What is the best treatment approach for recurrent urinary tract infections (UTIs) in women?

Treatment Approach for Recurrent Urinary Tract Infections in Women

For women with recurrent urinary tract infections (defined as ≥3 UTIs per year or ≥2 UTIs in 6 months), a structured approach including both preventive strategies and prophylactic antibiotics is recommended, with low-dose antibiotic prophylaxis being the most effective intervention for reducing recurrence rates. 1

Definition and Diagnosis

• Recurrent UTIs are defined as at least three episodes within a 12-month period or two episodes within 6 months following complete clinical resolution of previous UTIs 1, 2
• Before starting treatment:
  • Obtain urine culture to guide therapy, especially in complicated cases or treatment failures 1
  • Consider imaging (ultrasound or MRI) if symptoms persist to rule out complications like obstruction or abscess 1

First-Line Prevention Strategies (Non-Antibiotic)

1. Behavioral modifications:

   • Increased fluid intake (additional 1.5L daily, total 2-3L unless contraindicated) 1
   • Urge-initiated voiding and post-coital voiding 1
   • Avoiding spermicidal contraceptives 1

2. For postmenopausal women:

   • Topical vaginal estrogen (strongly recommended) to restore vaginal microbiome and reduce vaginal atrophy 1

3. Non-antibiotic prophylaxis:

   • Methenamine hippurate 1 gram twice daily 1

Antibiotic Prophylaxis Options

When non-antibiotic measures are insufficient, consider one of the following prophylactic regimens:

1. Post-coital prophylaxis (for UTIs related to sexual activity):

   • Nitrofurantoin 50-100 mg within 2 hours after intercourse 1
   • Trimethoprim-sulfamethoxazole (TMP-SMX) 40/200 mg within 2 hours after intercourse 1
   • Trimethoprim 100 mg within 2 hours after intercourse 1

2. Low-dose daily antibiotic prophylaxis (for UTIs unrelated to sexual activity):

   • Continue for 6-12 months 1
   • Options include nitrofurantoin, TMP-SMX, or other antibiotics based on susceptibility patterns 1, 3

Treatment of Acute Episodes

When breakthrough infections occur despite prophylaxis:

1. First-line treatment for uncomplicated UTI:

   • Nitrofurantoin 100mg twice daily for 5 days (preferred due to high efficacy and low resistance) 1, 2

2. Alternative options:

   • TMP-SMX for 3 days (if local resistance rates <20%) 1, 2
   • Cephalexin 500mg four times daily for 7 days 1

3. For complicated UTI or pyelonephritis:

   • Cephalexin 500mg four times daily for 14 days 1
   • Alternative: Amoxicillin-clavulanate 500mg three times daily for 14 days 1
   • Consider initial parenteral therapy if symptoms are severe 1

Special Considerations and Caveats

• Antibiotic resistance concerns: Long-term antibiotic prophylaxis can lead to resistance; use non-antibiotic methods first when possible 1

• Pregnancy considerations:

  • Nitrofurantoin is safe in the second trimester 1
  • Cephalexin is safe throughout pregnancy 1
  • Avoid fluoroquinolones and TMP-SMX if possible during pregnancy 1, 4

• Medication contraindications:

  • Nitrofurantoin should not be used for pyelonephritis or in patients with G6PD deficiency 1
  • TMP-SMX should be avoided during first and third trimesters of pregnancy 1

• Efficacy of prophylaxis: During active prophylaxis, the rate of microbiological recurrence is significantly reduced (RR 0.21,95% CI 0.13 to 0.34) compared to placebo 3

• Post-prophylaxis recurrence: Limited evidence suggests recurrence rates may return to baseline after discontinuation of prophylaxis 3

Monitoring and Follow-up

• Monitor for side effects of antibiotics, including vaginal and oral candidiasis and gastrointestinal symptoms 3
• Consider urine cultures periodically during prophylaxis to detect resistant organisms
• Reassess the need for continued prophylaxis after 6-12 months 1