Oritavancin in Complicated Bloodstream Infections and Endocarditis in Spain and Italy (ORIBAC Study): A Retrospective...

The management of complicated Gram-positive bloodstream infections (cBSI) and infective endocarditis (IE) often requires prolonged intravenous therapy. Transition to oral therapy is frequently unfeasible because of resistance, drug interactions, or adherence concerns, increasing the risk of intravenous-related complications and healthcare burden. The pharmacokinetic profile and spectrum of oritavancin may enable effective treatment and early discharge. This study evaluated its effectiveness, safety, and impact on hospital resource use in patients with cBSI or IE.

We conducted a multicenter, retrospective, observational study across eight hospitals in Italy and Spain (April 2023-February 2025). Adult patients with Gram-positive cBSI (persistent/refractory BSI or prosthetic material) or IE (2023 modified Duke criteria) treated with ≥ 1 dose of oritavancin were included. Dosing was determined by the treating physicians. Data on outcomes, adverse events (AEs) and healthcare use were collected from medical records. Patients were followed for at least 6 months.

Twenty-seven patients were included: 13 (48.1%) cBSI and 14 (51.9%) IE. Median age  was 73 years (IQR 65-81); 18 out of 27 (66.7%) were male; Charlson Comorbidity Index 6 (IQR 4-7). In cBSI, oritavancin was first-line in 6/13 (46.2%) and given in multiple doses in 8/13 (61.6%), median of 2 doses (IQR 2-2.5). Clinical success was 100%, with no recurrence or BSI-related mortality. In IE, Staphylococcus aureus was identified in 5 of 14 cases (35.7%), of which 40% were methicillin-resistant. Native valves were involved in 6/14 (42.8%), prosthetic valves in 6/14 (42.8%), cardiac devices in 2/14 (14.3%). Clinical success was achieved in 85.7% of patients with IE (12/14). Two AEs occurred: nausea and a non-fatal acute coronary syndrome in a patient with pre-existing ischemic heart disease. Oritavancin use reduced 369 hospital days with potential savings of approximately €4235 per patient.

Oritavancin may represent a safe, effective treatment option for selected patients with cBSI or IE, with advantages in outcomes, reduced hospital stay, and cost containment.