The Role of Adjunctive Ascorbic Acid in the Prevention of Colistin-Induced Nephrotoxicity in Critically Ill Patients: A Retrospective Study

BackgroundColistin antibiotic is considered a valuable and last-resort therapeutic option for MDR gram-negative bacteria. Nephrotoxicity is the most clinically pertinent adverse effect for colistin. Vivo studies suggest that administering oxidative stress-reducing agents, such as ascorbic acid, is a promising strategy to overcome colistin-induced nephrotoxicity (CIN). However, limited clinical data explores the potential benefit of adjunctive ascorbic acid therapy for preventing CIN. Therefore, this study aims to assess the potential nephroprotective role of ascorbic acid as adjunctive therapy against CIN in critically ill patients. MethodThis was a retrospective cohort study at King Abdulaziz Medical City (KAMC) for all adult critically ill patients who have received IV Colistin. Eligible patients were classified into two groups based on the ascorbic acid use as concomitant therapy within three days of colistin initiation. The primary outcome was CIN odds after colistin initiation, while the secondary outcomes were 30-day mortality, in-hospital mortality, ICU, and hospital LOS. Propensity score (PS) matching was used (1:1 ratio) based on the patient’s age, SOFA score, and serum creatinine. ResultsA total of 451 patients were screened for eligibility; 90 patients were included after propensity score matching based on the selected criteria. The odds of developing CIN after colistin initiation were similar between patients who received ascorbic acid (AA) as adjunctive therapy compared to patients who did not (OR (95%CI): 0.83 (0.33, 2.10), p-value=0.68). In addition, the 30-day mortality, in-hospital mortality, ICU, and hospital LOS were similar between the two groups. ConclusionConcomitant use of Ascorbic acid with colistin was not associated with lower odds of colistin-induced nephrotoxicity. Further studies with a larger sample size are required to confirm these findings.