Treatment of Urinary Tract Infections
First-line treatment for uncomplicated urinary tract infections should be nitrofurantoin, trimethoprim-sulfamethoxazole (TMP-SMX), or fosfomycin, depending on local antibiogram patterns, for a duration of no longer than 7 days. 1
Diagnosis and Classification
- UTIs are classified as uncomplicated or complicated based on patient factors and presence of structural/functional abnormalities 1
- Microbial confirmation through urine culture prior to treatment is important to establish diagnosis and guide appropriate therapy 1
- Asymptomatic bacteriuria should not be treated except in pregnant women and patients undergoing invasive urinary procedures 1
First-Line Treatment for Uncomplicated UTIs
Recommended Antimicrobials
- Nitrofurantoin: Effective with low resistance rates 1, 2
- Trimethoprim-sulfamethoxazole (TMP-SMX): For adults with UTIs, typical dosage is 4 teaspoonfuls (20 mL) every 12 hours for 10-14 days 3
- Fosfomycin: Single 3g dose option 2
Duration of Therapy
- Treatment should be as short as reasonable, generally no longer than 7 days 1
- Single-dose antibiotics are associated with higher risk of bacteriological persistence compared to 3-6 day courses 1
- For TMP-SMX specifically, FDA labeling recommends 10-14 days for UTIs 3
Treatment Considerations for Special Populations
Complicated UTIs
- Requires broader antimicrobial coverage based on local resistance patterns 1
- Treatment duration typically 7-14 days depending on severity 1
- For culture-directed parenteral antibiotics when oral options are not viable due to resistance 1
Pediatric UTIs
- Children 2 months and older: TMP-SMX dosed at 40 mg/kg sulfamethoxazole and 8 mg/kg trimethoprim per 24 hours in two divided doses for 10 days 1, 3
- Alternative options include cephalosporins and amoxicillin-clavulanate 1
- Agents that don't achieve therapeutic blood concentrations (like nitrofurantoin) should not be used for febrile infants 1
Catheter-Associated UTIs
- Require culture-directed therapy and catheter removal/replacement when possible 1
- Higher risk of multidrug-resistant organisms 1
Antimicrobial Stewardship Considerations
- Local antibiogram patterns should guide empiric therapy choices 1, 2
- Urine culture prior to treatment helps tailor therapy and reduce unnecessary antibiotic use 1
- Avoid surveillance urine testing in asymptomatic patients with history of recurrent UTIs 1
- Do not treat asymptomatic bacteriuria except in specific populations (pregnant women, pre-urologic procedures) 1
Management of Recurrent UTIs
- For postmenopausal women: Consider vaginal estrogen with or without lactobacillus-containing probiotics 1
- For premenopausal women with post-coital infections: Consider low-dose antibiotic prophylaxis within 2 hours of sexual activity 1
- Daily antibiotic prophylaxis may be prescribed to decrease future UTI risk after discussing risks and benefits 1
- Non-antibiotic alternatives include methenamine hippurate and lactobacillus-containing probiotics 1
Common Pitfalls to Avoid
- Using fluoroquinolones as first-line empiric therapy (due to increasing resistance rates and collateral damage) 1, 2, 4
- Treating asymptomatic bacteriuria, which increases antimicrobial resistance without clinical benefit 1
- Using unnecessarily broad-spectrum antibiotics or prolonged treatment courses 1, 5
- Failing to adjust therapy based on culture and sensitivity results 1
- Using nitrofurantoin in patients with suspected pyelonephritis or urosepsis (inadequate tissue/blood levels) 1
Emerging Concerns with Antimicrobial Resistance
- Increasing rates of extended-spectrum β-lactamases (ESBLs) and multidrug-resistant organisms require judicious antibiotic use 2, 4
- Second-line options for resistant organisms include oral cephalosporins and β-lactams such as amoxicillin-clavulanate 2
- For multidrug-resistant organisms, treatment should be guided by susceptibility testing 2, 4