Antipsychotic medication and venous thrombosis

Pulmonary embolism incidence among patient admitted under psychiatry department: a case-control study

Background

Pulmonary embolism (PE) is a serious and potentially life-threatening condition that requires prompt diagnosis and treatment. Identifying risk factors and diagnostic markers can aid in the early detection and management of this condition.

Methods

This case-control study examined 10,077 patients admitted to Shenzhen Kangning Hospital's psychiatry facility in 2020. Among these, 65 patients were diagnosed with PE, including 50 new cases. After survival sampling for controls and age-and-gender matching, the study included 41 new PE cases and 41 age-and-gender-matched controls. Data on demographics, comorbidities, and medication use were extracted from electronic records. Conditional logistic regression analyses were performed to determine the association between each predictor and PE risk. Additionally, the sensitivity and specificity of the d-dimer diagnostic tool were assessed.

Results

In univariable conditional logistic regression, active alcoholism was associated with a higher PE risk (OR=3.675, 95% CI 1.02-13.14, P=0.046). A history of physical restraint (OR=4.33, 95% CI 1.24-15.21, P=0.022) and chemical restraint (OR 4.67, 95% CI 1.34-16.24, p=0.015) also increased PE risk, as did benzodiazepine use (OR=3.33, 95% CI 1.34-8.30, P=0.010). Conversely, psychotropic medication before admission was associated with a lower risk of PE (OR=0.07, 95% CI 0.01-0.59, P=0.013). Stepwise multivariable forward conditional regression identified two subsets of psychiatric patients at higher risk of PE: new psychiatric cases without medication at admission who were chemically restrained, and cases without medication at admission who were started on antipsychotics and benzodiazepines. The d-dimer diagnostic tool, with an optimal threshold of 570 ng/ml determined by the Youden index (J statistic of 0.6098), showed a sensitivity of 73.17% and specificity of 87.80% for detecting PE, with an AUC of 0.833 (95% CI: 0.735-0.906).

Conclusion

Our findings suggest that a history of restraint, alcoholism, and the use of antipsychotics and benzodiazepines are important predictors of PE in psychiatric inpatients. Conversely, psychotropic medications at admission may be linked to a lower PE risk. The d-dimer diagnostic tool shows good value for screening PE in psychiatric inpatients. These predictors and diagnostic markers could help clinicians identify high-risk patients and implement appropriate prevention strategies.

COVID-19 and Antipsychotic Therapy: Unraveling the Thrombosis Risk

In the context of the COVID-19 pandemic, this study investigates the potential correlation between the increased use of antipsychotic medications and the rising incidence of venous thromboembolism (VTE). As psychiatric disorders surged, the consequential escalation in antipsychotic drug use raised concerns about thrombotic risks. We conducted a comprehensive literature review using PubMed, focusing on articles that intersected COVID-19, antipsychotic medication, and thrombosis. This approach allowed for a nuanced examination of the historical and recent data on antipsychotic drugs and their association with thrombotic events. Our findings reveal a notable link between the use of antipsychotic medications, particularly second-generation antipsychotics, and an increased risk of VTE, including pulmonary embolism and deep vein thrombosis. This association was evident, despite variations in study designs and populations. The study underscores the need for cautious medication management in psychiatric care, especially during pandemic conditions like COVID-19, to mitigate thrombotic risks. It advocates a personalized approach to prescribing antipsychotics, considering individual patient factors and comorbidities, to balance the benefits against potential thrombotic complications.

Fatal pulmonary embolism in patients on antipsychotics: case series, systematic review and meta-analysis

Since the 1950 s, several studies have reported that patients using first generation and/or second-generation antipsychotics had increased risk of venous thromboembolism events. These events include deep vein thrombosis and/or pulmonary embolism (PE). However, data about fatal PE in patients on antipsychotics (APs) remain scarce. Thus, the current study aimed to investigate sociodemographic, clinical and pharmacological characteristics related to psychiatric patients on APs and who died from a fatal PE. We reported a case-series, then conducted a literature review of relevant studies and performed a meta-analysis of studies with usable data. The main outcome of the study suggested a significantly high risk of fatal PE in patients using APs compared to nonusers (Odds Ratio=6.68, with 95% confidence interval 1.43-31.11). Clozapine was the most incriminated drug. Low potency first generation APs were the second most exhibited medication. Studies about the topic remain scarce with a high heterogeneity and a high probability of bias. Further studies are needed to ascertain this risk and to establish target preventive measures in this particularly vulnerable population.

