The British Society for Antimicrobial Chemotherapy’s National OPAT Conference 2025 captured the evolution of OPAT in the midst of increasingly complex health service provision in the UK. As pressures on acute care intensify and clinical practice shifts beyond hospital walls, OPAT is emerging as a cornerstone of modern infection management across specialities, as Gerry Hughes reports.
In the current highly pressurised healthcare environment, outpatient parenteral antimicrobial therapy (OPAT) offers somewhat of a lifeline for infection management in medically stable patients.
The British Society for Antimicrobial Chemotherapy (BSAC)’s recent National OPAT Conference 2025 opened with a candid assessment of the forces reshaping OPAT: rising patient complexity, surges in emergency attendances, pressures on bed capacity and the continued expansion of community-based care. OPAT was presented not as an adjunct but as a clinical necessity that increasingly bridges gaps between acute, ambulatory and home settings.
Indeed, OPAT offers a vital opportunity for preventing hospital admissions, reducing a patient’s length of stay in hospital through early discharge and limiting the risk of hospital acquired infections – among other benefits.
Governance keeping pace with OPAT
The theme of OPAT as a clinical necessity was explored in detail by Devon Elliott, national antimicrobial resistance lead at NHS England. His session recognised that the time is right for the widespread develop OPAT services but asked – and answered – the question of how that should be achieved.
Mr Elliott highlighted that many patients are frequently admitted to hospital as emergency cases for infection related reasons, often with multiple comorbidities and high clinical complexity.
‘Patients turning up in our emergency departments appear to be increasing in acuity and complexity,’ he noted. ‘And if we’re seeing more complex patients, we need to think carefully about the optimal place to manage stable ones to create capacity.’
Mr Elliott argued that OPAT must therefore be positioned more prominently in both local and national planning as a strategic lever for performance, patient flow and system resilience.
A starting point for this is NHS England’s guidance on developing OPAT services, which was published in April 2025 with the goal of improving productivity, supporting service recovery, integrating with home-based care models and reducing hospital stays.
The importance of intravenous (IV)-to-oral switch strategies was emphasised by Mr Elliott as an essential adjunct to OPAT and its expansion. He also underscored the need for demonstrable impact, capturing the conference’s data-driven tone with his reminder about the importance of ‘data, data, data’ to show OPAT’s value for patients and systems.
Getting OPAT right for complex patients
Expanding on Mr Elliott’s reference to complex patients, the president of BSAC, Professor Andrew Seaton, consultant in infectious diseases in NHS Greater Glasgow and Clyde, highlighted the evolution of OPAT towards complex outpatient antimicrobial therapy.
Known as COpAT, this reflects the growing reality that OPAT services must adapt to more complex patient cohorts and function within an increasingly pressurised health system. Professor Seaton also noted the importance of collaboration across the primary-secondary care interface to get antimicrobial stewardship right.
Dr Ann Noble, infectious diseases consultant at NHS Lanarkshire, presented the scale of evidence now supporting OPAT practice and a preview of the upcoming OPAT Good Practice Recommendations (GPRs) update.
First introduced in 2019 as a foundation for consistent, safe, equitable care, the OPAT GPRs will be updated in 2026 and will include the deployment of new quality indicators and recommendations for services to identify and address inequity of access reasons.
Reflecting on the earlier session where COpAT was discussed Dr Noble noted a new recommendation for additional monitoring of patients prescribed oral, subcutaneous or long-acting IV antimicrobials for infections.
Clinical lessons from OPAT
Throughout the conference sessions, speakers used real cases to explore nuances of OPAT in practice. For example, Mr Gianni Acuram, OPAT lead clinical nurse specialist at King’s College Hospital in London, challenged the exclusion of vulnerable adults from self-administration.
His example of a patient with learning difficulties, anxiety and limited support revealed how tailored teaching and multidisciplinary involvement can produce safer, more person-centred OPAT pathways. His message that risk should be assessed holistically, not assumed resonated across specialities.
Dr Carolyn Hemsley, infectious diseases and microbiology consultant at Guy’s and St Thomas’ NHS Foundation Trust, highlighted that patients on haemodialysis have ‘the perfect OPAT scenario’ because they already have reliable parenteral access and the frequency of dialysis often aligns naturally with OPAT dosing regimens.
