Population Pharmacokinetics of Vancomycin in Critically Ill Patients Undergoing Continuous Renal Replacement Therapy: Influence of Adsorptive Membranes

Vancomycin is commonly used to treat Staphylococcus aureus infections. In critically ill patients receiving continuous renal replacement therapy (CRRT), adsorptive membranes like oXiris may alter drug pharmacokinetics. This retrospective study developed a population pharmacokinetics (PopPK) model using MonolixSuite software, incorporating adsorptive membrane use as a covariate. The final one-compartment model estimated that the population volume of distribution of vancomycin was 94.97 L (RSE 10.5%) and population clearance was 2.82 L/h (RSE 19.0%). Adsorptive membrane use was a significant covariate, slightly increasing vancomycin clearance, while aging was associated with reduced clearance. Monte Carlo simulations indicated that a regimen of 2 g loading dose followed by 1 g every 24 h achieved an AUC_0–24/MIC ≥ 400 mg h/L in more than 90% of patients. Individualized vancomycin dosing in this population should consider membrane type, along with patient-specific factors such as age, to optimize therapeutic outcomes.