Evaluation of daptomycin, telavancin, teicoplanin, and vancomycin activity in the presence of albumin or serum

We evaluated the calculated protein binding based on arithmetic means of MIC values in the presence and absence of protein for daptomycin, telavancin, vancomycin, and teicoplanin against 5 Staphylococcus aureus isolates. The extent of protein binding was lower than expected, particularly for daptomycin and telavancin. These drugs may be more active than predicted based on unbound drug concentrations alone.