What is a suitable urinary tract infection (UTI) prophylaxis regimen for a male patient with a history of recurrent UTIs who is self-catheterizing?

UTI Prophylaxis for Male Patients Using Clean Intermittent Self-Catheterization

For males with recurrent UTIs who perform clean intermittent self-catheterization (CISC), continuous low-dose antibiotic prophylaxis with nitrofurantoin, trimethoprim-sulfamethoxazole, or fosfomycin for 6-12 months is recommended after non-antimicrobial interventions have failed, as this reduces UTI frequency by approximately 48-90%. 1, 2, 3, 4

When to Initiate Prophylaxis

• Start prophylaxis only after the patient has experienced ≥3 UTIs per year or ≥2 UTIs in 6 months, and after attempting behavioral modifications and non-antimicrobial measures first 1, 2
• Obtain urine culture with antimicrobial susceptibility testing before initiating prophylaxis to guide antibiotic selection and document baseline resistance patterns 1, 5, 6

First-Line Prophylactic Antibiotic Options

Nitrofurantoin is the preferred first-line prophylactic agent due to its remarkably low resistance rates even with repeated use (only 20.2% persistent resistance at 3 months versus 83.8% for fluoroquinolones) 2

• Nitrofurantoin 50-100 mg once daily at bedtime for 6-12 months 1, 3
• Trimethoprim-sulfamethoxazole (TMP-SMX) 40/200 mg or half of a single-strength tablet once daily if local resistance is <20% 1, 3
• Fosfomycin trometamol as an alternative first-line option 3

Evidence Supporting Prophylaxis in CISC Users

• The AnTIC trial specifically studied adult CISC users with recurrent UTIs and demonstrated that continuous antibiotic prophylaxis reduced UTI incidence from 2.6 cases per person-year to 1.3 cases per person-year (48% reduction, p<0.0001) 4
• Prophylaxis was well tolerated with only minor adverse events: gastrointestinal disturbance (6 participants), skin rash (6 participants), and candidal infection (4 participants) out of 203 treated patients 4
• General prophylaxis studies show that continuous or postcoital prophylaxis can reduce recurrence rates by approximately 90% 3

Non-Antimicrobial Interventions to Try First

Before initiating antibiotic prophylaxis, implement these measures:

• Increase fluid intake to dilute urine and reduce bacterial concentration 1, 5
• Methenamine hippurate 1 gram twice daily is a strong alternative for prophylaxis without promoting antimicrobial resistance 1, 5
• Ensure proper catheterization technique and frequency to minimize residual urine 7

Critical Monitoring and Pitfalls

Monitor for antimicrobial resistance development, as the AnTIC trial showed increased resistance in urinary isolates at 9-12 months: nitrofurantoin resistance increased from 9% to 24%, trimethoprim from 33% to 67%, and co-trimoxazole from 24% to 53% 4

• Do NOT treat asymptomatic bacteriuria, as this increases antimicrobial resistance and risk of symptomatic infections without providing benefit 1, 2
• Avoid fluoroquinolones as prophylactic agents due to their propensity for collateral damage, high persistent resistance rates (83.8%), and FDA warnings about disabling adverse effects 2
• Avoid beta-lactam antibiotics as first-line prophylaxis due to disruption of protective periurethral and vaginal microbiota, which paradoxically promotes more rapid UTI recurrence 2

Treatment Duration and Reassessment

• Prescribe prophylaxis for 6-12 months initially 1, 3
• Reassess the need for continued prophylaxis after this period based on UTI frequency during and after prophylaxis 3
• If breakthrough UTIs occur during prophylaxis, obtain culture and susceptibility testing to guide acute treatment, which may require different antibiotics than the prophylactic agent 1, 5

Acute UTI Treatment During Prophylaxis

When breakthrough symptomatic UTIs occur despite prophylaxis:

• Treat acute episodes for 5-7 days maximum with culture-guided antibiotics 1, 5
• For men, the treatment duration is 7 days (longer than the 5 days used for uncomplicated UTIs in women) 6
• Select antibiotics based on culture results, avoiding the agent used for prophylaxis if possible 1

Special Considerations for Males

• Men with UTI symptoms should always receive antibiotics and have urine culture performed, as the diagnosis is less straightforward than in women 6
• Consider urethritis and prostatitis as alternative or concurrent diagnoses in males with UTI symptoms 6
• Evaluate for structural abnormalities or complicating factors if UTIs persist despite appropriate prophylaxis 7, 1