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.

Outcome of COVID-19 mRNA Vaccination in Patients Treated With Clozapine WHO Previously Went Through SARS-COV-2 Infection.

BACKGROUND: The outbreak of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic had multiple consequences for the health care system, especially for patients with mental illnesses. Schizophrenia patients particularly appear to have a higher risk of complications due to coronavirus-19 (COVID-19). Clozapine remains the gold standard for treatment-resistant schizophrenia (TRS). However, the COVID-19 pandemic had an important negative impact on clozapine treatment, mainly because of its administration protocol, which was very difficult to follow during the restrictions imposed in the pandemic, and its side effects in patients with COVID-19 infection. Vaccination is an effective method of avoiding SARS-CoV-2 infection or its severe complications, especially in susceptible populations. Data on adverse events after vaccination against COVID-19 are limited, both in the general population and in schizophrenia patients. STUDY QUESTION: The study aimed to investigate the safety of COVID-19 vaccination in patients treated with clozapine for hematological parameters. STUDY DESIGN: We conducted an analytical cross-sectional study between July 1, 2021, and June 30, 2022. We compared 2 groups of COVID-19 vaccinated patients who had previously experienced SARS-CoV-2 infection: The first group was treated with clozapine, whereas the second group was treated with other antipsychotics. MEASURES AND OUTCOMES: The primary objective was to identify granulocytopenia, leukocytopenia, and lymphocytopenia. The results were measured after the second dose of the Pfizer-BioNTech vaccine. RESULTS: This study included 100 patients. White blood cell count changes were limited to a few cases of mild granulocytopenia (8.16% in the clozapine group and 3.92% in the nonclozapine group, P = 0.37) with no cases of severe granulocytopenia or agranulocytosis. CONCLUSIONS: As far as leukocyte counts are concerned, mRNA COVID-19 vaccination seems to be safe in patients treated with clozapine who previously had SARS-CoV-2 infection. Leukocyte changes had no clinical implications.

A study to evaluate the role of eosinophil count as a prognostic marker for assessing the outcome in patients with COVID 19 infection.

The triaging of COVID 19 patients is of paramount importance to plan further management. There are several clinical and laboratory parameters that help in categorizing the disease severity, triaging, and prognostication. Little is known about the prognostic significance of eosinopenia in predicting the severity of COVID 19 from large hospital data especially from low- and middle-income countries. The objective of this study is to evaluate the level of eosinopenia as an early prognostic marker for assessing the outcomes in COVID 19 patients and to assess the superiority of eosinopenia as a prognostic marker for assessing the outcomes in COVID 19 patients compared to lymphopenia and neutrophil: lymphocyte ratio (NLR). MATERIAL: The study was carried out in a tertiary care hospital. A retrospective longitudinal approach was adopted wherein the hospital records of COVID 19 patients were analysed. Two separate groups of patients were included for analysis to describe the association between initial eosinophil counts of the patients and the clinical outcomes. In the first group, the disease severity in terms of clinical and radiological parameters was compared in patients of COVID 19 presenting with and without the presence of initial eosinopenia. Commonly used markers for triage namely lymphopenia and NLR were compared with the presence of initial eosinopenia among the patients who progressed to moderate and severe disease. In the second group, an analysis of eosinopenia was made among the patients who succumbed to the illness. OBSERVATION: It was seen that 29.6% of patients with eosinopenia had moderate and severe disease compared to those without eosinopenia where only 10.8 % had moderate disease, none had severe disease. It was seen that 19.7% of patients with eosinopenia but no lymphopenia had more severe disease compared to patients with lymphopenia but no eosinopenia where 10.8% of the patients had moderate disease, none had severe disease. In patients younger than 60 years who died of COVID 19, it was found that initial eosinopenia was found in 86 % whereas a high neutrophil: lymphocyte ratio >17 was seen in only 25.6% of patients who died. Thus, implying that is eosinopenia is an important marker of disease severity in COVID 19. CONCLUSION: Eosinopenia is an important parameter in the evaluation of COVID 19 and the presence of it should alert the clinicians regarding the further progression of the disease. It is not only an important marker but also an early marker for severe disease.

Clozapine and COVID-19 Vaccination: Effects on blood levels and leukocytes. An observational cohort study.

