROUND

Although preventable, venous thromboembolism remains a common cause of hospital acquired morbidity and mortality. Guidelines, such as the one produced by the American College of Chest Physicians (ACCP), are aimed at reducing hospital associated venous thromboemboli. Unfortunately the majority of studies have revealed inadequate adherence to these guidelines.

OBJECTIVE

The objective of this study was to evaluate the use of venous thromboembolism prophylaxis at Cork University Hospital.

SETTING

Cork University Hospital, Wilton, Cork, Ireland.

METHODS

Data from the patient's chart, drug kardex and laboratory results were recorded during April 2010. A Caprini score, a venous thromboembolism risk factor assessment tool, was subsequently calculated for each patient based on data collected. Appropriate prophylaxis was determined after examining data collected, Caprini score and prophylactic regime according to the ACCP 8th edition guidelines.

MAIN OUTCOME MEASURE

Primary outcome was to analyse adherence to VTE prophylaxis guidelines.

RESULTS

A total of 394 patients met the inclusion criteria and were reviewed, of which, 60% (n = 236) were medical and 37% (n = 146) were surgical patients. In total 63% of patients received some form of venous thromboembolism prophylaxis. Furthermore, 54% of medical and 76% of surgical patients received prophylaxis. However only 37% of the patients studied received appropriate thromboprophylaxis according to the ACCP 8th edition guidelines (Geerts et al. in chest 133(6 Suppl):381S-453S, 2008). Additionally 51% of surgical and 27% of medical patients received appropriate prophylaxis.

CONCLUSION

Data collected from Cork University Hospital revealed poor adherence to international venous thromboembolism prophylaxis guidelines. As stated in the ACCP 8th edition guidelines, every hospital should develop a formal strategy for venous thromboembolism prevention (Geerts et al. in chest 133(6 Suppl):381S-453S, 2008). In order to improve adherence to guidelines, Cork University Hospital should develop, implement and re-evaluate a specific protocol for venous thromboembolism prophylaxis.

Risk of venous thromboembolism during treatment with antipsychotic agents

The evidence to date on the relation between the risk of venous thromboembolic disease (VTE) and antipsychotic agents derives primarily from observational and case history studies. While an increased risk of VTE has been associated with first-generation low-potency antipsychotic agents, particularly clozapine, there appears to be a growing number of reports on the occurrence of this adverse reaction during the use of second-generation antipsychotics, such as risperidone and olanzapine. The highest risk of pathological blood clotting emerges during the first 3 months after initiation of treatment with the product. Potential etiopathogenetic factors leading to VTE during treatment with antipsychotic agents include sedation, obesity, elevation of antiphospholipid antibodies, increased platelet activation and aggregation, hyperhomocysteinemia, and hyperprolactinemia. Diagnoses of schizophrenia and/or bipolar affective disorder, as well as hospitalization or stress with sympathetic activation and elevation of catecholamine levels, have been reported as known prothrombogenic factors. The present article contains the new version of the guideline for the prevention of VTE in psychiatric patients with limited mobility. Further prospective studies are necessary to elucidate the biological mechanisms of the relations between antipsychotic agents and VTE.

[Specific treatments of the psychiatric community and thrombogenesis]

BACKGROUND

The causes of venous thrombosis (DVT) are multifactorial. Psychiatric patients present several etiologic features.

AIM

Our objective was to determine the role of specific treatments of the psychiatric community on thrombogenesis.

METHODS

STUDY POPULATION

retrospective, descriptive and analytical study of 20 cases of DVT in psychiatric patients.

LITERATURE REVIEW

We searched MEDLINE (PubMed) between 1959 and 2009. We reviewed article titles and abstracts and full text of selected studies of psychiatric patients with venous thromboembolism (VTE) disease. We identified 31 studies that investigated the association between psychiatric disease and venous thromboembolic events.

RESULTS

Our population was young, with an average age of 44.8 years. Lower limb VT is predominant (16 cases). The most common psychiatric disorders are: anxiety-depression (12 cases), unclassifiable psychotic disorders (seven cases) and major depressive disorder (five cases). Their average duration was of 6.4 years. Seventy percent of our patients were taking first generation neuroleptics (NLP), of short half-life (13/14 cases) and at high doses (11/14 patients). Our sample is characterized by the frequency of thrombophilia (45%) and detention in a psychiatric community (35%). Our results are relatively consistent with aggregate data from the literature, underlining a facilitating and pejorative role of the psychiatric community with regard to venous thromboembolic disease. In the psychiatric community, venous thromboembolic disease is conditioned by a combination of several thromboembolism risk factors: linked in part to the psychiatric illness itself; but above all to the specific therapeutic methods in the psychiatric community (antipsychotics, restraint…) which are easily preventable. The relationship between antipsychotic medication and VTE was first suggested about four decades ago, only a few years after the introduction of phenothiazines and reserpine. An association between atypical antipsychotic agents and VTE has been previously suggested for clozapine among young adults with psychiatric disorders. More recently, an increased risk of VTE was suspected for olanzapine or risperidone. The risk for VTE seems to be highest during the initial months of treatment with antipsychotics. Several biological mechanisms of action have been proposed to explain this relationship. One plausible mechanism derives from research suggesting that conventional antipsychotic drugs are associated with enhanced platelet aggregation. A second possible explanation stems from the presence of anticardiolipin antibodies, which increase the risk of venous or arterial thrombosis, as well as in some patients prescribed chloropromazine. A third hypothesis is that venous stasis exacerbated by sedation, commonly found in patients treated with low-potency antipsychotic drugs, may contribute to processes that increase the risk of thrombosis.

