Dalbavancin

Dalvance / Xydalba

Dalbavancin is a semisynthetic lipoglycopeptide antibiotic — a glycopeptide (related to teicoplanin) modified with a lipophilic side chain. Like vancomycin and teicoplanin, it inhibits bacterial cell-wall synthesis by binding the D-alanyl-D-alanine terminus of peptidoglycan precursors, blocking the enzymes that cross-link the wall. The added lipid tail anchors the molecule in the bacterial membrane, which both increases potency against Gram-positive organisms (including methicillin-resistant Staphylococcus aureus) and dramatically extends how long the drug persists in the body. That long persistence is dalbavancin's defining feature. Its terminal half-life is on the order of a week to two weeks, so a complete treatment course can be delivered as a single intravenous infusion, or as two doses given one week apart — instead of the daily dosing that vancomycin or many other antibiotics require. This makes it especially useful for acute bacterial skin and skin-structure infections (ABSSSI) in situations where daily IV access, adherence to oral regimens, or prolonged hospital stays are problematic; a patient can complete therapy without an indwelling line or a full inpatient course. Dalbavancin is an approved prescription antibiotic (FDA 2014 as Dalvance; EMA as Xydalba) for ABSSSI caused by susceptible Gram-positive bacteria. Its activity is confined to Gram-positive organisms, like other glycopeptides. Because a single dose commits the patient to a long duration of drug exposure that cannot be quickly removed, it is used with appropriate diagnosis and stewardship. It is a clinician-administered medicine, not a research or wellness peptide.