OBJECTIVE: To investigate the safety of COVID-19 vaccination in patients on clozapine as regards plasma clozapine concentration and haematological parameters. METHODS: We conducted a multicentre observational cohort study from 22 February 2021 to 2 September 2021. Primary outcomes were clinically relevant increase in clozapine blood levels (>100 µg/L increase compared to baseline) and clozapine alert levels (>1000 µg/L). Secondary outcomes were granulocytopenia, leukocytopenia and lymphocytopenia. Outcomes were measured approximately 5 days after the first and (where applicable) second dose of COVID-19 vaccine. RESULTS: This study included 139 patients. Compared to baseline, clozapine blood levels increased significantly (ES = 0.28, p = 0.003) after the second vaccination. Clinically relevant increases in clozapine blood levels occurred in 20/92 patients (22%) and in 16/56 patients (29%) during the first and second phases, respectively. Clozapine alert levels developed in one patient (1%) following the first dose and in three patients (5%) after the second dose. In both phases, changes in white blood cells (WBC) were limited to mild granulocytopenia (3% and 5%), moderate granulocytopenia (1% and 0%) and leukocytopenia (2% and 3%) without cause for extra monitoring according to the guideline. CONCLUSION: In general, as regards WBC counts COVID-19 vaccination seems to be safe in patients with SMI. Changes in WBC had no clinical implications. Psychoeducation on the symptoms of clozapine intoxication is recommended, especially in patients with clozapine blood levels approaching the upper limit of the therapeutic range. Increase in the C-reactive protein (CRP) level can signal inflammation rapidly and help to prevent clozapine intoxication following vaccination.

No adverse events were observed in clozapine-treated patients on extended hematologic monitoring intervals during the coronavirus pandemic in four psychiatric centers in Japan.

AIM: As an emergency measure during the coronavirus disease pandemic, the monitoring interval for clozapine use was temporarily extended beyond the regulatory requirement in Japan, which is the safest monitoring interval worldwide. In this study, we aimed to explore the effect of this measure on patients undergoing clozapine treatment. METHODS: This retrospective chart review study included patients with treatment-resistant schizophrenia (TRS) who were undergoing clozapine treatment at four psychiatric institutions in Japan. Demographic characteristics and clinical information of these patients were collected on April 27, 2020, when Japanese psychiatrists were virtually allowed to prescribe clozapine beyond the regulatory requirement. Furthermore, information of adverse events related to the emergency measure was collected and analyzed. RESULTS: Of the 41 patients with TRS included in this study, 19 patients underwent extended hematological monitoring during clozapine treatment. No psychiatric or hematological adverse events were observed in the patients during the extended monitoring interval. CONCLUSION: This study suggested that there were few adverse events of clozapine-treated patients related to emergency measures in Japan. However, hematological monitoring intervals during clozapine treatment have been emergently extended worldwide; hence, it is necessary to verify the results of these measures.

Austrian syndrome, ceftriaxone-induced agranulocytosis and COVID-19.

We present a case of a 75-year-old woman with Austrian syndrome: pneumonia, meningitis and endocarditis all due to Streptococcus pneumoniae Transoesophageal echocardiogram demonstrated a large mitral valve vegetation with severe mitral regurgitation. She was treated with intravenous ceftriaxone and listed for surgical repair of her mitral valve. Preoperatively, she developed an idiosyncratic drug-induced agranulocytosis secondary to ceftriaxone, which resolved on cessation of the medication. However, while awaiting neutrophil recovery, she developed an acute deterioration, becoming critically unwell. This deterioration was multifactorial, with acute decompensated heart failure alongside COVID-19. After multidisciplinary discussion, she was considered too unwell for surgery and palliated.

