A 6-year retrospective study of olanzapine plasma concentration inpatients with schizophrenia CYP1A2 polymorphisms in real-life settings

Aim: to investigate the potential influence of CYP1A2 polymorphisms on olanzapine plasma concentration of inpatients with schizophrenia in real-life settings.

Methods: 409 inpatients who received OLA for at least 2 weeks, from June 2016 to March 2022 were included in the retrospective investigation. Moreover, 503 samples of above inpatients receiving OLA was built to investigate the influence of the relevant OLA plasma concentration, polymorphisms CYP1A2 -163C/A on the inpatients outcome.

Results: Scale score reduction rate (SSRR) in 1 mutated CYP1A2 -163C/A alleles (CA) was significantly higher than other CYP1A2 alleles (CC + AA) (P = 0.002). Inverse S-curve correlations relationship was between SSRR and plasma concentrations of OLA (r = 0.130, P < 0.005). When remove ineffective subjects (ineffective group), the results of all CYP1A2 -163C/A genotype showed perfect correlations relationship tendencies with SSRR (r = 1.000). The best concentrations of OLA corrected for daily dose (C/D) range and the best concentration range of OLA of all CYP1A2 -163C/A genotype was 3.18-3.53 ng/mL/mg and 17.42-57.33 ng/mL. The C/D range and concentration range of OLA were 2.722-4.221 ng/mL/mg and 13.61-84.42 ng/mL, which belong CYP1A2 -163C/A CA genotype subjects, was largest.

Conclusions: The best effective C/D range and concentration range of OLA respective were 3.18-3.53 ng/mL/mg and 17.42-57.33 ng/mL, which range values of CYP1A2 -163C/A CA genotype of inpatients with schizophrenia was largest.