What is the dose of amoxicillin (amoxicillin) for vaginal Enterococcus faecalis infections?

Amoxicillin Dosing for Vaginal Enterococcus faecalis Infections

For vaginal Enterococcus faecalis infections, amoxicillin should be administered at a dose of 500 mg orally every 8 hours. 1

Treatment Recommendations

First-line Treatment

• Amoxicillin 500 mg PO every 8 hours is the recommended dose for uncomplicated vaginal infections caused by E. faecalis 1
• Ampicillin is considered the drug of choice for enterococcal infections, with amoxicillin being an equivalent oral alternative 1
• Treatment duration should be based on clinical response and symptom resolution 1

Alternative Options for Uncomplicated Vaginal/UTI Infections

• Fosfomycin 3 g PO as a single dose for uncomplicated urinary tract infections due to E. faecalis 1
• Nitrofurantoin 100 mg PO every 6 hours for uncomplicated infections 1

Special Considerations

For Resistant Strains

• If dealing with vancomycin-resistant E. faecalis (VRE), high-dose ampicillin (18-30 g IV daily in divided doses) or amoxicillin 500 mg PO/IV every 8 hours may still be effective due to high urinary/vaginal concentrations 1
• One retrospective study reported that patients with UTI due to ampicillin-resistant VRE treated with ampicillin had promising clinical outcomes with clinical and microbiological eradication rates of 88.1% and 86%, respectively 1

For Severe Infections

• For severe or systemic infections, combination therapy may be required:
  • Amoxicillin plus gentamicin for susceptible strains 1
  • Double β-lactam combinations (such as amoxicillin plus cefotaxime) have shown synergistic effects against E. faecalis 2

Important Clinical Considerations

• Before initiating treatment, it's crucial to differentiate between true infection and colonization 1
• E. faecalis is commonly found in the vaginal flora of women who have recently received antibiotic treatment (44% vs 17.33% in untreated women) 3
• Susceptibility testing is important as resistance patterns can vary, though most E. faecalis strains remain susceptible to amoxicillin 4, 5
• The MIC of amoxicillin against E. faecalis is typically lower than that of benzylpenicillin, making it a more effective choice 5

Treatment Pitfalls to Avoid

• Avoid using cephalosporins as monotherapy as they have minimal activity against enterococci 1
• Do not use vancomycin empirically unless there is confirmed resistance to amoxicillin or severe penicillin allergy 1
• Recognize that E. faecalis in vaginal cultures may represent colonization rather than infection, especially following recent antibiotic use for other conditions 3
• Be aware that while amoxicillin-clavulanate can be used, the addition of clavulanate offers no advantage unless β-lactamase production is confirmed (which is rare in E. faecalis) 5