This study was supported by Astellas Pharmaceuticals.
ORIGINAL RESEARCH ARTICLES
Effects of Targeting Higher Vancomycin Trough Levels on Clinical Outcomes and Costs in a Matched Patient Cohort
Article first published online: 28 FEB 2012
© 2012 Pharmacotherapy Publications, Inc.
Pharmacotherapy: The Journal of Human Pharmacology and Drug Therapy
Volume 32, Issue 3, pages 195–201, March 2012
How to Cite
Kullar, R., Davis, S. L., Taylor, T. N., Kaye, K. S. and Rybak, M. J. (2012), Effects of Targeting Higher Vancomycin Trough Levels on Clinical Outcomes and Costs in a Matched Patient Cohort. Pharmacotherapy, 32: 195–201. doi: 10.1002/j.1875-9114.2011.01017.x
Dr. Davis has received research support from Ortho-McNeil; has served as a consultant to Pfizer, Cubist, and Ortho-McNeil; and has served on a speaker's bureau for Pfizer. Dr. Taylor has received research support from Abraxis Bioscience and Merck. Dr. Kaye has received research grants from Merck and Wyeth; has served as a consultant to Schering Plough, Forest, and Ortho-McNeil; and has served on speakers’ bureaus for Cubist, Merck, Wyeth, Pfizer, and Ortho-McNeil. Dr. Rybak has received research grants from Astellas, Cubist, Forest, and Pfizer; has served as a consultant to Astellas, Cubist, Forest, and Ortho-McNeil; and has served on speakers’ bureaus for Cubist, Novartis, and Pfizer.
- Issue published online: 28 FEB 2012
- Article first published online: 28 FEB 2012
- Manuscript Accepted: 14 SEP 2011
- Manuscript Revised: 19 AUG 2011
- Manuscript Received: 22 JUL 2011
Vol. 32, Issue 9, 869, Article first published online: 4 SEP 2012
- vancomycin consensus guidelines;
- MRSA bacteremia;
- costs and patient outcomes
To compare clinical outcomes and costs in patients treated with the new vancomycin guidelines recommending goal serum trough concentrations of 15–20 mg/L versus patients treated with vancomycin doses targeting trough concentrations 5–20 mg/L prior to the new guidelines.
Retrospective quasi-experimental study.
Urban level I trauma center.
A total of 200 patients treated with vancomycin for at least 72 hours for confirmed, complicated methicillin-resistant Staphylococcus aureus (MRSA) bacteremia during one of two study phases relative to the implementation of the vancomycin dosing guidelines targeting serum trough concentrations of 15–20 mg/L: 2005–2007 (preperiod phase) and 2008–2010 (postperiod phase). One hundred patients in each phase were matched in a 1:1 ratio according to diagnosis, any concomitant nephrotoxic agents (e.g., aminoglycosides, colistin, acyclovir), and age ± 5 years.
Measurements and Main Results
Patients in the preperiod had significantly lower success rates with vancomycin than those in the postperiod (45% vs 60%, p=0.034). Median length of stay (LOS) was not significantly higher in patients in the preperiod versus postperiod (15 days vs 13.5 days; p=0.28), and patients in the preperiod received a longer median duration of vancomycin versus those in the postperiod (13 days vs 8.5 days; p<0.001). No statistically significant difference was noted in total hospital costs for patients treated with vancomycin during the preperiod versus the postperiod ($32,754 vs $27,709, p=0.147). However, total drug and monitoring costs of vancomycin were significantly higher for patients in the postperiod. Initial vancomycin trough levels were significantly lower in patients in the preperiod versus postperiod (12.3 mg/L vs 15.8 mg/L, p=0.02). Patients in the preperiod had lower rates of nephrotoxicity than those in the postperiod, although this difference was not statistically significant (15% vs 18%; p=0.85). Median (interquartile range) LOS was significantly longer in patients who developed nephrotoxicity compared with patients who did not develop nephrotoxicity (17 days [11.5–36.5 days] vs 14 days [9–24 days], p=0.017). Costs associated with measurement of serum creatinine concentrations and vancomycin trough levels as well as labor were significantly higher in patients who developed nephrotoxicity.
Higher vancomycin trough concentrations improved outcomes in patients with complicated MRSA bacteremia. In addition, more aggressive dosing was shown to significantly decrease overall duration of vancomycin therapy, which may affect total hospital LOS and cost. Patients who experienced nephrotoxicity had a significantly longer hospital LOS. Additional studies evaluating optimal therapy for MRSA bacteremia in a larger cohort of matched patients are warranted.