Oritavancin is a semisynthetic glycopeptide antibiotic that inhibits the growth of Gram-positive bacteria. It inhibits transglycosylation and transpeptidation in the bacterial cell wall to disrupt membrane integrity. Oritavancin inhibits the growth of clinical isolates from skin and soft-tissue infections, including methicillin-resistant and -susceptible S. aureus (MRSA, MSSA), vancomycin-resistant and -susceptible E. faecium (VREF, VSRF), as well as other staphylococci, streptococci, and enterococci (MIC90s = ≤0.008-0.5 mg/L). Oritavancin inhibits growth of S. aureus in a neutropenic-mouse thigh model of infection (ED50 = 0.95 mg/kg for a single dose). It improves survival in a mouse inhalation model of B. anthracis Ames anthrax when administered prophylactically pre- and postexposure and when administered post symptom development. Formulations containing oritavancin have been used to treat bacterial skin infections.