Colistin- and polymyxin-induced nephrotoxicity: focus on literature utilizing the RIFLE classification scheme of...

With the reintroduction of colistimethate and polymyxin B into clinical practice, a review of their individual and comparative nephrotoxicity attributes as reported in contemporary literature was undertaken. Given variability in definitions used for acute kidney injury, a particular focus was placed on studies utilizing the Risk-Injury-Failure-Loss-End Stage Kidney Disease (RIFLE) criteria of assessment to provide for standardized comparison. Primary risk factors examined included the influence of dosing and the receipt of concomitant nephrotoxins. The typical severity and time course of renal injury that develops were also analyzed. Nephrotoxicity rates with colistimethate appear to approach 50%, and could be of lower frequency and severity with polymyxin B based on limited literature. Acute kidney injury generally appears to be mild to moderate in magnitude and reversible in nature, though as many as 20% of patients experiencing it may require renal replacement therapy of some duration. The majority of studies showed some relationship with dosing- variably reported as being associated with daily dose or cumulative exposure. Traditional nephrotoxic agents did not appear to confer additional risk individually in the majority of investigations, though receipt of multiple concurrent nephrotoxins did yield a relationship in several. Further studies will be required to better characterize the renal adverse effect profile of these agents, particularly in the case of polymyxin B.