Colistin (Polymyxin E) Use in Abdominal Solid Organ Transplant Recipients

Background: Patients undergoing solid organ transplantation are at a higher risk of multi-drug resistant (MDR) bacterial infections especially during the immediate post operative period. Objective: To audit the usage, dosage appropriateness and safety of colistin use in abdominal solid organ transplant recipients to treat immediate post-transplant bacterial infections. Methods: After completion of 1000 abdominal solid organ transplants at our institute, data of the transplant recipients who received colistin between October 2010 and December 2019 was extracted from the hospital health information system. Data of all microbiological culture isolates, the minimum inhibitory concentration (MIC) of colistin, appropriateness of colistin dosing and nephrotoxicity associated with colistin use was assessed. Results: Of the 1170 (732 liver and 438 renal) solid organ transplant recipients, 82 (66 liver and 16 renal) received colistin to treat posttransplant MDR bacterial infections. Nearly 60% received colistin as definitive therapy and 87.81% received colistin as combination. Mean duration of colistin therapy was found to be higher in renal than liver transplant recipients. Out of the total 89 bacterial isolates, there were 2 colistin resistant Klebsiella strains. Colistin in combination with meropenem (36.4%) was the most commonly used dual therapy. Out of the total 89 bacterial isolates, there were 2 colistin resistant Klebsiella strains. Overall in-hospital mortality of patients who received colistin was 43.9%. Renal impairment occurred in 28.8% of liver transplant recipients. Conclusion: Infection necessitating colistin use increases mortality by three folds in liver transplant recipients and by five percentage points in renal transplant recipients.