Clozapine: the commitment to patient safety.

Clozapine represents the "gold standard" therapy for treatment-resistant schizophrenia including use for symptom reduction and use in patients intolerant of extrapyramidal side effects associated with other antipsychotics. Despite its clear benefit in these areas, its use has been associated with a serious, and sometimes life-threatening, risk for agranulocytosis. Effective white blood cell monitoring systems have been developed by Novartis affiliates across the world to ensure its safe use and to meet local health standards. The goals of the monitoring programs include: (1) weekly white blood cell monitoring during the initial months of therapy for early detection of severe leukopenia; (2) immediate discontinuation of clozapine if severe leukopenia is observed; (3) exclusion from reexposure to clozapine if a patient experiences clozapine-induced agranulocytosis; and (4) early cessation of treatment if hematologic guidelines are not followed ("no blood, no drug" policy). Together, these systems have demonstrated a worldwide reduction in the observed rate of agranulocytosis and in fatalities related to the emergence of agranulocytosis when rigorous monitoring systems are in place.