First-Line Treatment for Uncomplicated UTI
For uncomplicated cystitis in adult women, nitrofurantoin (100 mg twice daily for 5 days) is the preferred first-line antibiotic, with fosfomycin trometamol (3 g single dose) and trimethoprim-sulfamethoxazole (160/800 mg twice daily for 3 days) as equally appropriate alternatives, based on the most recent 2024 European and international guidelines. 1
Recommended First-Line Antibiotics
The 2024 European Association of Urology guidelines establish three first-line options for uncomplicated cystitis: 1
- Nitrofurantoin macrocrystals: 50-100 mg four times daily for 5 days 1
- Fosfomycin trometamol: 3 g single dose (recommended only for women with uncomplicated cystitis) 1
- Trimethoprim-sulfamethoxazole: 160/800 mg twice daily for 3 days 1
Nitrofurantoin is prioritized because it demonstrates robust efficacy while sparing more systemically active agents for other infections, and it maintains low resistance rates even with repeated use. 1, 2
Antibiotic Selection Rationale
The choice among first-line agents should be guided by: 1
- Local resistance patterns: TMP-SMX should only be used if local E. coli resistance is <20% 1, 3
- Antimicrobial stewardship: Nitrofurantoin and fosfomycin cause minimal "collateral damage" (selection of multi-resistant pathogens) compared to fluoroquinolones and cephalosporins 1, 3
- Patient factors: Previous antibiotic exposure within 6 months increases resistance risk to that same class 2
Agents to Avoid as First-Line
- Fluoroquinolones (ciprofloxacin, levofloxacin): Should be reserved for pyelonephritis or complicated infections due to increasing resistance rates and significant collateral damage, despite E. coli resistance still being <10% in many regions 1, 3
- β-lactam agents (amoxicillin-clavulanate, cefpodoxime): Less effective than first-line therapies for empiric treatment 4
- Cephalosporins: Not recommended as first-line due to ecological effects 3
Treatment Duration
Specific durations based on 2024 guidelines: 1
- Nitrofurantoin: 5 days 1
- Fosfomycin: Single dose 1
- TMP-SMX: 3 days 1
- Fluoroquinolones (if used): 3 days 1
Diagnostic Considerations
For typical uncomplicated cystitis in women: 1
- Diagnosis can be made clinically based on acute-onset dysuria with urgency/frequency and absence of vaginal discharge 1, 4
- Urine culture is NOT required for straightforward cases with typical symptoms 1, 4
- Obtain urine culture before treatment in these situations: 1
- Suspected pyelonephritis
- Symptoms not resolving or recurring within 4 weeks
- Atypical symptoms
- Pregnant women
- Recurrent UTIs (≥3 UTIs/year or ≥2 UTIs in 6 months) 1
Alternative Approach: Symptomatic Treatment
For women with mild to moderate symptoms, symptomatic therapy with ibuprofen may be considered as an alternative to immediate antibiotics, though this approach requires shared decision-making with the patient. 1 Evidence suggests supportive care with analgesics can be attempted while awaiting cultures, though immediate antimicrobial therapy remains standard practice. 1, 4
Special Populations
Men with uncomplicated UTI: 1, 5
- Always obtain urine culture before treatment
- First-line options: TMP-SMX, trimethoprim, or nitrofurantoin for 7 days (not 3-5 days as in women)
- Consider urethritis and prostatitis in differential diagnosis
Older adults (≥65 years): 5
- Obtain urine culture with susceptibility testing
- Same first-line antibiotics and durations as younger adults if nonfrail with no relevant comorbidities
Critical Pitfalls to Avoid
- Do not treat asymptomatic bacteriuria in non-pregnant, non-surgical patients—this increases antimicrobial resistance and risk of symptomatic infections 1, 2
- Do not use antibiotics from the past 6 months due to increased resistance risk 2
- Do not routinely obtain cystoscopy or imaging for uncomplicated recurrent UTI 1
- Do not use broad-spectrum antibiotics when narrower options are available 2