Rechallenge Following Clozapine-Associated Eosinophilia: A Case Report and Literature Review

Adverse hematological profiles associated with chlorpromazine antipsychotic treatment in male rats: Preventive and reversal mechanisms of taurine and coenzyme-Q10

Chlorpromazine (CPZ) is one of the most effective antipsychotic drugs used for managing psychotic related disorders owing to its dopamine receptor blocking action. However, pharmacological investigations against CPZ's cytotoxic effect have remained scarce. Hence, this study investigated the preventive and reversal effects of taurine and coenzyme-Q10 (COQ-10), which are compounds with proven natural antioxidant properties, against CPZ-induced hematological impairments in male rats. In the preventive study, rats received oral saline (10 ml/kg), taurine (150 mg/kg/day), COQ-10 (10 mg/kg/day) or in combination for 56 days, alongside CPZ (30 mg/kg, p.o.) between days 29-56. In the reversal protocol, rats had CPZ repeatedly for 56 days before taurine and COQ-10 treatments or their combination from days 29-56. Rats were also given taurine (150 mg/kg/day), and COQ-10 (10 mg/kg/day) alone for 56 days. Serums were extracted and assayed for hematological, with oxidative and inflammatory markers. CPZ induced decreased red/white blood cells, erythropoietin, platelet count, packed cell volume and hemoglobin, neutrophil, and lymphocyte, which were prevented and reversed by taurine and COQ-10, or their combination. Taurine and COQ-10 improved mean corpuscular volume, hemoglobin concentration, with increased erythropoietin levels relative to CPZ groups. CPZ-induced increased malondialdehyde, tumor necrosis factor-alpha and interleukin-6 levels with decreased interleukin-10, glutathione, and superoxide-dismutase were prevented and reversed by taurine and COQ-10 in comparison with CPZ groups. Taurine and COQ-10 alone notably improved the antioxidant/anti-inflammatory status relative to controls. Among other mechanisms, taurine and COQ-10 abated CPZ-induced hematological deficiencies, via decreased serum levels of oxidative stress, and pro-inflammatory cytokines release, with increased antioxidants and anti-inflammation function.

Clozapine-induced eosinophilia: A case report

Schizophrenia is a chronic neuropsychiatric illness defined by the appearance of positive, and negative symptoms and/or cognitive impairment. Antipsychotic drugs are predominantly used in the treatment of psychotic disorders, but not all patients with schizophrenia respond to every antipsychotic medication. Clozapine is one of the best atypical antipsychotics and is highly effective in treating treatment-resistant schizophrenia. Evidence suggests that clozapine appears to be effective in lowering the risk of suicide, extrapyramidal side effects, and relapse in patients with schizophrenia. Per contra, clozapine is not the first-line treatment due to its unalterable aftereffects such as agranulocytosis, metabolic syndrome, seizures, and rarely, eosinophilia. Eosinophilia can be life-threatening. Eosinophils infiltrate different tissues and cause inflammation in multiple organs causing end-organ damage. The current study aimed to report the incidence of eosinophilia associated with clozapine use in patients with schizophrenia. Literature on clozapine-induced eosinophilia is relatively scarce. Understanding the progression and management of clozapine-induced eosinophilia and its end-organ effects is imperative. While there is insufficient data about the guidelines in the management of clozapine-induced eosinophilia, this study contributes to understanding the patterns of the disease progression with clozapine dosage. A case study was done on a patient with schizophrenia and autistic spectrum disorder who was on clozapine. Data on how eosinophil levels varied with clozapine dosing was analyzed and documented. The evidence of clozapine dosage affecting eosinophil and C-reactive protein levels in this patient was summarized in a table and a narrative review.

Clozapine Optimization: A Delphi Consensus Guideline From the Treatment Response and Resistance in Psychosis Working Group

BACKGROUND AND HYPOTHESIS

There is limited evidence to guide the approaches to clozapine treatment. Accordingly, an international initiative was undertaken with the aim of developing consensus recommendations for the optimization of clozapine monotherapy.

