Telavancin is a bactericidal lipoglycopeptide that is active against a broad range of gram-positive bacteria. Telavancin prevents polymerization of N-acetylmuramic acid (NAM) and N-acetylglucosamine (NAG) and cross-linking of peptidoglycan by binding to D-Ala-D-Ala. As a result, inhibition of bacterial cell wall synthesis occurs. Furthermore, telavancin disrupts membrane potential and cell permeability as a result of the lipophillic side chain moiety. This additional bactericidal mechanism is what sets telavancin apart from vancomycin.
Telavancin is a semi-synthetic derivative of vancomycin, therefore the mode of bactericidal action is similar to vancomycin in which both antibiotics inhibit cell wall synthesis. Not only that, it displays concentration-dependent bactericidal action. Furthermore, telavancin is a more potent inhibitor (10-fold) of peptidoglycan synthesis and, unlike vancomycin, disrupts cell membrane integrity via its interaction with lipid II. AUC/MIC ratio best predicts the extent of in-vivo response in which the higher the ratio, the greater the bactericidal activity. The smallest ratio in which one would be able to observe no bacterial growth at 24 hours is 50. Maximal bactericidal activity is observed at a AUC/MIC ratio of 404.
Metabolism of telavancin does not involve the cytochrome P450 enzyme system. Primary metabolite is called THRX-651540, but the metabolite pathway has not been identified.