Dalbavancin has a spectrum and mechanism of action similar to vancomycin, a naturally formed glycopeptide antimicrobial. The bactericidal action of dalbavancin results primarily from inhibition of cell-wall biosynthesis. Specifically, dalbavancin prevents incorporation of N-acetylmuramic acid (NAM)- and N-acetylglucosamine (NAG)-peptide subunits from being incorporated into the peptidoglycan matrix; which forms the major structural component of Gram-positive cell walls. The large hydrophilic molecule is able to form hydrogen bond interactions with the terminal D-alanyl-D-alanine moieties of the NAM/NAG-peptides, which is normally a five-point interaction. Binding of dalbavancin to the D-Ala-D-Ala prevents the incorporation of the NAM/NAG-peptide subunits into the peptidoglycan matrix. In addition, dalbavancin alters bacterial-cell-membrane permeability and RNA synthesis.
Dalbavancin is not a substrate, inhibitor, or inducer of CYP450 isoenzymes. A minor hydroxy metabolite has been observed in the urine of healthy subjects.
Treatment with antibacterial agents can alter the normal flora of the colon leading to growth of C. difficile and commonly occurs in the development of C. difficile-associated diarrhea. Other common side effects include nausea, vomiting, diarrhea, headache, rash, and pruritis. Side effects that occurred in less than 2% of patients during clinical trials include blood and lymphatic system disorders, gastrointestinal disorders, hepatotoxicity, anaphylactoid reactions, hepatic enzyme elevation, hypoglycaemia, dizziness, bronchospasm, urticaria, and vascular disorders. There have been no adequate or well-controlled studies to conclude that use of dalbavancin is safe during pregnancy or breastfeeding.