Outpatient parenteral antimicrobial therapy for patients with Enterococcus faecalis endocarditis using continuous infusion IV benzylpenicillin plus IV ceftriaxone.

Background: Many patients with Enterococcus faecalis endocarditis are clinically stable and able to leave hospital before completing antibiotic treatment, but data are lacking regarding some outpatient treatment options.

Objectives: To assess the outcomes for adults with E. faecalis endocarditis receiving outpatient parenteral antimicrobial therapy (OPAT) with continuous infusion IV benzylpenicillin plus bolus/continuous infusion IV ceftriaxone.

Patients and methods: We retrospectively reviewed adults who received at least 2 weeks duration of OPAT for E. faecalis endocarditis with the above treatment regimen in the Auckland and Christchurch regions between July 2019 and September 2022.

Results: Forty-four patients met inclusion criteria. Fifteen were female (34%). The median age was 80 (IQR 71.5 to 84) years. Twenty-two (50%) had prosthetic valve (PV), 15 (34%) native valve (NV), 3 (7%) NV and/or cardiac implantable electronic device (CIED) infection, 3 (7%) PV and/or CIED infection, and 1 (2%) repaired valve endocarditis. Patients received a median of 16.5 days inpatient and 28 days OPAT antibiotic treatment. The 12 month outcome was cure (n = 25; 57%), antibiotic suppression (n = 9; 20%), relapse (n = 2; 5%; both possible) or death (n = 8; 18%). Compared with a historical cohort treated with OPAT continuous infusion IV benzylpenicillin plus bolus IV gentamicin, there was no difference in the relapse rate.

Conclusions: This study adds to the accumulating evidence supporting the treatment of E. faecalis endocarditis with OPAT continuous infusion IV benzylpenicillin plus bolus/continuous infusion IV ceftriaxone. This is an option for patients requiring further antibiotic treatment at the time of hospital discharge.