In a prospective randomized trial in the United States, the efficacy of daptomycin was not less than the standard treatment regimen for bacteremia and right endocarditis caused by Staphylococcus aureus.

Due to the fact that the frequency of infections caused by strains of methicillin-resistant Staphylococcus aureus (MRSA) is increasing, and that the result of treatment with bacteremia with MRSA is generally worse than the bacteremia caused by strains sensitive to methicillin S. aureus, the study analyzed the clinical features and treatment outcomes of MRSA-infected patients who received daptomycin versus the low dose vancomycin + gentamicin combination. Treatment effectiveness was considered clinical improvement with disappearance of bacteremia in patients who followed appropriate antibiotic treatment, did not receive additional potentially effective antibacterial drugs that were not approved for use in the study, and the presence of negative bacteriological blood tests 6 weeks after the end of treatment.

Twenty of the 45 patients (44.4%) who received daptomycin and 14 of the 43 patients (32.6%) who received vancomycin + gentamicin were successfully treated (differences of 11.9%, range of confidence -8.3-32, 1). The success rate in the daptomycin group compared to the vancomycin + gentamicin combination was 45% vs 27% for complicated bacteremia, 60% vs 45% for uncomplicated bacteremia and 50% vs 50% for right endocarditis caused by MRSA. The cure rate in patients with septic embolism and in patients who received vancomycin before being included in the study was comparable between the groups compared. However, it should be noted that in both treatment groups, the frequency of successful treatment was lower in elderly patients (over 75 years). Persistence or recurrence of bacteremia was observed in 27% of patients in the daptomycin group and in 21% of patients receiving vancomycin + gentamicin. Among this category of patients, in 5 patients in the daptomycin group and 4 patients in the vancomycin + gentamicin group, BMD values greater than 2 mg / L were recorded.

Daptomycin is therefore an alternative to the combination vancomycin + gentamicin in the treatment of MRSA bacteremia or right endocarditis.