To study the clinical efficacy and nephrotoxicity along with the risk factors for acute kidney injury associated with parenteral polymyxin B

The aim of this study was to evaluate the clinical efficacy and nephrotoxicity along with the risk factors for acute kidney injury (AKI) associated with the parenteral polymyxin B in patients with the multidrug resistance (MDR) gram -ve infections in a tertiary Intensive care unit (ICU).A retrospective cohort study (March 2010-October 2011) was conducted in Medical ICU of a 23 bedded tertiary care hospital in Northern India.Out of 71 ICU patients who were administered polymyxin B, only 32 (M:F = 1:0.8) met the inclusion criteria. Patients with concurrent administration of nephrotoxic drugs were excluded from the study. Mean age of patients was 48.53 ± 13.90 years ranging from 16 years to 68 years. 6 out of 32 (18.7%) patients progressed to AKI, whereas renal functions remained normal in 26 (81.2%) patients. No statistically significant difference was observed in mortality between AKI and non AKI patients at the end of therapy (33.3% vs. 26.9%, P value 0.756). Older age (62.33 ± 11.90 vs. 45.34 ± 2.45, P value 0.005) was found to be an independent risk factor for causing nephrotoxicity.In the present scenario of rising infections with MDR gram -ve micro-organisms, this pilot study suggests that polymyxin B can be used effectively and safely in patients not receiving other nephrotoxic drugs, with cautious administration in older patients as they are more vulnerable to nephrotoxicity caused by polymyxin B.