A Clinician’s Guide to the Treatment of Vancomycin Resistant Enterococci Bacteremia and Endocarditis

Treatment of serious enterococcal infections is often difficult due to the inherent high level of antimicrobial resistance seen among some species including a rising level of high level aminoglycoside resistance (HLAR), vancomycin resistance (VRE), and multidrug resistance. Prior to the turn of this century, therapeutic options were limited and relied primarily on the use of ampicillin, aminoglycosides, and vancomycin. Over the past two decades, treatment has changed with the introduction of new antimicrobials with activity against VRE and an increasing use of aminoglycoside sparing regimens including the use of ampicillin and ceftriaxone. For the treatment of ampicillin susceptible infections with or without the presence of HLAR, the combination of ampicillin and ceftriaxone is now the preferred regimen due to the lower risk of adverse reactions including nephrotoxicity. Among the two antibiotics recommended for VRE severe infections in the 2015 AHA/IDSA infective endocarditis guidelines, daptomycin and linezolid, there is ongoing debate about the merits of both due to concerns about perceived mortality differences, adverse drug reactions, and proper dosing. Given the bactericidal activity of daptomycin, we currently prefer this agent for the initial treatment of serious VRE infections with proper dosing of at least 8 mg/kg and up to 10–12 mg/kg.