Evaluation of the Efficacy of Colistin Therapy with or without Loading Dose in the Treatment of Multi Drug Resistant Gram-negative Bacterial Infections

Aim: Colistin (Col) is an agent used in the treatment of multidrug-resistant gram-negative (MDRGN) bacterial infections. This drug has been administered with a loading dose in recent years to provide rapid clinical response and therapeutic blood levels. In our study, we aimed to evaluate whether there is a relationship between the efficacy of the loading dose of Col treatment, mortality, microbiological clearance during treatment, nephrotoxicity, and neurotoxicity side effects for the treatment of MDRGN bacterial infections. Material method: In this retrospective study, which included a control group, 6-years data was analyzed. Totally, 323 patients who received Col treatment with or without loading dose (LD) were included in the study. Patients were divided into two groups; I: without Col-LD regimen (those who were hospitalized in 2011-2014), II: with Col-LD regimen (those who were hospitalized in 2015-2017). Demographic characteristics such as age, gender, microbiological cultures, laboratory results, side effects, and mortality of the patients were evaluated. Results: A statistically significant relationship was found between with Col-LD regimen and nephrotoxicity. However, it was determined that there was no statistically significant relationship between microbiological clearance without a Col-LD regimen. Nephrotoxicity was found to be decreased with the Col-LD regimen. Neurotoxicity was observed more frequently (3.7%) in with Col-LD regimen. Initial and final C-reactive protein (CRP) and procalcitonin (PCT) levels were statistically significantly lower in with Col-LD regimen. Conclusion: It was found that with Col-LD regimen had a statistically significant effect on nephrotoxicity, neurotoxicity, and treatment outcome, but had no effect on microbiological clearance. In addition, with Col-LD regimen was effective in decreasing CRP and PCT values.