1832. Comparison of Nephrotoxicity Associated with Vancomycin in Combination with Piperacillin-tazobactam (PTZ) Extended Infusion (EI) versus Standard Infusion (SI)
Session: Poster Abstract Session: Treatment of HAIs/Antimicrobial Resistant Infections
Saturday, October 10, 2015
Room: Poster Hall
  • CDI IDSA Poster 09282015.pdf (269.5 kB)
  • Background: Recent studies reported an increased nephrotoxicity when vancomycin (VAN) is given in combination with PTZ compared to VAN monotherapy or VAN in combination with cefepime.  In these studies, rates of nephrotoxicity with VAN plus PTZ SI have ranged from 16 – 29% vs. 36% with VAN plus PTZ EI.  At our University Medical Center VAN in combination with PTZ is a commonly prescribed empiric or targeted therapy for hospitalized patients.  In 2009 we launched a PTZ EI protocol in intensive care units and in 2013 we expanded PTZ EI hospital wide.  To this effect, we sought to compare nephrotoxicity when VAN is given in combination PTZ EI (EI Group) vs. PTZ SI (SI Group).

    Methods: In a single center retrospective cohort study, we evaluated adult (≥18 years old) patients with Creatinine Clearance (CrCl) ≥40 mL/min who received a minimum of 96 hours of VAN plus PTZ. Nephrotoxicity as defined by the RIFLE criteria was the primary endpoint of this study. A sample size of 272 patients was calculated to detect a 15% difference between groups. Chi-square, Fisher’s exact and Mann-Whitney U tests were used for data analysis. All values are given as median [Interquartile Range].

    Results: A total of 280 patients (140 patients in each group) were evaluated.  Overall, patient age was 67 [54-77] years, weight was 75 [61-88] kg, CrCl was 75 [55-107] mL/min, and these variables were comparable between EI and SI groups. Receipt of vasopressors and VAN maximum trough >20 mg/L at any point during combination therapy were more common in EI Group (17% vs. 8% in SI Group, P=0.03; 45% vs. 29% in SI Group, P=0.009), respectively.  Duration of combination therapy was 5 [4-6] days in both groups, P=0.4. Overall, 17.5% (49/280) of patients developed nephrotoxicity; 17.9% (25/140) in EI Group vs. 17.1% (24/140) in SI Group, P=1. Time to nephrotoxicity was 4 [3-6] days. In logistic regression, a VAN trough >20 mg/L at any point during therapy was an independent predictor of nephrotoxicity (Odds Ratio 3.2; 95% CI 1.5-6.9, P=0.002) after adjustment for receipt of vasopressors, chronic liver disease and PTZ EI administration.

    Conclusion: Our findings suggest comparable nephrotoxicity among patients who received VAN in combination with PTZ EI vs. PTZ SI. Close monitoring of VAN trough levels during combination therapy is warranted.

    Mariam Mousavi, PharmD1, Tanya Zapolskaya, PharmD1, Marco R. Scipione, PharmD1, Eddie Louie, MD2, John Papadopoulos, PharmD1 and Yanina Dubrovskaya, PharmD1, (1)Department of Pharmacy, NYU Langone Medical Center, New York, NY, (2)Infectious Diseases, NYU Langone Medical Center, New York, NY


    M. Mousavi, None

    T. Zapolskaya, None

    M. R. Scipione, None

    E. Louie, None

    J. Papadopoulos, None

    Y. Dubrovskaya, 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.