Recommended Dosage of Augmentin for E. faecalis UTI
For treating urinary tract infections caused by Enterococcus faecalis, amoxicillin-clavulanate (Augmentin) should be administered at a dosage of 500/125 mg orally three times daily for 7 days. 1
Rationale for Dosing Recommendation
The recommended dosage is supported by clinical evidence and guidelines:
- The FDA-approved dosing for complicated UTIs includes 875/125 mg every 12 hours or 500/125 mg every 8 hours 2
- Clinical trials have shown comparable efficacy between these two dosing regimens for complicated UTIs 2
- While the 875/125 mg twice daily regimen had slightly lower rates of severe diarrhea (1% vs 2%), both regimens demonstrated similar overall efficacy 2
Treatment Considerations for E. faecalis UTI
First-line options for E. faecalis UTI:
- Amoxicillin-clavulanate: 500/125 mg orally three times daily for 7 days 1
- Amoxicillin: 500 mg orally three times daily for 5-7 days (for susceptible strains) 1
- Fosfomycin: 3 g single oral dose (convenient option with good efficacy) 1
- Nitrofurantoin: 100 mg orally every 6 hours (effective for uncomplicated UTIs) 3
Why Augmentin is effective for E. faecalis UTI:
- The addition of clavulanic acid to amoxicillin reduces resistance in many urinary pathogens 4
- Clinical trials have shown success rates of approximately 70% even for amoxicillin-resistant organisms 4
- In elderly patients with UTIs, Augmentin demonstrated significantly better efficacy (87.5%) compared to amoxicillin alone (43%) 5
Duration of Therapy
- 5-7 days for uncomplicated lower UTI
- 7-14 days for complicated or upper UTI 1
Special Considerations
Patient assessment:
- Differentiate colonization from true infection before initiating therapy, especially in catheterized patients 1
- Consider renal function when selecting dosage - no adjustment needed for mild-moderate renal impairment 6
Monitoring:
- Clinical improvement should be assessed within 48-72 hours
- If symptoms persist, consider repeat urine culture or alternative antibiotic therapy 1
Potential side effects:
- Diarrhea (most common adverse effect, occurring in 14-15% of patients) 2
- Severe diarrhea requiring discontinuation occurs in 1-2% of patients 2
- Other potential side effects include light-headedness and abdominal pain 7
Alternative Options for Resistant Strains
If E. faecalis is vancomycin-resistant (VRE):
- Linezolid: 600 mg IV or PO every 12 hours 3
- High-dose ampicillin: 18-30 g IV daily in divided doses (may overcome resistance) 3
- Fosfomycin: 3 g PO single dose for uncomplicated UTIs 3
- Nitrofurantoin: 100 mg PO every 6 hours 3
Clinical Pearls
- Local antibiogram data should guide therapy when available to reduce resistance risk
- Adequate hydration is essential to promote urinary flow and antibiotic efficacy
- Patients should complete the full course of antibiotics even if symptoms resolve quickly
- For complicated UTIs, consider parenteral therapy initially if the patient is severely ill