Oral Antibiotics for Enterococcus faecalis UTI
Amoxicillin 500 mg orally every 8 hours for 7 days is the first-line treatment for uncomplicated E. faecalis UTI, achieving clinical cure rates of 88.1% and microbiological eradication rates of 86%. 1
First-Line Oral Treatment
Ampicillin/Amoxicillin remains the drug of choice for enterococcal urinary tract infections, even when in vitro testing suggests resistance, because high urinary concentrations can overcome elevated MICs. 2, 1
- Amoxicillin 500 mg orally every 8 hours for 7 days is recommended by the American College of Physicians as first-line therapy for uncomplicated E. faecalis UTIs. 1
- Ampicillin 500 mg orally every 8 hours for 7 days is an equivalent alternative with similar efficacy. 1
- For beta-lactamase producing strains, switch to amoxicillin-clavulanate for 7 days. 1
Alternative Oral Agents
When ampicillin/amoxicillin cannot be used, several alternatives exist:
- Nitrofurantoin 100 mg orally every 6 hours for 7 days has excellent in vitro activity against E. faecalis with resistance rates below 6%, making it an effective alternative particularly for penicillin-allergic patients. 1, 3
- Fosfomycin 3 g orally as a single dose is FDA-approved specifically for UTI caused by E. faecalis and is recommended for uncomplicated infections. 2, 1, 3
Agents to Avoid
- Fluoroquinolones (ciprofloxacin/levofloxacin) should be avoided due to high resistance rates of 46-47% in E. faecalis and unfavorable risk-benefit ratios for uncomplicated UTIs. 1, 4
- Ciprofloxacin resistance is particularly high in hospital-acquired infections, patients treated in urological departments, and those transferred from healthcare centers. 4
Critical Clinical Considerations
Always obtain susceptibility testing before initiating therapy, even for strains described as "pansensitive," as resistance patterns vary significantly by institution and patient population. 1
- Differentiate colonization from true infection before prescribing antibiotics, as asymptomatic bacteriuria with E. faecalis does not routinely require treatment. 1, 5, 3
- Remove indwelling urinary catheters when possible, as this is an important non-pharmacologic intervention. 5
Treatment Duration
- 7 days is the standard duration for uncomplicated UTI with E. faecalis. 1
- For complicated UTIs, treatment duration of 7-14 days is recommended, with 14 days considered for males when prostatitis cannot be excluded. 6
- Treatment duration should be based on clinical response and site of infection. 1
Special Populations and Complicated Infections
For patients requiring parenteral therapy who can transition to oral agents, the same oral options apply once clinical improvement occurs. 1
For complicated UTIs with systemic symptoms requiring initial IV therapy, amoxicillin plus an aminoglycoside is recommended as empirical treatment before transitioning to oral therapy. 6