Empiric Weight-Based Vancomycin in Intensive Care Unit Patients With Methicillin-Resistant Staphylococcus aureus Bacteremia

• Published in: The American journal of the medical sciences 2014-11, Vol.348 (5), p.371-376
• Main Authors: Alvarez, Carlos A., PharmD, MSc, MSCS, Giuliano, Christopher A., PharmD, Haase, Krystal K., PharmD, Thompson, Kathleen A., PharmD, Frei, Christopher R., PharmD, Forcade, Nicolas A., PharmD, Brouse, Sara D., PharmD, Mortensen, Eric M., MD, MSc, Bell, Todd, MD, Bedimo, Roger J., MD, MSc, Toups, Nolan M., PharmD, Hall, Ronald G., PharmD, MSCS
• Format: Article
• Language: English
• Subjects: Aged; Anti-Bacterial Agents - pharmacology; Anti-Bacterial Agents - therapeutic use; Bacteremia - diagnosis; Bacteremia - drug therapy; Cohort Studies; Female; Humans; ICU; Intensive Care Units; Internal Medicine; Male; Methicillin-Resistant Staphylococcus aureus - drug effects; Methicillin-Resistant Staphylococcus aureus - isolation & purification; Middle Aged; MRSA; Nephrotoxicity; Practice Guidelines as Topic - standards; Retrospective Studies; Staphylococcal Infections - diagnosis; Staphylococcal Infections - drug therapy; Vancomycin; Vancomycin - pharmacology; Vancomycin - therapeutic use; Weight
• ISSN: 0002-9629; 1538-2990
• DOI: 10.1097/MAJ.0000000000000262

Abstract Background Previous studies were conducted in all hospitalized patients with methicillin-resistant Staphylococcus aureus (MRSA) bacteremia to determine safety and effectiveness of guideline-recommended, weight-based dosing of vancomycin. in these studies, it was observed that severely ill patients (Pitt bacteremia score ≥ 4 or intensive care unit [iCU] patients) were at an increased risk of mortality and/or nephrotoxicity. Therefore, a subanalysis of the effect of guideline-recommended vancomycin dosing on in-hospital mortality and nephrotoxicity in ICU patients with MRSA bacteremia was conducted. Methods This multicenter, retrospective, cohort study was conducted in a subset of ICU patients from a previous MRSA bacteremia study. Patients were ≥ 18 years old and received ≥ 48 hours of empiric vancomycin from July 1, 2002, to June 30, 2008. The incidence of nephrotoxicity and in-hospital mortality was compared in patients who received guideline-recommended dosing (at least 15 mg/kg per dose) to patients who received non-guideline-recommended dosing of vancomycin. Multivariable generalized linear mixed-effects models were constructed to determine independent risk factors for in-hospital mortality and nephrotoxicity. Results Guideline-recommended dosing was received by 34% of patients (n = 137). Nephrotoxicity occurred in 35% of patients receiving guideline-recommended dosing and 39% receiving non-guideline-recommended dosing ( P = 0.67). In-hospital mortality rate was 24% among patients who received guideline-recommended dosing compared with 31% for non-guideline-recommended dosing ( P = 0.40). Guideline-recommended dosing was not associated with nephrotoxicity (odds ratio: 1.10; 95% confidence interval: 0.43-2.79) or in-hospital mortality (odds ratio: 0.54; 95% confidence interval: 0.22–1.36) in the multivariable analysis. Conclusions Guideline-recommended dosing of vancomycin in ICU patients with MRSA bacteremia is not significantly associated with nephrotoxicity or in-hospital mortality. However, the 7% absolute difference for in-hospital mortality suggests that larger studies are needed.