Comparison of Hematologic Variability between Clozapine Monotherapy and Augmentation Therapy with Atypical Antipsychotics for Schizophrenia: Results from a 6-Month Retrospective Follow-Up Study / 대한정신분열병학회지

ABSTRACT

OBJECTIVES: Clozapine is an antipsychotic agent commonly prescribed in patients with treatment-resistant schizophrenia. A drawback of using clozapine is risk of hematologic side effects ranging from mild neutropenia to fatal agranulocytosis. In clinical settings, other atypical antipsychotic agents are frequently combined with clozapine because some treatment-resistant patients would not respond to clozapine alone. Unfortunately, other atypical antipsychotics may also cause hematologic side effects, and the combination therapy might aggravate the possible neutropenic side effects. The purpose of this study was to investigate the difference in the incidence of hematologic side effects between clozapine monotherapy and augmentation therapy. METHODS: We retrospectively reviewed the medical records of 114 patients who were diagnosed with schizophrenia and being prescribed with clozapine in a single university hospital. White blood cell count (WBC) and absolute neutrophil count (ANC) were identified every 1 month in clozapine monotherapy group and clozapine-atypical antipsychotics augmentation therapy group. RESULTS: Compared with clozapine monotherapy group, augmentation therapy group showed no significant differences in WBC and ANC for the first 6 months of combination. Amisulpride augmentation showed temporary increases in WBC and ANC, especially compared with paliperidone augmentation. CONCLUSION: Augmentation of amisulpride to clozapine might be associated with temporary increases in WBC and ANC during the first 3 months of combination. Further investigations should be carried out to clarify the clinical significance of our findings.