Psychological and Psychopharmacological Interventions in Psychocardiology

Patients with mental disorders have an increased risk to develop cardiovascular disease (CVD), and CVD are frequently comorbid with especially adjustment, anxiety and depressive disorders. Therefore, clinicians need to be aware of effective and safe psychological and pharmacological treatment strategies for patients with comorbid CVD and mental disorders. Cognitive behavioral therapy and third-wave of cognitive-behavioral therapy are effective for patients with CVD and mental disorders. Internet-based psychological treatments may also be considered. In more severe cases, psychopharmacological drugs are frequently used. Although generally well tolerated and efficacious, drug- and dose-dependent side effects require consideration. Among antidepressants, selective serotonin reuptake inhibitors, selective serotonin and noradrenalin reuptake inhibitors, and newer antidepressants, such as mirtazapine, bupropion, agomelatine, and vortioxetine, can be considered, while tricyclic antidepressants should be avoided due to their cardiac side effects. Mood stabilizers have been associated with arrhythmias, and some first- and second-generation antipsychotics can increase QTc and metabolic side effects, although substantial differences exist between drugs. Benzodiazepines are generally safe in patients with CVD when administered short-term, and may mitigate symptoms of acute coronary syndrome. Laboratory and ECG monitoring is always recommended in psychopharmacological drug-treated patients with CVD. Presence of a heart disease should not exclude patients from necessary interventions, but may require careful risk-benefit evaluations. Effectively and safely addressing mental disorders in patients with CVD helps to improve both conditions. Since CVD increase the risk for mental disorders and vice versa, care providers need to screen for these common comorbidities to comprehensively address the patients' needs.

Psychiatrists and COVID-19: what is our role during this unprecedented time?

The declaration of a COVID-19 (Severe Acute Respiratory Syndrome - CoronaVirus2) pandemic by the World Health Organization in March 2020 has vastly changed the landscape in which mental health services function. Consideration is required to adapt services during this unusual time, ensuring continued provision of care for current patients, availability of care for patients with new-onset mental health difficulties and delivery of evidence-based support for healthcare professionals working with affected patients. Lessons can be learned from research carried out during the severe acute respiratory syndrome, Middle East respiratory syndrome and Ebola epidemics to ensure the delivery of efficient and effective mental health services both now and into the future.

Benzodiazepines increase the likelihood of both infectious and thrombotic complications

INTRODUCTION

Benzodiazepines (BZDs) modulate peripheral γ-amino-butyric acid type A on macrophages causing immunomodulation. They inhibit proinflammatory cytokines increasing infections. Prior studies have also shown that infections can increase thrombotic complications. We sought to examine this relationship in trauma patients. We hypothesized that the presence of BZDs on admission urine drug screen (UDS) would increase rates of both complications.

METHODS

All patients submitted to the Pennsylvania Trauma Outcome Study database from 2003 to 2018 were queried. Those with a positive UDS for BZDs were analyzed. Infectious complications were defined as pneumonia, urinary tract infection, sepsis, wound, and soft tissue infection, and thrombotic complications were defined as presence of pulmonary embolism or deep vein thrombosis. Logistic regressions controlling for demographic and injury covariates assessed the adjusted impact of BZDs on infectious and thrombotic complications.

RESULTS

A total of 3,393 patients (2.08%) had infectious complications, and 3,048 (1.87%) had thrombotic complications. Furthermore, 33,260 patients (20.4%) had a positive UDS for BZDs on admission. Univariate analysis showed that those positive for BZDs had higher rates of infectious (3.33% vs. 1.76%, p < 0.001) and thrombotic (2.84% vs. 1.62%, p < 0.001) complications. Multivariate analysis revealed that BZDs significantly increased the odds of infectious and thrombotic complications. Patients who tested positive for BZDs and subsequently developed infection had increased odds (adjusted odds ratio, 1.65; p < 0.001) of developing thrombotic complications.

CONCLUSION

Trauma patients with a positive UDS for BZDs had higher odds of both infectious and thrombotic complications. Moreover, odds of thrombotic complications were higher in those with infections.

LEVEL OF EVIDENCE

Epidemiological, level III.

Central retinal vein occlusion in a patient using the antipsychotic drug olanzapine: a case report

Background

We report our findings in a patient who developed central retinal vein occlusion (CRVO) and was a chronic user of olanzapine, an antipsychotic medication.

Case presentation

A 50-year-old Caucasian man, non-smoker, was referred to our clinic with the chief complaint of floater appearance in his left eye for the past 3 days. His past medical history indicated that he had been taking antipsychotic drugs (olanzapine) for about 3 years, with no other systemic disease or risk factors for CRVO.

In the examination, his best-corrected visual acuity (BCVA) was 0.7 in the left eye. The fundus showed signs of nonischemic CRVO with subhyaloid hemorrhage and intraretinal hemorrhage in the posterior pole and superior and inferior retina, without macular edema, confirmed by optical coherence tomography (OCT).

We ruled out other probable differential diagnoses and risk factors which lead to CRVO through a complete physical exam and blood analysis (complete blood count, glucose, urea, creatinine, lipid profile, erythrocyte sedimentation rate, C-reactive protein, prothrombin time, partial thromboplastin time, Bleeding time (BT), fibrinogen level, proteins, antiphospholipid antibodies, homocysteine blood level, antithrombin III, protein C and S, factor V Leiden, prothrombin mutation, angiotensin-converting enzyme level, other autoantibodies, and human leukocyte antigen [HLA]-B51). Finally, we confirmed the probable side effect of olanzapine in CRVO, which has not been previously reported. A possible pro-thrombogenic mechanism of olanzapine at the molecular level is an affinity for 5-HT_2Aserotonin receptors. Blocking these receptors results in increased platelet aggregation and increased blood coagulability.

