Therapeutic Drug Monitoring Coupled with Bayesian Forecasting Could Prevent Vancomycin-Associated Nephrotoxicity in Renal Insufficiency Patients: A Prospective Study and Pharmacoeconomic Analysis

Background: Vancomycin is a critical antibiotic used in important infections, and therapeutic drug monitoring (TDM) is recommended. Bayesian forecasting is demonstrated to provide an approach that can improve trough concentration monitoring for dose adjustment. The objective of this study was to determine whether TDM coupled with a Bayesian approach could increase trough concentration target attainment and prevent vancomycin-associated nephrotoxicity in patients with renal insufficiency. Methods: A prospective study was performed using propensity score matching to provide covariate balance in renal insufficiency patients with gram-positive bacterial infections treated with vancomycin. Patients were divided into non-TDM (84 cases) and TDM (84 cases) groups, and their clinical outcomes were compared. The primary endpoints were probability of trough concentration target attainment and incidence of vancomycin-associated nephrotoxicity. A decision-tree model was developed to assess the cost effectiveness of TDM to prevent vancomycin-associated nephrotoxicity. Results: Of the 168 eligible patients, 69 from each group (non-TDM and TDM) were matched based on propensity scores. In the matched cohort, trough concentration target attainment was higher with TDM (P = 0.003). Furthermore, reaching toxic trough concentrations was avoided (P = 0.027) in the TDM group. Multivariate logistic regression analysis confirmed that TDM practice independently reduced the incidence of vancomycin-associated nephrotoxicity in renal insufficiency patients (P = 0.021). According to this reduced nephrotoxicity, the incremental cost-effectiveness ratios of ¥22,638 per nephrotoxic episode prevented was found for vancomycin TDM. Conclusions: TDM coupled with Bayesian forecasting led to an increase in trough concentration target attainment and a decrease in the incidence of vancomycin-associated nephrotoxicity in renal insufficiency patients. In this high-risk population, TDM was demonstrated to be a cost-effective procedure.