Treatment of Urinary Tract Infection (UTI)
For uncomplicated UTI in women, use first-line therapy with nitrofurantoin, trimethoprim-sulfamethoxazole (TMP-SMX), or fosfomycin based on your local antibiogram, treating for no longer than 7 days. 1
Diagnostic Approach
Before initiating treatment, obtain urinalysis, urine culture, and sensitivity testing with each symptomatic acute cystitis episode. 1 This microbial confirmation establishes the diagnosis and allows for tailoring therapy based on bacterial antimicrobial sensitivities. 1
Common pitfall: Do not treat asymptomatic bacteriuria (ASB) in non-pregnant patients—this leads to unnecessary antibiotic exposure and resistance development. 1
First-Line Antibiotic Treatment
The 2019 AUA/CUA/SUFU guidelines provide a strong recommendation for using first-line agents dependent on local resistance patterns: 1
- Nitrofurantoin: 50-100 mg four times daily for 5 days, or 100 mg twice daily for 5 days 1
- Trimethoprim-sulfamethoxazole (TMP-SMX): 160/800 mg twice daily for 3 days 1, 2
- Fosfomycin trometamol: 3 g single dose 1
The 2024 European Association of Urology guidelines align with these recommendations, emphasizing that these agents are less likely to produce "collateral damage" (disruption of normal flora and resistance development) compared to second-line agents. 1
Duration of Therapy
Treat for as short a duration as reasonable, generally no longer than 7 days. 1 The evidence shows that single-dose antibiotics are associated with increased risk of bacteriological persistence compared to short courses (3-6 days), making them less favorable. 1
Second-Line Options
Use these when first-line agents are contraindicated due to resistance patterns or allergies: 1
- Fluoroquinolones (ciprofloxacin, levofloxacin): Reserve due to increasing resistance and collateral damage concerns 1, 3
- Cephalosporins (cefadroxil): 500 mg twice daily for 3 days if local E. coli resistance is <20% 1
- Beta-lactams: Consider as second-line only 4
Important caveat: Fluoroquinolones and cephalosporins should be avoided as first-line therapy to minimize antimicrobial resistance development. 1 High rates of resistance to TMP-SMX and ciprofloxacin in many communities preclude their empiric use, particularly in patients recently exposed to these agents. 5
Special Considerations
Patient-Initiated Treatment
You may offer self-start treatment to select patients with recurrent UTIs while awaiting urine cultures. 1 This approach requires documented positive cultures with prior symptomatic episodes. 1
Resistant Organisms
For acute cystitis episodes with cultures resistant to oral antibiotics, treat with culture-directed parenteral antibiotics for no longer than 7 days. 1
Treatment Failure
If symptoms do not resolve by end of treatment or recur within 2 weeks, obtain urine culture and antimicrobial susceptibility testing. 1 Assume the organism is not susceptible to the originally used agent and retreat with a 7-day regimen using another agent. 1
Antimicrobial Stewardship Principles
The choice of antimicrobial should balance: 1
- Spectrum and susceptibility patterns of aetiological pathogens
- Efficacy in clinical studies
- Tolerability and adverse reactions
- Adverse ecological effects (collateral damage)
- Local resistance patterns
Critical point: Combine knowledge of your local antibiogram with selection of antimicrobial agents having the least impact on normal vaginal and fecal flora. 1 This approach significantly mitigates increasing fluoroquinolone and cephalosporin resistance. 1