STUDY DESIGN

We conducted an online Delphi survey among members of the Treatment Response and Resistance in Psychosis (TRRIP) working group comprising experts from twenty-nine countries. The threshold criterion for a consensus recommendation was ≥ 75% agreement ("agree" and "strongly agree" responses) on a question. Agreement of ≥ 50% but < 75% in a second or third Delphi round was deemed to provide guidance.

STUDY RESULTS

Forty-nine (first round), 32 (second round), and 48 (third round) of the 91 current TRRIP members participated. Expert recommendations at ≥ 75% comprised second-line treatment with clozapine in cases of persistent positive symptoms with co-occurring extrapyramidal symptoms, tardive dyskinesia, or suicidality/aggression. There was considerable disagreement on myocarditis screening parameters. The management of somatic and neuropsychiatric adverse drug reactions warrants further research for more evidence-based recommendations. Rechallenge with clozapine was recommended for eosinophilia, sinus tachycardia and fever and guidance (agreement ≥ 50%) was reached for pneumonia and thrombocytopenia.

CONCLUSIONS

Given the limited evidence available, this consensus-based series of recommendations and guidance statements supports clinical decision-making to optimize clozapine monotherapy and provides guidance for future research in treatment-resistant schizophrenia.

Clozapine-Induced Eosinophilia: a Case Report

INTRODUCTION

Clozapine is an atypical antipsychotic drug eligible for treatment-resistant schizophrenia. It frequently represents the best and the only choice in resistant schizophrenia. However, its use is feared by many professionals due to its possible adverse effects, such as eosinophilia.

CASE REPORT

We report a case of a young white male suffering from treatment-resistant schizophrenia who rapidly developed eosinophilia after starting clozapine.

DISCUSSION

We present a case of a 26-year-old white man diagnosed with schizophrenia with poor clinical response to several antipsychotics owing to which clozapine was started. Psychotic symptoms improved dramatically but a progressively ascendant eosinophilia was reported during serial haematological analyses. The patient remained physically asymptomatic. An exhaustive assessment with ancillary diagnostic tests revealed no cause for eosinophilia. Thus, a diagnosis of clozapine-induced eosinophilia was made. The drug was discontinued and eosinophil count progressively returned to normal but psychotic symptoms worsened.

CONCLUSIONS

Clozapine treatment is frequently feared due to its possible side effects and complications, delaying its use in refractory schizophrenia. Also, to our knowledge, there are no specific guidelines on how to manage haematological side effects such as eosinophilia. This is problematic as, in some cases, it may lead to an unnecessary withdrawal of clozapine with a worsening of psychotic symptoms. We present a brief discussion of the recent literature on the subject.

Second to none: rationale, timing, and clinical management of clozapine use in schizophrenia

Despite its enduring relevance as the single most effective and important evidence-based treatment for schizophrenia, underutilization of clozapine remains considerable. To a substantial degree, this is attributable to a reluctance of psychiatrists to offer clozapine due to its relatively large side-effect burden and the complexity of its use. This underscores the necessity for continued education regarding both the vital nature and the intricacies of clozapine treatment. This narrative review summarizes all clinically relevant areas of evidence, which support clozapine's wide-ranging superior efficacy - for treatment-resistant schizophrenia (TRS) and beyond - and make its safe use eminently feasible. Converging evidence indicates that TRS constitutes a distinct albeit heterogeneous subgroup of schizophrenias primarily responsive to clozapine. Most importantly, the predominantly early onset of treatment resistance and the considerable decline in response rates associated with its delayed initiation make clozapine an essential treatment option throughout the course of illness, beginning with the first psychotic episode. To maximize patients' benefits, systematic early recognition efforts based on stringent use of TRS criteria, a timely offer of clozapine, thorough side-effect screening and management as well as consistent use of therapeutic drug monitoring and established augmentation strategies for suboptimal responders are crucial. To minimize permanent all-cause discontinuation, re-challenges after neutropenia or myocarditis should be considered. Owing to clozapine's unique efficacy, comorbid conditions including substance use and most somatic disorders should not dissuade but rather encourage clinicians to consider clozapine. Moreover, treatment decisions need to be informed by the late onset of clozapine's full effects, which for reduced suicidality and mortality rates may not even be readily apparent. Overall, the singular extent of its efficacy combined with the high level of patient satisfaction continues to distinguish clozapine from all other available antipsychotics.

