Daptomycin Therapy for Vancomycin-Resistant Enterococcus Bacteremia in Neutropenic Patients With Hematologic Malignancies and Hematopoietic Cell Transplantation Recipients

Abstract

Background: Vancomycin-resistant Enterococcus fascium (VRE) are rapidly emerging nosocomial pathogens in the United States and worldwide. Vancomycin resistance is recognized to be an independent risk factor for increased morbidity and mortality among patients with enterococcal bloodstream infections (BSI); thus, early appropriate therapy is vital in improving outcomes. We report our experience in treating VRE BSI in patients with hematologic malignancies with daptomycin, a cyclic lipopeptide antibiotic with bactericidal activity against VRE. Methods: We performed retrospective chart review for patients with hematologic malignancies treated with daptomycin for a VRE BSI from January 2005 to May 2009. Patients were assessed for microbiological cure and survival. Patients were identified using a computerized clinical microbiology laboratory records. Results: Of 74 patients with a VRE BSI, 40 patients (31 male patients; median age, 61 years) met criteria and were included in the study. In this series, 35.6% of the patients had received a hematopoietic stem cell transplant, and 57.8% of the patients were neutropenic. Vancomycinresistant Enterococcus BSI occurred at a median of 20 days (4Y109 days) of neutropenia among these patients. The patients were treated with daptomycin monotherapy (62.5%) or daptomycin plus other antimicrobial(s) (37.5%). For those who were successfully treated with daptomycin alone, the median duration of therapy was 9 days (1Y36 days). Overall, 92.3% of the patients achieved a microbiological cure, which was evident at a median of 1 day (1Y16 days) after the initiation of therapy. Conclusion: Daptomycin is an effective agent for the treatment of VRE BSI. For both daptomycin monotherapy or combination therapy, we would recommend an intravenous dose of 8 mg/kg once daily for 10 to 14 days.