Antibiotic Policy for Prevention and Treatment of Urinary Tract Infections
Treatment of Acute UTIs
For uncomplicated cystitis in adults, nitrofurantoin 100 mg twice daily for 5 days is the preferred first-line agent, with fosfomycin 3 g single dose and TMP-SMX 160/800 mg twice daily for 3 days as alternatives when local resistance is <20%. 1
Uncomplicated Cystitis (Lower UTI)
First-line agents:
- Nitrofurantoin 100 mg twice daily for 5 days - preferred due to low resistance rates (2.6% initial, 5.7% at 9 months) and ability to spare broader-spectrum agents 1, 2
- Fosfomycin trometamol 3 g single dose - excellent alternative with single-dose convenience 1, 3
- TMP-SMX 160/800 mg twice daily for 3 days - only if local E. coli resistance is <20% 1, 4
Second-line agents (when first-line unavailable or contraindicated):
- Fluoroquinolones (ciprofloxacin) for 3 days - reserve for more invasive infections due to resistance concerns and adverse effects 1, 3
- β-lactams (amoxicillin-clavulanate, cephalexin) - less effective as empirical therapy 5, 3
Critical caveat: Avoid fluoroquinolones as first-line due to increasing resistance rates and risk of collateral damage to protective microbiota 1, 6
Pyelonephritis (Upper UTI)
For pyelonephritis, TMP-SMX or first-generation cephalosporins are reasonable first-line oral agents when local resistance permits, while ceftriaxone is the recommended empirical IV choice. 1
Oral therapy:
- TMP-SMX 160/800 mg twice daily - duration unclear from evidence but typically 7-14 days 1
- First-generation cephalosporins - 7 days 1
- Fluoroquinolones (ciprofloxacin, levofloxacin) - 5-7 days 1
Intravenous therapy (for severe cases):
- Ceftriaxone is the recommended empirical IV choice due to low resistance rates and clinical effectiveness, unless risk factors for multidrug resistance exist 1
- β-lactams - 7 days total duration 1
Important: Nitrofurantoin should NOT be used for pyelonephritis due to insufficient data on efficacy for upper tract infections 2
Treatment Duration Summary
| Syndrome | Agent | Duration |
|---|---|---|
| Uncomplicated cystitis | Nitrofurantoin | 5 days [1] |
| Uncomplicated cystitis | Fosfomycin | Single dose [1] |
| Uncomplicated cystitis | TMP-SMX | 3 days [1] |
| Uncomplicated cystitis | Fluoroquinolones | 3 days [1] |
| Pyelonephritis | β-lactams | 7 days [1] |
| Pyelonephritis | Fluoroquinolones | 5-7 days [1] |
| Gram-negative bacteremia from urinary source | Any appropriate agent | 7 days [1] |
Diagnostic Approach
Obtain urine culture before initiating therapy when possible to guide definitive treatment and assess for antimicrobial resistance. 1, 2
- Uncomplicated cystitis in young healthy women can be diagnosed clinically without office visit or culture in straightforward cases 3
- For recurrent UTI, obtain pretreatment urine culture when acute UTI is suspected 1
- Use prior culture data when available to guide empirical choices while awaiting new culture results 1
Critical pitfall: Urinalysis has very low specificity in patients with indwelling catheters or ileal conduits but excellent negative predictive value - a negative UA rules out catheter-associated UTI, but a positive UA does not confirm it 1
Empirical Treatment Selection Framework
Base empirical antibiotic selection on local resistance patterns (antibiograms), patient risk factors for resistance, clinical severity, and prior culture data. 1, 2
Risk factors requiring broader coverage:
- Recent antibiotic exposure (especially fluoroquinolones or TMP-SMX) 5
- Healthcare-associated infection 1
- Known colonization with resistant organisms 5, 6
- Recent hospitalization or nursing home residence 5
Agents with antipseudomonal activity should only be used in patients with risk factors for nosocomial pathogens. 1
Prevention of Recurrent UTIs
For women with recurrent UTI (≥2 episodes in 6 months or ≥3 in 12 months), implement an algorithmic approach prioritizing non-antibiotic interventions before antimicrobial prophylaxis. 1, 2
Postmenopausal Women
First-line prevention:
- Vaginal estrogen with or without lactobacillus-containing probiotics - strong recommendation 1, 2
- Methenamine hippurate 1 g twice daily - strong recommendation for women without urinary tract abnormalities 1, 2
- Oral immunostimulant (OM-89) - appears most promising among non-antibiotic options 1
Antibiotic prophylaxis (only after non-antibiotic interventions fail):
- Daily nitrofurantoin prophylaxis is most effective strategy, reducing UTI rate to 0.4/year 1
- Choice should account for prior organism susceptibility, drug allergies, and antibiotic stewardship 1
Premenopausal Women
For infections associated with sexual activity:
- Low-dose post-coital antibiotics 1
For infections unrelated to sexual activity:
- Low-dose daily antibiotic prophylaxis (after non-antibiotic options fail) 1
- Methenamine hippurate and/or lactobacillus-containing probiotics as non-antibiotic alternatives 1
Evidence note: Cranberries (100-500 mg daily) showed some benefit in reducing recurrent UTIs (RR 0.53) but evidence quality is critically low 1
Special Populations
Elderly Women
- Atypical presentations (confusion, functional decline, delirium) may be the only manifestation of UTI 2
- Adjust dosing for renal function, particularly with nitrofurantoin which requires adequate renal function 2
- Consider comorbidities and polypharmacy for drug interactions 2
- Treatment approach is otherwise similar to younger adults for uncomplicated cystitis 2
Men with UTI
- Limited observational studies support 7-14 days of therapy for acute UTI in men 3
- Obtain urine culture given higher likelihood of complicated infection 3
Women with Diabetes
- Women with diabetes without voiding abnormalities presenting with acute cystitis should be treated similarly to women without diabetes 3
- No evidence supports longer treatment courses 3
Critical Pitfalls to Avoid
Do NOT treat asymptomatic bacteriuria - this increases antimicrobial resistance, increases recurrence risk, and provides no clinical benefit 1, 2
Do NOT classify patients with recurrent UTI as "complicated" - this leads to unnecessary use of broad-spectrum antibiotics with long durations 1
Reserve "complicated UTI" classification for:
- Congenital or acquired structural/functional urinary tract abnormalities 1
- Immune suppression 1
- Pregnancy 1
Do NOT use unnecessarily broad-spectrum antibiotics - causes collateral damage to protective vaginal/periurethral microbiota and promotes rapid recurrence 1, 2
Do NOT use unnecessarily long treatment courses - no evidence supports longer courses in most patients, and this increases adverse effects and resistance 2
If symptoms persist despite treatment:
- Repeat urine culture to assess for ongoing bacteriuria before prescribing additional antibiotics 1
- Consider imaging (ultrasound) if history of urolithiasis, renal dysfunction, or remains febrile after 72 hours 2
- Reassess at 48-72 hours and adjust antibiotics based on culture/sensitivity results 2, 7
Resistance Considerations
High persistent resistance has been documented to:
Low resistance documented to:
Local antibiogram data should guide empiric therapy when available - resistance patterns vary significantly by geographic region and healthcare setting 2, 5, 6