The British Society for Antimicrobial Chemotherapy’s National OPAT Conference 2025 explored the evolution of OPAT amid 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 and pharmacists have a central role to play, 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’s National OPAT Conference 2025brought together leading clinicians, policy specialists and researchers to examine how OPAT is evolving in the face of rising patient and system complexity and mounting operational pressures. For hospital pharmacists, the meeting offered a valuable update on the direction of OPAT and the standards required for safe, contemporary practice.
OPAT in an evolving NHS landscape
The opening session from Devon Elliott, national antimicrobial resistance lead at NHS England set out the important and timely message that OPAT is no longer a niche service. It now sits at the centre of NHS ambitions to facilitate home-based care, where it is deemed clinically appropriate, and the mitigation of antimicrobial resistance.
To support this, in April 2025, NHS England published guidance on developing OPAT services, with the goal of improving productivity, supporting service recovery, integrating with home-based care models and reducing hospital stays. Antimicrobial stewardship (AMS) pharmacists were identified as key stakeholders in OPAT’s multidisciplinary delivery.
This includes supporting the transfer of care across the primary-secondary care interface, which was the subject of a session from BSAC president Professor Andrew Seaton, consultant in infectious diseases at NHS Greater Glasgow and Clyde. He reflected on the rapidly evolving interface between hospital and home-based care, with implications for pharmacists as medicines experts overseeing safe therapy in the community.
Referring to the NHS 10-Year Health Plan, Professor Seaton expressed concern that OPAT is not mentioned at all, despite its centrality to shifting care closer to home. And he cautioned that OPAT risks being overshadowed by better-branded initiatives such as hospital-at-home and virtual wards.
Professor Seaton described OPAT as ‘an integral part of AMS’, and highlighted the need for shorter durations, intravenous (IV)-to-oral switch and de-escalation strategies to be embedded in OPAT service design – some of which were central to the 2019 OPAT Good Practice Recommendations (GPRs) update.
These medicines-focused initiatives place pharmacists in a pivotal position as evidence for optimal antimicrobial therapy continues to evolve. Professor Seaton described a key stewardship challenge as the ‘dis-benefit of using IV therapy when you could give oral therapy’, which he said is important for the patient as well as having financial advantages.
He also referenced a term gaining traction across the field of evidence: complex outpatient antimicrobial therapy. Known as COpAT, this reflects an emerging evidence base for shorter, safer and increasingly oral outpatient antimicrobial pathways, which demand robust, pharmacy-led stewardship.
The expanding OPAT evidence base
Dr Ann Noble, infectious diseases consultant at NHS Lanarkshire, shared a preview of the new OPAT GPRs, which are due to be published in 2026.
The scale of evidence now available for OPAT has doubled since 2019, she reported, with more than 7,000 publications screened and 1,000 reviewed in full. While most existing recommendations remain valid, reflecting a robust core evidence base, she noted some new sections focusing on patient selection, antimicrobial management and drug delivery.
Reflecting on the earlier session where COpAT was discussed, Dr Noble also highlighted a new recommendation for the additional monitoring of patients prescribed oral, subcutaneous or long-acting IV antimicrobials.
Professor Mark Gilchrist, consultant pharmacist at Imperial College Healthcare NHS Trust, presented on the rapidly evolving technical landscape surrounding antimicrobial stability in OPAT devices. He highlighted the growing complexity clinicians and pharmacists now face and referred to the elastomeric devices frequently used for ambulatory OPAT management as an example.
‘If you detach a pump versus having it continuously attached when you sleep, the temperature under the bed cover compared with outside can alter the flow rate,’ he said. ‘Teams across Australia, Spain, the UK and others are now looking at degradation and clinical outcomes.’
He also outlined the challenges of working with newly introduced antimicrobials, particularly newer gram-negative agents.
‘We still have a need to use older drugs wisely, but at the same time we’re facing a gram-negative threat. So, we’ve begun evaluating ceftazidime-avibactam, for example, for once-daily infusions,’ Professor Gilchrist explained. ‘For some patients, who have been in hospital for months, we’ve used these pumps to get them home.’
