Approach to managing enterococcal endocarditis
Management of enterococcal endocarditis should involve a multidisciplinary team-based approach; see Approach to managing infective endocarditis.
Enterococci are the third most common cause of infective endocarditis. The majority of these cases (at least 90%) are caused by Enterococcus faecalis. Enterococcus faecium accounts for approximately 5% of cases. Enterococci are intrinsically more resistant to bactericidal antibiotics than other common causes of infective endocarditis, so require a synergistic combination of bactericidal antibiotics for a prolonged duration (usually 6 weeks). Therefore, even if the pathogen is susceptible to penicillin or vancomycin, treat enterococcal endocarditis concomitantly with gentamicin (unless there is high-level gentamicin resistance, or gentamicin is contraindicated or relevant precautions preclude its use). Antibiotic resistance in enterococci is an increasing problem – test all enterococcal isolates for high-level aminoglycoside resistance.
For principles of antimicrobial therapy for infective endocarditis (including duration of therapy following valve surgery and considerations for ambulatory antimicrobial therapy), see Principles of antimicrobial therapy for infective endocarditis.
Treatment of enterococcal endocarditis may require up to 6 weeks of gentamicin therapy, which can prove complex to manage safely. Monitor the gentamicin plasma concentration and regularly assess for nephrotoxicity as well as vestibular and auditory toxicity – see Gentamicin in the management of infective endocarditis.
Patients with enterococcal endocarditis are often older and more debilitated than patients with other types of endocarditis and may have significant medical comorbidities (eg chronic kidney disease). The potential harm associated with completing a 4 to 6 week course of gentamicin may exceed the benefit in patients who are older, debilitated or have significant medical comorbidities. For these patients, a shortened (2 week) course of gentamicin may be appropriate – seek expert advice.