232. Safety and Effectiveness of Intravenous to Oral De-escalation Compared to Continued Vancomycin Therapy in Orthopedic Infections

Abstract Background The Oral versus Intravenous Antibiotics for Bone and Joint Infection (OVIVA) trial determined oral antibiotics administered during the first six weeks of therapy were non-inferior to parenteral antibiotics. There was no difference in the incidence of serious adverse effects. The objective of this study was to evaluate the safety and effectiveness of de-escalating to oral therapy compared to continuing parenteral vancomycin therapy in patients with orthopedic infections in a real-world setting. Methods We conducted a single-center, retrospective cohort study of patients discharged between April 1, 2018 and April 1, 2020 with an orthopedic infection, a prescription for at least four weeks of parenteral vancomycin, and documented follow-up. The primary outcome was incidence of adverse events defined as provider documentation of the event and changes to therapy. The secondary outcome was incidence of 6-month treatment failure defined as repeat surgical intervention or therapy escalation. Results One hundred fifty-seven patients were included. Twenty-nine (18.5%) patients were de-escalated to oral therapy. Three (10%) patients in the oral therapy group had an adverse event compared to 35 (27%) in the vancomycin group (p=0.058). Of the 35 patients with an adverse event in the vancomycin group, eight were due to parenteral access-related complications. Treatment failure occurred in three (10%) patients in the oral therapy group compared to 27 (21%) patients in the vancomycin group (p=0.29). Three (10%) patients in the oral therapy group had an unplanned readmission compared to 25 (20%) patients in the vancomycin group (p=0.24). Baseline Characteristics, Unplanned Readmission Rates, and Incidence of Adverse Events and 6-Month Treatment Failure Conclusion Patients de-escalated to oral therapy had fewer adverse events and similar incidences of treatment failure compared to patients maintained on parenteral vancomycin. Switching to oral therapy avoids some adverse events related to parenteral access. Our results in an uncontrolled, real-world setting are consistent with the OVIVA trial. Though limited by sample size, our data indicate switching to oral therapy in patients with an orthopedic infection improves safety outcomes without compromising effectiveness compared to continued parenteral vancomycin therapy. Disclosures Russell J. Benefield, PharmD, Paratek Pharmaceuticals (Grant/Research Support)

Background. The use of oral (PO) antibiotics and lipoglycopeptides are challenging the previous standard of osteomyelitis (OM) treatment, but there is currently a paucity of comparative data between these approaches.
Methods. This retrospective study included patients diagnosed with OM treated with intravenous (IV) antibiotics, PO antibiotics, or lipoglycopeptides between January 1, 2010 and June 1, 2020. Patients in the PO group could receive no more than 14 days of IV antibiotics prior to the PO course, and inclusion into the lipoglycopeptide group required at least 2 doses of drug to be administered. The primary outcome was occurrence of clinical failure within six months of completion of therapy, which was defined as new antibiotics or unplanned surgical intervention for an infection at the same site. Secondary outcomes included in-hospital length of stay (LOS), amputation within 6 months of therapy completion, and incidence of drug and line-related adverse effects. Previous osteomyelitis at index site, surgical intervention as a part of initial management, presence of Staphylococcus aureus on culture, utilization of outpatient parenteral antibiotic therapy (OPAT) services (IV group only), and concomitant PO therapy (lipoglycopeptide group only) were included in a bivariate analysis and variables with a p-value < 0.2 were included in a multivariate regression model.
Results. The IV group included 257 patients, while the PO and lipoglycopeptide groups included 20 and 15 patients respectively. In the IV group, 89 (35%) of the patients experienced clinical treatment failure compared to 5 (25%) in the PO group and 5 (33%) in the lipoglycopeptide group (p=0.71). Median LOS was significantly shorter in the PO group compared to the IV and LGP groups [1 day (IQR 0-2.5) vs. 7 days (IQR 4-10) and 4 days (IQR 4-9), p=0.003]. No difference between groups was observed for amputation within 6 months or incidence of adverse effects. The only variable included in the multivariate regression model was previous osteomyelitis at index site [OR 1.75, 95% CI (1.07 -2.87)].
Conclusion. PO and lipoglycopeptide therapy resulted in similar outcomes compared to IV antibiotics. Only previous OM at the same site was identified as an independent risk factor for failure.

Safety and Effectiveness of Intravenous to Oral De-escalation Compared to Continued Vancomycin Therapy in Orthopedic Infections
Chanah Gallagher, PharmD, MS 1 ; Russell J. Benefield, PharmD 2 ; Laura Certain, MD, PhD 1 ; 1 University of Utah, Salt Lake City, Utah; 2 University of Utah Health, Salt Lake City, UT Session: P-12. Bone and Joint

Background. The Oral versus Intravenous Antibiotics for Bone and Joint
Infection (OVIVA) trial determined oral antibiotics administered during the first six weeks of therapy were non-inferior to parenteral antibiotics. There was no difference in the incidence of serious adverse effects. The objective of this study was to evaluate the safety and effectiveness of de-escalating to oral therapy compared to continuing parenteral vancomycin therapy in patients with orthopedic infections in a real-world setting.
Methods. We conducted a single-center, retrospective cohort study of patients discharged between April 1, 2018 and April 1, 2020 with an orthopedic infection, a prescription for at least four weeks of parenteral vancomycin, and documented follow-up. The primary outcome was incidence of adverse events defined as provider documentation of the event and changes to therapy. The secondary outcome was incidence of 6-month treatment failure defined as repeat surgical intervention or therapy escalation.
Results. One hundred fifty-seven patients were included. Twenty-nine (18.5%) patients were de-escalated to oral therapy. Three (10%) patients in the oral therapy group had an adverse event compared to 35 (27%) in the vancomycin group (p=0.058). Of the 35 patients with an adverse event in the vancomycin group, eight were due to parenteral access-related complications. Treatment failure occurred in three (10%) patients in the oral therapy group compared to 27 (21%) patients in the vancomycin group (p=0.29). Three (10%) patients in the oral therapy group had an unplanned readmission compared to 25 (20%) patients in the vancomycin group (p=0.24).
Baseline Characteristics, Unplanned Readmission Rates, and Incidence of Adverse Events and 6-Month Treatment Failure S226 • OFID 2021:8 (Suppl 1) • Abstracts Conclusion. Patients de-escalated to oral therapy had fewer adverse events and similar incidences of treatment failure compared to patients maintained on parenteral vancomycin. Switching to oral therapy avoids some adverse events related to parenteral access. Our results in an uncontrolled, real-world setting are consistent with the OVIVA trial. Though limited by sample size, our data indicate switching to oral therapy in patients with an orthopedic infection improves safety outcomes without compromising effectiveness compared to continued parenteral vancomycin therapy.