ORITAVANCIN

Definition

ChEBI: A semisynthetic glycopeptide used (as its bisphosphate salt) for the treatment of acute bacterial skin and skin structure infections caused or suspected to be caused by susceptible isolates of designated Gram-positive microorganisms including MRSA.

Clinical Use

Antibacterial agent

Enzyme inhibitor

This novel, semi-synthetic glycopeptide antibiotic (FW = 1793.10 g/mol; CAS 171099-57-3), also known as LY333328, Orbactiv?, and (4R)-22-O- (3-amino-2,3,6-trideoxy-3-C-methyl-a-L-arabinohexopyranosyl)-N3-(p-(pchlorophenyl) benzyl)vancomycin, disrupts the cell membrane of Grampositive bacteria and inhibits both transglycosylation and transpeptidation. Oritavancin differs from vancomycin by the presence of a hydrophobic N-4-(4-chlorophenyl)benzyl substituent on the disaccharide, the addition of a 4-epi-vancosamine monosaccharide to the amino acid residue in Ring-6, and replacement of the vancosamine moiety by 4-epi-vancosamine. When compared vancomycin, teicoplanin, and quinupristin-dalfopristin (Synercid) against 219 strains of enterococci and staphylococci, including vancomycin-resistant enterococci and methicillinresistant methicillinresistant Staphylococcus aureus, LY333328 demonstrated superior activity against vancomycin-resistant enterococci and was the only antibiotic which was bactericidal. Indeed, a single infusion of this antibiotic (1200 mg) can clear serious bacterial skin infections, including methicillin-resistant Staphylococcus aureus, or MRSA, as effectively as the usual 7-10 day, twice-daily regimen of vancomycin now needed to treat patients.

Drug interactions

Potentially hazardous interactions with other drugs
Anticoagulants: possibly increases warfarin concentration.

Metabolism

In vitro human liver microsome studies indicated that oritavancin is not metabolised. It is excreted unchanged; less than 1% and 5% of a dose is recovered in the urine and the faeces.