Granulocyte colony stimulating factor (G-CSF) can allow treatment with clozapine in a patient with severe benign ethnic neutropaenia (BEN): a case report.

Clozapine is the treatment of choice for treatment-resistant schizophrenia, but it is associated with a risk of neutropaenia and agranulocytosis. Clozapine use is regulated by mandatory blood monitoring in the UK, requiring cessation of treatment should the absolute neutrophil count (ANC) drop below specified values. Benign reductions in the ANC in non-white populations are common, and this can preclude a patient from receiving treatment with clozapine. A diagnosis of benign ethnic neutropaenia can reduce these treatment restrictions (UK specific), but the degree of neutropaenia can be significant enough to still prevent treatment. In this report, we show that response to granulocyte colony stimulating factor (G-CSF) may be quite variable and difficult to predict, but with careful monitoring it can be used to increase the ANC count and allow continued treatment with clozapine.