Nephrotoxicity Associated with Intravenous Colistin in Critically Ill Patients

Abstract

To determine the frequency of nephrotoxicity associated with colistin therapy by using a standardized definition and to identify risk factors for colistin-induced nephrotoxicity in critically ill patients. Single-center, retrospective cohort analysis. University-affiliated tertiary care center. Forty-nine adults admitted to an intensive care unit who received intravenous colistin for at least 48 hours between July 2007 and July 2009. Nephrotoxicity was determined by using the standardized RIFLE criteria: risk, injury, failure, loss, and end-stage renal disease. Patients who had end-stage renal disease or required renal replacement therapy before initiation of colistin were excluded. Of the 49 patients included in the analysis, 15 (31%) developed nephrotoxicity, and only two patients (4%) had irreversible cases. Patients with chronic kidney disease (40% in the group with nephrotoxicity vs 3% in the group without nephrotoxicity, p=0.002) and hypertension (87% vs 56%, p=0.037) at baseline had a higher risk of developing nephrotoxicity. In addition, patients with nephrotoxicity were more likely to have received intravenous contrast material (33% vs 0%, p=0.002). The risk of developing nephrotoxicity was 6.5 times higher in patients who had been given at least two concomitant nephrotoxic agents compared with no other nephrotoxic agents (p=0.034). The frequency and severity of colistin-induced nephrotoxicity in critically ill patients was consistent with previous reports in non-critically ill patients. Most cases of nephrotoxicity demonstrated in this study were mild and reversible. Patients receiving colistin therapy who have hypertension or chronic kidney disease should be monitored closely, and administration of additional nephrotoxic agents should be avoided in all patients when possible. Large, prospective trials are warranted to confirm these results.