Polymyxin B loading doses, multiple nephrotoxic drug use up risk of AKI

Polymyxin B-associated nephrotoxicity is still a major concern in China, with the use of polymyxin B loading doses and the combined use of multiple nephrotoxic drugs independently adding to an increased risk of acute kidney injury (AKI), a study has found.

The analysis included 251 patients who received polymyxin B for hospital-acquired pneumonia (HAP) due to carbapenem-resistant A. baumannii or carbapenem-resistant Enterobacteriaceae in China. Researchers reviewed the patients’ medical records and applied logistic regression models to determine the factors associated with polymyxin B-associated incident AKI.

Of the patients, 84 (33.5 percent) developed AKI. Patients in the AKI and non-AKI groups were not significantly different in terms of disease severity (SOFA score: p=0.1946; APACHE II score: p=0.6811). However, the AKI group had lower estimated glomerular filtration rate (eGFR; mean, 94.90 vs 112.55; p=0.0008) and higher creatinine levels (mean, 71.50 vs 57.95; p=0.0008) when HAP was diagnosed, although the values remained within the normal range.

A multivariate logistic regression model showed that the occurrence of AKI was independently associated with the polymyxin loading dose (hazard ratio [HR], 1.84, 95 percent confidence interval [CI], 1.01–3.38; p=0.0491) and use of two or more nephrotoxic drugs (HR, 3.56, 95 percent CI, 1.55–8.18; p=0.0029).

Meanwhile, a higher eGFR exerted a protective effect against AKI risk (HR, 0.99, 95 percent CI, 0.98–0.99; p=0.0006). The daily dose, cumulative dose, and treatment duration of polymyxin B did not influence the occurrence of AKI.