Patients who meet all inclusion criteria and exhibit none of the exclusion criterial will be randomized to one of two treatment arms:~daptomycin Intravenously (IV) 10 mg/kg every 24 hours~vancomycin IV dosed to maintain trough levels of 15 to 20 μg/mL.~The suggested duration of therapy with daptomycin or vancomycin will be 28 days (or up to 42 days if clinically indicated). Dose adjustments for both drugs will be made by an unblinded pharmacist at each site. To minimize the duration with which patients are treated with antibacterial agents effective against S. aureus prior to enrollment, patients with suspected MRSA bacteremia will be enrolled pending definitive culture results. Suspected MRSA bacteremia will be defined clinically or as initial blood cultures that grow Gram-positive cocci and that were obtained from a patient at increased risk for methicillin-resistant S. aureus infections. However, only patients with confirmed MRSA bacteremia or right-sided infective endocarditis will remain in the study and be evaluated for efficacy. During treatment, regular assessments will be performed. An End-of Therapy (EOT) will be performed 1-3 days after stopping therapy or upon Early Termination (ET). All patients will have a post therapy visit for Test of Cure (TOC) performed 35-49 days following last dose of study drug.
The overall goals of this study are to compare the safety and efficacy of daptomycin monotherapy 10 mg/kg/day and vancomycin monotherapy dosed to achieve vancomycin trough levels of 15 to 20 μg/mL for the treatment of methicillin-resistant S. aureus bacteremia (MRSA), including right-sided infective endocarditis (RIE).