For many years, I’ve tossed out the idea of using fosfomycin for uncomplicated urinary tract infections to various trainees – the vast majority of whom looked at me as though I had three heads. Even now, it’s easy to find folks who’ve never heard of fosfomycin, despite its mention in the most recent guidelines for UTIs. In the United States, the land of low-value health care, fosfomycin is preposterously expensive for a single dose – and rarely used.
The story, however, is a little different outside the U.S. Thus, the question – which is a better options, fosfomycin or nitrofurantoin? The answer: in Israel, Switzerland, and Poland, nitrofurantoin, probably.
This is an open-label trial with 513 patients randomized either to five days of nitrofurantoin or a single 3g dose of fosfomycin. Outcomes included clinical and microbiologic cure, and both favored nitrofurantoin by an absolute margin of ~10%. Oddly enough, their primary outcome was a 28-day clinical cure – which starts to stretch the measurement window into the range of subsequent, unrelated infection, rather than response to the initial therapy. This is apparent when looking at the 14-day and 28-day microbiologic response, in which bacterial counts were clearly creeping back up after an initial nadir.
Regardless, both agents are options – and fine options, depending on local resistance patterns, suspected pathogens, and other contextual clinical features. That said, in the U.S., most of the current appropriate prescribing is for trimethoprim-sulfamethoxazole – so, a similar trial comparing this with these alternative agents would need to be performed to better inform practice here.
“Effect of 5-Day Nitrofurantoin vs Single-Dose Fosfomycin on Clinical Resolution of Uncomplicated Lower Urinary Tract Infection in Women”
https://jamanetwork.com/journals/jama/article-abstract/2679131