Recommended Antibiotics for Urinary Tract Infections
For uncomplicated cystitis in women, use nitrofurantoin (100 mg twice daily for 5 days), fosfomycin trometamol (3 g single dose), or pivmecillinam (400 mg three times daily for 3-5 days) as first-line therapy, with trimethoprim-sulfamethoxazole (160/800 mg twice daily for 3 days) reserved as an alternative only when local E. coli resistance is below 20%. 1
First-Line Treatment for Women with Uncomplicated Cystitis
The 2024 European Association of Urology guidelines establish a clear hierarchy of antibiotic choices based on efficacy, resistance patterns, and minimizing collateral damage to normal flora 1:
Primary Options:
- Fosfomycin trometamol: 3 g single dose (1 day treatment) 1
- Nitrofurantoin: Multiple formulations available 1
- Macrocrystals: 50-100 mg four times daily for 5 days
- Monohydrate or macrocrystals: 100 mg twice daily for 5 days
- Prolonged release: 100 mg twice daily for 5 days
- Pivmecillinam: 400 mg three times daily for 3-5 days 1
These agents are preferred because they maintain high susceptibility rates against common uropathogens while causing minimal ecological damage compared to broader-spectrum agents 1.
Alternative Options (Use Only When First-Line Agents Are Inappropriate):
- Cephalosporins (e.g., cefadroxil 500 mg twice daily for 3 days): Only if local E. coli resistance is <20% 1
- Trimethoprim: 200 mg twice daily for 5 days (contraindicated in first trimester of pregnancy) 1
- Trimethoprim-sulfamethoxazole: 160/800 mg twice daily for 3 days (contraindicated in last trimester of pregnancy) 1
Critical caveat: Fluoroquinolones should be avoided for uncomplicated cystitis due to high resistance rates in many communities and their propensity to cause collateral damage 2, 3. Reserve these agents for more invasive infections like pyelonephritis 4.
Treatment for Men with UTI
Men require longer treatment duration than women 1:
- Trimethoprim-sulfamethoxazole: 160/800 mg twice daily for 7 days 1, 5
- Fluoroquinolones: Can be prescribed according to local susceptibility testing 1
The extended 7-day course in men accounts for potential prostatic involvement even in seemingly uncomplicated cases 1.
Treatment Duration Principles
Use the shortest effective duration to minimize resistance development and adverse effects 1:
- Most uncomplicated cystitis in women: 3-5 days depending on agent 1
- Single-dose therapy: Only fosfomycin has proven efficacy 1
- Men with UTI: Minimum 7 days 1
- Treatment failures or recurrence within 2 weeks: 7-day regimen with a different agent 1
Special Considerations for Symptomatic Treatment
For women with mild to moderate symptoms, consider symptomatic therapy with ibuprofen as an alternative to immediate antibiotics 1. This approach:
- Reduces antibiotic exposure and resistance development 6
- Allows time for immune response (risk of progression to pyelonephritis is only 1-2%) 6
- Should be discussed with individual patients regarding risks and benefits 1
When to Obtain Urine Culture Before Treatment
Obtain urine culture and sensitivity testing in these situations 1:
- Suspected acute pyelonephritis 1
- Symptoms not resolving or recurring within 4 weeks after treatment completion 1
- Atypical symptoms 1
- Pregnant women 1
- All episodes of recurrent UTI 1
Treatment Failures and Resistant Organisms
If symptoms persist at end of treatment or recur within 2 weeks, assume the organism is not susceptible to the original agent 1. Management includes:
- Obtain urine culture and antimicrobial susceptibility testing 1
- Retreat with a 7-day regimen using a different agent 1
- Consider culture-directed parenteral antibiotics for organisms resistant to oral agents, using as short a course as reasonable (generally ≤7 days) 1
Recurrent UTI Prevention
For women with recurrent UTI (≥3 UTIs/year or ≥2 UTIs in 6 months), implement a stepwise prevention strategy 1:
Postmenopausal Women:
- Vaginal estrogen replacement (strong recommendation) 1
- Methenamine hippurate for women without urinary tract abnormalities (strong recommendation) 1
Premenopausal Women with Post-Coital UTIs:
- Low-dose post-coital antibiotics within 2 hours of sexual activity 1
- Preferred agents: Nitrofurantoin 50 mg, trimethoprim-sulfamethoxazole 40/200 mg, or trimethoprim 100 mg 1
When Non-Antimicrobial Interventions Fail:
- Continuous antimicrobial prophylaxis (strong recommendation) 1
- Self-administered short-term therapy for patients with good compliance (strong recommendation) 1
Important pitfall: Do not treat asymptomatic bacteriuria except in pregnant women or patients scheduled for invasive urinary procedures 1. Routine post-treatment cultures are not indicated in asymptomatic patients 1.
Antibiotic Selection Based on Local Resistance
Always consider local antibiogram data when selecting empiric therapy 1. The choice should be guided by:
- Spectrum and susceptibility patterns of local uropathogens 1
- Efficacy in clinical studies 1
- Tolerability and adverse reactions 1
- Ecological effects (collateral damage) 1
- Cost and availability 1
Trimethoprim-sulfamethoxazole and fluoroquinolones should not be used empirically in areas where E. coli resistance exceeds 20% 2, 3, 4.