Oritavancin as consolidation or suppressive therapy in infective endocarditis and device-related infections: real-world experience with therapeutic drug monitoring.

BACKGROUND

Oritavancin is a long-acting semisynthetic lipoglycopeptide with potent activity against a broad range of Gram-positive pathogens. Its multimodal mechanism of action and prolonged terminal half-life allow for extended dosing intervals, making it an off-label option for invasive infections requiring long-term antimicrobial exposure. However, evidence supporting its use in infective endocarditis and cardiac device-related infections remain limited.

METHODS

We performed a retrospective multicentre observational study including adult patients treated with multidose oritavancin for infective endocarditis and cardiac device-related infections between 2020 and 2025. Oritavancin was administered as consolidation or as long-term suppressive therapy. Demographic, clinical, microbiological, pharmacological, and outcome data were collected. Therapeutic drug monitoring was performed, and pre-dose plasma concentrations were analysed. Clinical outcomes included clinical cure, microbiological failure, adverse events, and 30- and 90-day all-cause mortality.

RESULTS

Nine patients were included. Oritavancin was mainly administered at 1200 mg per dose, with a median dosing interval of 10 days. Clinical success was achieved in 6/9 patients (66.7%). One patient discontinued therapy due to infusion-related adverse events, and two experienced microbiological failure, both in left ventricular assist device-related infections. No 30- or 90-day mortality was observed. TDM, when performed, demonstrated persistent pre-dose plasma concentrations over several weeks, with marked interindividual variability across patients and intra-individual temporal changes over time, including drug accumulation in some cases.

CONCLUSION

Multidose oritavancin appears to be a promising consolidation or suppressive strategy in selected patients with complex Gram-positive endovascular infections. Prospective studies are needed to define optimal dosing regimens and the role of TDM in this setting.