OBJECTIVE: Extended meropenem infusion is increasingly employed to enhance clinical outcomes in critically ill patients. Nonetheless, investigations into such dosing regimens in renal-impaired patients undergoing continuous renal replacement therapy (CRRT) are scarce. This study aims to perform a population pharmacokinetic (PK) analysis of prolonged meropenem infusion in critically ill CRRT patients to inform optimal dosing regimens. METHODS: Ninety-four concentrations from 21 Chinese critically ill CRRT patients receiving 1 g meropenem every 8-12 hours infused over 2-3 hours were utilized to construct the population PK model. Monte Carlo simulations were employed to assess the efficacy based on PK/PD targets (100% RESULTS: Meropenem concentration data was adequately described by a one-compartment model with linear elimination, and creatinine clearance (CLCR) significantly influenced meropenem's endogenous clearance. 0.5 g q6h and 1 g q8h could achieve desirable attainment of 100% CONCLUSION: A population PK model was developed for prolonged meropenem infusion in Chinese CRRT patients, and 0.5 g q6h and 1 g q8h may be the optimal regimen for prolonged infusion.