What is the recommended treatment for a urinary tract infection (UTI) in women?

Treatment of UTIs in Women

For uncomplicated urinary tract infections in women, first-line treatment includes nitrofurantoin 100 mg twice daily for 5 days, fosfomycin trometamol 3 g single dose, or trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days (if local E. coli resistance is <20%). 1, 2

First-Line Antimicrobial Options

• Nitrofurantoin 100 mg twice daily for 5 days - shown to be more effective than fosfomycin in clinical and microbiological resolution 1, 3
• Fosfomycin trometamol 3 g single dose - convenient single-dose option 1, 2
• Pivmecillinam 400 mg three times daily for 3-5 days (where available) 1, 2
• Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days - only if local E. coli resistance is <20% and not in first or last trimester of pregnancy 1, 2, 4

Alternative Options

• Cephalosporins (e.g., cefadroxil 500 mg twice daily for 3 days) - if first-line agents cannot be used and local resistance patterns for E. coli are <20% 1, 2
• Trimethoprim 200 mg twice daily for 5 days - not in first trimester of pregnancy 1
• For patients with mild to moderate symptoms, symptomatic therapy (e.g., ibuprofen) may be considered as an alternative to antimicrobial treatment 1, 2

Diagnostic Considerations

• Urine culture is recommended in the following situations:
  • Suspected acute pyelonephritis 1
  • Symptoms that do not resolve or recur within 4 weeks after treatment 1
  • Women with atypical symptoms 1
  • Pregnant women 1

Follow-up Recommendations

• Routine post-treatment urinalysis or urine cultures are not indicated for asymptomatic patients 1
• For women whose symptoms do not resolve by the end of treatment or recur within 2 weeks:
  • Obtain urine culture and antimicrobial susceptibility testing 1
  • Assume the infecting organism is not susceptible to the original agent 1
  • Retreat with a 7-day regimen using a different antimicrobial agent 1

Management of Recurrent UTIs

Recurrent UTIs (defined as ≥3 UTIs/year or ≥2 UTIs in 6 months) require a different approach:

Diagnostic Evaluation

• Confirm diagnosis via urine culture 1
• Extensive workup (cystoscopy, abdominal ultrasound) is not routinely needed in women <40 years without risk factors 1

Prevention Strategies

• Non-antimicrobial measures (try these first):

  • Increased fluid intake for premenopausal women 1
  • Vaginal estrogen replacement for postmenopausal women (strong recommendation) 1
  • Methenamine hippurate for women without urinary tract abnormalities 1
  • Immunoactive prophylaxis 1
  • Probiotics containing effective strains for vaginal flora regeneration 1

• Antimicrobial prophylaxis (when non-antimicrobial interventions fail):

  • Continuous or post-coital antimicrobial prophylaxis 1
  • Self-administered short-term therapy for patients with good compliance 1
  • For post-coital infections: low-dose antibiotic within 2 hours of sexual activity for 6-12 months 1
  • Preferred antibiotics: nitrofurantoin 50 mg, trimethoprim-sulfamethoxazole 40/200 mg, or trimethoprim 100 mg 1

Important Caveats and Pitfalls

• Avoid using fluoroquinolones as first-line agents due to ecological adverse effects 2
• Do not use amoxicillin or ampicillin for empirical treatment due to high resistance rates 2
• Avoid treating asymptomatic bacteriuria in women with recurrent UTIs as this increases antimicrobial resistance 1
• Be cautious with trimethoprim-sulfamethoxazole in areas with resistance rates >20% 2, 5
• Consider rotating antibiotics at 3-month intervals for prophylaxis to avoid selection of antimicrobial resistance 1
• Avoid classifying patients with recurrent UTIs as "complicated" as this often leads to unnecessary use of broad-spectrum antibiotics 1

By following these evidence-based recommendations, clinicians can effectively treat UTIs in women while practicing good antimicrobial stewardship.