Vancomycin Monitoring: Is AUC Monitoring Appropriate for More Than Just Serious MRSA Infections?

Methodist Health System146 enrolled

Overview

Vancomycin, a glycopeptide antibiotic, is commonly prescribed as initial therapy for hospitalized patients due to its broad gram-positive coverage. Vancomycin is used for the treatment and prevention of a variety of bacterial infections ranging from streptococcal to methicillin-resistant Staphylococcus aureus (MRSA) infections.1 Notable adverse effects of intravenous vancomycin include nephrotoxicity, ototoxicity and hypersensitivity reactions. Given its pharmacokinetic profile, therapeutic drug monitoring is essential in determining the therapeutic efficacy of vancomycin as well as for avoiding nephrotoxicity. The 2020 guidelines continue to enforce AUC/MIC as the preferred PK/PD parameter, but now recommend utilizing vancomycin peak and trough concentrations to target an AUC/MIC of 400-600 mg\*h/L for serious MRSA infections. Although this AUC goal is not new, the 2009 consensus guidelines previously recommended trough only monitoring as a simplistic surrogate marker for attaining this AUC goal. Furthermore, the most accurate way of calculating AUC requires obtaining two steady state vancomycin serum concentrations over one dosing period. In this way, AUC guided monitoring requires more pharmacist and nursing time, the use of more hospital resources and additional cost to the patient. As was true of the 2009 guidelines, the 2020 guidelines also leave certain questions unanswered. The paucity and conflicting data of vancomycin monitoring in patients with non-serious MRSA infections (skin and soft tissue infections, urinary tract infections, etc.), methicillin-sensitive Staphylococcus aureus (MSSA) infections and non-staphylococcal pathogen infections has left no guidance on the ideal vancomycin PK/PD targets in these patient populations. A literature search of AUC/MIC monitoring in patients with streptococcal and enterococcal infections yielded very few studies in patients with enterococcal infections and no studies in patients with streptococcal infections.

Study Type

OBSERVATIONAL

Interventions

Retrospective chart reviewOTHER

Retrospective chart review to be conducted at Methodist Charlton Medical Center (MCMC) in Dallas, TX. Adult patients who received vancomycin while inpatient at MCMC with at least one corresponding vancomycin trough level taken at steady state will be included. All vancomycin orders by providers are entered as pharmacy to dose; thus dosing and routine monitoring is conducted by pharmacists.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 100 Years

Medical Language ↔ Plain English

Inclusion Criteria: * Patients hospitalized from June 2020- January 2021. * 18 years and older * At least 1 vancomycin trough concentration drawn at steady state * Organism with an MIC of 2 mg/L, if vancomycin was continued and in whom a steady state trough concentration was obtained Exclusion Criteria: * Patients with end stage renal disease (on hemodialysis or peritoneal dialysis) or on continuous renal replacement therapy

Locations (1)

Methodist Dallas Medical Center

Dallas, Texas, United States

Outcomes

Primary Outcomes

Efficacy of trough and AUC vancomycin monitoring

To compare the efficacy of targeting troughs of 10-20 mg/L vs targeting AUC of 400-600 for vancomycin monitoring without the use of vancomycin peak serum concentrations. o AUC will be calculated via the trapezoidal method.o Troughs will be stratified in the following categories: \< 10 mg/L, 10-15 mg/L, 15-20 mg/L and \> 20 mg/L.

Time frame: up to 1 year

• Determine differences in efficacy/clinical outcome and re-admission rates of AUC monitoring compared to trough monitoring in severe or deep-seeded infections (pneumonia, endocarditis, osteomyelitis or bacteremia)

Readmission rate of AUC monitoring compared to trough monitoring. Re-admission within 30 days will be classified as due to previous infection or all-cause.