What are the recommended treatments for urinary tract infections (UTIs)?

Treatment of Urinary Tract Infections (UTIs)

For uncomplicated UTIs in women, first-line treatments include fosfomycin trometamol (3g single dose), nitrofurantoin (100mg twice daily for 5 days), or pivmecillinam (400mg three times daily for 3-5 days). 1, 2

Diagnosis and Initial Assessment

• UTI diagnosis in uncomplicated cases can be made with high probability based on:
  • Focused history of lower urinary tract symptoms (dysuria, frequency, urgency)
  • Absence of vaginal discharge 1
• Urine culture is recommended in the following situations:
  • Suspected acute pyelonephritis
  • Symptoms that don't resolve or recur within 4 weeks after treatment
  • Women with atypical symptoms
  • Pregnant women 1

Treatment Algorithm for UTIs

1. Uncomplicated Cystitis in Women

First-line options:

• Fosfomycin trometamol: 3g single dose (1 day)
• Nitrofurantoin macrocrystals: 100mg twice daily for 5 days
• Nitrofurantoin monohydrate/macrocrystals: 100mg twice daily for 5 days
• Pivmecillinam: 400mg three times daily for 3-5 days 1, 2

Alternative options (if first-line not suitable):

• Cephalosporins (e.g., cefadroxil): 500mg twice daily for 3 days (if local E. coli resistance <20%)
• Trimethoprim: 200mg twice daily for 5 days (avoid in first trimester of pregnancy)
• Trimethoprim-sulfamethoxazole: 160/800mg twice daily for 3 days (avoid in last trimester of pregnancy) 1, 3

2. UTIs in Men

• Trimethoprim-sulfamethoxazole: 160/800mg twice daily for 7 days
• Fluoroquinolones can be prescribed according to local susceptibility testing 1

3. Failed Initial Treatment

When symptoms don't resolve by end of treatment or recur within 2 weeks:

• Perform urine culture and antimicrobial susceptibility testing
• Assume the infecting organism is not susceptible to the original agent
• Retreat with a 7-day regimen using a different antimicrobial agent 1

4. Recurrent UTIs

Defined as ≥3 UTIs/year or ≥2 UTIs in the last 6 months 1

Prevention strategies (in order of preference):

1. Non-antimicrobial measures:

   • Increased fluid intake for premenopausal women
   • Vaginal estrogen replacement for postmenopausal women
   • Immunoactive prophylaxis
   • Probiotics with proven efficacy
   • Cranberry products (evidence is weak and contradictory)
   • D-mannose (evidence is weak and contradictory)
   • Methenamine hippurate for women without urinary tract abnormalities 1, 2

2. Antimicrobial prophylaxis (when non-antimicrobial interventions fail):

   • Continuous or postcoital antimicrobial prophylaxis
   • Self-administered short-term antimicrobial therapy for patients with good compliance 1, 2

Special Considerations

Multidrug-Resistant (MDR) Organisms

• For uncomplicated UTIs due to MDR organisms:
  • Fosfomycin: 3g PO single dose
  • Nitrofurantoin: 100mg PO every 6 hours 1, 4
• For complicated UTIs due to carbapenem-resistant Enterobacteriaceae (CRE):
  • Single-dose aminoglycoside (if susceptible)
  • Plazomicin 15mg/kg IV every 12 hours 1

Elderly Patients

• Genitourinary symptoms in elderly women are not necessarily related to cystitis
• Avoid treating asymptomatic bacteriuria 1, 5

Important Clinical Pearls

• Do not perform extensive routine workup (e.g., cystoscopy, abdominal ultrasound) in women <40 years with recurrent UTI and no risk factors 1
• Avoid fluoroquinolones as first-line agents due to increasing resistance rates and potential adverse effects; reserve them for more invasive infections 6, 4
• Post-treatment cultures are not indicated for asymptomatic patients 1
• Resistance patterns vary geographically; consider local resistance rates when selecting empiric therapy 7
• Repeated pyelonephritis should prompt consideration of a complicated etiology 1

By following this evidence-based approach to UTI management, clinicians can optimize treatment outcomes while minimizing antimicrobial resistance and adverse effects.