The importance of the recognition of benign ethnic neutropenia in black patients during treatment with clozapine: case reports and database study

Clozapine is the treatment of choice in refractory schizophrenia. Its more extensive use is limited by adverse effects and the need for regular blood monitoring. However, black patients are disadvantaged with respect to clozapine usage. Lower baseline Absolute Neutrophil Count compared with Whites leads to a greater frequency of blood testing, treatment interruptions and discontinuation. This may in part be explained by Benign Ethnic Neutropenia, but too few black patients are thus registered. The four cases described in this report underline some of the difficulties if this problem is under-recognized. Moreover, in our sample of 191 clozapine recipients in an inner London hospital, black patients account for approximately half, but only a small proportion, 8/95 (8.4%) are registered as having Benign Ethnic Neutropenia. None of the Benign Ethnic Neutropenia-registered patients discontinued treatment for haematological reasons. To optimize clozapine treatment and improve long-term outcomes, a significantly greater proportion of Black patients should be registered as having Benign Ethnic Neutropenia.