Continuation of Clozapine During Chemotherapy: A Case Report and Review of Literature

Abstract

Clozapine is an atypical antipsychotic medication that has been shown to bemore effective in the treatment of refractory schizophrenia and the reduction of suicidal behavior in individuals with schizophrenia and schizoaffective disorder than other antipsychotics. Because of the 0.38% annual risk of agranulocytosis associated with clozapine use, prescription requires enrollment in a national registry with submission of complete blood count results before the medication is dispensed. Standard protocols require clozapine discontinuation or increased monitoring or both if absolute neutrophil counts (ANC) go below certain thresholds. Concerns about prolonged clozapine-induced neutropenia arise when patients require chemotherapy for the treatment of malignancy, which frequently induces a predictable but temporary period of neutropenia. We present the case of a patient being treated with clozapine who was diagnosed with lung cancer and who, in collaboration with his psychiatrist and oncologist, decided to continue clozapine during treatment with myelosuppressive chemotherapy.