Oritavancin for the Treatment of Staphylococcus aureus Bacteremia-A Retrospective Single-arm Cohort Study

Patients who require prolonged intravenous antibiotics for Staphylococcus aureus bacteremia (SAB) and who are ineligible for outpatient parental antibiotic therapy (OPAT) present a challenge in regard to delivering appropriate and cost-effective treatment. Oritavancin, a novel long-acting lipoglycopeptide, shows promise as an alternative to OPAT for patients with complex Gram-positive infections, including those with SAB.

To assess the outcomes, including safety and impact on length of stay and cost-effectiveness of using oritavancin for patients with SAB who are ineligible for OPAT.

Retrospective single-arm cohort study of adult patients with SAB who received at least 1 dose of oritavancin within the Hunter New England Local Health District between January 2020 and July 2023.

A total of 27 patients were identified: mean age, 43 years, 52% male, and 59% people who currently inject drugs. Sources/foci of infection included bone/joint infection (26%), skin/soft-tissue infection (15%), infective endocarditis (26%), catheter-associated bacteremia (7%), and bacteremia with no clear source/focus (26%). Intravenous antibiotics were administered for a mean duration of 10 days before oritavancin therapy. Clinical cure was seen in 26/27 (96%) of patients, with 1 patient lost to follow-up and deemed not clinically evaluable. Twenty-four of 27 (89%) patients were alive at the end of the 180-day follow-up period, with 2 patient deaths unrelated to their index infection and 1 patient not clinically evaluable. A total of 89% of patients demonstrated a positive return on investment, with on average 18 hospital days per patient avoided.

Oritavancin is promising as a suitable and potentially cost-effective alternative for patients with SAB who are ineligible for OPAT. Prospective studies are required to confirm its utility in clinical practice, in particular in patients who do not receive oral antibiotic stepdown therapy.