Safety profile of clozapine: Analysis using national registry data in Japan

Recurrent reactive hypoglycemia due to clozapine-induced glucose intolerance: A case report

Background

Although diabetes is one of the most common side effects of clozapine, a medication for the treatment of schizophrenia, to the best of our knowledge no study exists on clozapine-induced glucose intolerance or hypoglycemia in patients with schizophrenia.

Case Presentation

We report a case of schizophrenia with repeated reactive hypoglycemia due to abnormal glucose tolerance during clozapine treatment. During clozapine administration in patients with schizophrenia, it is necessary to monitor physical and psychiatric symptoms due to reactive hypoglycemia and hyperglycemia. If abnormal glucose tolerance is a concern, it should be promptly detected using blood or oral glucose tolerance tests.

Conclusion

Early intervention for impaired glucose tolerance may prevent clozapine discontinuation due to diabetes or hyperglycemia.

Data Mining for Risks of Clozapine Side Effects, Including Neutropenia, Associated with Lithium Carbonate Administration: Analysis Using the Japanese Adverse Drug Event Report Database

BACKGROUND AND OBJECTIVE

Clozapine use is associated with development of neutropenia, and lithium carbonate may be co-administered to reduce this risk; however, this has not yet been adequately investigated. The present study examined whether lithium administration is associated with the risks of clozapine side effects, including neutropenia.

METHODS

Data on patients taking clozapine, extracted from the Japanese Adverse Drug Event Report (JADER) database, were analyzed. Patients who developed clozapine side effects were identified by the Standardized Medical Dictionary for Regulatory Activities Queries. The relationship between the use of lithium and risk of clozapine side effects was examined using logistic regression analysis.

RESULTS

The use of lithium was reported in 530 out of 2,453 clozapine users. Hematopoietic leukopenia, convulsion, and noninfectious myocarditis/pericarditis developed in 109, 87, and seven lithium-treated patients, and in 335, 173, and 62 untreated patients, respectively. Univariate analysis showed no relationship between lithium administration and the risks of hematopoietic leukopenia (adjusted odds ratio (aOR) 1.11; 95% confidence interval (CI) 0.98-1.25), and the association with the risks of convulsion (aOR 1.41; 95% CI 1.23-1.62) and noninfectious myocarditis/pericarditis (aOR 0.63; 95% CI 0.43-0.94). Multivariate analysis revealed that lithium use was independently associated with the risks of convulsion (aOR 1.40; 95% CI 1.21-1.60) and noninfectious myocarditis/pericarditis (aOR 0.62; 95% CI 0.41-0.91).

CONCLUSION

The risks of seizure and myocarditis, but not of neutropenia, in clozapine-treated patients may be altered by lithium. Although the JADER database is based on spontaneous reporting, the present results warrant further study.

A case study of the utilization of clozapine treatment for treatment-resistant schizophrenia associated with 22q11.2 deletion syndrome

BACKGROUND

The optimal treatment strategy for patients with treatment-resistant schizophrenia (TRS) associated with 22q11.2 deletion syndrome (DS) remains a subject of debate.

CASE PRESENTATION

We present the case of a 40-year-old female patient diagnosed with TRS and 22q11.2DS who was effectively treated with clozapine. She was diagnosed with schizophrenia and mild intellectual disability during her adolescence; despite being hospitalized for a period of 10 years beginning in her 30s, she continued to exhibit symptoms of impulsivity, and explosive behavior, requiring periods of isolation. We ultimately decided to switch her medication to clozapine, which was administered with caution and gradually titrated upward, with no discernable adverse effects, resulting in a marked improvement in her symptoms and obviated the need for isolation. Subsequently, the patient's history of congenital heart disease and facial abnormalities prompted initial suspicions of a 22q11.2DS diagnosis, which was subsequently confirmed through genetic testing.

CONCLUSION

Clozapine may serve as an efficacious pharmacological intervention for TRS patients with 22q11.2DS, including those of Asian descent.

Long-lasting leukocytosis in patients with schizophrenia treated with clozapine after electroconvulsive therapy : ECT stabilizes white blood cell count

INTRODUCTION

The present study was conducted to investigate the possible hematologic impact of long-term electroconvulsive therapy (ECT) in patients with drug-resistant schizophrenia and receiving clozapine therapy.

SUBJECTS AND METHODS

In this retrospective study, clinical charts of 57 hospitalized patients with schizophrenia who required clozapine therapy because of active psychotic symptoms resistant to other antipsychotics were examined. For 18 who underwent ECT, the first assessment was conducted at the end of that therapy (average two months after start, 7.68 sessions) and the second two months later. As for the 39 patients who did not undergo ECT, the first and second assessment points were at two and four months, respectively, after a randomly chosen time point.

RESULTS

Multiple regression analysis revealed that modified ECT (m-ECT) (ß = 0.346, p = 0.005), gender (males showed greater increase) (ß = 0.273, p = 0.023), and disease duration (longer associated with greater increase) (ß = 0.258, p = 0.033) were correlated with a change in white blood cell (WBC) count (ΔR2 = 0.277, p < 0.001) at the first assessment point. At the second assessment point, multiple regression analysis showed that m-ECT (ß = 0.262, p = 0.039), gender (males showed greater increase) (ß = 0.264, p = 0.036), and disease duration (longer associated with greater increase) (ß = 0.234, p = 0.068) were again correlated with changed WBC count (ΔR2 = 0.203, p < 0.007).

DISCUSSION

An increase in leukocytes may have a protective influence against the adverse myelosuppressive effects of clozapine. However, a simple mobilization of leukocytes from bone marrow to peripheral circulation may not enhance the immune system, leading to only a masking of the effects of a potential immuno-insufficient state in the treated patient. In either case, should leukocytosis be induced and then remain for an extended period, hematologists, as well as psychiatrists involved in electroconvulsive intervention for clozapine-treated patients, must keep this factor in mind.