UMEM Educational Pearls

Category: Pharmacology & Therapeutics

Title: Fosfomycin for UTIs

Keywords: Fosfomycin, urinary tract infection, cystitis (PubMed Search)

Posted: 3/3/2018 by Wesley Oliver
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Fosfomycin is an antibiotic infrequently used for the treatment of urinary tract infections (UTIs). It has a broad spectrum of activity that covers both gram-positive (MRSA, VRE) and gram-negative bacteria (Pseudomonas, ESBL, and carbapenem-resistant Enterobacteriaceae), which is useful in the treatment of multidrug-resistant bacteria. 

Fosfomycin is FDA approved for the treatment of uncomplicated UTIs in women due to susceptible strains of Escherichia coli and Enterococcus faecalis (3g oral as a single dose). Data has also demonstrated that it can be used for complicated UTIs; however, dosing is different in this population (3 g oral every 2-3 days for 3 doses).  Fosfomycin is not recommended for pyelonephritis.

The broad spectrum of activity, in addition to only needing a single dose in most cases, makes fosfomycin an attractive option; however, it should be reserved for use in certain circumstances.  Fosfomycin should not be considered as a first-line option.  It is also more expensive than other medications (~$100/dose) and in countries with high rates of utilization bacteria are developing resistance to fosfomycin.  In addition, most outpatient pharmacies do not keep this medication in stock.

Take-Home Point:

Fosfomycin should be reserved for multidrug-resistant UTIs in which other first-line options have been exhausted.


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