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

Treatment of Urinary Tract Infections (UTIs)

For uncomplicated UTIs, first-line treatment options include a 5-day course of nitrofurantoin, a single 3g dose of fosfomycin trometamol, or a 3-day course of trimethoprim-sulfamethoxazole (if local resistance is <20%). 1

First-Line Treatment Options

• Nitrofurantoin is recommended as a first-line agent for uncomplicated UTIs with a 5-day course (50-100 mg four times daily) due to low resistance rates and minimal impact on normal flora 1, 2
• Fosfomycin trometamol is effective as a single 3g dose, making it convenient for patient adherence 1, 3
• Trimethoprim-sulfamethoxazole (TMP-SMX) can be used as a 3-day course but should only be considered when local resistance patterns are <20% 1, 4

Treatment Approach Algorithm

Step 1: Diagnosis Confirmation

• Obtain urinalysis and urine culture with sensitivity testing prior to initiating treatment to confirm diagnosis and guide appropriate antibiotic selection 1
• For recurrent UTIs, confirm diagnosis (defined as >2 culture-positive UTIs in 6 months or >3 in one year) 2

Step 2: Empiric Treatment Selection

• Consider local antibiogram patterns when selecting empiric therapy 1
• Choose antibiotics with the least impact on normal vaginal and fecal flora 1, 2
• Avoid fluoroquinolones as first-line agents due to:
  • FDA advisory warning about unfavorable risk-benefit ratio 2
  • Potential for collateral damage to normal flora 2
  • Increasing resistance rates 3, 5

Step 3: Treatment Duration

• Use as short a duration of antibiotics as reasonable, generally no longer than 7 days 1
• Specific durations by medication:
  • Nitrofurantoin: 5-day course 1, 3
  • Fosfomycin: single 3g dose 1, 3
  • TMP-SMX: 3-day course 1, 4

Special Populations and Situations

Recurrent UTIs

• Obtain pretreatment urine culture when an acute UTI is suspected 2
• Use prior culture data (if available) to choose among first-line treatments while culture is pending 2
• Consider self-start antibiotic therapy in reliable patients who can obtain urine specimens before starting therapy 2
• For prevention of recurrent UTIs:
  • In postmenopausal women: Consider vaginal estrogen with or without lactobacillus-containing probiotics 2
  • In premenopausal women with post-coital infections: Consider low-dose antibiotics within 2 hours of sexual activity 2
  • For non-antibiotic alternatives: Consider methenamine hippurate and/or lactobacillus-containing probiotics 2

Antibiotic Resistance Considerations

• For E. coli UTIs, nitrofurantoin shows low resistance rates (only 20.2% at 3 months, decreasing to 5.7% at 9 months) 2
• High resistance rates have been observed for:
  • Ampicillin (84.9%) 2
  • Amoxicillin-clavulanate (54.5%) 2
  • Ciprofloxacin (83.8%) 2
  • Trimethoprim (78.3%) 2
• Recent studies show E. coli resistance to fluoroquinolones (39.9%) and TMP-SMX (46.6%) is significant 6

Common Pitfalls and Caveats

• Avoid classifying patients with recurrent UTIs as "complicated" as this often leads to inappropriate use of broad-spectrum antibiotics 2
• Reserve the classification of complicated UTI for those with structural/functional abnormalities of the urinary tract, immune suppression, or pregnancy 2
• Avoid treatment of asymptomatic bacteriuria in women with recurrent UTIs, as this fosters antimicrobial resistance and increases recurrence episodes 2, 1
• For persistent symptoms despite treatment, repeat urine culture to assess for ongoing bacteriuria before prescribing additional antibiotics 2
• Single-dose antibiotic regimens (except fosfomycin) are associated with higher rates of treatment failure 1

Second-Line Treatment Options

• If first-line agents cannot be used, consider:
  • Oral cephalosporins such as cephalexin or cefixime 3
  • Amoxicillin-clavulanate 3, 5
  • Beta-lactams (though these may promote more rapid recurrence of UTI) 2