Population pharmacokinetics and limited sampling strategies of polymyxin B in critically ill patients

Therapeutic drug monitoring of polymyxin B in critically ill patients would benefit from a simplified sampling approach, but characterizing its population pharmacokinetics in Chinese patients was a necessary first step. This study analyzed 212 samples from 30 critically ill patients to build a two-compartment population pharmacokinetic model with Phoenix NLME, then developed a limited sampling strategy using Bayesian estimation and regression methods. Continuous renal replacement therapy and body weight significantly affected polymyxin B clearance, and a two-sample strategy (plasma collected 0.5 and 8 hours after infusion) was identified as sufficient for therapeutic drug monitoring. This limited sampling approach could facilitate more practical, individualized polymyxin B dosing in critically ill patients.