Relationship between clinical efficacy and plasma concentration-dose ratio of risperidone in patients with schizophrenia

Abstract

This study aimed to retrospectively explore the relationship between clinical efficacy and plasma concentration–dose ratio of risperidone (RIS) in 252 patients with schizophrenia taking RIS orally. After the same dose of RIS treatment, the plasma concentration of RIS/9-hydroxyrisperidone (9-OH-RIS), the total plasma concentration of RIS, and the ratio of the steady-state plasma concentration to the daily dose of the total active product (C/D) showed individual difference. The RIS plasma concentration was significantly higher in patients taking high doses than those taking lower doses (P = 0.003). There was a statistically significant difference in C/D ratio between males and females (P = 0.003). There were significant differences in ratio of C/D and the total plasma concentration of RIS between patients under 60 years and over 60 years (P = 0.016; P = 0.005). Logistic regression analysis showed that the therapeutic effect and adverse reactions of RIS were correlated with the ratio of C/D in patients with schizophrenia (P = 0.038; P < 0.001). It has been suggested that the importance of monitoring of the plasma concentration of RIS in patients with schizophrenia and the ratio of C/D may be used as the reference for RIS personalized treatment.