Ziprasidone population pharmacokinetics and co-medication effects in Chinese patients

Ziprasidone is widely used in the treatment of psychiatric disorders. Despite its prevalence, there is a notable lack of population pharmacokinetics (PPK) studies on ziprasidone in serum, both domestically and internationally. This study aimed to comprehensively investigate the various factors influencing the PPK characteristics of Ziprasidone, thereby providing a scientific basis for personalized treatment strategies in clinical settings. This is a retrospective study. A non-linear mixed-effects modeling method was used for data analysis, with the ziprasidone PPK model established using the Phoenix NLME 8.1 software. Model evaluation employed goodness-of-fit plots, visual predictive checks, and Bootstrap methods to ensure reliability and accuracy. To further validate the model's applicability, data from an additional 30 patients meeting the same inclusion criteria but not included in the final model were collected for external validation. Simulations were performed to explore the personalized dosage regimens. This retrospective analysis collected 547 drug concentration data points from 185 psychiatric disorder patients, along with related medical records. The data included detailed demographic information (such as age, gender, weight), dosing regimens, laboratory test results, and concomitant medication details. In the final model, Ka was fixed at 0.5 h^-1 based on literature, and the population typical values for ziprasidone clearance (CL) and volume of distribution (V) were 18.74 L/h and 110.24 L, respectively. Co-administration of lorazepam and valproic acid significantly influenced the clearance of ziprasidone. Moreover, the model evaluation indicated good stability and predictive accuracy. A simple to use dosage regimen table was derived based on the results of simulations. This study successfully established and validated a PPK model for ziprasidone in Chinese patients with psychiatric disorders. The model provides a scientific reference for individualized dosing of ziprasidone and holds the potential to optimize treatment strategies, thereby enhancing therapeutic efficacy and safety.