Clozapine-related neutropenia, myocarditis and cardiomyopathy adverse event reports in Australia 1993-2014

Metabolic Side Effects from Antipsychotic Treatment with Clozapine Linked to Aryl Hydrocarbon Receptor (AhR) Activation

Metabolic syndrome (MetS) is the most common adverse drug reaction from psychiatric pharmacotherapy. Neuroreceptor blockade by the antipsychotic drug clozapine induces MetS in about 30% of patients. Similar to insulin resistance, clozapine impedes Akt kinase activation, leading to intracellular glucose and glutathione depletion. Additional cystine shortage triggers tryptophan degradation to kynurenine, which is a well-known AhR ligand. Ligand-bound AhR downregulates the intracellular iron pool, thereby increasing the risk of mitochondrial dysfunction. Scavenging iron stabilizes the transcription factor HIF-1, which shifts the metabolism toward transient glycolysis. Furthermore, the AhR inhibits AMPK activation, leading to obesity and liver steatosis. Increasing glucose uptake by AMPK activation prevents dyslipidemia and liver damage and, therefore, reduces the risk of MetS. In line with the in vitro results, feeding experiments with rats revealed a disturbed glucose-/lipid-/iron-metabolism from clozapine treatment with hyperglycemia and hepatic iron deposits in female rats and steatosis and anemia in male animals. Decreased energy expenditure from clozapine treatment seems to be the cause of the fast weight gain in the first weeks of treatment. In patients, this weight gain due to neuroleptic treatment correlates with an improvement in psychotic syndromes and can even be used to anticipate the therapeutic effect of the treatment.

Clozapine-Induced Severe Toxicity: Exploring the Pharmacokinetic Profile of Clozapine and Its Significance in Hemodynamic Instability - A Case Report

Hemodynamic instability in patients with clozapine intoxication can indirectly reflect the serum concentration of clozapine.We have described a case of a 32-year-old pregnant woman who developed life-threatening clozapine toxicity at 28 weeks of gestation. The levels of clozapine and norclozapine in the serum were high. We initiated hemoperfusion(HP) and other detoxification therapies to remove the drug. The patient had severely dilated peripheral blood vessels, which led to cardiac symptoms such as fatal hypotension and uncontrollable tachycardia, resulting in very high cardiac output and elevated Central venous oxygen saturation (ScvO2). Pharmacological intervention significantly improved the hemodynamics.In light of our observations in the ongoing case, we posit that evaluating hemodynamic parameters before and after blood detoxification could serve as a valuable means to gauge effectiveness and provide guidance for treatment.

Escaping the Long Shadow Cast by Agranulocytosis: Reflections on Clozapine Pharmacovigilance Focused on the United Kingdom

PURPOSE/BACKGROUND

A recent article in this journal presented a US perspective regarding the modernization of clozapine prescription and proposed an escape from the long shadow cast by agranulocytosis.

METHODS

Here, an international group of collaborators discusses a point of view complementary to the US view by focusing on worldwide outcomes of clozapine usage that may be uneven in terms of frequency of clozapine adverse drug reactions.

FINDINGS/RESULTS

Studies from the Scandinavian national registries (Finland and Denmark) did not find increased mortality in clozapine patients or any clear evidence of the alleged toxicity of clozapine. Data on clozapine-associated fatal outcomes were obtained from 2 recently published pharmacovigilance studies and from the UK pharmacovigilance database. A pharmacovigilance study focused on physician reports to assess worldwide lethality of drugs from 2010 to 2019 found 968 clozapine-associated fatal outcomes in the United Kingdom. Moreover, the United Kingdom accounted for 55% (968 of 1761) of worldwide and 90% (968 of 1073) of European fatal clozapine-associated outcomes. In a pharmacovigilance study from the UK database (from 2008 to 2017), clozapine was associated with 383 fatal outcomes/year including all reports from physicians and nonphysicians. From 2018 to 2021, UK clozapine-associated fatal outcomes increased to 440/year.