Conclusions

These results indicate that CRVO can be a complication of chronic use of antipsychotic medications such as olanzapine, as shown for the first time in our case report. Clinicians should question patients who develop a sudden CRVO whether they are using antipsychotic medications such as olanzapine.

The Association and Influencing Factors between Antipsychotics Exposure and the Risk of VTE and PE: A Systematic Review and Meta-analysis

BACKGROUND

Different clinical studies have given inconsistent results on whether the use of antipsychotics increases the risk of thromboembolism. In this paper, we reviewed all relevant literature to provide suggestions for clinical diagnosis and treatment.

METHODS

PubMed, Web of Science, EMBASE, MEDLINE, Cochrane and Scopus databases were thoroughly searched up to June 2019. Two researchers independently searched the literature, extracted data. Data were analyzed by Stata 12.0 software.

RESULTS

A total of 22 studies involving 31514226 subjects were included. This meta-analysis showed that patients taking the first- or second-generation antipsychotics had a higher risk of venous thromboembolism and pulmonary embolism than those who did not, and low potency first-generation agents increased the risk of venous thromboembolism more than high potency antipsychotics, and olanzapine, clozapine, haloperidol, perphenazine and risperidone also significantly increased the risk of it. The risk of venous thrombosis in obese people was higher than that in overweight people, patients not less than 65 years old had an increased risk compared with younger patients. In addition, women taking antipsychotics had a higher risk of pulmonary embolism than men.

CONCLUSION

The use of antipsychotics will increase the risk of venous thromboembolism and pulmonary embolism, which will be affected by the type of antipsychotics and patient characteristics.

Effect of Living Environment Factors on Quality of Life in Patients With Chronic Thromboembolic Pulmonary Hypertension After Completion of Balloon Pulmonary Angioplasty - A Cross-Sectional Study

Background: This study investigated factors related to quality of life (QoL) in patients with chronic thromboembolic pulmonary hypertension who completed balloon pulmonary angioplasty (BPA).

Methods and Results: Patient QoL and living environment after BPA were evaluated prospectively using the 5-level EQ-5D questionnaire and International Physical Activity Questionnaire Environmental Module (IPAQ-E), respectively. Patients were mailed copies of both surveys. In addition, we reviewed patient charts and collected retrospective clinical data. Relationship between the clinical data and QoL and environmental living factors were investigated. Of the 33 subjects mailed the surveys, sufficient responses were obtained from 22 (71%). Spearman’s rank correlation coefficient showed that psychiatric disorders (r=−0.6865, P<0.01) and IPAQ-E Question 5 (r=0.5192, P=0.02), Question 6 (r=0.5265, P=0.02), and Question 13 (r=0.4552, P=0.04) were significantly correlated with EQ-5D scores after BPA.

Conclusions: A living environment that was difficult to walk around was associated with a worse QoL. A multidisciplinary approach will be required to improve QoL even after completion of BPA treatment.

Deep vein thrombosis on the fourth day of risperidone therapy

Deep vein thrombosis has been recognised as a complication of antipsychotic treatment and is reported to be more common with atypical antipsychotics. Risperidone is a second-generation atypical antipsychotic and there have been case reports of risperidone-associated deep vein thrombosis, most of them reporting the complication from 2 weeks to a few months of initiation of therapy. Here, we are reporting a case of deep vein thrombosis in a male patient in his early forties with paranoid schizophrenia, which presented on the fourth day of starting risperidone therapy. This case is being reported to highlight the fact that deep vein thrombosis can occur as early as fourth day of initiation of risperidone therapy, that too at a low dose (2 mg/day). The case also emphasises the importance of monitoring these patients for this rare but potentially serious adverse effect from the first day itself after initiation of a new antipsychotic.

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.

Current antipsychotic agent use and risk of venous thromboembolism and pulmonary embolism: a systematic review and meta-analysis of observational studies

BACKGROUND

Antipsychotic agents (APS) are widely used drugs to treat psychotic symptoms and can effectively reduce both positive and negative symptoms of schizophrenia. For decades, some studies suggested that there is a relationship between using APS and the risk of venous thromboembolism (VTE) and pulmonary embolism (PE). However, results remain inconclusive.

METHOD

This review has been registered in International Prospective Register of Systematic Reviews (PROSPERO, ID: CDR42020155620). Relevant studies were identified among observational studies published up to 1 October 2019 in the databases MEDLINE, EMBASE, and Cochrane Library. Random or fixed-effects models were used to calculate the pooled odds ratio (OR).

RESULTS

In total, 28 observational studies were included. The results showed that compared with non-users, current APS users have significantly increased risks of VTE [OR 1.55 95% confidence interval (CI) 1.36, 1.76] and PE (OR 3.68, 95% CI 1.23, 11.05). Subgroup analyses suggested that new users were associated with a higher risk of VTE (OR 2.06, 95% CI 1.81, 2.35). For individual drugs, increased risk of VTE and PE was observed in taking haloperidol, risperidone, olanzapine, prochlorperazine but not in chlorpromazine, quetiapine or aripiprazole. However, careful interpretation is needed because of high heterogeneity among studies and scarce data.

