Download Usage Criteria for Fosfomycin in UTI

Fosfomycin Suggested Usage in ESBL+ and Enterococcus UTI
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Fosfomycin is useful for UTI, but NOT useful for pyelonephritis or other indications due to poor
drug distribution.
o Due to high cost ($157 per dose), use is limited to ESBL+ and resistant enterococcus
UTI (traditional agents are preferred for less resistant infections unless confirmed
allergies are present)
o Sensitivities are not readily available at most institutions. Literature suggests the
following:
 ESBL+ E.coli: >95% susceptible
 ESBL+ K. pneumonia: 80-93% susceptible
 Enterococcus (including VRE) : >95% susceptible
 SNF residents should be expected to have lower susceptibilities.
o Outcomes are better for uncomplicated UTI vs. complicated UTI
 One study found a clinical cure rate of 100% for uncomplicated VRE UTI vs 76%
for complicated VRE UTI
o FHS hospitals will stock at least 1 fosfomycin dose
o FHS outpatient pharmacies will stock 3 doses of fosfomycin
o Beta-lactam antibiotics are not reliable treatment options for ESBL+ organisms even if
they are reported as sensitive
Definition of complicated UTI: UTI in the presence of an anatomic abnormality, a functional
abnormality, or urinary catheter.
 Factors that may increase risk of failing therapy: diabetes, pregnancy, ≥7 days of symptoms
before seeking care, hospital-acquired infection, renal failure, urinary tract obstruction,
presence of catheter/stent/nephrostomy tube, recent urinary tract instrumentation, functional
abnormality
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Fosfomycin for OUTPATIENT UTI (Not for use in pyelonephritis)
For patients returning to facilities that are able to provide IV infusions ertapenem is the
preferred agent for ESBL+ organisms and IV vancomycin is preferred for enterococcus.
Uncomplicated ESBL+/enterococcus UTI:
o Enterococcus (including VRE) and ESBL+ E.coli: 1st line oral agent
 Dose: 3 grams PO x1
o ESBL+ K. pneumonia: Increase dose to 3 grams po q48hrs x3 doses due to higher
resistance
Complicated UTI: 2nd line agent for complicated UTI caused by resistant enterococcus (i.e.
resistant to amoxicillin or confirmed amoxicillin allergy), ESBL+ E.coli, and ESBL+ K. Pneumoniae.
Recommend requesting fosfomycin E-test on the sample to confirm sensitivity.
o IV ertapenem is 1st line treatment for E.coli and K. Pneumoniae (unless resistant). IV
vancomycin is 1st line agent for enterococcus (unless resistant)
o Fosfomycin dose: 3 grams PO q48hrs x3 doses
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Fosfomycin for INPATIENT UTI (Not for use in pyelonephritis)
Uncomplicated UTI:
o Enterococcus (e.g. VRE): 1st line oral agent if amoxicillin and nitrofurantoin are resistant
or not appropriate (i.e. fosfomycin can be used in place of linezolid).
 Dose: 3 grams PO x1
o ESBL+ E.coli: Consider as oral alternative if meropenem is not appropriate, or if patient
has inpatient status solely to receive IV antitibiotics (i.e. if patient can be discharged
after fosfomycin dose)
 Dose: 3 grams PO x1
o ESBL+ K. Pneumoniae: Consider as 2nd-3rd line oral agent if meropenem cannot be used
 Dose: 3 grams PO q48hrs x3 doses
Complicated UTI:
o Consider as 2nd line oral agent (failure rates are higher with complicated infection).
Recommend requesting fosfomycin E-test on the sample to confirm sensitivity.
 Dose: 3 grams PO q48hrs x3 doses
References:
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Arias, C., Contreras, G., & Murray, B. (n.d.). Management of multidrug-resistant enterococcal infections.
Clinical Microbiology and Infection, 555-562.
Allerberger, F. (1999). In-vitro activity of fosfomycin against vancomycin-resistant enterococci. Journal of
Antimicrobial Chemotherapy, 211-217
Shrestha, N., Chua, J., Tuohy, M., Wilson, D., Procop, G., Longworth, D., ... Hall, G. (2003). Antimicrobial
Susceptibility of Vancomycin-Resistant Enterococcus faecium: Potential Utility of Fosfomycin.
Scandinavian Journal of Infectious Diseases, 12-14
Pullukcu, H., Tasbakan, M., Sipahi, O., Yamazhan, T., Aydemir, S., & Ulusoy, S. (n.d.). Fosfomycin in the
treatment of extended spectrum beta-lactamase-producing Escherichia coli-related lower urinary tract
infections. International Journal of Antimicrobial Agents, 62-65.
Falagas, et.al. Fosfomycin for the treatment of multidrug-resistant, including extended-spectrum betalactamase producing, Enterobacteriaceae infections: a systematic review. Lancet Infect Dis. 2010
Jan;10(1):43-50
Chislet, et.al Fosfomycin susceptibility among extended-spectrum-β-lactamase-producing Escherichia coli
in Nottingham, UK. Journal of Antimicrobial Chemotherapy Volume 65, Issue 5. Pp. 1076-1077.
Harada Y, Morinaga Y, Kaku N, et al. In vitro and in vivo activities of piperacillin-tazobactam and
meropenem at different inoculum sizes of ESBL-producing Klebsiella pneumoniae. Clin Microbiol Infect.
2014;
Prakash V, Lewis JS, Herrera ML, Wickes BL, Jorgensen JH. Oral and parenteral therapeutic options for
outpatient urinary infections caused by enterobacteriaceae producing CTX-M extended-spectrum betalactamases. Antimicrob Agents Chemother. 2009;53(3):1278-80.