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

Treatment of Urinary Tract Infections (UTIs)

For patients with urinary tract infections, first-line treatment should include nitrofurantoin, trimethoprim-sulfamethoxazole (TMP-SMX), or fosfomycin, with the specific choice depending on local resistance patterns. 1

Classification and Diagnosis

• UTIs are classified as either uncomplicated (occurring in patients without structural or functional abnormalities) or complicated (occurring in patients with underlying structural or medical problems) 1
• Diagnosis should include urinalysis and urine culture before initiating treatment to confirm the infection and guide antibiotic selection 1
• E. coli is the most common causative organism (approximately 75% of UTIs), with other infections caused by Enterococcus faecalis, Proteus mirabilis, Klebsiella, or Staphylococcus saprophyticus 1, 2

Treatment Algorithm for UTIs

Uncomplicated UTIs in Women

First-line treatment options:

• Nitrofurantoin 100 mg twice daily for 5 days 1
• Fosfomycin 3 g single dose 1
• TMP-SMX 160/800 mg twice daily for 3 days (if local resistance <20%) 1, 3
• Pivmecillinam 400 mg three times daily for 3-5 days 1

Second-line options (when resistance or allergies are concerns):

• Cephalosporins (e.g., cefadroxil 500 mg twice daily for 3 days) 1
• Trimethoprim 200 mg twice daily for 5 days 1

Uncomplicated UTIs in Men

• TMP-SMX 160/800 mg twice daily for 7 days 1
• Fluoroquinolones according to local susceptibility patterns (but avoid if resistance >10%) 1
• Treatment duration should be longer than for women (7 days) 1

Complicated UTIs

For patients with systemic symptoms or complicated factors:

• Amoxicillin plus an aminoglycoside, OR
• Second-generation cephalosporin plus an aminoglycoside, OR
• Intravenous third-generation cephalosporin 1
• Treatment duration: 7-14 days (14 days for men when prostatitis cannot be excluded) 1

Pyelonephritis

• Third-generation cephalosporins are preferred 2
• If using fluoroquinolones, initial intravenous dose of a long-acting parenteral antimicrobial (e.g., ceftriaxone) should be administered 1
• Treatment duration: 7-14 days 1

Special Considerations

Recurrent UTIs

• Defined as at least three episodes within 12 months or two episodes in the last 6 months 1
• Non-antimicrobial prevention strategies should be tried first:
  • Increased fluid intake 1
  • Vaginal estrogen replacement in postmenopausal women 1
  • Immunoactive prophylaxis 1
• Antibiotic prophylaxis should be considered when non-antimicrobial interventions have failed 1

Catheter-Associated UTIs

• Remove catheter if possible 1
• Obtain urine culture before starting antibiotics 1
• Treatment duration: 7 days if patient is hemodynamically stable and afebrile for at least 48 hours 1

Common Pitfalls to Avoid

• Treating asymptomatic bacteriuria: Do not treat asymptomatic bacteriuria except in pregnant women and patients scheduled for urological procedures 1
• Overuse of fluoroquinolones: Do not use ciprofloxacin and other fluoroquinolones for empirical treatment when local resistance rates are >10% or when patients have used fluoroquinolones in the last 6 months 1
• Inadequate treatment duration: Too short a course may lead to treatment failure, while unnecessarily long courses increase risk of resistance 1
• Failure to obtain cultures: Always obtain cultures before starting antibiotics in complicated or recurrent cases 1
• Ignoring underlying abnormalities: Appropriate management of urological abnormalities or underlying complicating factors is mandatory for successful treatment 1

By following these evidence-based guidelines, clinicians can effectively treat UTIs while minimizing antibiotic resistance and optimizing patient outcomes.