569. Efficacy of Continuous Infusion Vancomycin for the outpatient treatment of Methicillin-Resistant Staphylococcus aureus Infections
Session: Poster Abstract Session: MRSA Surveillance and Infection Prevention
Friday, October 21, 2011
Room: Poster Hall B1
  • vancomycin poster.pdf (2.8 MB)
  • Background: The IDSA MRSA treatment guidelines recommend against vancomycin continuous infusion (CI) on the basis of insufficient clinical studies on CI and postulated pharmacodynamic advantages of intermittent infusions (II). Practice in Singapore includes both II and CI in the outpatient setting where once a day infusion changes are practical. We sought to test the hypothesis that II is superior to CI among outpatients completing treatment for MRSA infections with vancomycin.

    Methods: This retrospective cohort study includes data from two Singapore hospitals between 2005 and 2010.

    Results: 247 patients were included, 190 (77%) received CI vancomycin and 57 (23%) received II.  The cohort included 122 cases of osteomyelitis (49.4%), 20 septic arthritis (8.1%), 25 skin or soft tissue infection (10.1%), 20 blood stream infections (8.1%), 7 endocarditis cases (2.8%) with no difference in the site of infection according to infusion method (P =0.52). The CI group included 61 (32.1%) prosthetic infections versus 9 in II group (15.8%) (P=0.02). There was no significant difference in the duration of treatment for CI (32.2 days) versus II (33.9 days) (P =0.61).  All MRSA isolates had vancomycin MIC ≤2mg/L at entry. The mean age of patients was 50 years for CI (sd 15.7) and 63 years for II (sd  17.7) (P<0.01).  The primary endpoint (death, readmission, unplanned extension of therapy or change of antibiotics) occurred in 41 (21.6%) treated by CI and 17 (29.8%) by II. The risk ratio for the primary endpoint was 0.72 (95% CI 0.45-1.17), a non-significant trend towards better outcomes with CI. Stratification for age, comorbidity and the presence of prosthesis did not alter this finding.

    Conclusion: We observe no evidence that II is superior to CI in this large outpatient cohort. The different group characteristics did not result in confounding. Given the practical advantages of therapy by CI a prospective study of CI and II vancomycin dosing is needed to inform future practice and guidelines.

    Subject Category: C. Clinical studies of bacterial infections and antibacterials including sexually transmitted diseases and mycobacterial infections (surveys, epidemiology, and clinical trials)

    Ayesha Verrall, MBChB, MBHL, DTMH1, Ryan Llorin, MBBS2, David Lye, MBBS2 and Dale Fisher, FRACP3, (1)University Medicine Cluster, National University Singapore, Singapore, Singapore, (2)Tan Tock Seng Hospital, Singapore, Singapore, (3)National University Hospital, Singapore, Singapore


    A. Verrall, None

    R. Llorin, None

    D. Lye, None

    D. Fisher, None

    Findings in the abstracts are embargoed until 12:01 a.m. EST Thursday, Oct. 20 with the exception of research findings presented at IDSA press conferences.