CHAMGAP
APPROVEDReviewed and approved by the Chamgap Editorial Team (2026-07-20). The draft was written by AI, the existence of all 3 cited sources was verified at the original page, and the verdict passed blind grading and adversarial audit. Methodology v0.6.
Verdict No. 862 · Search date 2026-07-20 · Methodology v0.6

Single-dose fosfomycin 3 g,
does it really help with Clinical cure of acute uncomplicated cystitis in nonpregnant women with a single 3-g dose?

30-Second Summary
B
Evidence Grade B · 62 · Safety unknown
One-dose treatment is convenient, but recent direct comparisons found lower resolution than nitrofurantoin
What the
research shows
Single-dose fosfomycin clinically cures many cases of acute uncomplicated cystitis and is rated B. A pooled comparison of 11 randomized trials and 1,976 women found no significant difference in clinical resolution, with an OR of about 1.16. In Huttner 2018, however, 28-day resolution was 70% with nitrofurantoin (171/244) versus 58% with fosfomycin (139/241), a 12-percentage-point disadvantage. In SCOUT, single-dose fosfomycin was lowest among the four regimens at 59%. One-dose convenience is a product characteristic rather than superior efficacy; direct cure evidence plus repeated comparative inferiority support B with 62 points.
What the
ads claim
One sachet cures it converts convenience into a guarantee. Fever, flank pain, pregnancy, male sex, and recurrent or complicated infection are outside this evidence.
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Useful facts when choosing a product

  • Prescription fosfomycin trometamol 3 g is dissolved in water and taken once for appropriately diagnosed uncomplicated cystitis in nonpregnant women.
  • Oral single-dose fosfomycin should not be used for pyelonephritis with fever, chills, flank pain, or sepsis features.
  • Persistent or recurrent symptoms require culture, susceptibility testing, and reassessment rather than unsupervised repeat dosing.
  • Common effects include diarrhea, nausea, abdominal discomfort, headache, and vaginitis; local susceptibility matters.
Gap Measurement · Verdict 862 · B 62
What advertising claims
What independent, higher-quality research supports
△ GAP
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What the research actually shows

Huttner 2018 randomized 513 women; 28-day clinical resolution was 70% with nitrofurantoin (171/244) versus 58% with single-dose fosfomycin (139/241), a 12-percentage-point difference (95% CI 4 to 21). Cai 2020 pooled 11 randomized trials and 1,976 women and found no significant clinical-resolution difference across comparators, OR 1.16 (95% CI 0.91 to 1.49). In the pragmatic, multicentre, open-label, randomised SCOUT trial, the primary analysis of 720 women found the lowest resolution with single-dose fosfomycin, 59% (109/185), versus 74% (128/172) with nitrofurantoin.

02

Why this is classified as B (62)

The pooled 11-trial, 1,976-woman analysis found no significant difference from comparators, but Huttner found 70% resolution with nitrofurantoin versus 58% with fosfomycin and SCOUT found single-dose fosfomycin lowest at 59%. Direct clinical-resolution efficacy remains established, while repeated comparative inferiority and resistance epidemiology support B with 62 points. Convenience and safety remain separate.

Counterpoint. It remains reasonable for a selected patient who cannot use nitrofurantoin or needs simple completion.

Rejudgment record. New verdict — Accepted direct clinical-cure randomized evidence while incorporating lower resolution than nitrofurantoin in 2018 and 2026 and local resistance variability

Sub-claim grades by effect

This ingredient is marketed for several effects. A single overall grade blends strong and weak claims together, so each effect is graded separately here. The overall grade reflects the strongest disconfirming or core claim.

Effect (sub-claim)GradeBasis
Clinical cure of uncomplicated cystitisBA pooled comparison of 11 randomized trials and 1,976 women found no significant clinical-resolution difference, but cure is not guaranteed.
Effectiveness versus nitrofurantoinBResolution was 58% versus 70% with nitrofurantoin in Huttner, a 12-point disadvantage, and the single-dose regimen was lowest at 59% in SCOUT.

Cross-check — Codex and Claude

This verdict was drafted by Codex through literature review and source-existence checks, cross-checked through blind grading and adversarial audit, and settled by reapplying the methodology boundary rules. Cases with split grades were resolved through rejudgment.
03

Evidence Table

StudyDesignSampleFundingEndpointResultWeight
Huttner A et al. 2018Multinational open-label randomized active control513Academic and public support28-day clinical resolutionNitrofurantoin achieved 70% (171/244) versus 58% (139/241) with fosfomycin, a 12-percentage-point difference.Key direct comparison
Cai T et al. 2020Systematic review and meta-analysis1,976Academic studyClinical and microbiological resolutionClinical resolution OR 1.16 (95% CI 0.91 to 1.49).Pooled evidence
Llor C et al. 2026 SCOUTPragmatic multicenter open-label randomized trial720Public and academic supportClinical resolution59% versus 74% with nitrofurantoin.Latest direct comparison
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Receipt — 3 References

All 3 cited sources were verified for existence at the original page (as of 2026-07-20).

Huttner A, Kowalczyk A, Turjeman A, et al. Effect of 5-Day Nitrofurantoin vs Single-Dose Fosfomycin on Clinical Resolution of Uncomplicated Lower Urinary Tract Infection in Women: A Randomized Clinical Trial. JAMA. 2018;319(17):1781-1789. PMID: 29710295. DOI: 10.1001/jama.2018.3627.
checked
Cai T, Tamanini I, Tascini C, et al. Fosfomycin Trometamol versus Comparator Antibiotics for the Treatment of Acute Uncomplicated Urinary Tract Infections in Women: A Systematic Review and Meta-Analysis. J Urol. 2020;203(3):570-578. PMID: 31651226. DOI: 10.1097/JU.0000000000000620.
checked
Llor C, Monfa R, Garcia-Sangenis A, et al. Clinical and bacteriological effectiveness of three different short-course antibiotic regimens and single-dose fosfomycin for uncomplicated lower urinary tract infections in women (SCOUT): a pragmatic, multicentre, open-label, randomised clinical trial. Lancet. 2026;407(10539):1603-1613. PMID: 42026010. DOI: 10.1016/S0140-6736(25)02171-3.
checked
Draft and rewrite: Codex (AI) · Verification: Codex blind grading and adversarial audit · Final adjudication: Claude
Reviewed and approved: Chamgap Editorial Team · Approval date: 2026-07-20 · Corrections: none

Cite this verdict

Single-dose fosfomycin 3 g x clinical cure of acute uncomplicated cystitis in nonpregnant women Evidence Grade B card
[Chamgap] Single-dose fosfomycin 3 g x clinical cure of acute uncomplicated cystitis in nonpregnant women — Evidence Grade B·62. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/womens/fosfomycin-single-dose-uncomplicated-cystitis-women/ · CC BY 4.0

CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.

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Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.