From the Guidelines
Oral amoxicillin is not recommended for treating Enterococcus faecalis endocarditis due to its inadequate bactericidal activity against this organism. The recommended treatment for Enterococcus faecalis endocarditis involves combination therapy with intravenous antibiotics, such as ampicillin or amoxicillin, plus an aminoglycoside like gentamicin, as outlined in the 2015 ESC guidelines for the management of infective endocarditis 1.
Key Considerations
- The guidelines suggest using ampicillin or amoxicillin at a dose of 200 mg/kg/day intravenously in 4-6 doses, in combination with gentamicin 3 mg/kg/day intravenously or intramuscularly in 1 dose, for 4-6 weeks 1.
- Oral therapy is not recommended as a first-line treatment due to concerns about achieving adequate blood levels and effectively penetrating vegetations on heart valves.
- If oral therapy is considered necessary after initial intravenous treatment and clinical improvement, high-dose amoxicillin could be an option, but this should be done with caution and close monitoring.
Treatment Approach
- The primary approach should involve intravenous combination therapy to ensure bactericidal activity against Enterococcus faecalis.
- Regular blood tests and blood cultures should be performed to monitor for treatment failure and ensure clearance of bacteremia.
- Close clinical follow-up with an infectious disease specialist is essential, especially if considering oral therapy or considering alternative treatments due to resistance or other complications.
From the Research
Recommended Oral Amoxicillin Dose
There is no direct evidence in the provided studies to support a specific oral Amoxicillin dose for treating Enterococcus faecalis endocarditis.
Alternative Treatment Options
- The combination of ampicillin and ceftriaxone is effective and safe for treating HLAR E. faecalis endocarditis and could be a reasonable alternative for patients with non-HLAR E. faecalis endocarditis who are at increased risk for nephrotoxicity 2.
- A continuation combination regimen of ceftriaxone 4 g once daily in a short infusion plus ampicillin 2 g/4 h using a programmable pump may be as effective and safe as the usual lengthy in-hospital regimen in patients with E. faecalis infective endocarditis 3.
- Guidelines suggest treating fully penicillin-susceptible Enterococcus faecalis strains causing infective endocarditis with amoxicillin combined with gentamicin or ceftriaxone, but clinical evidence to support this practice is limited 4.
- International guidelines recommend 4 weeks of treatment with ampicillin plus gentamicin for uncomplicated native valve Enterococcus faecalis infective endocarditis and 6 weeks in the remaining cases 5.
- Ampicillin plus ceftriaxone 2 g iv./12 h is a good option for Enterococcus faecalis IE caused by HLAR strains, but randomized clinical trials are essential to demonstrate its efficacy for non-HLAR EFIE and to compare it with ampicillin plus short-course gentamicin 6.
Key Considerations
- The optimal treatment for Enterococcus faecalis infective endocarditis is still a topic of debate, and more research is needed to determine the best approach 4, 5, 6.
- The choice of treatment should be individualized based on the patient's specific circumstances, including the presence of comorbidities and the risk of nephrotoxicity 2, 3.