Treatment of Urinary Tract Infection
For acute uncomplicated UTI in women, use nitrofurantoin, trimethoprim-sulfamethoxazole (TMP-SMX), or fosfomycin as first-line therapy for no longer than 7 days, with treatment selection guided by local antibiogram patterns. 1
First-Line Antibiotic Selection
The three recommended first-line agents are equally effective for clinical and bacteriological cure but differ in their propensity to cause collateral damage (antimicrobial resistance) 1:
- Nitrofurantoin: Preferred when possible due to low resistance rates and rapid decay of resistance when present 1
- Trimethoprim-sulfamethoxazole (TMP-SMX): Effective but should only be used if local resistance rates are <20% 1
- Fosfomycin: Single 3-gram dose option, particularly useful for patient convenience 1
Important caveat: Fluoroquinolones (ciprofloxacin, levofloxacin) should be reserved as second-line agents due to resistance concerns and collateral damage, despite their efficacy 1, 2. Only use fluoroquinolones when local resistance to first-line agents exceeds 10%, when the entire treatment can be given orally without hospitalization, or in patients with anaphylaxis to β-lactams 1.
Treatment Duration
Treat for as short a duration as reasonable, generally no longer than 7 days 1:
- 3-5 days is typically sufficient for uncomplicated cystitis 3, 4
- Single-dose antibiotics show increased bacteriological persistence compared to 3-6 day courses 1
- Avoid prolonged courses to minimize resistance development 1
Diagnostic Approach Before Treatment
Obtain urine culture and sensitivity testing before initiating antibiotics in patients with recurrent UTIs (≥2 infections in 6 months or ≥3 in one year) 1. This provides:
- Baseline data for evaluating interventions 1
- Antimicrobial susceptibility patterns for tailored therapy 1
- Confirmation that symptoms correlate with bacteriuria 1
For reliable patients, patient-initiated (self-start) treatment while awaiting culture results is acceptable, provided they obtain urine specimens before starting therapy 1.
Critical Management Principles
Do NOT treat asymptomatic bacteriuria 1. This is a strong recommendation as treatment fosters antimicrobial resistance and increases recurrent UTI episodes 1. Exceptions include pregnant women and patients scheduled for invasive urinary procedures 1.
Avoid classifying recurrent UTIs as "complicated" unless true complicating factors exist (structural/functional urinary tract abnormalities, immunosuppression, pregnancy) 1. This classification leads to unnecessary broad-spectrum antibiotics with prolonged treatment durations 1.
Complicated UTI Management
For truly complicated UTIs with systemic symptoms, use combination therapy 1:
- Amoxicillin plus aminoglycoside, OR
- Second-generation cephalosporin plus aminoglycoside, OR
- Intravenous third-generation cephalosporin 1
Treatment duration is typically 7-14 days (14 days for men when prostatitis cannot be excluded) 1.
Multidrug-Resistant Organisms
For carbapenem-resistant Enterobacterales (CRE) causing UTI 1:
- Ceftazidime-avibactam 2.5g IV q8h 1
- Meropenem-vaborbactam 4g IV q8h 1
- Imipenem-cilastatin-relebactam 1.25g IV q6h 1
- Plazomicin 15 mg/kg IV q12h 1
For simple cystitis due to CRE, single-dose aminoglycoside may be considered 1.
Men with UTI
Based on observational data, treat men with acute UTI for 7-14 days 4. The longer duration accounts for potential prostatic involvement that may not be clinically apparent 1.
Recurrent UTI Prevention
This is distinct from acute treatment. For prevention strategies in patients with documented recurrent UTIs:
- Postmenopausal women: Vaginal estrogen with or without lactobacillus-containing probiotics 1
- Premenopausal women with post-coital infections: Low-dose antibiotic within 2 hours of sexual activity 1
- Premenopausal women with non-coital infections: Daily antibiotic prophylaxis (nitrofurantoin 50mg, TMP-SMX 40/200mg, or trimethoprim 100mg preferred over fluoroquinolones) 1