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, use first-line antibiotics—nitrofurantoin, trimethoprim-sulfamethoxazole (TMP-SMX), or fosfomycin—for 3-5 days based on local resistance patterns, with treatment duration tailored to the specific agent chosen. 1

Uncomplicated Cystitis in Women

First-Line Treatment Options

The European Association of Urology (2024) provides specific dosing regimens for uncomplicated cystitis 1:

• Fosfomycin trometamol: 3g single dose (1 day treatment) - recommended only for women with uncomplicated cystitis
• Nitrofurantoin: 50-100mg four times daily OR 100mg twice daily for 5 days
• Pivmecillinam: 400mg three times daily for 3-5 days
• TMP-SMX: 160/800mg twice daily for 3 days (avoid in last trimester of pregnancy) 1

Alternative Agents

When first-line options are unsuitable, consider 1:

• Cephalosporins (e.g., cefadroxil 500mg twice daily for 3 days) - only if local E. coli resistance is <20%
• Trimethoprim alone: 200mg twice daily for 5 days (not in first trimester of pregnancy)

Critical Treatment Principles

Avoid fluoroquinolones for empirical treatment due to collateral damage and increasing resistance rates, reserving them only when local resistance to first-line agents exceeds 20% or for specific patient allergies 1, 2. The AUA/CUA/SUFU guidelines emphasize that while most antibiotics achieve similar cure rates, the key considerations are resistance prevalence and collateral damage to normal flora 1.

Treatment duration should be as short as reasonable, generally no longer than 7 days for acute cystitis episodes 1. The evidence supports 3-day courses for most first-line agents, which effectively eradicate infection while minimizing resistance development 1.

Uncomplicated Cystitis in Men

Men require longer treatment duration 1:

• TMP-SMX: 160/800mg twice daily for 7 days
• Fluoroquinolones may be prescribed according to local susceptibility testing
• The extended duration accounts for potential subclinical prostatic involvement 1

Uncomplicated Pyelonephritis

For upper tract infections, treatment escalates to 1:

• Fluoroquinolones (if local resistance <10%):
  • Ciprofloxacin 500-750mg twice daily for 7 days
  • Levofloxacin 750mg once daily for 5 days
• Alternative oral options:
  • TMP-SMX 160/800mg twice daily for 14 days
  • Cefpodoxime 200mg twice daily for 10 days
  • Ceftibuten 400mg once daily for 10 days

If using oral agents empirically, administer an initial IV dose of long-acting parenteral antibiotic (e.g., ceftriaxone) to ensure adequate initial coverage 1.

Complicated UTI

For complicated UTI with systemic symptoms, use combination IV therapy initially 1:

• Amoxicillin plus aminoglycoside, OR
• Second-generation cephalosporin plus aminoglycoside, OR
• Third-generation cephalosporin IV

Treatment duration is 7-14 days (14 days for men when prostatitis cannot be excluded), with duration tied to management of underlying abnormalities 1. Once hemodynamically stable and afebrile for 48 hours, consider transitioning to oral therapy based on culture results 1.

Only use ciprofloxacin if local resistance is <10% and avoid in patients from urology departments or those who used fluoroquinolones in the last 6 months 1.

Diagnostic Approach

When to Obtain Urine Culture

Obtain urine culture and sensitivity before treatment in 1:

• All cases of suspected pyelonephritis
• Recurrent UTI patients with each symptomatic episode
• Symptoms not resolving or recurring within 4 weeks after treatment
• Women with atypical symptoms
• Pregnant women
• All complicated UTI cases

Do NOT obtain cultures for 1:

• Asymptomatic patients (asymptomatic bacteriuria should not be screened for or treated, except in pregnancy or before urologic procedures)
• Routine post-treatment follow-up in asymptomatic patients after successful treatment

Clinical Diagnosis

For uncomplicated cystitis, diagnosis can be made clinically with 1:

• Characteristic symptoms (dysuria, frequency, urgency, suprapubic pain)
• Urinalysis showing pyuria, hematuria, or bacteriuria
• No fever or flank pain (which would suggest pyelonephritis)

Recurrent UTI Management

Definition and Initial Approach

Recurrent UTI is defined as ≥3 UTIs per year or 2 UTIs in the last 6 months 1.

Obtain urine culture with each symptomatic episode to confirm infection and guide therapy 1. However, do NOT perform extensive workup (cystoscopy, full abdominal ultrasound) in women <40 years without risk factors, as imaging yields are low 1.

Non-Antimicrobial Prevention (Attempt First)

Before considering antibiotic prophylaxis, implement 1:

• Increased fluid intake to promote frequent urination
• Post-coital voiding
• Avoid spermicidal contraceptives
• Vaginal estrogen in postmenopausal women (strong recommendation) 1

Additional Preventive Measures

The EAU guidelines provide strength ratings for various interventions 1:

• Immunoactive prophylaxis (strong recommendation)
• Methenamine hippurate in women without urinary tract abnormalities (strong recommendation)
• Probiotics with proven efficacy strains (weak recommendation)
• Cranberry products (weak recommendation - inform patients of low-quality, contradictory evidence) 1
• D-mannose (weak recommendation - inform patients of weak, contradictory evidence)

Antibiotic Prophylaxis

Use continuous or post-coital antimicrobial prophylaxis only when non-antimicrobial interventions have failed 1. This approach is justified because prophylaxis increases antibiotic resistance risk in both causative organisms and indigenous flora 1.

Consider patient-initiated self-start treatment for select patients with recurrent UTI, allowing them to begin therapy while awaiting culture results 1.

Common Pitfalls

• Do not treat asymptomatic bacteriuria except in pregnancy or before invasive urologic procedures 1
• Do not use fluoroquinolones empirically when first-line agents are appropriate, given resistance concerns and collateral damage 1, 2
• Do not obtain routine post-treatment cultures in asymptomatic patients, as this leads to overtreatment of asymptomatic bacteriuria 1
• Do not assume all dysuria is UTI - consider vaginitis, vulvar lesions, chemical irritants, and sexually transmitted diseases 3
• Escherichia coli causes 75-85% of uncomplicated UTIs, with most remaining cases from Enterococcus faecalis, Proteus mirabilis, Klebsiella, or Staphylococcus saprophyticus 1, 4