Early acute kidney injury is a risk factor that predicts mortality in patients treated with colistin.

The nephrotoxicity of colistin has been reported in the literature. A previous report has shown that acute kidney injury (AKI) occurred after an average of 13.5 days, but we have experienced that AKI developed with colistin administration earlier. We investigated clinical features of patients who developed AKI according to the time of AKI development after colistin use. We retrospectively collected the data of the patients who were admitted to 4 hospitals between January 2007 and May 2009. This study included 119 patients who had received intravenous colistin for over 72 h. We compared the early AKI group (AKI developed within 7 days) with the late AKI group. The patients' age was 64.1 ± 14.0 years. AKI occurred in 65 of the 119 patients (54.6%). The duration of colistin use was 7.7 ± 6.4 days. AKI occurred in 46 patients within 7 days after colistin treatment and in 19 patients after 7 days. The patients with early AKI had a higher mortality rate than those with late AKI (OR: 4.37, 95% CI: 1.34, 14.18). In conclusion, clinicians might be cautioned that the mortality rate is higher for the patients with early occurrence of AKI than that for the patients with late occurrence of AKI.