Comprehensive Assessment of Colistin Induced Nephrotoxicity: Incidence, Risk Factors and Time Course.

Purpose: In recent years, the emergence of multidrug-resistant (MDR) microorganisms had caused the resurgence of colistin use after it was previously abandoned due to its side effects, nephrotoxicity in particular. However, the specific incidence of colistin-induced nephrotoxicity varies in reports with different populations. This study aims to assess the incidence of colistin-associated nephrotoxicity and the associated risk factors. Patients and Methods: This study was on 178 patients who received colistin for more than 48 hours during the years 2019-2022, who were followed up for 14 days after the initiation of colistin, and demographic and clinical data were gained from medical reports. Logistic regression was used to assess the relationship between nephrotoxicity and study variables. Results: The incidence of nephrotoxicity was 44.9% (95% confidence interval (CI); 37% to 53%), and the overall mortality was 33%, with a significantly higher level among patients with nephrotoxicity. The significant risk factors for nephrotoxicity after adjustment were; higher weights (OR = 1.1, 95% CI; 0.03-1.2), P-value: 0.006, and the combination with carbapenem showed a significant protective effect (OR = 0.09, 95% CI; 0.01-0.8), P-value: 0.03. The severity, according to KDIGO classification, was stage 1 (47%), stage 2 (21%), and stage 3 (31%). Higher stages had earlier onset acute kidney injury, a lower percentage of returning to baseline, and exposure to a higher colistin dose. Conclusion: Colistin-induced nephrotoxicity was a frequent issue associated with higher weights, mitigated by the combination with carbapenems. While higher colistin dosages, and earlier onset AKI, were linked to the progression to higher AKI stages and the need for dialysis.