The role of long-acting antibiotics in the clinical practice: a narrative review

Introduction: The increasing emergence of bacterial strains with new resistance determinants has become a threat to current antibiotic therapies in recent years. This has prompted research for innovative options with improved efficacy and safety profiles: long-acting glycopeptides, such as dalbavancin and oritavancin, are currently approved for the treatment of acute bacterial skin and skin structure infections (ABSSSI). Their efficacy, microbiological profile, and ease of administration may provide an answer to this challenge, as well as reducing length of stay and hospital costs. This narrative review aims to explore the current evidence on the real-word use of dalbavancin and oritavancin, in labelled and off-label indications in clinical practice.

Methods: A PubMed library database search with no time limits was performed using the following terms: long-acting antibiotics, dalbavancin, oritavancin.

Discussion: Registration studies confirmed non-inferiority of long-acting glycopeptides to standard of care in ABSSSI (dalbavancin DISCOVER 1 and 2: 79.7% clinical success in the dalbavancin group and 79.8% in the vancomycin-linezolid group; oritavancin SOLO I: 82,3% clinical success in the oritavancin group versus 78,9% for the vancomycin group; SOLO II: 80,1% clinical success versus 82,9%). Large cohorts have confirmed similar success rates in ABSSSI treatment in real-world practice. Evidence for off-label indications is still rather scarce but promising, especially in bone and joint infections therapy for both dalbavancin and oritavancin, and infective endocarditis for dalbavancin. Moreover, these drugs may have their place in non-adherent patients, in setting of addition or difficult access to healthcare. Another potential use of these drugs is in patients with oral intake impairment or reduced gastro-intestinal absorption. However, the low penetration in cerebrospinal fluid of dalbavancin and the unfavourable outcomes in the only case report of oritavancin treatment in human meningitis despite encouraging animal models would seem to make these molecules unsuitable for central nervous system infection therapy. Most of the available evidence is based on small retrospective cohorts, so robust prospective studies investigating off-label indications are needed.