CONCLUSION

The present comprehensive meta-analysis further indicates a significantly increased risk of VTE and PE in current APS users compared with non-users. Subgroup analyses suggest that new users are more likely to develop VTE. However, due to significant heterogeneity among studies, conclusions should be considered with caution.

Antipsychotic Drugs and Risk of Developing Venous Thromboembolism and Pulmonary Embolism: A Systematic Review and Meta-Analysis

Background:

Antipsychotic (AP) medications are the cornerstone treatment for schizophrenia and some other psychiatric diseases. However, some observational studies suggest that these medications might increase the risk of venous thromboembolism (VTE) and pulmonary embolism (PE).

Objectives:

The aim of this study was to assess whether AP medications are associated with the development of VTE or PE, and to assess the risk based on any type of AP drugs, quality of studies and after adjustment of risk factors.

Data sources:

To identify relevant studies, we searched PubMed and EMBASE databases up to February 2019. We also searched the reference lists of relevant articles for related studies.

Study Selection:

Twenty studies fulfilled the eligibility criteria and were included in our meta-analysis after screening relevant observational cohort and case-control studies.

Primary Outcome:

The primary outcome of our meta-analysis was the occurrence of all VTE or PE only attributed to exposure to AP medications compared with non-exposure to AP medications.

Results:

Exposure to AP drugs was associated with a significant increase in the risk of VTE (RR 1.53, 95% CI 1.30-1.80, I2 = 85%) and PE (RR 3.69, 95% CI 1.23-11.07, I2 = 90%). In the subgroup metaanalysis, the use of low-potency AP drugs was associated with a higher risk of VTE, (RR 1.90, 95% CI 1.04-3.47, I2 = 78%).

Conclusion:

AP exposure was associated with a 1.5-fold increase in the risk of VTE and a 3.7-fold increase in the risk of PE. Low-potency AP drugs were associated with a higher risk of VTE. However, high heterogeneity among studies limits the generalizability of the results.

Causes of Sudden Unexpected Death in Schizophrenia Patients: A Forensic Autopsy Population Study

BACKGROUND

Schizophrenia is a detrimental psychiatric disorder, with an increased mortality from natural and nonnatural causes.

METHODS

This study was a retrospective review of autopsy cases of all the individuals with history of schizophrenia investigated by the Office of the Chief Medical Examiner, State of Maryland, for a 5-year period from 2008 to 2012.

RESULT

A total of 391 schizophrenia patients were autopsied at the Office of the Chief Medical Examiner because they died suddenly and unexpectedly. Their age ranged from 15 to 100 years with the mean age of 49.5 years. Of the 391 deaths, 191 (48.8%) were white, 185 (47.3%) were African American, and 15 (3.9%) were either Hispanic or Asian. The male and female ratio was 1.5:1. The majority of deaths (64.2%) were caused by natural diseases, 12.0% deaths were accidents, 11.5% deaths were suicides, and 9.7% deaths were homicides. The manner of death remained undetermined in 38 cases (9.7%). Of the 251 natural deaths, 198 cases (78.9%) were owing to cardiovascular diseases. Cause of death was listed as cardiac arrhythmia in 11 cases. This diagnosis of cardiac arrhythmia was made by exclusion based on death scene investigation, review of medical history, complete autopsy, and toxicological tests. Drug intoxication was the second most common cause of death.

CONCLUSIONS

The study shows high fatality caused by cardiovascular diseases and drug intoxication among schizophrenia patients, which calls attention of the medical community to closely monitor the high risk factors of sudden death among schizophrenia patients.

Increased risk for venous thromboembolism among patients with concurrent depressive, bipolar, and schizophrenic disorders

OBJECTIVE

The study aim was to investigate the risk of venous thromboembolism (VTE) in patients with concurrent depressive, bipolar, and schizophrenic disorders.

METHODS

A population-based cohort study was conducted in which information regarding psychiatric illnesses and medical comorbidities in 29,467 patients with concurrent depressive, bipolar, and schizophrenic disorders and regarding 117,868 controls were extracted. We compared the incidence of VTE between the study and control cohorts. Cox proportional hazard regression models were used to analyze the risk of VTE after adjusting for potential confounders, including sex, age, and comorbidities.

RESULTS

Compared with the control cohort, the overall study cohort had a 2.995-fold higher adjusted hazard ratio (aHR) for development of deep vein thrombosis (DVT) and a 2.591-fold higher aHR for development of pulmonary embolism (PE). Moreover, patients with depressive, bipolar, and schizophrenic disorders all exhibited higher aHRs for development of both DVT and PE.

CONCLUSION

The relative risks of DVT and PE were higher in patients with concurrent depressive, bipolar, and schizophrenic disorders than those of the general population. Further research is needed to develop effective prevention strategies for different patient populations.