Clozapine: An Updated Overview of Pharmacogenetic Biomarkers, Risks, and Safety—Particularities in the Context of COVID-19 (preprint)

Background: Clozapine (CLZ) use is precarious due to its neurological, cardiovascular, and hematological side effects; however, it is the gold standard in therapy-resistant schizophrenia (TRS) in adults and is underused. Objective: to examine the most recent CLZ data on (a) side effects concerning (b) recent pharmacological mechanisms, (c) therapy benefits, and (d) the particularities of the COVID-19 pandemic. Data sources: a search was performed in two databases (PubMed and Web of Science) using the specific keywords "clozapine" and "schizophrenia," "side effects," "agranulocytosis," "TRS," or "bipolar affective disorder (BAF)" for the last ten years. Study eligibility criteria: clinical trials on adults with acute symptoms of schizophrenia or related disorders. Results: We selected 37 studies, randomized controlled trials (RCTs), and clinical case series (CCS), centered on six main topics in the search area: (a) CLZ in schizophrenia, (b) CLZ in bipolar disorder, (c) side effects during the clozapine therapy, (d) CLZ in pregnancy, (e) CLZ in early-onset schizophrenia, and (f) CLZ therapy and COVID-19 infection. Limitations: We considered RCTs and CCS from two databases, limited to the search topics. Conclusions and implications of key findings: (a) Clozapine doses should be personalized for each patient based on pharmacogenetics testing when available; the genetic vulnerability postulates predictors of adverse reactions' severity; patients with a lower genetic risk could have less frequent hematological monitoring; (b) CLZ-associated risk of pulmonary embolism imposes prophylactic measures for venous thromboembolism; (c) convulsive episodes are not an indication for stopping treatment; the plasma concentration of clozapine is a better side effect predictor than the dosage; (d) COVID-19 infection may enhance clozapine toxicity, generating an increased risk of pneumonia. Therapy must be continued with proper monitoring of the white blood count, and the clozapine dose decreased by half until three days after the fever breaks; psychiatrists and healthcare providers must act together. Background: Clozapine (CLZ) use is precarious due to its neurological, cardiovascular, and hematological side effects; however, it is the gold standard in therapy-resistant schizophrenia (TRS) in adults and is underused. Objective: to examine the most recent CLZ data on (a) side effects concerning (b) recent pharmacological mechanisms, (c) therapy benefits, and (d) the particularities of the COVID-19 pandemic. Data sources: a search was performed in two databases (PubMed and Web of Science) using the specific keywords "clozapine" and "schizophrenia," "side effects," "agranulocytosis," "TRS," or "bipolar affective disorder (BAF)" for the last ten years. Study eligibility criteria: clinical trials on adults with acute symptoms of schizophrenia or related disorders. Results: We selected 37 studies, randomized controlled trials (RCTs), and clinical case series (CCS), centered on six main topics in the search area: (a) CLZ in schizophrenia, (b) CLZ in bipolar disorder, (c) side effects during the clozapine therapy, (d) CLZ in pregnancy, (e) CLZ in early-onset schizophrenia, and (f) CLZ therapy and COVID-19 infection. Limitations: We considered RCTs and CCS from two databases, limited to the search topics. Conclusions and implications of key findings: (a) Clozapine doses should be personalized for each patient based on pharmacogenetics testing when available; the genetic vulnerability postulates predictors of adverse reactions' severity; patients with a lower genetic risk could have less frequent hematological monitoring; (b) CLZ-associated risk of pulmonary embolism imposes prophylactic measures for venous thromboembolism; (c) convulsive episodes are not an indication for stopping treatment; the plasma concentration of clozapine is a better side effect predictor than the dosage; (d) COVID-19 infection may enhance clozapine toxicity, generating an increased risk of pneumonia. Therapy must be continued with proper monitoring of the white blood count, and the clozapine dose decreased by half until three days after the fever breaks; psychiatrists and healthcare providers must act together.

Clozapine. Pharmacodynamic Mechanisms, Potential Pharmacogenetic Biomarkers, and Risks in Schizophrenia. Particularities in the Context of Covid-19. An Updated Overview (preprint)

