Clozapine Dose-Concentration Relationship and Other Factors Associated With Clozapine Plasma Concentration in Korean Schizophrenia Patients
10.16946/kjsr.2023.26.2.46
- Author:
Seonghyeon RYU
1
;
Gyeonghyeong CHO
Author Information
1. Jeollabuk-do Maeumsarang Hospital, Wanju, Korea
- Publication Type:Original Article
- From:Korean Journal of Schizophrenia Research
2023;26(2):46-51
- CountryRepublic of Korea
- Language:Korean
-
Abstract:
Objectives:Some reports suggest that the concentration-to-dosage ratio (C/D ratio) of clozapine (CZP) in Asian treatment-resistant schizophrenia (TRS) patients differs from that of Caucasian TRS patients. However, there is insufficient research on the differences in C/D ratio between Korean TRS patients and Caucasian TRS patients. Therefore, this study aimed to investigate prescribed CZP dosage, CZP concentration and C/D ratio in Korean TRS patients.
Methods:The study included TRS patients aged 18 years or older who were prescribed CZP for at least 12 weeks at a psychiatric hospital in Korea. We collected demographic information, smoking status, hospitalization status, CZP serum concentration, total CZP dosage, and norclozapine (NCZP) serum concentration and analyzed their statistical correlations.
Results:The study found that the average daily CZP dosage was 266.1 mg, and the average CZP concentration was 568.0 ng/mL. There was a significant correlation between CZP serum concentration and smoking status, as well as sex. CZP dosage was not significantly associated with age, weight, BMI, or metabolic rate. The study also found a significant difference in C/D ratio between groups based on CZP serum concentration.
Conclusion:Our study suggests that recommended CZP dosages for Caucasians may not be suitable for Koreans due to C/D ratio differences. We found a relationship between CZP serum concentration and C/D ratio in Korean TRS patients. Therefore, it is crucial to confirm CZP serum concentration to avoid side effects and to find optimal dosage.
