OBJECTIVES: This study documents the incidences of agranulocytosis and neutropenia, and the patterns of incidence of the side effects of long-term clozapine treatment in order to determine an appropriate time to stop the Clozaril Patient Monitoring System (CPMS). METHODS: Hematological, demographic, and other data from the CPMS for 6782 patients who took clozapine for the past 11 years in the Republic of Korea has been analyzed. RESULTS: Twenty-nine (53.7%) of fifty-four agranulocytosis cases occurred within the first 18 weeks. The cumulative incidence of agranulocytosis was 1.64% between 6 and 11 years and the crude incidence was 0.8%. Neutropenia occurred in 697 patients, and 365 (52.4%) of these cases occurred within the first 18 weeks. The cumulative incidence of neutropenia was 19.8% between 8 and 11 years, and the crude incidence was 10.3%. There were no cases of agranulocytosis or neutropenia after the 9th year of clozapine treatment. CONCLUSIONS: The incidence of agranulocytosis in the Republic of Korea was similar to those in the rest of the world. While agranulocytosis began several years after clozapine treatment, long-term monitoring of white blood cells is necessary. We suggest that the CPMS should be stopped or less frequently after the 9th year of treatment.
OBJECTIVES: This study documents the incidences of agranulocytosis and neutropenia, and the patterns of incidence of the side effects of long-term clozapine treatment in order to determine an appropriate time to stop the ClozarilPatient Monitoring System (CPMS). METHODS: Hematological, demographic, and other data from the CPMS for 6782 patients who took clozapine for the past 11 years in the Republic of Korea has been analyzed. RESULTS: Twenty-nine (53.7%) of fifty-four agranulocytosis cases occurred within the first 18 weeks. The cumulative incidence of agranulocytosis was 1.64% between 6 and 11 years and the crude incidence was 0.8%. Neutropenia occurred in 697 patients, and 365 (52.4%) of these cases occurred within the first 18 weeks. The cumulative incidence of neutropenia was 19.8% between 8 and 11 years, and the crude incidence was 10.3%. There were no cases of agranulocytosis or neutropenia after the 9th year of clozapine treatment. CONCLUSIONS: The incidence of agranulocytosis in the Republic of Korea was similar to those in the rest of the world. While agranulocytosis began several years after clozapine treatment, long-term monitoring of white blood cells is necessary. We suggest that the CPMS should be stopped or less frequently after the 9th year of treatment.
Authors: Kristin N Maher; Marcus Tan; Julia W Tossell; Brian Weisinger; Peter Gochman; Rachel Miller; Deanna Greenstein; Gerald P Overman; Judith L Rapoport; Nitin Gogtay Journal: J Child Adolesc Psychopharmacol Date: 2013-03 Impact factor: 2.576