Changes for clozapine monitoring in the United States

Clozapine is a unique compound that is particularly effective for treatment-resistant schizophrenia (TRS). The use of clozapine is limited, however, due to the 0.8% risk of agranulocytosis,1 which necessitates a strict monitoring of neutrophil counts to detect early neutropenia and prevent progression to agranulocytosis. The US Food and Drug Administration (FDA) in 2015 allowed greater flexibility to continue or re-challenge clozapine in patients who have experienced neutropenia on clozapine.2 Lithium and granulocyte-colony stimulating factor (G-CSF) have been used as preventative therapies for patients with a history of clozapine-induced neutropenia upon clozapine re-challenge.