Influence of the minimum inhibitory concentration of daptomycin on the outcomes of Staphylococcus aureus bacteremia.

Abstract Recent studies have shown that MRSA bacteremia with vancomycin MIC > 1 µg/mL is associated with a higher rate of treatment failure and a higher mortality rate. Daptomycin is an alternative to vancomycin, but has not been as well studied. The aim of this literature review was to evaluate effect of the MIC of daptomycin on the outcomes of S. aureus bacteremia. We conducted a literature search for the period from January 2010 to January 2019 using the MEDLINE and EMBASE databases. Four studies were included in the review. The outcomes were clinical cure and 30- or 60-day mortality. In two retrospective studies, 60-70% of S. aureus isolates had a low daptomycin MIC (≤0.5 µg/mL), patients with MRSA bacteremia who were treated with daptomycin had a lower mortality rate. In another study, patients with methicillin sensitive S. aureus bacteremia with low daptomycin MICs had lower risk of developing septic thrombophlebitis. One study showed that patients with MRSA bacteremia had a higher mortality rate if daptomycin MIC > 0.5 µg/mL. The included studies in this review suggest possible association between high daptomycin MIC and unfavorable clinical outcomes of S. aureus bacteremia. Further prospective studies are required to evaluate the impact of the daptomycin MIC on the clinical outcomes of S. aureus bacteremia.