Inappropriate vancomycin therapeutic drug monitoring in hospitalized pediatric patients increases pediatric trauma and hospital costs

Objectives: The objective of this study was to measure the appropriateness of vancomycin monitoring in a pediatric tertiary care center and to evaluate the effectiveness of two interventions, autonomous pharmacy therapeutic drug monitoring and health care provider education, in reducing avoidable pediatric patient trauma and hospital cost.

Methods: A retrospective chart review evaluating vancomycin therapeutic drug monitoring (TDM) in pediatric inpatients was performed before and after the introduction of an autonomous pharmacy TDM program and health care provider (HCP) education.

Results: Thirty-five patients were included in our study, prior to any intervention. Of these, 9% of patients had trough concentrations appropriately deferred. Of the total of 64 trough concentrations obtained, 94% were considered to be inappropriate. After the start of the autonomous pharmacy TDM program, of the 54 eligible patients (111 troughs), 9% had trough concentrations appropriately deferred, and 34% were inappropriate. In the 3-month period following the introduction of HCP education in combination with pharmacy TDM, we identified 27 eligible patients. Among those, 15% of the patients had trough concentrations appropriately deferred. Of the 43 trough concentrations obtained, only 9% were considered to be inappropriate. The combination of pharmacy TDM with HCP education decreased annualized hospital cost by 60%, from $13,080 to $5232.

Conclusions: Inappropriate vancomycin TDM occurs commonly in our institution, resulting in unnecessary hospital cost and patient trauma. The combination of pharmacy TDM and HCP education significantly improved clinical practice; however, results were short-lived. Further interventions, such as computer based order entry, will likely be needed to reinforce and improve long-term TDM practice in pediatric patients.