IMPLICATIONS/CONCLUSIONS

The interpretation of fatal outcomes in each country using pharmacovigilance databases is limited and only allows gross comparisons; even with those limitations, the UK data seem concerning. Pneumonia and myocarditis may be more important than agranulocytosis in explaining the uneven distribution of fatal outcomes in clozapine patients across countries.

A systematic review on sex differences in adverse drug reactions related to psychotropic, cardiovascular, and analgesic medications

Background and objective: Adverse drug reactions (ADRs) are the main safety concerns of clinically used medications. Accumulating evidence has shown that ADRs can affect men and women differently, which suggests sex as a biological predictor in the risk of ADRs. This review aims to summarize the current state of knowledge on sex differences in ADRs with the focus on the commonly used psychotropic, cardiovascular, and analgesic medications, and to aid clinical decision making and future mechanistic investigations on this topic. Methods: PubMed search was performed with combinations of the following terms: over 1,800 drugs of interests, sex difference (and its related terms), and side effects (and its related terms), which yielded over 400 unique articles. Articles related to psychotropic, cardiovascular, and analgesic medications were included in the subsequent full-text review. Characteristics and the main findings (male-biased, female-biased, or not sex biased ADRs) of each included article were collected, and the results were summarized by drug class and/or individual drug. Results: Twenty-six articles studying sex differences in ADRs of six psychotropic medications, ten cardiovascular medications, and one analgesic medication were included in this review. The main findings of these articles suggested that more than half of the ADRs being evaluated showed sex difference pattern in occurrence rate. For instance, lithium was found to cause more thyroid dysfunction in women, and amisulpride induced prolactin increase was more pronounced in women than in men. Some serious ADRs were also found to exert sex difference pattern, such as clozapine induced neutropenia was more prevalent in women whereas simvastatin/atorvastatin-related abnormal liver functions were more pronounced in men.

Characteristics of adverse reactions among antipsychotic drugs using the Korean Adverse Event Reporting System database from 2010 to 2019

BACKGROUND

Retrospective studies using spontaneous reporting system databases have provided a great understanding of adverse drug reactions (ADRs) in the real world, complementing the data obtained from randomized controlled trials. However, there have been few reports on large-scale epidemiological studies on the adverse effects of antipsychotics in Asia.

AIM

This study aimed to investigate the characteristics of antipsychotic ADRs using a nationwide pharmacovigilance database.

METHODS

Data were collected from the Korea Adverse Event Reporting System database between 2010 and 2019. The study subjects were selected using the International Classification of Disease codes for diseases related to psychosis and Electronic Data Interchange codes for amisulpride, aripiprazole, clozapine, haloperidol, olanzapine, paliperidone, quetiapine, risperidone, and ziprasidone. The causality assessment of "possible," "probable," or "certain" by the World Health Organization-Uppsala Monitoring Center System causality category was selected. All data were descriptively analyzed.

RESULTS

In total, 5067 adverse events associated with antipsychotic drugs were reported. The antipsychotics that commonly resulted in ADRs were quetiapine (47.7%), olanzapine (11.3%), and clozapine (10.7%). Serious ADRs were most commonly observed with clozapine. Gastrointestinal and central nervous system problems occurred within a month when ADRs were classified according to the time of onset. In contrast, metabolic and bone marrow-related symptoms occurred after long-term use. Sedation and nausea were the most common ADRs in children and adolescents, whereas constipation and dizziness were common in adults and the elderly.

CONCLUSIONS

This study extends our knowledge of antipsychotic ADRs in the Asian population.

Prevalence and clinical characteristics of COVID-19 in inpatients with schizophrenia in Wuhan, China

BACKGROUND

In contrast to many Western countries, China has maintained its large psychiatric hospitals. The prevalence and clinical characteristics of coronavirus disease 2019 (COVID-19) in inpatients with schizophrenia (SCZ) are unclear.

AIM

To assess the prevalence of COVID-19 among inpatients with SCZ and compare the infected to uninfected SCZ patients in a Wuhan psychiatric hospital.

