Daptomycin is a bactericidal lipopeptide with a spectrum of activity similar to that of linezolid or quinupristin-dalfopristin. This spectrum includes methicillin-resistant staphylococci and VRE; however, MICs are much lower for the former than the latter. Daptomycin has poor oral bioavailability and thus is only available as a parenteral product. Its long pharmacologic half-life allows for once-daily dosing (approved at 4 mg/kg every 24 hours in skin and soft tissue infection and 6 mg/kg, every 24 hours in the treatment of bacteremia and right-sided endocarditis); dosage adjustment is necessary in the presence of kidney disease. IDSA recommends 8–10 mg/kg daily to treat serious infection; doses up to 12 mg/kg are recommended by some experts for treatment of vancomycin-resistant Enterococcus. The primary adverse event associated with daptomycin is a reversible, dose-dependent myopathy observed with 7 days or more of therapy. Considering this complication, monitoring of serum creatine kinase levels is recommended, particularly in those patients receiving long-term therapy. Daptomycin cannot be used in the treatment of primary respiratory tract infection because pulmonary surfactant binds daptomycin, resulting in subtherapeutic free drug concentrations in pulmonary secretions.
et al. Musculoskeletal toxicities in patients receiving concomitant statin and daptomycin therapy. Am J Health Syst Pharm. 2019;76:206.