Clinical characteristics and prognosis in patients with chronic thromboembolic pulmonary hypertension and a concomitant psychiatric disorder

Chronic thromboembolic pulmonary hypertension (CTEPH) can cause right heart failure. A concomitant psychiatric disorder (PD) is thought to increase the risk of acute pulmonary thromboembolism; however, whether PDs are associated with deterioration in CTEPH pathophysiology is unclear. In this study, we evaluated the clinical characteristics and prognoses in patients with CTEPH and a co-existing PD. We retrospectively identified 229 consecutive patients (mean age = 58.7 ± 12.5 years; 160 women) with CTEPH and categorized them according to whether they had a PD (PD group; n = 22, 9.7%) or not (non-PD group; n = 207, 90.3%). We compared the clinical characteristics, respiratory function, hemodynamics, and clinical courses in the two groups. Those in the PD group had significantly lower exercise tolerance compared to the non-PD group (6-min walk test, 309.5 ± 89.5 m vs. 369.4 ± 97.9 m, P = 0.008, percent vital capacity 85.5% ± 17.3% vs. 96.0% ± 15.5%, P = 0.003) and partial pressure of oxygen (PaO2) (54.4 ± 8.6 mmHg vs. 59.3 ± 10.7 mmHg, P = 0.039). Three-year survival was significantly poorer in the PD group compared to the non-PD group (66.1% vs 89.7%, P = 0.0026, log-rank test), particularly in patients who underwent surgery (62.2% vs 89.5%, P < 0.001, log-rank test). A concomitant PD was associated with low exercise tolerance and impaired respiratory function in patients with CTEPH and predicted poor survival, especially in those who underwent a pulmonary endarterectomy.

Direct and indirect effects of psychopharmacological treatment on the cardiovascular system

Background Severe mental disorders, i.e. psychotic disorders, unipolar and bipolar disorders are associated with increased morbidity and mortality from cardiovascular and metabolic disorders. The underlying cause of this association is complex and comprises disorder specific alterations such as dysfunctions of immunological and hormonal systems, body-composition changes and health associated behaviors (smoking, sedentary lifestyle, alcohol intake and treatment compliance). Furthermore, some psychopharmacological drugs may exert unwanted side effects that impact the cardiovascular system. Methods This paper reviews studies concerning commonly used antidepressant and antipsychotics drugs with a particular focus on direct and indirect cardiovascular side effects. Results Newer antidepressant drugs have a favorable cardiovascular safety profile compared to tricyclic antidepressants. However, QTc prolongation, increased blood pressure and potentially higher risks of bleeding have been observed in some newer antidepressants. Some second generation (atypical) antipsychotics have raised concern because of indirect cardiovascular, metabolic side effects such as weight gain and disturbances in lipid and glucose metabolism. Conclusions Psychiatrists need to be aware of potential direct and indirect cardiovascular side effects and to include them in the risk/benefit assessment when choosing a specific individualized treatment.

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.

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.

Central Retinal Vein Occlusion in 2 Patients Using Antipsychotic Drugs

Purpose

To report our findings in 2 patients who developed a central retinal vein occlusion (CRVO) and were chronic users of antipsychotic medications.

Case Presentation

Case 1 was a 62-year-old woman who had a sudden reduction of vision in her right eye to 20/2,000. Her fundus showed signs of an impending CRVO with marked macular edema. She had been taking antipsychotic drugs (quetiapine fumarate and risperidone) for about 2 years. She refused anti-VEGF therapy for her macular edema but selected systemic kallidinogenase. Two days later, the macular edema was significantly reduced but the number of cotton wool spots (CWS) was increased. Ten days later, the macular edema was resolved and her BCVA improved to 20/60. The CWS gradually disappeared, and her BCVA improved to 20/20. Case 2 was a 43-year-old man who presented with vision reduction in his right eye of 1 week's duration. His BCVA was 20/50 and his fundus showed signs of a CRVO-related macular edema with CWS in the peripapillary area. He had been taking sulpiride (Dogmatyl^™) for depression for 1 year, and his blood test showed an increase in red blood cells and hematocrit. Anti-VEGF therapy was performed, and the macular edema was resolved with vision improving to 20/20. There has been no recurrence to date in both cases.

Conclusions

These results indicate that a CRVO can be a complication of chronic use of antipsychotic medications. However, early treatment can lead to good outcomes. Clinicians should question patients who develop a sudden CRVO whether they are using antipsychotic medications.

Antidepressants, Depression, and Venous Thromboembolism Risk: Large Prospective Study of UK Women

BACKGROUND

Some investigators have reported an excess risk of venous thromboembolism (VTE) associated with depression and with use of antidepressant drugs. We explored these associations in a large prospective study of UK women.