METHODS

We retrospectively collected demographic characteristics and clinical profiles of all SCZ patients with COVID-19 at Wuhan’s Youfu Hospital.

RESULTS

Among the 504 SCZ patients, 84 had COVID-19, and we randomly sampled 174 who were uninfected as a comparison group. The overall prevalence of COVID-19 in SCZ patients was 16.7%. Among the 84 SCZ patients with confirmed COVID-19, the median age was 54 years and 76.2% were male. The most common symptom was fever (82%), and less common symptoms were cough (31%), poor appetite (20%), and fatigue (16%). Compared with SCZ patients without COVID-19, those with COVID-19 were older (P = 0.006) and significantly lighter (P = 0.002), and had more comorbid physical diseases (P = 0.001). Surprisingly, those infected were less likely to be smokers (< 0.001) or to be treated with clozapine (P = 0.03). Further logistic regression showed that smoking [odds ratio (OR) = 5.61], clozapine treated (OR = 2.95), and male (OR = 3.48) patients with relatively fewer comorbid physical diseases (OR = 0.098) were at a lower risk for COVID-19. SCZ patients with COVID-19 presented primarily with fever, but only one-third had a cough, which might otherwise be the most common mode of transmission between individuals.

CONCLUSION

Two unexpected protective factors for COVID-19 among SCZ inpatients are smoking and clozapine treatment.

Clozapine in patients with schizoaffective disorder: A systematic review

Schizoaffective disorder is defined by the appearance of positive psychotic symptomatology as well as affective features, even when it is considered a controversial nosologic entity, proving difficult to accord on its definition or diagnostic criteria. Due to these conceptual differences, it has been a challenge to study effective therapeutic measures and, consequently, the availability of data in the current literature, resulting in the extrapolation of clinical guidelines and recommendations initially established for patients with schizophrenia or bipolar disorder. The current study aimed to systematically search and summarize the published evidence to date about the use of clozapine in patients with schizoaffective disorder. Seven studies were identified, that are heterogeneous on their designs and methodology, including samples of patients mixed with bipolar or schizophrenic disorders. The evidence was summarized both in a table and a narrative fashion, suggesting that clozapine may be an effective treatment for both psychotic and affective symptoms, indistinctively of an acute or maintenance phase.

Monitoring for myocarditis during treatment initiation with clozapine

OBJECTIVE

Clozapine use is associated with myocarditis. In this study, we investigated what clinical signs and symptoms, and/or laboratory test(s), alert clinicians to presumptive myocarditis (PrMy) most accurately and at the earliest time point. We also investigated the incidence of PrMy during the initial exposure to clozapine versus in patients restarted on clozapine after extended interruption of prior prolonged treatment.

METHODS

100 patients admitted to state psychiatric hospital started on clozapine were recruited into the study. 76 patients were treated with clozapine for the first time and 24 patients were restarts. Creatine kinase (CK), troponin I (TROP), eosinophil count (EOS), and C-reactive protein (CRP) were obtained at baseline and weeks 1, 2, 3, and 4. Descriptive statistics were calculated for demographic and clinical variables. Student's t test and chi-squared test were used to compare means and proportions between initial exposure and restart groups.

RESULTS

Clinical features and laboratory tests suggestive of PrMy were seen in 4 patients (5.3%) in initial exposure group and none in restart group. 3.5% of TROP levels were abnormal in initial exposure group and no abnormal levels were found in the restart group. 30% and 46% of CK, 23% and 39% of CRP, and 14% and 23% of EOS were abnormal in initial exposure group and restart groups, respectively.

CONCLUSIONS

PrMy was common (5.3%) during clozapine initiation. Prospective management through serial laboratory monitoring with weekly TROP levels was sensitive enough to allow for timely clozapine discontinuation.

