305. Pilot study of fosfomycin trometamol compared with trimethoprim-sulfamethoxazole for acute uncomplicated cystitis in women
Session: Poster Abstract Session: Antimicrobial Therapy: Clinical Studies
Friday, October 21, 2011
Room: Poster Hall B1
Background: Acute uncomplicated cystitis (AUC) is common among young women, causing considerable morbidity and annual costs in the US. In the updated 2011 IDSA Guidelines (GL) for treatment of acute uncomplicated cystitis and pyelonephritis, fosfomycin trometamol (FT) appeared on the list of first-line therapies for cystitis for the first time since the last GL (1999), in part because of a favorable profile for antimicrobial resistance rates and collateral damage. However, data on the efficacy of FT in AUC are sparse, and decades-old data submitted to FDA indicated the agent had inferior efficacy (81% cure rate) compared with standard short-course regimens. Thus, we conducted a pilot study of single-dose FT compared with 3-day therapy with trimethoprim-sulfamethoxazole (TMP-SMX) in young women with AUC.

Methods: 68 healthy women age 18-45 with AUC were randomized to treatment with FT 3g single dose given as a sachet or TMP-SMX DS tablet bid x 3 days and followed prospectively for one month. Urinalysis and urine culture were performed at baseline and at follow-up visits at 5-9 and 28-30 days after completion of therapy. Cure was defined as no further treatment for subsequent or unresolved symptoms.

Results: 62 subjects were evaluable at the end of six months. The cure rate for FT was 88% (30/34) vs 82% (23/28) for TMP/SMX. For E. coli, resistance to the treating antimicrobial occurred in 0% of FT subjects and 20% of TMP-SMX subjects.

Conclusion: Fosfomycin trometamol appears to be a promising agent for treatment of AUC in young women, with cure rates comparable to TMP-SMX. Larger trials of this agent are warranted.

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

Ann Stapleton, MD1, Pacita Roberts, MS2, Marsha Cox, MS1 and Thomas Hooton, MD, FIDSA3, (1)University of Washington, Seattle, WA, (2)Medicine, University of Washington, Seattle, WA, (3)Medicine, University of Miami, Miami, FL


A. Stapleton, None

P. Roberts, None

M. Cox, None

T. Hooton, 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.