The association between acute kidney injury and Polymyxin B treatment: A retrospective cohort study

Purpose This retrospective study aimed to analyse the impact of polymyxin B (PMB) on nephrotoxicity parameters and identify associated variables. Patients and methods The study, which was conducted at a tertiary general hospital in China, included 84 patients over the age of 18 who had received PMB for a period of more than 48 h. Patients were divided into two groups based on the presence or absence of acute kidney injury (AKI) according to KDIGO standards. The identification of risk factors for PMB–associated AKI was facilitated by data collection and multivariate logistic regression analysis. Results The majority of patients were male, with a median age of 80 years (interquartile range (IQR): 68.5, 87.0) and a median weight of 60.0 kg (IQR: 50.0, 65.0). PMB was administered with a median loading dose of 1.73 mg/kg (IQR: 1.67, 1.82) and a median daily maintenance dose of 1.82 mg/kg (IQR: 1.67, 2.22) over a median treatment duration of 7.75 days (IQR: 5.00, 10.38). The development of AKI was observed in 36 patients (42.9%), with a median time to onset of 5 days (IQR: 3, 6). In the cohort of patients who developed AKI, 11 (30.6%) patients discontinued PMB therapy, while 8 (16.7%) patients required renal replacement therapy (RRT). The study revealed that concurrent chronic kidney disease (CKD) (odds ratio (OR) = 5.47, 95% confidence interval (CI) 1.52–19.64, P = 0.01) and the daily maintenance dose (OR = 12.57, 95% CI 2.84–55.59, P = 0.00) were independently associated with AKI onset following PMB therapy. Conclusions The potential association between PMB therapy and AKI raises clinical concern. Concurrent CKD and higher PMB maintenance doses were identified as independent risk factors for AKI associated with PMB therapy. Consequently, rigorous monitoring of renal function indices and therapeutic drug concentrations is recommended to facilitate early detection of nephrotoxic risks, thereby minimizing renal injury and ensuring the safe administration of PMB.