Overuse of Vancomycin Therapeutic Drug Monitoring: High Effort for Low Risk
Year: 2015
Type: article
Study design: Observational Study
Abstract: Background. Vancomycin is the second most highly utilized antibiotic at UCLA Health. The intention of this investigation was to evaluate the impact of vancomycin therapeutic drug monitoring (TDM) on patient care, including frequency of dosing changes made based on appropriate and inappropriately drawn trough concentrations as well as rate of nephrotoxicity. Methods. This was a retrospective chart review of inpatients during September 2014. Eligible subjects were those who received vancomycin and had TDM with a trough concentration > 20 mcg/mL. Appropriate timing of trough concentrations was assessed in relation to vancomycin doses in subjects not dependent on renal replacement therapy (RRT). We recorded whether dosing decisions were made based upon these serum concentrations. Rate of acute kidney injury (AKI), defined according to the risk-injury-failure-loss-end-stage renal disease (RIFLE) classification scheme, was collected in subjects not on RRT at baseline. Confirmed MRSA infection per clinical and microbiological data was documented. Results. Three hundred ninety individuals received vancomycin and had TDM, resulting in 714 vancomycin serum concentrations. We included 94 subjects with a trough concentration >20 mcg/mL. Of these, 15 were dependent on RRT at baseline. The median duration of vancomycin therapy was 4 days. Per course of vancomycin therapy, a median of 4 vancomycin serum concentrations were drawn. For those on RRT, a median of 7 concentrations were drawn. Tenty-five percent of subjects (20 of 79 not on RRT) had troughs drawn inappropriately. Vancomycin dosing changes were made in 11 of 20 (55%) of these cases. AKI occurred in 28 of 79 subjects (35%). The majority was categorized as risk or injury; however, 5 subjects (6%) met criteria for failure. MRSA infection was confirmed by culture in 5 of 94 subjects (5%). Conclusion. Frequent serum TDM of vancomycin requires high-resource utilization from nursing, phlebotomy, pharmacy, and physicians. Given low rates of confirmed MRSA infection and low rates of renal failure, 5% and 6% in this investigation, the significant time spent monitoring serum drug concentrations may be unwarranted and associated with increased patient-care costs. Disclosures. All authors: No reported disclosures.
Source: Open Forum Infectious Diseases
Language: English
Subfield: Pharmacology
Field: Medicine
Domain: Health Sciences
Open Access status: gold
Estimated APC paid: $4,053
OpenAlex ID: W2280723904