However, she also emphasised a challenge familiar to many clinicians: while haemodialysis units routinely administer parenteral antimicrobials, these treatments frequently fall outside established OPAT governance structures.
Antimicrobial use in dialysis-based OPAT differs markedly from wider national OPAT patterns, Dr Hemsley added. In her local cohort, for example, vancomycin, meropenem and cefazolin are the more commonly used agents. In contrast, national registry data shows ceftriaxone, teicoplanin and ertapenem as the leading choices.
Dr Hemsley also described scenarios in which IV-to-oral switch is not always appropriate for this population. ‘In this patient population there are some patients we don’t do IV-to-oral switch because delivery of the antibiotic on dialysis ensures compliance, removes the polypharmacy that they already have with multiple pills, so there are some patients where we want them to stay on IVs because it makes sense for the patient,’ she explained.
This person-centred care was also highlighted as an important clinical safeguard for OPAT in a presentation from Dr Simon Pybus, consultant clinical microbiologist at Golden Jubilee National Hospital in Glasgow.
His analysis showed that screening OPAT referrals helps to identify alternative management strategies, including oral therapy, as some referred patients are simply not suitable for OPAT.
Reducing OPAT line-associated thrombosis
Dr Grace Barnes, specialty registrar in infectious diseases and microbiology at Oxford University Hospitals NHS Foundation Trust, described a local initiative to reduce line-associated thrombosis in OPAT patients with midline venous catheters (MVCs).
She highlighted emerging evidence that MVCs are associated with higher rates of line-related complications compared with peripherally inserted central catheters.
In January 2024, her centre initiated a recommendation for venous thromboembolism (VTE) prophylaxis for OPAT patients discharged with an MVC in situ. Although acknowledging the limitations of this single-centre study with relatively small patient numbers, Dr Barnes presented encouraging early findings.
The rate of line-associated thrombosis fell from 10.5% (n=10) in 2023 to 2.7% (n=4) in 2024, with no additional bleeding events reported in patients receiving prophylaxis. Dr Barnes therefore advised clinicians to consider VTE prophylaxis for appropriate OPAT patients with MVCs, noting its potential to reduce preventable complications and support OPAT.
Innovation and emerging therapies
The conference concluded with several sessions focusing on innovation and the emerging therapies and models that could further augment OPAT care.
Dr Nikolas Rae, consultant in infectious diseases at Ninewells Hospital in Dundee, discussed the real-world application of oral antimicrobial therapy in infective endocarditis (IE). Drawing on applicable evidence from the POET trial, his institution introduced a multidisciplinary team-led policy in 2022 to transition eligible patients from IV to oral therapy.
He presented data on 29 patients, predominantly with aortic or mitral valve involvement and infections caused by Streptococcus or Staphylococcus species. All patients who transitioned to oral therapy completed their treatment courses. In a subset of six patients initially prescribed oral linezolid, all subsequently required a second antimicrobial switch, reflecting the importance of close monitoring and multidisciplinary oversight.
Dr Rae emphasised that oral therapy for IE is feasible in routine clinical practice when systems are in place to identify suitable patients, support patient adherence and ensure consistent multidisciplinary review.
His key message was that oral antimicrobial therapy represents a practical and evidence-supported option for selected real-world IE patients, with the potential to reduce hospitalisation without compromising clinical outcomes.
Professor Tihana Bicanic, professor of infectious diseases and mycology at City St George’s, University of London, and consultant in infectious diseases at St George’s University Hospitals NHS Foundation Trust, shared insights into the once-weekly novel echinocandin rezafungin, suggesting a step change for antifungal therapy.
Early use at her institution has been driven by patient preference and convenience, the ability to support earlier discharge, and cost-efficiency. Rezafungin has been straightforward to implement, well tolerated and particularly suitable for complex invasive candidiasis cases, she reported, including those involving bone and joint infection, endovascular involvement and prosthetic material.
Conclusion
The BSAC National OPAT Conference 2025 captured the current evolution of OPAT in the UK and beyond. Across the varied sessions, the message for clinicians was clear: OPAT is expanding in scope, complexity and relevance for practice. Multidisciplinary coordination and a willingness to innovate in the interests of person-centred care are key, as well as supporting local and national planning to ensure best practice and optimal patient outcomes in infection management.