Daptomycin, a new drug class for the treatment of Gram-positive infections

Daptomycin is the first member of a new class of bactericidal antibiotics, the cyclic lipopeptides. In September 2003, daptomycin was approved for the treatment of Gram-positive infections associated with complicated skin and skin structure infections. A key feature of daptomycin is its rapid, concentration-dependent bactericidal activity against significant Gram-positive pathogens, including methicillin-resistant Staphylococcus aureus, glycopeptide-intermediate and -resistant S. aureus and vancomycin-resistant Enterococcus faecalis and Enterococcus faecium (VRE). Daptomycin also has a unique mechanism of action, no cross-resistance with any other class of antibiotic and a relatively prolonged concentration-dependent postantibiotic effect in vitro. In the United States, daptomycin has been approved for use at a dose of 4 mg/ kg once daily in the treatment of S. aureus (including methicillin-resistant strains), three beta-hemolytic streptococci (S. pyogenes, S. agalactiae and S. dysgalactiae subsp. equisimilis) and E. faecalis associated with complicated skin and skin structure infections. In addition, daptomycin is undergoing a phase III evaluation for the treatment of bacteremia and endocarditis due to S. aureus. With its once-daily dosing, favorable safety profile and low potential for resistance, daptomycin is a powerful new antibiotic therapy against Gram-positive infections.