The Incidence Rate of Hypertension in Schizophrenic Patients Treated with Clozapine or Olanzapine

Kim, Won; Woo, Young Sup; Yoon, Bo Hyun; Kim, Seung Lyong; Chae, Jeong Ho; Bahk, Won Myong

Abstract

OBJECTIVE
There were reports about weight gain, hyperglycemia, diabetes mellitus and hyperlipidemia associated with atypical antipsychotics. Moreover, these adverse effects of atypical agents, especially clozapine and olanzapine were reported to be able to precipitate cardiovascular disease. Accordingly, we investigated the incidence rate of hypertension in schizophrenic patients treated with clozapine or olanzapine by retrospective chart review. METHOD: We reviewed charts of patients with schizophrenia who admitted at St. Mary's Hospital, The Catholic University of Korea, and Naju National Hospital and selected records of patients treated with clozapine and olanzapine during at least 6 weeks. Patients treated with mood stabilizers, antidepressants, and antipsychotics other than clozapine and olanzapine were excluded. Finally, the records of 52 clozapine-treated patients and 76 olanzapine-treated patients were analyzed. Changes of systolic and diastolic blood pressure between before treatment and discharge time were analyzed by paired t-test. The incidence rates of hypertension before and after treatment were compared by McNemar test, and Cochran-Mantel-Haenszel test was used to compare incidence rates between clozapine and olanzapine treated group. Group difference of changes were analyzed by repeated measures ANOVA. RESULTS: The incidence rate of hypertension in clozapine treated group was increased after treatment. There was significant differences in the change of hypertension incidence rate in patients receiving clozapine versus olanzapine. However, there was no significant change in both systolic blood pressure and diastolic blood pressure in clozapine-treated patients. In olanzapine-treated patients, there was significant change in systolic and diastolic blood pressure. Repeated measures ANOVA indicated that antipsychotics medication induced decrease in systolic blood pressure, and diastolic blood pressure was decreased in olanzapine-treated patients. CONCLUSION: Our findings suggest that long-term clozapine treatment is associated with increased rates of hypertension, which may have a significant impact on medical morbidity and mortality.