Nephrotoxicity and efficacy assessment of polymyxin use in 92 transplant patients.

Polymyxins are old antimicrobials, discontinued for many years because of nephrotoxicity and neurotoxicity reports and reintroduced recently due to the increasing frequency of multiresistant Gram-negative bacterial infections. There are very few data related to toxicity and efficacy from transplanted patients, the major subjects of this study. All solid-organ-transplanted patients from our institution during January 2001 to December 2007 who used polymyxins were retrospectively assessed for nephrotoxicity and treatment efficacy. Microbiological and clinical cure rates were 100% and 77.2%, respectively. Only transplant patients subjected to at least 72 h of intravenous polymyxin were entered in the study. Overall, 92 transplant patients were included, and the nephrotoxicity rate was 32.6%. Multivariate analysis showed a statistically significant association between duration of polymyxin treatment (P = 0.037; odds ratio [OR], 1.06; 95% confidence interval [CI], 1.00 to 1.12) and significant renal dysfunction. Polymyxin use is associated with very high rates of significant decrease in renal function; therefore, polymyxin must be used only when no other option is available and for as briefly as possible in the solid organ transplant setting.