801. Factors Associated with Supratherapeutic Vancomycin Trough Concentrations in a Referral Center
Session: Poster Abstract Session: Antimicrobial Agents: PK/PD Studies
Friday, October 9, 2015
Room: Poster Hall
Posters
  • Vanc troughs poster final.pdf (565.0 kB)
  • Background: Supratherapeutic vancomycin (VAN) concentrations are a known risk factor for nephrotoxicity; however, factors leading to increased VAN trough concentrations are not well characterized. The purpose of this study was to identify risk factors for supratherapeutic VAN levels.

    Methods: Clinical data were obtained from the University of Kentucky Center for Clinical and Translational Science Enterprise Data Trust. Basic demographic information, VAN dosing, VAN serum concentrations, serum creatinine levels, severity of illness (Charlson Comorbidity Index [CCI]), and nephrotoxin exposure were collected from 9/1/10 through 8/31/14. Multivariate logistic regression was performed to determine independent risk factors for supratherapeutic VAN levels. VAN levels were classified as non-supratherapeutic (≤ 20 µg/mL) or supratherapeutic (> 20 µg/mL).

    Results: 7,147 patient encounters received VAN and had a least one VAN level, 34.4% of patients had supratherapeutic VAN trough concentrations. Patients with supratherapeutic VAN levels were: older (52.2 vs. 50.3 years, p<0.0001), female (47.3 vs 39.6%, p<0.0001), sicker (median CCI 3 vs 2, p<0.0001), and had lower admission creatinine clearances (median 92.2 vs. 103.7 mL/min, p<0.0001). In-hospital mortality or transfer to a hospice facility (13.6% vs. 7.8%, p<0.0001) and increased lengths of hospitalization (median 13 vs. 8 days, p<0.0001) were  more common in the supratherapeutic VAN group. Average daily VAN doses were roughly equivalent (2161.6 vs. 2200 mg/day, p=0.03). After logistic regression, factors associated with increased odds of experiencing supratherapeutic VAN troughs were baseline CrCl between 60 and 89 mL/min (OR = 1.91; 95% CI 1.26-2.88), increasing CCI (OR=1.02; 95% CI 1.01-1.04), emergency department or urgent admission (OR= 1.22; 95% CI 1.03-1.44 and 1.5; 95% CI 1.25-1.8, respectively), loop diuretic use (OR=1.57; 95% CI 1.29-1.9), increasing average daily VAN doses (OR = 1.14; 95% CI 1.04-1.26), and piperacillin/tazobactam use (OR=1.12; 95% CI 1.00-1.25).

    Conclusion: Increasing severity of illness, higher VAN doses, emergency and urgent care admissions, and loop diuretic exposure were associated with higher incidence of supratherapeutic VAN levels.

    W. Cliff Rutter, PharmD1, Jeffrey C. Talbert, PhD2,3 and David S. Burgess, PharmD, FCCP1, (1)University of Kentucky, College of Pharmacy, Lexington, KY, (2)Institute for Pharmaceutical Outcomes and Policy, University of Kentucky, College of Pharmacy, Lexington, KY, (3)Center for Clinical and Translational Science, University of Kentucky, Lexington, KY

    Disclosures:

    W. C. Rutter, None

    J. C. Talbert, None

    D. S. Burgess, None

    Findings in the abstracts are embargoed until 12:01 a.m. PDT, Wednesday Oct. 7th with the exception of research findings presented at the IDWeek press conferences.