Clozapine related risk of lymphoid malignancies in Treatment-Resistant Schizophrenia – A case report and review of the literature

Abstract

Clozapine is an atypical antipsychotic drug, without extrapyramidal side effects, showing potential for the treatment of resistant forms of schizophrenia, which affects approximately 30% of patients diagnosed with this disease. The risk of agranulocytosis encountered in patients using clozapine is not the only reason that psychiatrists hesitate. Moreover, has been observed a correlation between clozapine use and the development of lymphomas and even acute leukemia in some patients. We present a 47-years-old patient diagnosed with Treatment-Resistant Schizophrenia (TRS) on clozapine medication for almost eight years, who developed Chronic Lymphocytic Leukemia/Small Cell Lymphoma (CLL/SCL). We also performed a literature review using the PUBMED database regarding the hematological malignancy– induced effects of clozapine in long-term treatment-resistant schizophrenia patients.
In our patient, interruption of clozapine treatment was followed by severe acute psychosis and agitation, but the reuse of clozapine stabilized him. We treated the patient with chemotherapeutic agents without interrupting clozapine, and we did not observe any additional hematological worsening during the treatment. Clozapine is the drug of choice for patients with TRS. Numerous studies have demonstrated a correlation between clozapine use and the development of hematological malignancies. In such a situation, it is strongly recommended to perform blood tests on TRS patients while receiving therapy, bearing in mind that each of them may be at risk of developing hematological malignancies.