Influence of daptomycin doses on the outcomes of VRE bloodstream infection treated with high-dose daptomycin

Objectives The CLSI recommended high-dose daptomycin (8-12 mg/kg) for treating Enterococcus faecium bloodstream infections (BSI). The current study was designed to determine the safety and efficacy of increasing the daptomycin dose for VRE BSI patients receiving >= 8 mg/kg. Methods We conducted a multicentre prospective observational study of patients who received a >= 8 mg/kg dose of daptomycin for treatment of VRE BSI. The primary outcome was 28 day mortality. Results A total of 661 patients were included. The 28 day mortality rate was 45.1%. The survivors received higher doses of daptomycin than non-survivors (10.1 versus 9.8 mg/kg; P 0.001). An increase in the daptomycin dose independently predicted lower mortality [adjusted OR (aOR) = 0.85; 95% CI = 0.73-0.99; P = 0.03]. Eighty-six survivors (23.7%) and 43 non-survivors (14.4%) received a >= 11 mg/kg dose of daptomycin (P = 0.003). The 8 to <11 and >= 11 mg/kg doses of daptomycin differed in the 28 day mortality in the higher MIC group (>= 2 mg/L) (49.4% versus 33.3%; P = 0.004), but not in the lower MIC group (<= 1 mg/L) (29.3% versus 29.4%; P = 0.99). A dose of >= 11 mg/kg was associated with a higher (3.9%) rate of highly elevated creatine kinase (>2000 U/L) compared with 1.1% with 8 to <11 mg/kg (P = 0.04). Conclusions The efficacy of daptomycin is dose dependent. A high daptomycin dose, especially at >= 11 mg/kg, improved survival in patients with VRE BSI, but was associated with highly elevated creatine kinase. We recommend a >= 11 mg/kg dose of daptomycin be considered for treatment of VRE BSI, particularly for isolates with higher MICs.

Automated summary

This study found that a high dose of daptomycin can improve the survival rate of patients with VRE bloodstream infections, but it is also associated with highly elevated creatine kinase.