Colistin-induced nephrotoxicity and the role of N-acetylcysteine: a retrospective cohort study

Introduction: Colistin is associated with dose-dependent nephrotoxicity. N-acetylcycteine (NAC) may reduce the risk of concomitant acute kidney injury (AKI) due to its antioxidant properties. We report a retrospective cohort study evaluating the role of N-acetylcysteine (NAC) in the development of colistin (COL) associated nephrotoxicity. Methodology: A single centre retrospective cohort study was conducted in a university hospital between January 2014 and June 2015. Nephrotoxicity was defined and staged per the RIFLE (Risk, Injury, Failure, Loss of kidney function, and End-stage kidney disease) criteria. We evaluated the association between NAC use and COL-related nephrotoxicity by comparing the incidence of nephrotoxicity in patients receiving colistin with or without adjunctive NAC. Results: Forty-six patients received intravenous (IV) COL and 46 patients received IV NAC+COL. The cumulative COL doses did not differ between the two groups (p = 0.802). The initial creatinine value doubled in 29 (63%) patients undergoing NAC+COL therapy and in 27 (58.7%) patients in the COL group (p = 0.669). The median doubling time of baseline creatinine was 6 and 7 days in the NAC+COL and COL groups, respectively. The mean hospital stay, potentially nephrotoxic agent use, and mortality rates were statistically higher for the patients receiving NAC+COL (p < 0.005). Conclusions: The present study was not able to reveal any beneficial effect of NAC for patients undergoing COL therapy. The NAC+COL group had a higher baseline risk for development of AKI. However, the incidence of AKI was comparable between the groups. The results of the study would not solely exhibit the protective effect of adjunctive NAC therapy.