477 posters, 14 topics, 2,065 authors, 1,055 institutions

The Joint EBJIS-MSIS 2026 Conference

17 - 19 September, 2026 | Porto, Portugal

EP008

Real-World Oritavancin PK-Guided Suppressive Therapy for Chronic Non-faecalis Enterococci Prosthetic Joint and Fracture-Related Infections: A Case Series from Reference Centre

Preview of Real-World Oritavancin PK-Guided Suppressive Therapy for Chronic Non-faecalis Enterococci Prosthetic Joint and Fracture-Related Infections: A Case Series from Reference Centre

View Poster Contact Presenter

Poster Presenter

Francesco Petri

Authors

Francesco Petri, Letizia Scandiffio, Carlo Montagna, Giovanni De Capitani, Dario Cattaneo, Simona Landonio, Stefania Merli, Massimo Coen, Alberto Dolci, Andrea Gori, Matteo Passerini

Affiliations

Department of Infectious Diseases, "Luigi Sacco" University Hospital, Milan, Milano, Italy, Unit of Clinical Pathology, ASST Fatebenefratelli-Sacco, Luigi Sacco University Hospital, Milan, Italy., Milano, Italy, Department of Biomedical and Clinical Sciences, Universit? degli Studi di Milano, Milano, Italy, Milano, Italy, IRCCS Humanitas Research Hospital, Milan, Italy; Department of Biomedical Sciences, Humanitas University, Pieve Emanuele, Italy., Milano, Italy, Department of Pathophysiology and Transplantation, Universit? degli Studi di Milano, Milano, Italy, Milano, Italy, Department of Infectious Diseases, "Luigi Sacco" University Hospital, Milan

Part of Topic

Antibiotics

Background. Suppressive antibiotic treatment (SAT) for prosthetic joint infections (PJIs) or fracture-related infections (FRIs) due to non-faecalis enterococci remains challenging. Long-acting lipoglycopeptides such as oritavancin may facilitate outpatient management, yet real-world experience is limited, especially for therapeutic drug monitoring (TDM)-guided administration. We describe the first four off-label oritavancin cases treated at our referral centre.

Methods. Clinical, laboratory, tolerability, and PK data were collected prospectively during oritavancin therapy for non-faecalis enterococci isolated from intraoperative deep bone cultures. Oritavancin was administered as 1200 mg on days 1 and 8, with TDM monitoring, and then weekly. Multiple serial PK samples (including Cmin and Cmax) were collected for each infusion up to 72-hour post-dose when feasible.

Results.

• Case 1: An 88-year-old male with chronic vancomycin-resistant E.faecium (VRE) PJI of the arthrodesis of the knee, uneligible for surgical revision, discontinued linezolid due to severe anaemia. No microbiological or clinical evidence of recurrence was observed. Treatment was complicated by PICC-related bloodstream infection and by a probable infusion-related adverse event (isolated febrile episode after the fourth infusion). Oritavancin was discontinued and linezolid successfully re-introduced (Figure 1).

• Case 2: A 74-year-old woman with complex post-traumatic VRE FRI and PJI involving tibial hardware and knee prosthesis experienced neurological toxicity on linezolid suppressive therapy. Oritavancin was initiated. Early outpatient follow-up showed clinical stability, and no acute drug-related toxicity (Figure 2) up to 17 drug administrations until recurrence. Further evaluation identified Pseudomonas aeruginosa on repeat synovial fluid culture, and additional surgery was planned.

• Cases 3 and 4: Two men aged 55 and 64 years with osteomyelitis with hardware retention and PJI due to E.gallinarum and VRE developed skin rash during first oritavancin infusion, unresponsive to slower infusion rates; treatment was discontinued in both cases.

Across cases, PK profiles showed consistent exposure with levels falling to the 3 mg/L target within 1 week, supporting weekly dosing; only after the fifth infusion in Case 2 were higher levels achieved that might have allowed a longer interval (Figure 2).

The dynamic of the observed adverse events and the following tolerability to other (lypo)-(glyco)-peptides suggest infusion related problems rather than true allergic reactions.

Conclusions. TDM-guided oritavancin may represent a feasible off-label SAT option for selected patients with PJI/FRI due to non-faecalis enterococci. Tolerability and timing of injection remain key practical challenges. Larger prospective datasets with the new oritavancin formulation (tolerability) and more TDM assessments (timing) are warranted.

(1) Buonomo AR, Cattaneo L, Viceconte G, Calabria F, Di Troia G, Di Fusco A, Mula J, Cozzolino A, Ametrano L, D'Avolio A, Gentile I. Long-term oritavancin therapy for shoulder prosthetic joint infection: A case guided by therapeutic drug monitoring (TDM). IDCases. 2024 Oct 31;38:e02105. doi: 10.1016/j.idcr.2024.e02105. PMID: 39582750; PMCID: PMC11584596.