Saturday February 16, 2008
Synergistic agents for Daptomycin

Daptomycin is the first approved member of a new class of antibiotics, namely the cyclic lipopeptides. Daptomycin has rapid bactericidal activity against Gram-positive pathogens.

Daptomycin was shown to be not inferior to antimicrobial standard therapy for Staphylococcus aureus bacteremia and right-sided endocarditis.

This is of interest to know that there is a marked synergy between daptomycin and both rifampin and ampicillin against vancomycin-resistant enterococci (VRE) - despite high-level of ampicillin resistance alone. Also most strains of MRSA are found to have synergism between daptomycin and oxacillin despite it shows resistant alone to oxacillin (as in case of ampicillin in VRE). Ampicillin-sulbactam, ticarcillin-clavulanate, or piperacillin-tazobactam showed synergy comparable to or greater than daptomycin with oxacillin.

It may be of clinical benefit to add synergistic agents while using Daptomycin as it is a 'concentration-dependent' drug.



References: click to get abstract/articles

1. Synergy of Daptomycin with Oxacillin and Other ß-Lactams against Methicillin-Resistant Staphylococcus aureus Antimicrobial Agents and Chemotherapy, August 2004, p. 2871-2875, Vol. 48, No. 8

2. Daptomycin: A Review 4 Years after First Approval Pharmacology 2008;81:79-91