What is the recommended regimen for Urinary Tract Infection (UTI) prophylaxis?

UTI Prophylaxis Recommendations

For recurrent urinary tract infections (rUTIs), continuous or postcoital antimicrobial prophylaxis is strongly recommended when non-antimicrobial interventions have failed, with trimethoprim-sulfamethoxazole, nitrofurantoin, and methenamine hippurate being the most effective options. 1

Definition and Impact of Recurrent UTIs

• Recurrent UTIs are defined as at least three UTIs per year or two UTIs in the last 6 months 1
• rUTIs significantly impact quality of life, affecting social and sexual relationships, self-esteem, and work capacity 1

First-Line Non-Antimicrobial Prophylaxis Options

Before initiating antimicrobial prophylaxis, consider these non-antimicrobial interventions:

1. Increased Fluid Intake

   • Recommend additional 1.5L of water daily for premenopausal women 1
   • This simple intervention may reduce the risk of recurrent UTIs 1

2. Vaginal Estrogen for Postmenopausal Women

   • Strongly recommended for postmenopausal women 1
   • Available as vaginal rings, inserts, or creams 1
   • Helps restore vaginal microbiome and reduce vaginal atrophy 1

3. Methenamine Hippurate

   • Strongly recommended for women without urinary tract abnormalities 1
   • Dosing: 1g twice daily 1
   • Works by releasing formaldehyde in acidic urine 1

4. Cranberry Products

   • May be offered despite limited evidence 1
   • Products containing 36mg proanthocyanidins are preferred 1
   • Patients should be informed of contradictory evidence 1

5. Probiotics

   • May be recommended for vaginal flora regeneration 1
   • Evidence is heterogeneous regarding specific strains and administration routes 1

Antimicrobial Prophylaxis Regimens

When non-antimicrobial interventions fail, antimicrobial prophylaxis should be considered:

Continuous Daily Prophylaxis Options:

• Nitrofurantoin:

  • 50mg daily (preferred over 100mg due to better safety profile) 1, 2
  • 100mg daily associated with higher risk of cough, dyspnea, and nausea without improved efficacy 2

• Trimethoprim-Sulfamethoxazole (TMP-SMX):

  • 40mg/200mg once daily 1, 3
  • Alternative: 40mg/200mg three times weekly 1

• Trimethoprim alone:

  • 100mg once daily 4
  • Effective alternative for patients with sulfonamide sensitivity 5

Postcoital Prophylaxis Options:

• TMP-SMX: 40mg/200mg or 80mg/400mg single dose after intercourse 1
• Nitrofurantoin: 50mg or 100mg single dose after intercourse 1

Intermittent Prophylaxis:

• Fosfomycin: 3g every 10 days 1

Duration of Prophylaxis

• Typical duration ranges from 6 to 12 months 1, 3
• Clinical practice may vary from 3-6 months to 1 year with periodic monitoring 1
• Prophylaxis effect typically lasts only during active treatment period 1, 3
• After discontinuation, infection rates often return to pre-prophylaxis levels 3, 4

Important Considerations and Monitoring

• Obtain urine culture before initiating prophylaxis to confirm diagnosis 1
• Do not perform routine surveillance cultures in asymptomatic patients 1
• Do not treat asymptomatic bacteriuria 1
• Discuss potential adverse effects of antimicrobials with patients 1
• For nitrofurantoin, monitor for rare but serious pulmonary (0.001%) and hepatic toxicity (0.0003%) 1
• Consider emergence of resistant organisms, particularly non-E. coli infections after prophylaxis discontinuation 3

Special Populations

• Postmenopausal women: Prioritize vaginal estrogen therapy 1
• Women with UTIs related to sexual activity: Consider postcoital prophylaxis 1
• Men with rUTIs: TMP-SMX 160/800mg twice daily for 7 days; fluoroquinolones based on local susceptibility patterns 1