METHODS AND RESULTS

The Million Women Study recruited 1.3 million women through the National Health Service Breast Screening Programme in England and Scotland. Three years after recruitment, women were sent a second questionnaire that enquired about depression and regular use of medications in the previous 4 weeks. The present analysis included those who responded and did not have prior VTE, cancer, or recent surgery. Follow-up for VTE was through linkage to routinely collected National Health Service statistics. Cox regression analyses yielded adjusted hazard ratios and 95% CIs. A total of 734 092 women (mean age 59.9 years) were included in the analysis; 6.9% reported use of antidepressants, 2.7% reported use of other psychotropic drugs, and 1.8% reported being treated for depression or anxiety but not use of psychotropic drugs. During follow-up for an average of 7.3 years, 3922 women were hospitalized for and/or died from VTE. Women who reported antidepressant use had a significantly higher risk of VTE than women who reported neither depression nor use of psychotropic drugs (hazard ratio, 1.39; 95% CI, 1.23-1.56). VTE risk was not significantly increased in women who reported being treated for depression or anxiety but no use of antidepressants or other psychotropic drugs (hazard ratio, 1.19; 95% CI, 0.95-1.49).

CONCLUSIONS

Use of antidepressants is common in UK women and is associated with an increased risk of VTE.

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 Thrombosis—Experimental, Clinical, and Mechanistic Considerations

Awareness of the dangers of drug-induced thrombosis has recently been heightened and led to demand for improved testing methodology. For example, reports indicating that some selective inhibitors of cyclooxygenase-2 (COX-2) increase the risk of myocardial infarction and atherothrombotic events caused the withdrawal of rofecoxib from global markets and the issuance of warnings concerning the usage of other COX-2 inhibitors. Drugs may exert a prothrombotic state by a variety of mechanisms–those affecting the vessel wall, the blood flow, and/or different blood constituents. Our review serves as an update to that of Gerhard Zbinden published in 1976 by presenting recently acquired data that more fully elucidate the different mechanisms by which drugs are believed to induce thrombogenic effects and discussing new methods used to detect these without losing sight of the classical pathology of thrombosis. We offer correlations between experimental findings and clinical data and conclude that, because drugs may induce a prothrombotic state by a variety of mechanisms, they should be tested for these using appropriate experimental methods and animal models.

Platelet parameters (PLT, MPV, P-LCR) in patients with schizophrenia, unipolar depression and bipolar disorder

There are no studies comparing platelet parameters platelet parameters (platelet count (PLT), mean platelet volume (MPV) and platelet large cell ratio (P-LCR)) between patients with schizophrenia, bipolar disorder and unipolar depression. Therefore, the aim of this study was to determine and compare differences in PLT, MPV and P-LCR in patients with schizophrenia, unipolar depression and bipolar disorder. This was a retrospective, cross-sectional, naturalistic study of 2377 patients (schizophrenia n=1243; unipolar depression n=791; bipolar disorder n=343, including bipolar depression n=259 and mania n=84). There were significant differences for PLT, MPV and P-LCR values between study groups. A significant percentage of patients with bipolar disorder had abnormal (too low or too high) number of platelets. Negative correlation between PLT and age was found in all study groups and positive correlation between age and MPV and P-LCR was found in patients with schizophrenia.

Depression and risk of venous thromboembolism: a population-based retrospective cohort study

OBJECTIVE

This study investigated the relationship between depression and the risk of subsequent venous thromboembolism (VTE) development.

METHODS

We conducted a population-based retrospective cohort analysis by using data for the period of 2000 to 2011 from the Longitudinal Health Insurance Database 2000 of Taiwan. A depression cohort comprising 35,274 patients and a nondepression cohort comprising 70,548 patients matched according to sex, age, and index year with no history of VTE were evaluated. Cox proportional hazard regression analysis was used to assess the effects of depression and comorbidities, and the Kaplan-Meier method was applied to estimate the cumulative VTE incidence curves.

RESULTS

Compared with individuals without depression, depressed patients had a 1.38-fold greater risk (95% confidence interval = 1.09-1.73) of developing VTE. This risk was significantly higher in male and younger (≤49 years) patients. In addition, patients with comorbidities such as hypertension, diabetes, heart failure, and cancer had a higher risk of depression-associated VTE that was attenuated, although nonsignificantly, by antidepressant use.

CONCLUSIONS

The incidence of VTE in Taiwan is higher in depressed patients than in nondepressed patients. Moreover, men, people 49 years or younger, and patients with comorbidities have a significantly greater risk of VTE after depression.

Hyperprolactinemia during antipsychotics treatment increases the level of coagulation markers

OBJECTIVE

The strong association between psychiatric patients who receive antipsychotics and the incidence of venous thromboembolism (VTE) is known. Although previous reports suggest that hyperprolactinemia often increases markers of activated coagulation, few studies have examined the direct relationship between the prolactin level elevated by antipsychotics and activated markers of activated coagulation.

METHOD

The participants included 182 patients with schizophrenia (male =89, female =93) who received antipsychotic treatments for at least 3 months. Markers of VTE (D-dimer, fibrin/fibrinogen degradation products, and thrombin-antithrombin complex) and serum prolactin concentrations were measured.

RESULTS

Prolactin levels were significantly correlated with the logarithmic transformation of the D-dimer (r=0.320, P=0.002) and fibrin/fibrinogen degradation product levels (r=0.236, P=0.026) but not of the thrombin-antithrombin complex level (r=0.117, ns) among men. However, no correlations were found between the VTE markers and prolactin levels among women. These results were confirmed using multiple regression analyses that included demographic factors and antipsychotic dosages.

