UTI in women: Is nitrofurantoin or fosfomycin best?

Results of a multinational trial show that a 5-day course of nitrofurantoin may produce better outcomes in women with uncomplicated lower urinary tract infection (UTI) than a single dose of fosfomycin. The findings, published in JAMA, reflect experience in patients in Switzerland, Poland, and Israel.

The participants in the study were women aged 18 and older with symptoms of lower UTI (dysuria, urgency, frequency, or suprapubic tenderness), a urine dipstick positive for nitrites or leukocyte esterase and no known colonization or previous infection with uropathogens resistant to nitrofurantoin or fosfomycin. Between October 2013 and April 2017, the patients were recruited from hospitals and clinics in the three countries.

In the open-label, analyst-blinded trial, 513 patients aged 31 to 64 were randomized, 475 (93%) of whom completed the trial and 377 (73%) of whom had a confirmed positive baseline culture. Randomization was 1:1 to oral nitrofurantoin, 100 mg 3 times a day for 5 days (n=255) or a single, 3-g dose of oral fosfomycin (n=258). The women returned 14 and 28 days after completing therapy for clinical evaluation and urine culture collection.

Of the 244 women on nitrofurantoin who completed the trial, 171 (70%) had clinical resolution through Day 28 versus 139 of 241 patients (58%) on fosfomycin (12% difference; 95% CI, 4% to 21%; P = .004). Microbiologic resolution was seen in 129 of 175 women on nitrofurantoin (74%) vs 103 of 163 women on fosfomycin (63%) (11% difference; 95% CI, 1% to 20%; P = .04).

Of the few adverse events, most were gastrointestinal. Nausea and diarrhea were most common, in 7 (3%) and 3 (1%) of the 248 women, respectively, who took nitrofurantoin. In the fosfomycin group, 5 of the 248 women had nausea and 5 had diarrhea (2% each).

The authors concluded that at 28 days after completing therapy, 5 days of nitrofurantoin resulted in a significantly greater likelihood of clinical and microbiologic resolution of uncomplicated UTI in women than did a single dose of fosfomycin.