What is the best treatment for urinary tract infections (UTIs)?

Best Treatment for Urinary Tract Infections (UTIs)

First-line therapy for uncomplicated UTIs should be nitrofurantoin, trimethoprim-sulfamethoxazole (TMP-SMX), or fosfomycin, depending on local antibiogram patterns. 1

Treatment Algorithm for UTIs

Uncomplicated UTIs in Women

• First-line agents (choose based on local resistance patterns): 1

  • Nitrofurantoin 50-100 mg four times daily or 100 mg twice daily for 5 days
  • Fosfomycin trometamol 3 g single dose
  • TMP-SMX 160/800 mg twice daily for 3 days (if local E. coli resistance <20%)

• Treatment duration: As short as reasonable, generally no longer than 7 days 1

• Second-line options (only when first-line agents cannot be used): 1, 2

  • Cephalosporins (e.g., cefadroxil 500 mg twice daily for 3 days)
  • Pivmecillinam 400 mg three times daily for 3-5 days

Complicated UTIs

• Empiric treatment options: 1

  • Amoxicillin plus an aminoglycoside
  • Second-generation cephalosporin plus an aminoglycoside
  • IV third-generation cephalosporin

• Treatment duration: 7-14 days (14 days for men when prostatitis cannot be excluded) 1

• Culture-directed therapy: Adjust based on urine culture results 1

Important Considerations

Antibiotic Resistance

• Fluoroquinolones (e.g., ciprofloxacin) should not be used as first-line therapy due to: 1

  • Increasing resistance rates
  • FDA warning about unfavorable risk-benefit ratio for uncomplicated UTIs
  • Greater potential for collateral damage to gut microbiota

• E. coli resistance patterns from recent studies show: 3

  • High resistance to fluoroquinolones (39.9%) and TMP-SMX (46.6%)
  • Highest susceptibility to fosfomycin (95.5%), nitrofurantoin (85.5%), and cefuroxime (82.3%)

Special Populations

• Recurrent UTIs: 1

  • Obtain urine culture for each symptomatic episode
  • Consider patient-initiated treatment for select patients
  • Antibiotic prophylaxis may be considered after discussing risks and benefits
  • Non-antibiotic options include increased fluid intake, vaginal estrogen in postmenopausal women, and immunoactive prophylaxis

• Catheter-associated UTIs: 1

  • Treat symptomatic infections according to complicated UTI guidelines
  • Do not treat asymptomatic bacteriuria

• Multidrug-resistant organisms: 1, 2

  • For ESBL-producing organisms: nitrofurantoin, fosfomycin, or pivmecillinam (oral options)
  • For carbapenem-resistant Enterobacterales: newer agents like ceftazidime-avibactam, meropenem-vaborbactam, or imipenem-cilastatin-relebactam

Asymptomatic Bacteriuria

• Do not treat asymptomatic bacteriuria in most populations 1
• Do not perform surveillance urine testing in asymptomatic patients with recurrent UTIs 1
• Exceptions: Pregnant women and patients scheduled for invasive urologic procedures 1

Common Pitfalls to Avoid

• Overtreatment: Treating asymptomatic bacteriuria increases risk of symptomatic infection, bacterial resistance, and healthcare costs 1

• Inappropriate antibiotic selection: Using broad-spectrum antibiotics when narrow-spectrum would suffice 2, 4

• Inadequate treatment duration: Single-dose antibiotics (except fosfomycin) are associated with higher rates of bacteriological persistence compared to 3-7 day courses 1

• Ignoring local resistance patterns: Treatment should be guided by local antibiograms whenever possible 1, 4

• Failing to adjust therapy based on culture results: Initial empiric therapy should be tailored once culture and sensitivity results are available 1