CONCLUSION

The current study indicates that hyperprolactinemia is associated with an increase in markers of activated coagulation among men receiving antipsychotics. This finding clinically implies that monitoring and modulating prolactin levels among men are important to decrease the risk of VTE.

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.

An Irish case of pulmonary emboli secondary to clozapine therapy

Background: Clozapine is the prototype atypical antipsychotic used for treatment-resistant schizophrenia, but its use has been limited by the well-established association with agranulocytosis. An increased risk of other serious adverse events such as myocarditis and thromboembolism has also been suggested to be associated with clozapine therapy.

Aims: We describe an Irish case of multiple pulmonary emboli detected by CT pulmonary angiogram thought to be secondary to clozapine therapy.

Conclusion: Although clozapine is a very efficacious antipsychotic its many side-effects limit its use. Pulmonary embolism must be remembered as a potential rare side-effect in clozapine therapy. Underlying mechanisms are still unclear although several have been proposed.

Muddy clinical waters: a missed pulmonary embolus

The diagnosis of pulmonary embolism (PE) can be difficult to make. The consequences of missing a PE can be fatal and clinicians should always be vigilant. This case presents a patient admitted with fluctuations in consciousness and in a septic state. A preliminary diagnosis of aspiration pneumonia was made, and the patient went on to have an exploratory surgical procedure with no remarkable findings. Only after further investigation of the patient's fluctuations in consciousness was a retrospective diagnosis of a large PE made. The patient was anticoagulated and made a full recovery, with no outstanding pulmonary issues at follow-up 6 weeks after discharge. A prolonged immobile state, likely in part due to the patient's septic state and psychiatric history, along with recent surgery and hospitalisation were the most obvious risk factors.

Pulmonary thromboembolism due to paliperidone: report of 2 cases

Venous thromboembolism (VTE) is serious medical condition, which might be caused by psychotropic medications. Previously, antipsychotic-induced VTE due to olanzapine, risperidone, clozapine, and amisulpiride was reported. In this report, we present 2 cases of paliperidone-induced 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.

Association between antidepressants and venous thromboembolism in Taiwan

OBJECTIVE

To investigate the association between venous thromboembolism (VTE) and antidepressant use in an Asian population.

METHODS

The authors conducted a nested case-control study of 1888 patients with VTE and 11,222 matched controls enrolled in the National Health Insurance Research Database in Taiwan from 2001 to 2009. The antidepressant exposure status and potential confounding factors were measured and included in the analyses. Conditional logistic regressions were applied to determine the effect of antidepressant use on VTE.

RESULTS

We found a significant association of current antidepressant use with VTE in the total study sample (adjusted odds ratio [aOR], 1.59; 95% confidence interval (CI), 1.27-2.00). With regard to antidepressant classes and potency, we found that tricyclic antidepressants (aOR, 1.56; 95% CI, 1.11-2.18), serotonin 5-HT2A receptor blockers (aOR, 2.03; 95% CI, 1.27-3.24), and antidepressants with a low potency of serotonin reuptake inhibition (aOR, 1.57; 95% CI, 1.18-2.08) were associated with a significantly increased risk of VTE. When further stratifying by age, sex, and comorbid conditions, the VTE risk with antidepressant use was elevated among young and middle-aged adults, but not among the elderly. In addition, an elevated risk of VTE was observed in women and subjects without severe comorbid conditions, but not in men and subjects with severe comorbid conditions.

CONCLUSIONS

There was a small increase in VTE risk with antidepressant use. The prescription of antidepressant drugs should be cautious, and especially, should be based on clinical evaluations of benefits and risks. The underlying mechanisms of the interaction between antidepressants and VTE warrant further investigation.

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.

Deep venous thrombosis and atypical antipsychotics: three cases report

Background

Deep venous Thrombosis is a serious, possible life threatening event which is often ignored in psychiatric Settings.

Purpose

In this paper three cases of deep venous Thrombosis (DVT) following the use of olanzapine and risperidone are presented.

Methods

The data of Three patients was collected from hospital records.

Results

The patients were in good general physical health and had no personal or familial history of DVT. The patients were not overweight (BMI < 25) but they suffered from DVT after initiating risperidone and olanzapine.

Conclusion

Risk of DVT exists in patients under treatment with atypical antipsychotics in spite of no pre existing risk factor.

[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.

Idiopathic pulmonary thromboembolism in the course of intensive psychiatric inpatient care: case report and treatment guidelines

Idiopathic thromboembolism can occur in psychiatric patients who have been inactive during a period of inpatient hospital treatment. These patients are usually treated with antipsychotic medication which has also been reported to increase risk for thromboembolic disease. Here the authors describe a patient with neither prior history of thromboembolism nor any medical risk factors for thromboembolic disease, who was admitted with an acute relapse of psychotic illness. During the course of her intensive psychiatric treatment, she had chest pain and CT-pulmonary arteriogram revealed bilateral lower lobe pulmonary embolism. She was anticoagulated and made a full medical recovery. Treatment with high dosages of typical and atypical antipsychotic medication and a lack of mobility related to intensive nursing care and sedation were likely risk factors in her development of pulmonary emboli.