Clozapine-Induced Eosinophilia: a Case Report

INTRODUCTION

Clozapine is an atypical antipsychotic drug eligible for treatment-resistant schizophrenia. It frequently represents the best and the only choice in resistant schizophrenia. However, its use is feared by many professionals due to its possible adverse effects, such as eosinophilia.

CASE REPORT

We report a case of a young white male suffering from treatment-resistant schizophrenia who rapidly developed eosinophilia after starting clozapine.

DISCUSSION

We present a case of a 26-year-old white man diagnosed with schizophrenia with poor clinical response to several antipsychotics owing to which clozapine was started. Psychotic symptoms improved dramatically but a progressively ascendant eosinophilia was reported during serial haematological analyses. The patient remained physically asymptomatic. An exhaustive assessment with ancillary diagnostic tests revealed no cause for eosinophilia. Thus, a diagnosis of clozapine-induced eosinophilia was made. The drug was discontinued and eosinophil count progressively returned to normal but psychotic symptoms worsened.

CONCLUSIONS

Clozapine treatment is frequently feared due to its possible side effects and complications, delaying its use in refractory schizophrenia. Also, to our knowledge, there are no specific guidelines on how to manage haematological side effects such as eosinophilia. This is problematic as, in some cases, it may lead to an unnecessary withdrawal of clozapine with a worsening of psychotic symptoms. We present a brief discussion of the recent literature on the subject.

Clozapine in the treatment of refractory schizophrenia: a practical guide for healthcare professionals

BACKGROUND

Clozapine remains the only medication licensed for treating refractory schizophrenia. However, it remains underutilized in part due to concerns regarding adverse events.

SOURCES OF DATA

Published literature.

AREAS OF AGREEMENT

Common adverse events during clozapine treatment include sedation, hypersalivation, postural hypotension, dysphagia, gastrointestinal hypomotility, weight gain, diabetes mellitus and dyslipidaemia. Rare but serious events include agranulocytosis, cardiomyopathy, myocarditis, pneumonia, paralytic ileus and seizure.

AREAS OF CONTROVERSY

It remains unclear how best to minimize clozapine-induced morbidity/mortality (i) during dose titration, (ii) from hypersalivation and (iii) from gastrointestinal hypomotility. It is also unclear how clozapine pharmacokinetics are affected by (i) gastrointestinal hypomotility, (ii) systemic infection and (iii) passive exposure to cigarette smoke. Whether monthly haematological monitoring needs to continue after 12 months of uninterrupted therapy is also a subject of debate.

GROWING POINTS

There is a need for better management of serious clozapine-related adverse events in addition to agranulocytosis. There is also a need for better education of patients and carers, general practitioners, A&E and ITU staff and others of the problems posed in using clozapine safely.

AREAS TIMELY FOR DEVELOPING RESEARCH

There is a need for more research on assessing clozapine dosage (i) as patients get older, (ii) with respect to exposure to cigarette smoke and (iii) optimizing response if adverse events or other factors limit dosage.

Clozapine-associated severe eosinophilia following lithium rebound neutropenia: A case report

Background

Clozapine use is complicated by an increased risk of hematological adverse effects such as neutropenia and, rarely, eosinophilia.

Case presentation

We present the case of a 48‐year‐old man with treatment‐resistant schizophrenia. On day 12 after clozapine initiation, he had a cough with a temperature of 39.8°C. On day 16, his leukocyte count had increased to 9320 cells/mm³ (neutrophils 7550 cells/mm³ and eosinophils 680 cells/mm³). We discontinued lithium because of neutrophilia and damage to renal function on day 20. His eosinophil count increased until day 29, reaching 6750 cells/mm³. We suspected a drug‐induced reaction and discontinued clozapine on day 30. His eosinophil count gradually decreased, reaching the normal range by day 40. However, his leukocyte and neutrophil counts also gradually decreased to below than the normal range by day 40. His leukocytes and neutrophil counts had recovered by day 55.