Background: Clozapine use is precarious due to its side effects - neurological, cardiovascular, and hematological; however, it is the gold standard in the therapy of resistant schizophrenia (TRS) in adults and harshly underused. Objective: Our purpose is to systematically examine the most recent data regarding clozapine in order to update the knowledge in pharmacological mechanisms, therapy benefits versus side effects to optimize its use in the context of a narrow and scarce of resources pathology, with particularities in the COVID-19 pandemic. (2) Data sources: We performed an accurate search in the primary sources of Databases (PubMed, BMC Public Health, Global Health, Cross Ref, Scopus, Web of Science, and Google Scholar) with specific keywords: “clozapine” and “schizophrenia,” “risks” agranulocytosis” “TRS” “bipolar affective disorder” “pregnancy” “early-onset schizophrenia” “resistance”. Study eligibility criteria: we extracted information regarding drug treatment, side effects profile, and efficacy for each trial; (3) Results: Of all the searched data we selected RCT’s, C.T.’s, reviews, systematic reviews, and meta-analyses; Data were converted and analyzed in a random-effects model. We included 45 studies, centered on six main topics in the search area: (a) treatment-resistant schizophrenia, (b) use in bipolar disorder, (c) side effects during the clozapine therapy - agranulocytosis, metabolic side effects, pharmacogenetic severity markers, dysmetabolic side effects, pulmonary embolism, seizure risk – (d) safety of clozapine in pregnancy, (e) clozapine resistance and ECT augmentation, (f) clozapine therapy and COVID-19 infection. Limitations: _______(4) Conclusions and implications of key findings: (a) The genetic vulnerability postulates predictors of severity so clozapine doses should be personalises for each patient based on pharmacogenetic testing; patients with a lower genetic risk may benefit from a more relaxed hematological monitoring schedule; (b) Pulmonary embolism associated with clozapine has a mortality rate of 36.36%, prophylactic measures for venous thromboembolism for six months after initiating therapy is mandatory; (c) Convulsive episodes are not an indication for stopping the treatment, side effect (s.e.) incidence increases with the dose, the plasma concentration of clozapine (1300 ng/ml) it is a better s. e. predictor than the dosage; (d) clozapine refractory improves up to 69% early-onset schizophrenia, assesed by the Brief Psychiatric Rating Scale (BPRS) (e) more pharmacogenetic studies of the Romanian schizophrenic patients are needed in relation with the clozapine therapy in order to define more precise safety margins; (f) COVID-19 infection may enhance clozapine toxicity generating an increased risk of pneumonia therapy must be continued with proper monitoring of the white blood count and with the decrease of the clozapine dose by half until three days after the subside of the fever; psychiatrists and healthcare providers must act togheder. As in the past four decades, research has failed to generate effective novel psycho-pharmaceuticals, there is an urgent need to enhance the access to clozapine for people with TRS at the worldwide level. The progress of pharmacogenetic researches, endocrinology, genetic testing - offer the psychiatrists nowadays the chance to use this drug at its highest potential in a personalized manner for every patient - minimizing the adverse side-effects.

The impact of COVID-19 on ischemic stroke: A case report (preprint)

BackgroundThe outbreak of a novel coronavirus since December 2019 in Wuhan, became an emergency of major international concern. As of March 5, 2020, the SARS-CoV-2 epidemic has caused 80,565 confirmed infections with 3,015 fatal cases in China. The SARS-CoV-2 outbreak is a major challenge for clinicians. In our clinic, we found a rare case that a COVID-19 patient combined with ischemic stroke.Case PresentationA 79-year-old man was admitted to the Hubei Provincial Hospital of Chinese Traditional Medicine due to right limb weakness for 1 day and slight cough for 1 week. At presentation, his body temperature was 37.3°C (99.0°F) with some moist rales. Neurological examination showed right limb weakness, and the limb muscle strength was grade 4. The left leg and arms were unaffected. In addition, runs of speech were not fluent enough with tongue deviation. Laboratory studies showed lymphopenia and eosinophilic granulocytopenia. Chest CT revealed bilateral pulmonary parenchymal ground-glass and consolidative pulmonary opacities, with a peripheral lung distribution. Real-time polymerase chain reaction (RT-PCR) from throat swab sample was positive for SARS-CoV-2 nucleic acid. This patient was treated with antiviral drugs and anti-inflammatory drugs with supportive care until his discharge. Clopidogrel (75 mg) and atorvastatin (20 mg) were administered orally to treat acute ischemic stroke. After twelve days of treatment, he can walk normally and communicate with near fluent language.ConclusionWe report an even more unusual case, a patient who was hospitalized for right limb weakness and was later diagnosed with COVID-19. Here, SARS-CoV-2 infection caused hypoxemia and excessive secretion of inflammatory cytokines, which contribute to the occurrence and development of ischemic stroke. Once COVID-19 patients show acute ischemic stroke, neurologists should cooperate with infectious disease doctors to help patients.