CONCLUSION

Other than the medical aspect, the psychiatric community itself is characterized by a large number of variables, providing a particularly encouraging and derogatory hypothesis on the advent and development of VTE.

A review of the use of clozapine levels to guide treatment and determine cause of death

OBJECTIVE

To review the literature to examine the use of clozapine levels to (i) guide therapy and prevent toxicity in clinical care and (ii) determine cause of death in post-mortem examination of patients who were treated with clozapine.

METHODS

MEDLINE was searched in December 2010 using the following keywords: 'clozapine levels', 'clozapine and toxicity', 'clozapine and death', 'clozapine and mortality' and 'post-mortem redistribution'. Data was also collected from the 2010 MIMS Annual.

RESULTS

The literature reported significant variation in clozapine levels attained with any given dose, and considerable variability in the clinical response achieved at any given clozapine level. The lowest effective clozapine levels ranged from 250 to 550 µg/L, while the recommended upper limit to prevent toxicity varied from 600 to 2000 µg/L. There was minimal correlation between clozapine levels and side effects, with the exception of sedation, hypotension and seizure activity. The risk of seizures increased with plasma clozapine levels greater than 600 µg/L or rapid upward titration. In addition to prescribed dose, there are many factors that influence plasma clozapine levels. After death, the process of post-mortem drug redistribution resulted in 3.00 to 4.89 times increases in clozapine levels in central blood vessels and 1.5 fold increases in peripheral vessels compared to ante-mortem levels.

CONCLUSIONS

The exact range of clozapine levels that corresponds to toxicity remains unclear. However, levels between 350 µg/L and 1000 µg/L achieved with gradual upward titration are more likely to be effective and less likely to cause toxicity. Ongoing clozapine level monitoring is indicated, especially when (i) prescribing higher doses (> 600 mg/day) of clozapine, (ii) there has been a change in a patient's concomitant pharmacotherapy or cigarette use and (iii) there has been a suboptimal response to treatment. The use of post-mortem clozapine levels to determine clozapine toxicity as a cause of death is unreliable.

Venous thromboembolism in recipients of antipsychotics: incidence, mechanisms and management

Since chlorpromazine was introduced to the market in the early 1950s, the use of antipsychotic drugs has been associated with venous thromboembolism (VTE) in a number of reports. During the last decade the evidence has been strengthened with large epidemiological studies. Whether all antipsychotics increase the risk for VTE or the risk is confined to certain drugs is still unclear. The aim of this article is to present an updated critical review focusing on the incidence, mechanisms and management of VTE in users of antipsychotics. After searching the databases PubMed and Scopus for relevant articles we identified 12 observational studies, all of which were published after the year 2000. In most of these studies an elevated risk of VTE was observed for antipsychotic drugs, with the highest risk for clozapine, olanzapine and low-potency first-generation antipsychotics. The risk seems to be correlated with dose. The elderly, who mainly use lower doses, do not show an increased risk of VTE to the same extent as younger subjects. The underlying biological mechanisms explaining the association between antipsychotic medication and VTE are to a large extent unknown. Several hypotheses have been proposed, such as body weight gain, sedation, enhanced platelet aggregation, increased levels of antiphospholipid antibodies, hyperprolactinaemia and hyperhomocysteinaemia. The risk of VTE in schizophrenia and other psychotic disorders may also be related to the underlying disease rather than the medication. Very limited evidence exists to guide how cases of VTE in subjects using antipsychotics should be handled. An attempt to compile an algorithm where the patients' individual risk of VTE is assessed and preventive clinical measures are suggested has been published recently. Strong consideration should be given to discontinuation of the offending antipsychotic drug in patients experiencing a VTE, and another antipsychotic drug with a presumably lower risk should be chosen if antipsychotic drug treatment is still indicated. It is essential that physicians and patients are aware that VTE may be an adverse drug reaction to the antipsychotic treatment so the condition is identified early and treated appropriately.

Markers of thrombogenesis are activated in unmedicated patients with acute psychosis: a matched case control study

BACKGROUND

Antipsychotic treatment has been repeatedly found to be associated with an increased risk for venous thromboembolism in schizophrenia. The extent to which the propensity for venous thromboembolism is linked to antipsychotic medication alone or psychosis itself is unclear. The objective of this study was to determine whether markers of thrombogenesis are increased in psychotic patients who have not yet been treated with antipsychotic medication.

METHODS

We investigated the plasma levels of markers indicating activation of coagulation (D-dimers and Factor VIII) and platelets (soluble P-selectin, sP-selectin) in an antipsychotic-naive group of fourteen men and eleven women with acute psychosis (age 29.1 ± 8.3 years, body mass index 23.6 ± 4.7), and twenty-five healthy volunteers were matched for age, gender and body mass index.

RESULTS

D-dimers (median 0.38 versus 0.19 mg/l, mean 1.12 ± 2.38 versus 0.28 ± 0.3 mg/l; P = 0.003) and sP-selectin (median 204.1 versus 112.4 ng/ml, mean 209.9 ± 124 versus 124.1 ± 32; P = 0.0005) plasma levels were significantly increased in the group of patients with acute psychosis as compared with healthy volunteers. We found a trend (median 148% versus 110%, mean 160 ± 72.5 versus 123 ± 62.5; P = 0.062) of increased plasma levels of factor VIII in psychotic patients as compared with healthy volunteers.

CONCLUSIONS

The results suggest that at least a part of venous thromboembolic events in patients with acute psychosis may be induced by pathogenic mechanisms related to psychosis rather than by antipsychotic treatment. Finding an exact cause for venous thromboembolism in psychotic patients is necessary for its effective treatment and prevention.