O04 Oral antimicrobial therapy for infective endocarditis - real-world experience from a teaching hospital in Scotland

Sep 29, 2026

Oral antimicrobial therapy for infective endocarditis is uncommon in the UK, yet a Scottish infection unit adopted oral antibiotics for selected patients from late 2022. A retrospective review assessed clinical efficacy and outcomes, including within 6 months after completion, in patients treated with oral or IV-to-oral regimens. Among 29 cases, most met definite criteria; valves and causative organisms were characterized, inflammatory markers were tracked, POET-trial criteria were frequently met, and adverse outcomes remained relatively low, though regimen changes were often needed with linezolid.

LanguageEnglish

CategoryHealthcare

FormatPDF

Pages1

Reading Time3 min

AccessFree to download

Background

Objectives

Methods

Results

Conclusions

Oral Abstracts Abstract citation ID: dlaf239.004 O04 Oral antimicrobial therapy for infective endocarditis: real-world experience from a teaching hospital in Scotland Nikolas Rae1, Emma Duncan1, Neil Stevenson1 1Infection Unit, Ninewells Hospital and Medical School, Dundee, DD1 9SY, UK Background: Treatment of infective endocarditis with oral antibiotics is not common in the UK despite an evidence base supporting this approach in appropriate patients. From late 2022 onwards the Infection Unit in Ninewells Hospital, Dundee, has adopted the use of oral antibiotic therapy in the treatment of selected patients with infective endocarditis. Objectives: We aimed to review the clinical efﬁcacy and outcomes in patients treated with oral antimicrobial therapy for infective endocarditis in our unit. Methods: We retrospectively reviewed patients treated with oral antimicrobial therapy for infective endocarditis. Patient records were reviewed for basic demographics, endocarditis characteristics and treatment (both IVand oral). Adverse outcomes (deﬁned as all-cause mortality, unplanned cardiac surgery, recurrence of bacteraemia or embolic events) were assessed for within 6 months of completion of therapy. Results: In total 29 patients were identiﬁed, of which 21 (72%) were male. Mean age was 67 (range 36-94) . Of the patients included, 20 were classed as ‘deﬁnite’ endocarditis by Duke-ISCVID 2023 criteria, with the remaining 9 meeting ‘possible’Duke-ISCVID 2023 criteria. Structures involved included aortic valve (15 patients), mitral valve (11 patients), ICED (2 patients) and tricuspid valve (1 patient), with 9 of the 27 valve infections occurring in prosthetic valves. In total, 15 of 29 (52%) patients had moderate to severe valvular regurgitation, 5 (17%) patients had a vegetation of 10mm or greater and 4 patients underwent surgery during the course of their illness. With regards to microbiology, our cohort included 14 patients with Streptococcus spp., 12 patients with Staphylococcus aureus (all MSSA), 2 patients with Enterococcus faecalis and one patient with coagulase-negative Staphylococcus spp. Mean peak C-reactive protein was 163 mg/L (range 17–400) with mean C-reactive protein at transition to oral therapy of 21 mg/L (range 3–98). In total, 22 patients (76%) met the criteria used in the POET trial. Mean duration of IV therapy was 15 days (range 6–30). Mean duration of oral therapy was 26 days (range 14–42) . Mean total duration of therapy was 41 days (range 28-56) . The ﬁnal oral antibiotic regimens used included linezolid in 19 patients (65%), amoxicillin in 5 patients (17%), co-trimoxazole in 3 patients (10%) and amoxicillin with rifampicin in 2 patients (7%) . Change of oral agent due to adverse drug effects was required in 6 patients, all occurring in patients prescribed linezolid. Adverse outcomes occurred in three patients (embolic events in two patients and one death 4 months after treatment completion due to cardiac failure), with 5 patients yet to complete the full 6 month follow-up period. Conclusions: Oral antimicrobial therapy can be used in appropriate patients with infective endocarditis, with good efﬁcacy and relatively low rates of adverse effects despite signiﬁcant complexity of illness. Alteration of oral regimen was frequently required when linezolid was used.

FAQs

Why did the teaching hospital adopt oral antibiotic therapy for infective endocarditis?

The unit adopted oral therapy because evidence supports this approach in appropriately selected patients, even though it is not common in the UK.

How were treatment outcomes and adverse outcomes defined and assessed?

Outcomes were assessed for within 6 months after completion and included all-cause mortality, unplanned cardiac surgery, recurrence of bacteraemia, or embolic events.

What were the main findings regarding efficacy and adverse effects?

Oral antimicrobial therapy showed good efficacy with relatively low rates of adverse outcomes. Altering oral regimens was frequently required when linezolid was used, and adverse events occurred in three patients.

Sep 29, 2026

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