Metabolic Side-effects in Patients receiving Clozapine and Second-generation antipsychotics in an Out-patient Cinic

Abstract

[Objective]: This study aimed to investigate the metabolic side-effects in a cohort of Chinese subjects receiving clozapine and seven other commonly used second-generation antipsychotics (SGAs) in an out-patient setting. We hypothesized that the metabolic side-effects should be different for clozapine and amongst these SGAs. [Method]: This was a retrospective naturalistic cohort study with subjects recruited from a local psychiatric out-patient clinic from 2009 to 2011. Data was collected from those subjects consented to enroll in the territory-wide program—“Monitoring of Metabolic Side Effects for Patients on SGAs”. The diagnosis of metabolic syndrome was made in accordance to the definition proposed by the International Diabetes Federation (IDF) for the Chinese ethnicity. Parameters for metabolic syndrome, and body mass index (BMI) were compared from baseline to the 1-year follow-up end-point. [Results]: A total of 241 Chinese subjects with the mean age of 46.4 years were analyzed. 71% was suffered from schizophrenia. 35.7% of the subjects had been switched from the first generation antipsychotics to SGAs, 27.4% from one SGA to another SGA, and 36.9% started treatment with a SGA during the study period. None of the antipsychotics under study showed statistically significant association in causing metabolic syndrome at the study end-point. Quetiapine was the only SGA that showed a statistically significant increase in BMI from 22.3±3.7 at baseline to 27.2±4.5 at the 1-year end-point (p<0.05). [Conclusion]: Further study would be needed to explore factors that contribute to a lesser association of metabolic syndrome in Chinese population treated with clozapine and SGAs.