Conclusion

We concluded that this patient had clozapine‐associated severe eosinophilia following lithium rebound neutropenia.

The eosinophil count increased reaching 6750 cells/mm³ with bronchitis and hepatitis during clozapine treatment. The leukocyte and neutrophil counts gradually decreased to below than the normal range by day 40 after discontinuation of lithium.

Clozapine-related drug reaction with eosinophilia and systemic symptoms (DRESS) syndrome: a systematic review

INTRODUCTION

The Drug Reaction with Eosinophilia and Systemic Symptoms (DRESS) syndrome is a severe, multiorganic, and potentially life-threatening drug-induced hypersensitivity reaction, linked to several common drugs, including antiepileptics, antibiotics, and several psychotropic drugs, including clozapine. Due to the importance of clozapine in the management of treatment-resistant schizophrenia, a systematic review and characterization of clozapine-related DRESS syndrome is long overdue.

AREAS COVERED

This systematic review was conducted following PRISMA guidelines. PubMed, Embase, PsychINFO, and the Cochrane Library databases were independently reviewed up to 1 November 2019 for articles reporting clozapine-related DRESS syndrome cases. The RegiSCAR score system was applied to systematically characterize the clinical presentations of selected studies.

EXPERT OPINION

Clozapine-related DRESS syndrome was reported in six patients from four articles. Five patients received polypharmacy. Skin rash and liver involvement with elevated liver enzymes were very common. No fatal cases were found. Treatment mainly included clozapine discontinuation and immunosuppression. The mismatch between incidences of DRESS with other responsible drugs, the common misdiagnosis of this syndrome, and the fact that an extensive literature search only identified six cases suggests that clozapine-related DRESS may be overlooked. It is, therefore, necessary to optimize diagnostic strategies to identify immune-related side effects of clozapine.

Haematological side effects associated with clozapine: A retrospective study from India

OBJECTIVE

To evaluate the incidence of clozapine induced haematological side effects among patients receiving clozapine.

METHODS

Data of 333 patients who were on clozapine for a mean duration of 52.96 (45.18) months were reviewed for haematological abnormalities.

RESULTS

Most of the patients (n = 320; 96.1 %) were diagnosed with psychotic disorders, mainly schizophrenia. These patients were receiving clozapine in the dose range of 12.5 mg-600 mg/day, with a mean dose of 212.08 (102.43) mg/day at the time of review of their records. About one-tenth (N = 33; 9.9 %) of patients developed eosinophilia (absolute eosinophil count >600), and 8.2 % (N = 27) experienced thrombocytopenia (platelet count <100,000 cmm³) and 7 patients developed anaemia (haemoglobin level <10 gm%). Only 2 (0.6%) patients developed neutropenia. Mean dose (mg/day) at which haematological side-effects occurred were as follows: 159.85 (87.65) mg/day for eosinophilia; 193.98 (148.93) mg/day for thrombocytopenia; 78.57 (22.49) mg/day for anaemia. In a small proportion of patients, clozapine was discontinued due to the haematological abnormalities and in other patients these abnormalities normalized on its own in subsequent follow-up.

CONCLUSION

Clozapine is associated eosinophilia and thrombocytopenia, which are often benign and in majority of the patients these normalize with time.

Clozapine-Related Diarrhea and Colitis: Report of 4 Cases

BACKGROUND

During clozapine treatment, diarrhea is a rare but clinically relevant adverse effect. Cases of microscopic colitis and eosinophilic colitis have been previously reported.

PROCEDURES

We present 4 patients who developed severe diarrhea in early weeks of clozapine therapy.

FINDINGS

Two patients had significant peripheral eosinophilia 1 week after diarrhea symptoms. One of these patients also had Charcot-Leyden crystals in stool afterward, confirming the presence of eosinophils in the gut lumen. One of our patients had a confirmed microscopic colitis and later also neutropenia, which required treatment.

CONCLUSIONS

Charcot-Leyden crystals in stool may be associated with concurrent diarrhea and eosinophilia during clozapine treatment, which is a previously unreported finding. Occurrence of blood dyscrasias with diarrhea symptoms during clozapine treatment needs further investigation to understand the possible shared mechanisms.