Factors Affecting Colistin Nephrotoxicity: Advanced Age and/or Other Factors?

Introduction: The population is aging, and older adults comprise most patients in the intensive care units. Colistin (COL) has been re-introduced to treat increasingly common resistant Gram-negative bacterial infections. Our study aims to investigate the factors affecting COL nephrotoxicity in a general population and geriatric age group. Materials and Methods: This retrospective study included 170 patients, a total of 116 (68.2%) of whom were in the geriatric group (age ≥65). Acute renal failure was evaluated using the RIFLE score. Factors associated with COL nephrotoxicity were described firstly in a general population and then in the geriatric group patients. Results: Advanced age [Odds ratio (OR): 1.043; 95% confidence interval (CI): 1.018-1.068; p=0.001] and initial serum creatinine level (OR: 23.122; 95% CI: 3.123-171.217; p=0.002) were found to be the independent risk factors associated with nephrotoxicity. In the evaluation of the geriatric population based on nephrotoxicity, the initial serum urea and creatinine levels, and overall mortality rates were found to be statistically significantly higher in the group with nephrotoxicity (p