Daptomycin as an Adjuvant Agent in the Treatment of Enterococcal Native Valve Endocarditis.

The aim of this study is to determine the safety and efficacy of daptomycin when used as an adjuvant agent to standard care in the treatment of proven native valve Enterococcal endocarditis. Patients with this disease will be offered the option of receiving daptomycin at a dose of 8 milligrams/kilogram/day in addition to the antibiotics they are already receiving. The hypothesis of this study is that daptomycin added to standard therapy for Enterococcal endocarditis is safe and efficacious. Patients who receive daptomycin + standard therapy will be compared to patients who receive standard therapy alone with respect to the following outcomes: 1. Safety. 1. The frequency of any Grade 3 or 4 toxicity (DAIDS scale) will be measured. 2. The frequency of muscle toxicity or renal toxicity, as determined by predefined criteria. 2. Efficacy. 1. Clinical efficacy. * Time to clearance of bacteremia * Cure at 6 weeks following completion of antibiotic therapy * Mortality at 6 weeks following completion of antibiotic therapy 2. Microbiologic efficacy. * Peak and trough serum bactericidal titers * The minimum bactericidal concentration of Enterococci to daptomycin We expect to enroll 40 patients over 2 years.