The Impact of Protein Binding on Antibacterial Activities of Antibiotics is more than Predicted by Considering its Numerical Value Alone: Effects of Serum Proteins on Activities of Poorly Penetrating Agents and Inhibition of ß- Lactamase Activity-Part II.
Activities of antibacterials could be directly correlated with the extent of their protein binding causing a proportionate increase of MICs and a decrease of bactericidal activities. However, synergistic effects of human serum on antibacterial in vitro activities of tetracyclines, β-lactams, aminoglycosides, macrolides, glycopeptides, and fluoroquinolones have been described. Likewise, rat- or rabbit sera enhanced the activity of vancomycin against enterococci and staphylococci.