Single-Dose Fosfomycin Found as Safe, Effective as Other Antibiotics for Uncomplicated UTIs

Administering a single 3g dose of fosfomycin is just as safe and effective as using other antibiotics to treat women with uncomplicated urinary tract infections (UTIs), according to a study published in the Journal of Mid-Life Health.¹

Fosfomycin is a broad-spectrum antibiotic effective against both Gram-positive and Gram-negative bacteria, including drug-resistant organisms.² Past evidence demonstrated that a single oral dose of fosfomycin is a potential treatment option for lower UTIs in both pregnant and nonpregnant women.¹ Additionally, fosfomycin is considered more economically viable than many other primary UTI treatment alternatives.

Despite this, drug utilization studies have demonstrated significantly less use of fosfomycin compared with commonly used therapies, such as nitrofurantoin and fluoroquinolones. As a result, there is a lack of conclusive evidence for recommending single-dose fosfomycin as the first line of management for patients with uncomplicated UTIs.

Fosfomycin proved to be a safe, effective alternative for treating uncomplicated urinary tract infections (UTIs), potentially reducing antibiotic resistance and costs. | Image Credit: Bungon - stock.adobe.com

To address this gap, the researchers conducted a meta-analysis and systematic review to assess the safety and efficacy of fosfomycin in treating women with uncomplicated UTIs and pregnant women with asymptomatic bacteriuria (ASB).

By definition, patients with uncomplicated UTIs have the clinical features of lower UTIs, which include urgency, dysuria, suprapubic tenderness or frequency, and significant bacteriuria (> 10⁵ cfu/ml). Meanwhile, ASB was defined as significant bacteriuria without symptoms.

The study’s primary objective was to determine the clinical resolution of uncomplicated UTI during the follow-up period after the start of treatment with fosfomycin. It also examined microbiological resolution and drug safety, as measured by any adverse effects that occurred during the follow-up period.

Using related keywords, they systematically searched various databases from their respective inception dates until December 2023 for relevant research. The researchers included all randomized controlled trials (RCTs) published in English that were related to clinical or microbiological effectiveness, as well as any adverse events, associated with single-dose fosfomycin for treating uncomplicated UTIs in women and ASB in pregnant women. Additionally, they checked the references of eligible studies for other relevant research.

The researchers initially found 1362 eligible studies, which they narrowed down to 22. Of these, 14 trials were based on uncomplicated UTIs in women who were not pregnant, 3 on pregnant women with uncomplicated UTIs, and 5 on pregnant women with ASB.

A meta-analysis of 10 studies with relevant efficacy data revealed that there was no difference in clinical resolution between women who were treated with fosfomycin and those treated with other antibiotics for uncomplicated UTIs (OR, 1.11; 95% CI, 0.88-1.41; P = .37). Additionally, a comparison of fosfomycin with different drug classes showed that it had similar clinical efficacy as quinolones (P = .52), sulfonamides (P = .89), nitrofurantoin (P = .31), and β‑lactams and cephalosporins (P = .64).

Each of the 22 studies reported on microbiological resolution. In the overall analysis, the resolution rate did not significantly differ between patients treated with fosfomycin and those treated with other antibiotics (OR, 0.98; 95% CI, 0.81-1.18; P = .30).

Similarly, in 17 studies involving patients with uncomplicated UTIs, the rates of microbiological resolution were not significantly different between the 2 groups (P = .88). In 5 studies involving 577 pregnant participants with ASB, the microbiological resolution rate was also similar between groups (P = .30).

Lastly, the researchers found no notable differences in the incidence of adverse events when taking a single dose of fosfomycin vs other prescribed antibiotics to treat uncomplicated UTIs (OR, 0.97; 95% CI, 0.77-1.23; P = .82).

Within a subgroup analysis, pregnant patients who were given a single dose of fosfomycin had a similar incidence of adverse events as those who were given other types of antibiotics (P = .46). Likewise, there was no statistically significant difference in adverse event frequency among nonpregnant patients within the 2 different treatment groups (P = .88).

The researchers acknowledged their study’s limitations, including that most of the RCTs were found to be at high risk of selection and performance bias. As a result, the validity of these trials may be questionable. Still, they expressed confidence in their findings, adding that fosfomycin is an effective treatment to reduce antibiotic resistance.

One strategy used to reduce antibiotic resistance is to use them for shorter periods; the selective pressure on bacteria to develop resistance may decrease by reducing the treatment duration. The researchers highlighted that because fosfomycin has unique pharmacological properties, including the ability to be administered as a single dose, it is a promising candidate for this strategy, which could lower costs and improve patient compliance.

“Using antibiotics more selectively and judiciously, we can help preserve the effectiveness of antibiotics for future generations,” the authors wrote.

References

1. Verma T, Manhas GS, Manhas RS. Efficacy and safety of single-dose fosfomycin for uncomplicated urinary tract infection in women: systematic review and meta-analysis. J Midlife Health. 2025;16(2):124-136. doi:10.4103/jmh.jmh_77_24
2. Falagas ME, Vouloumanou EK, Samonis G, Vardakas KZ. Fosfomycin. Clin Microbiol Rev. 2016;29(2):321-347. doi:10.1128/CMR.00068-15