[Position Paper] Absolute neutrophil count and adverse drug reaction monitoring during clozapine treatment: consensus guidelines from a global Delphi panel

Despite its superior effectiveness for treatment-resistant schizophrenia, clozapine has a high burden of adverse drug reactions (ADRs), which require monitoring and treatment. This global Delphi study has established consensus guidelines for absolute neutrophil count (ANC) thresholds for consideration of clozapine cessation and provided monitoring protocols for ADR management. Recommendations include lowering ANC thresholds for consideration of clozapine cessation to 1·0 × 109 cells per L (0·5 × 109 cells per L for Duffy antigen receptor for chemokines-null individuals) and discontinuing routine ANC monitoring after 2 years.