215. Oral Fosfomycin in the Treatment of Vancomycin-Resistant Enterococcal Urinary Tract Infections
Session: Poster Abstract Session: Antimicrobial Resistance: Clinical Studies
Friday, October 21, 2011
Room: Poster Hall B1
Background: 

Vancomcyin-resistant enterococcus (VRE) is a significant pathogen in nosocomial urinary tract infections (UTI).  Oral therapy for VRE UTIs is limited and expensive. Oral fosfomycin is FDA approved for the treatment of uncomplicated UTIs and demonstrates in-vitro activity against enterococci. Fosfomycin may be a cost-effective treatment option for VRE UTIs, however data are lacking.  The objective of this study was to determine the clinical efficacy of fosfomycin for the treatment of VRE UTI.

Methods: 

A retrospective chart review of patients with VRE UTI treated with fosfomycin from December 2009 to April 2011 was conducted. UTI definition included urinalysis with pyuria (greater than 5 leukocytes/microliter) a urine culture with VRE greater than 50,000 colony forming units susceptible to fosfomycin, and one of the following clinical parameters: a white blood cell count greater than 11,000 cells/microliter, a temperature greater than 100.5F, or subjective complaints of dysuria, frequency, and/or urgency.  Patients were included if they received at least 1 dose of fosfomycin, and were excluded if they received antibiotics with anti-VRE activity. Uncomplicated and complicated urinary tract infections were evaluated. Clinical cure was defined as resolution of symptoms within 10 days of therapy.

Results: 

A total of 39 patients met inclusion criteria. The clinical cure rate for VRE UTI treated with fosfomycin was 82.0% (32/39). Of the cohort, 29/39 (74%) patients had complicated UTI, 26% had uncomplicated UTI. The clinical cure rate was 100% (10/10) for uncomplicated UTIs, compared to 76% (22/29) for complicated UTIs. There were 7 patients with relapse or reinfection; 3 of whom were kidney transplant recipients and 3 on hemodialysis. Treatment duration was similar in both groups (6.0 days, uncomplicated UTI v. 5.1 days, complicated UTI). The cost of a week of fosfomycin therapy was $120, compared to $1575 for daptomycin and $980 for linezolid.

Conclusion: 

Fosfomycin is a cost-effective alternative to daptomycin and linezolid for the treatment of VRE UTIs, including complicated UTIs. Kidney transplant and hemodialysis patients may be at higher risk of relapse; a longer treatment duration may reduce the risk of relapse in this patient population.


Subject Category: A. Antimicrobial agents and Resistance

Christy Varughese, PharmD1, Eric Tichy, PharmD1 and Jeffrey Topal, MD1,2,3, (1)Yale-New Haven Hospital, New Haven, CT, (2)Section of Infectious Diseases, Yale School of Medicine, New Haven, CT, (3)Yale School of Medicine, New Haven, CT

Disclosures:

C. Varughese, None

E. Tichy, None

J. Topal, 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.