Let's talk about sex: Differences in drug therapy in males and females

Professor Henry Higgins in My Fair Lady said, 'Why can't a woman be more like a man?' Perhaps unintended, such narration extends to the reality of current drug development. A clear sex-gap exists in pharmaceutical research spanning from preclinical studies, clinical trials to post-marketing surveillance with a bias towards males. Consequently, women experience adverse drug reactions from approved drug products more often than men. Distinct differences in pharmaceutical response across drug classes and the lack of understanding of disease pathophysiology also exists between the sexes, often leading to suboptimal drug therapy in women. This review explores the influence of sex as a biological variable in drug delivery, pharmacokinetic response and overall efficacy in the context of pharmaceutical research and practice in the clinic. Prospective recommendations are provided to guide researchers towards the consideration of sex differences in methodologies and analyses. The promotion of disaggregating data according to sex to strengthen scientific rigour, encouraging innovation through the personalisation of medicines and adopting machine learning algorithms is vital for optimised drug development in the sexes and population health equity.

Clozapine tolerability in Treatment Resistant Schizophrenia: exploring the role of sex

Clozapine is the only evidence-based drug indicated for Treatment Resistant Schizophrenia but it is largely underprescribed, partially due to its life-threatening adverse effects (AEs). However, clozapine treatment is burdened by other common AEs as constipation, hypersalivation, postural hypotension, tachycardia and metabolic abnormalities. Few studies have investigated sex-related differences in clozapine's tolerability, reporting women to experience more frequently weight gain, hyperglycemia and constipation, while men hypertension and dyslipidemia. Based on these premises, we investigated clinical, psychopathological and metabolic sex-related differences among 147 treatment-resistant patients treated with clozapine, with a specific focus on non-life-threatening AEs. We observed significant higher prevalence of tachycardia in men, and of orthostatic hypotension and constipation in women. Concerning metabolic alterations, we observed significant lower levels of HDL-cholesterol and higher prevalence of hypertriglyceridemia among men, whereas females showed higher prevalence of abdominal obesity. Consistently with previous studies, our data confirm the presence of sex-related differences in clozapine tolerability, with a main effect of sex especially for tachycardia, postural hypotension and constipation. Although non-life-threatening, these common AEs significantly affect patients' quality of life, undermine compliance and cause treatment discontinuation. A better understanding of this topic could contribute to tailor therapeutic approaches, thus improving tolerability, compliance and clinical stability.

Clozapine in patients with schizoaffective disorder: A systematic review

Schizoaffective disorder is defined by the appearance of positive psychotic symptomatology as well as affective features, even when it is considered a controversial nosologic entity, proving difficult to accord on its definition or diagnostic criteria. Due to these conceptual differences, it has been a challenge to study effective therapeutic measures and, consequently, the availability of data in the current literature, resulting in the extrapolation of clinical guidelines and recommendations initially established for patients with schizophrenia or bipolar disorder. The current study aimed to systematically search and summarize the published evidence to date about the use of clozapine in patients with schizoaffective disorder. Seven studies were identified, that are heterogeneous on their designs and methodology, including samples of patients mixed with bipolar or schizophrenic disorders. The evidence was summarized both in a table and a narrative fashion, suggesting that clozapine may be an effective treatment for both psychotic and affective symptoms, indistinctively of an acute or maintenance phase.

Systematic review and meta-analysis of rates of clozapine-associated myocarditis and cardiomyopathy

BACKGROUND

Clozapine is the most effective medication for treatment refractory schizophrenia, but is associated with cardiac adverse drug reactions. Myocarditis and cardiomyopathy are the most serious cardiac adverse drug reactions although reported rates of these conditions vary in the literature. We systematically reviewed and meta-analysed the event rates, the absolute death rates and case fatality rates of myocarditis and cardiomyopathy associated with clozapine.

METHODS

PubMed, EMBASE and PsycINFO were searched for studies that reported on the incidence of cardiomyopathy or myocarditis in people exposed to clozapine. Data were meta-analysed using a random effects model, with subgroup analysis on study size, time frame, region, quality, retrospective vs prospective, and diagnostic criteria of myocarditis or cardiomyopathy.

