What is the appropriate treatment for a patient with a urinary tract infection (UTI)?

Treatment of Urinary Tract Infection (UTI)

For uncomplicated UTI in women, initiate first-line treatment with nitrofurantoin 100 mg twice daily for 5 days, fosfomycin 3g single dose, or trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days, based on local resistance patterns. 1, 2

Diagnosis and Initial Assessment

Confirm the diagnosis before treating:

• In women with typical symptoms (dysuria, frequency, urgency, suprapubic pain) without vaginal discharge, clinical diagnosis alone is sufficient for uncomplicated UTI 1, 2
• Obtain urine culture and susceptibility testing for: recurrent infections, treatment failures, suspected resistant organisms, atypical presentations, all men, and all cases of pyelonephritis 1
• Do not routinely perform cystoscopy or upper tract imaging in women under 40 with recurrent UTI and no risk factors 1

Treatment by Clinical Scenario

Uncomplicated Cystitis in Women

First-line antibiotics (choose based on local resistance patterns): 1, 2

• Nitrofurantoin 100 mg twice daily for 5 days
• Fosfomycin 3g single dose
• Trimethoprim 200 mg twice daily for 5 days (if local E. coli resistance <20%) 1
• Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 3 days (if local resistance <20%) 1, 3

Critical caveat: Avoid fluoroquinolones as first-line therapy due to antimicrobial stewardship concerns and increasing resistance 1

Uncomplicated UTI in Men

Men require longer treatment duration and culture-guided therapy: 1, 2

• Always obtain urine culture before initiating treatment 1, 2
• First-line: Trimethoprim-sulfamethoxazole 160/800 mg twice daily for 7 days 1
• Alternative: Trimethoprim or nitrofurantoin for 7 days 2
• Treat for 14 days if prostatitis cannot be excluded 4

Uncomplicated Pyelonephritis

Requires more aggressive initial management: 1

• Obtain urine culture and antimicrobial susceptibility testing in all cases 1
• Perform ultrasound to rule out obstruction in patients with history of stones, renal dysfunction, or high urine pH 1
• Initiate prompt empiric antibiotic therapy while awaiting culture results 1
• If fever persists beyond 72 hours or clinical deterioration occurs, obtain contrast-enhanced CT immediately 1

Recurrent UTI (≥3 episodes in 12 months)

Stepwise prevention strategy: 1

1. Non-antimicrobial measures (try first):

   • Increase fluid intake 1
   • Vaginal estrogen for postmenopausal women (strong recommendation) 1
   • Cranberry products (weak evidence but low risk) 1
   • D-mannose (weak evidence) 1
   • Methenamine hippurate for women without urinary tract abnormalities 1, 2

2. Antimicrobial prophylaxis (if non-antimicrobial measures fail):

   • Continuous low-dose prophylaxis or postcoital prophylaxis 1
   • Patient-initiated self-start treatment for select patients 1

Important: Document positive urine cultures with each symptomatic episode to confirm true recurrence 1

Complicated UTI

Complicating factors include: male gender, pregnancy, immunosuppression, anatomic abnormalities, indwelling catheters, diabetes, cancer 4, 5

Treatment approach: 4

• Always obtain culture and susceptibility testing before initiating therapy 4
• Empiric options: amoxicillin plus aminoglycoside, second-generation cephalosporin plus aminoglycoside, or IV third-generation cephalosporin 4
• Tailor therapy once susceptibility results available 4
• Treat for 14 days minimum in men with cancer (prostatitis cannot be excluded) 4

Critical Pitfalls to Avoid

• Do not treat asymptomatic bacteriuria except in pregnant women and preschool children 1, 4
• Do not perform post-treatment urine cultures if patient becomes asymptomatic 1, 4
• Do not use fluoroquinolones if patient exposed in previous 6 months or local resistance >10% 4
• Do not use trimethoprim-sulfamethoxazole if local E. coli resistance ≥20% 1
• Do not routinely image young women with recurrent uncomplicated UTI 1
• Do not undertreate men - minimum 7 days, 14 days if prostatitis possible 1, 4, 2

Monitoring Response

• Expect clinical improvement within 48-72 hours of appropriate therapy 4
• Repeat urine culture only if symptoms persist beyond 7 days despite treatment 1
• Symptom resolution is sufficient endpoint; do not reculture asymptomatic patients 1, 4