What is the first-line treatment for uncomplicated urinary tract infections (UTIs) in women?

First-Line Treatment for UTI in Women

The recommended first-line treatments for uncomplicated urinary tract infections (UTIs) in women are 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

Treatment Selection Algorithm

• Choose empiric therapy based on:

  • Local antibiogram patterns and resistance rates 2, 1
  • Patient allergies and contraindications 1
  • Risk of collateral damage (ecological adverse effects) 1

• First-line options (in order of preference):

  • Nitrofurantoin 100 mg twice daily for 5 days 2, 1, 3
  • Fosfomycin trometamol 3 g single dose 1, 4
  • Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days (only if local E. coli resistance <20%) 2, 1, 5
  • Pivmecillinam 400 mg three times daily for 3-5 days (where available) 1

Evidence Supporting First-Line Recommendations

• Nitrofurantoin has demonstrated lower treatment failure rates compared to trimethoprim-sulfamethoxazole in recent studies 6
• Fosfomycin is FDA-approved specifically for uncomplicated UTIs in women 4
• Trimethoprim-sulfamethoxazole was traditionally the first-line agent but rising resistance rates have necessitated revising this recommendation 2
• All three first-line agents have shown efficacy while minimizing collateral damage to normal flora 1, 3

Second-Line Options

• Fluoroquinolones (e.g., ciprofloxacin, levofloxacin) are highly efficacious but should be reserved as alternative agents due to their propensity for collateral damage 2, 1
• β-Lactam agents (e.g., amoxicillin-clavulanate, cefdinir, cefaclor) can be used when first-line agents cannot be used, but generally have inferior efficacy and more adverse effects 2
• Oral cephalosporins such as cephalexin or cefixime can be considered as second-line options 3

Important Caveats

• Amoxicillin or ampicillin should not be used for empirical treatment due to high resistance rates 2, 1
• Urine culture is not necessary for initial diagnosis in women with typical symptoms (frequency, urgency, dysuria) without vaginal discharge 7
• Obtain urine culture before treatment in:
  • Suspected pyelonephritis
  • Symptoms that don't resolve within 4 weeks after treatment
  • Pregnant women
  • History of recurrent UTIs 1
• For treatment failure, retreatment with a 7-day regimen using a different agent is recommended 1

Special Considerations

• Trimethoprim should be avoided in the first trimester and trimethoprim-sulfamethoxazole in the last trimester of pregnancy 1
• For recurrent UTIs, documentation of positive urine cultures associated with prior symptomatic episodes is necessary for diagnosis 2
• Patient-initiated treatment (self-start treatment) may be offered to select patients with recurrent UTIs 2
• Symptomatic therapy (e.g., ibuprofen) may be considered as an alternative to antimicrobial treatment in patients with mild to moderate symptoms 1, 7