RESULTS

28 studies of 258,961 people exposed to clozapine were included. The event rate of myocarditis was 0.007 (95% confidence interval [CI] = [0.003, 0.016]), absolute death rate was 0.0004 (95% CI = [0.0002, 0.0009]) and case fatality rate was 0.127 (95% CI = [0.034, 0.377]). The cardiomyopathy event rate was 0.006 (95% CI = [0.002, 0.023]), absolute death rate was 0.0003 (95% CI = [0.0001, 0.0012]) and case fatality rate was 0.078 (95% CI = [0.018, 0.285]). Few included studies provided information on criteria for diagnosis of myocarditis and cardiomyopathy. Event rates of cardiomyopathy and myocarditis were higher in Australia.

CONCLUSION

Clarity of diagnostic criteria for myocarditis remains a challenge. Observation bias may, in part, influence higher reported rates in Australia. Monitoring for myocarditis is warranted in the first 4 weeks, and treatment of comorbid metabolic syndrome and diabetes may reduce the risk of cardiomyopathy. The risks of myocarditis and cardiomyopathy are low and should not present a barrier to people with treatment refractory schizophrenia being offered a monitored trial of clozapine.

A systematic review of sex-based differences in effectiveness and adverse effects of clozapine

Clozapine is one of the most widely used antipsychotics for treating psychiatric illnesses such as schizophrenia and bipolar disorder. This drug, however, is associated with adverse effects such as weight gain, metabolic syndrome, and blood dyscrasias. The manifestations of mental illness may differ between men and women. Yet, there is little evidence on the influence of sex on treatment response or the occurrence of AEs. To fill this gap of knowledge, we carried out a systematic review of the literature on sex differences in the effectiveness and adverse effects of clozapine. Scant evidence has been published on differences in effectiveness of clozapine between men and women. Indeed, to the best of our knowledge, this issue has only been addressed in a published study. Regarding adverse effects, males have been reported to be more likely to develop metabolic abnormalities such as cholesterol or triglycerides, hypertension, and cardiovascular risk, while females are at a higher risk for gaining weight, developing diabetes, and needing laxatives. Nevertheless, given the scarcity of sex-based studies on this drug, further studies are needed to explore sex-based differences, as the results obtained may be crucial to clinical practice and help improve the quality of life of patients.

A comparative study of detection of myocarditis induced by clozapine: With and without cardiac monitoring

The aim of this study was to investigate and compare the incidence of suspected or definite cases of clozapine induced myocarditis (SDM) and clinical factors which could influence its onset in two different time periods, defined by pre- and post-cardiac monitoring at an inpatient setting, during the initiation phase of clozapine treatment. Hospital records of patients started on clozapine in the inpatient unit between 2011 and 2018 were investigated. Eight in 38 patients (11.3%) were classified as SDM after the initiation of the monitoring protocol, whereas only 1 in 33 patients (1.4%) was classified as SDM, before. Monitored and non-monitored patient groups were similar with regard to demographic and clinical variables. Diagnosis of schizoaffective disorder and use of concominant lithium, valproic acid and atypical antipsychotics were higher in patients with SDM, while clozapine dose titration was similar compared to the rest of the patients. Cardiac monitoring seems to be the main factor leading to the increase in the detection of clozapine induced myocarditis (CIM). If not monitored, the outcome of CIM can be fatal without any warning signs and symptoms. Concominant use of mood stabilizers including valproic acid and lithium, are important risk factors for the development of CIM.

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.

Women who suffer from schizophrenia: Critical issues

Many brain diseases, including schizophrenia, affect men and women unequally - either more or less frequently, or at different times in the life cycle, or to varied degrees of severity. With updates from recent findings, this paper reviews the work of my research group over the last 40 years and underscores issues that remain critical to the optimal care of women with schizophrenia, issues that overlap with, but are not identical to, the cares and concerns of men with the same diagnosis. Clinicians need to be alert not only to the overarching needs of diagnostic groups, but also to the often unique needs of women and men.