A Retrospective Comparison of Daptomycin Thrice-Weekly versus Q48H Dosing in Hemodialysis Patients with Vancomycin-Resistant Enterococcus (VRE) or Methicillin-Resistant Staphylococcus aureus (MRSA) Bacteremia

Abstract

PURPOSE: This study retrospectively assessed clinical and microbiological outcomes in hemodialysis patients with vancomycinresistant enterococcus (VRE) or methicillin-resistant Staphylococcus aureus (MRSA) bacteremia treated with daptomycin thrice-weekly compared to traditional Q48H dosing. METHODS: All patients with positive blood cultures who received at least one dose of daptomycin between January 1st 2009 and December 31st 2010 at Indiana University Health Methodist and University Hospitals were identified. Subjects age > 18 years with end-stage renal disease on a stable thrice-weekly hemodialysis regimen, confirmed VRE or MRSA bacteremia, and at least three doses of inpatient daptomycin therapy on one of the study schedules were enrolled in the study. Data were obtained through a retrospective review of electronic medical records. Microbiologic cure was assessed using time to clearance of blood cultures. Clinical indicators of infection, including daily maximum temperature (Tmax) and WBC count, were used to assess clinical cure. RESULTS: Twelve patients were identified who met criteria for inclusion in this study. Nine received daptomycin every 48 hours for the treatment of bacteremia, and three received daptomycin thriceweekly after dialysis. There was no difference in time to clearance of blood cultures between the Q48H and thrice-weekly groups (2.11+/-2.15 days vs 4.33+/-4.16 days; p=0.241). No patients were febrile upon initiation of daptomycin, and only three patients in the Q48H group had a clinically significant white blood cell count on initiation of daptomycin. Length of hospital stay was not statistically significantly different between the two treatment regimens (22.8 days vs 14.9 days; p=0.065). CONCLUSION: Thrice-weekly dosing of daptomycin may be effective for the treatment of bacteremia in hemodialysis patients. Further research is needed to support the non-inferiority of this regimen compared to Q48H dosing.