Fosfomycin tromethamine for the Treatment of Cystitis in Abdominal Solid Organ Transplant Recipients With Renal Dysfunction.

BACKGROUND: Urinary tract infection (UTI) after abdominal solid organ transplantation (SOT) is associated with significant morbidity and mortality. Fosfomycin tromethamine (FOS), a uroselective antibiotic, is FDA approved for uncomplicated UTIs in women and is used off-label for complicated UTIs and prostatitis in men. Literature supporting the use of FOS in the SOT population is limited, and efficacy is questioned in the setting of renal dysfunction.

OBJECTIVE: To evaluate the success of FOS for the treatment of cystitis in SOT patients with renal dysfunction.

METHODS: This was a single-center, retrospective study using medical records. SOT recipients receiving at least 1 dose of FOS for treatment of cystitis between January 1, 2009, and April 30, 2015, were included. Treatment outcomes were analyzed with respect to renal function.

RESULTS: A total of 76 courses of FOS were identified in 64 patients. The renal dysfunction arm (creatinine clearance [CrCl] < 40 mL/min) included 33 patients with 39 FOS courses; the normal renal function arm (CrCl ≥ 40 mL/min) included 31 patients with 37 FOS courses. Mean CrCl was 23.3 ± 9.7 mL/min for the renal-dysfunction group and 65 ± 29.3 mL/min for the normal renal function group ( P < 0.01). No significant difference in treatment success was noted between CrCl <40 mL/min and CrCl ≥40 mL/min (31 [80%] vs 34 [92%], P = 0.12) in a unilateral analysis. After adjusting for confounders in a multivariable analysis, there was no difference in the risk of failure between CrCl <40 mL/min and CrCl ≥40 mL/min groups ( P = 0.70).

CONCLUSION: FOS appears to be successful for the treatment of cystitis in SOT recipients in the setting of renal dysfunction.