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.

Evidence-based guidelines for the pharmacological treatment of schizophrenia: recommendations from the British Association for Psychopharmacology

These guidelines from the British Association for Psychopharmacology address the scope and targets of pharmacological treatment for schizophrenia. A consensus meeting, involving experts in schizophrenia and its treatment, reviewed key areas and considered the strength of evidence and clinical implications. The guidelines were drawn up after extensive feedback from the participants and interested parties, and cover the pharmacological management and treatment of schizophrenia across the various stages of the illness, including first-episode, relapse prevention, and illness that has proved refractory to standard treatment. The practice recommendations presented are based on the available evidence to date, and seek to clarify which interventions are of proven benefit. It is hoped that the recommendations will help to inform clinical decision making for practitioners, and perhaps also serve as a source of information for patients and carers. They are accompanied by a more detailed qualitative review of the available evidence. The strength of supporting evidence for each recommendation is rated.

Association between antipsychotic medication and venous thromboembolism

OBJECTIVE

This study aims to identify and review available evidence in the literature to determine the strength of association between antipsychotic medications and thromboembolism as an adverse effect.

METHOD

Electronic databases were searched for evidence.

RESULTS

A total of 15 case reports, 14 case series, two observational studies and three case-control studies were found in the literature. Two case control studies found significantly increased risk of venous thromboembolism (OR 13.3 and 7.1 respectively). The risk was high for low potency antipsychotics. Studies were critically appraised to determine the strength of evidence.

CONCLUSION

The studies reviewed indicate a significant association between antipsychotics and venous thromboembolism. Patients using the antipsychotics and those who prescribe them should be aware of this association.

The first- and second-generation antipsychotic drugs affect ADP-induced platelet aggregation

OBJECTIVE

Blood platelets play an important role in haemostasis and their hyperaggregability may lead to thrombosis and cardiovascular diseases. Increased incidence of mortality, caused by cardiovascular disease, and the increased risk of thrombotic complication in schizophrenic patients treated with antipsychotics have been reported. The effects of antipsychotic drugs on blood platelet function are not fully explained, therefore the purpose of the present study was to examine and compare the effects of the second-generation antipsychotic drugs used in schizophrenia (clozapine, risperidone and olanzapine), with the effects of the first generation antipsychotic, haloperidol, on the platelet aggregation induced by ADP in vitro.

METHODS

Blood obtained from healthy volunteers (n=25) collected into sodium citrate was centrifuged (250xg, 10 min) at room temperature to obtain platelet-rich plasma. Aggregation of blood platelets (10 microM ADP) was recorded (Chrono-log aggregometer) in platelet-rich plasma preincubated with antipsychotic drugs (final concentration: clozapine 420 ng/ml, risperidone 65 ng/ml, olanzapine 40 ng/ml, haloperidol 20 ng/ml) for 30 min.

RESULTS

Our results showed that all tested drugs inhibit platelet aggregation induced by ADP in vitro. Among studied antipsychotic drugs clozapine and olanzapine significantly reduced platelet aggregability in vitro. In comparison with control platelets (without the drug), clozapine inhibited ADP-induced platelet aggregation by 21% (P=3.7x10(-6)) and olanzapine by 18% (P=2.8x10(-4)), respectively.

CONCLUSION

The obtained results indicate that antipsychotic drugs, especially clozapine and olanzapine, contrary to haloperidol, reduced response of blood platelets to ADP measured as platelet aggregation. This suggests that therapy with such antipsychotics, particularly with second-generation antipsychotics, may partly reduce prothrombotic events associated with the increased platelet activation observed in schizophrenic patients. The mechanism of antiaggregatory influence of antipsychotics requires further studies.

Risk of venous thromboembolism due to antipsychotic drug therapy

An increasing number of reports suggest a link between venous thromboembolism (VTE) and the use of antipsychotics. To better understand this association the available body of evidence has been critically scrutinised. Relevant articles were identified in the databases Scopus and PubMed. Several observational studies using different methodologies show an increased risk of VTE in psychiatric patients. This elevated risk seems to be related to the use of antipsychotic medication and in particular to the use of clozapine and low-potency first-generation drugs. Many studies investigating the association have, however, methodological limitations. The biological mechanisms involved in the pathogenesis of this possible adverse reaction are largely unknown but several hypotheses have been suggested such as drug-induced sedation, obesity, increased levels of antiphospholipid antibodies, enhanced platelet aggregation, hyperhomocysteinemia and hyperprolactinemia. The association may also be related to underlying risk factors present in psychotic patients. Physicians need to be aware of this possible adverse drug reaction. Although supporting evidence has not been published they should consider discontinuing or switching the antipsychotic treatment in patients experiencing VTE. In addition, although data is lacking, the threshold for considering prophylactic antithrombotic treatment should be low when risk situations for VTE arise, such as immobilisation, surgery and so on.