The importance of data
Professor Gilchrist raised the broader international challenge of non-harmonised drug stability standards in OPAT. He described this heterogeneity as a dilemma for doctors and pharmacists trying to implement OPAT programmes safely. ‘One size doesn’t fit all but we need to link up and become a global leader in in the harmonisation of data,’ he said.
Shay Khan, advanced practitioner OPAT pharmacist at Whittington Health NHS Trust in London, focused on the growing importance of digital governance within OPAT services.
He described his work developing a real-time data visualisation solution that automatically extracts electronic patient data relating to infection and converts it to a clinical business intelligence interface. This methodology is currently being piloted in collaboration with BSAC as part of the National OPAT/COpAT Point Prevalence Survey.
The automated live dashboard showcased by Mr Khan demonstrated the significant potential of real-time OPAT data extraction to reduce the manual workload traditionally associated with data collation and reporting. With OPAT activity often poorly coded or inconsistently recorded, a centralised digital tool has clear value for service benchmarking, pharmacy-led quality improvement, resourcing discussions and AMS oversight.
Looking ahead, the next phase of this initiative will involve expanding data capture to paediatric sites and establishing a national live data repository and visualisation platform. This centralised system is expected to launch in 2026 and represents an important milestone in delivering more transparent, standardised and data-driven OPAT governance across the UK.
OPAT in practice: person-centred care
Throughout the conference sessions, speakers used case-based insights to demonstrate the complexities encountered in managing the safety and efficacy of antimicrobial therapy.
One of the most resonant was from Gianni Acuram, OPAT lead clinical nurse specialist at King’s College Hospital in London, who challenged assumptions that vulnerable adults may be less suited for OPAT self-administration.
He described a wheelchair-bound patient with learning difficulties, anxiety and limited social support for whom home IV therapy initially seemed unsuitable. Yet after several structured teaching sessions, tailored pacing and multidisciplinary involvement, she became a safe, competent self-administering patient.
‘At a glance, this patient looks unsuitable,’ he says. ‘But instead of stopping there, let us reframe the barriers.’
He also advised on a patient-centred approach to OPAT services, with such initiatives as needle-free adapters and prefilled reconstitution solutions to assist with patient self-management of their OPAT.
OPAT in practice: implementing rezafungin
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, profiled early experience with the novel echinocandin rezafungin at her institution.
Authorised in the UK in January 2024, this once-weekly antifungal offers a practical advantage over existing echinocandins, which require daily administration.
Rezafungin was shown to be non-inferior to caspofungin in the phase 3 ReSTORE trial for candidaemia and invasive candidiasis, meeting endpoints for 14-day global cure and 30-day all-cause mortality.
Professor Bicanic highlighted that their adoption of rezafungin at St George’s was driven by patient preference and convenience, the ability to support earlier discharge, and cost-efficiency when compared with daily caspofungin.
A total of 109 doses of equivalent echinocandin therapy were saved through weekly rezafungin dosing. A direct cost comparison demonstrated an estimated £9,964 for a 14-day caspofungin course versus £2,258 for an equivalent rezafungin regimen.
Professor Bicanic concluded that, based on their experience, rezafungin has been straightforward to implement, well tolerated, and particularly suitable for complex invasive candidiasis cases, including those involving bone and joint infection, endovascular involvement, and prosthetic material.
OPAT in practice: determining safety and efficacy
Dr Simon Pybus, consultant clinical microbiologist at Golden Jubilee National Hospital in Glasgow, presented data on the vetting of OPAT referrals, describing it as the essential clinical and pharmacological assessment that determines whether OPAT is safe, appropriate and feasible for an individual patient.
His retrospective review of 5,024 referrals between 2022 and 2024 found that 29% (n=1,467) were not accepted into an OPAT programme. Of these, 43% were declined for AMS reasons, with and the majority recommended for oral therapy. Notably, most oral-switch recommendations related to patients with bone and joint infections. A further 35% were not suitable for OPAT on patient-related grounds, highlighting the importance of structured suitability screening.
These findings reinforce the value of systematic referral evaluation in preventing inappropriate IV therapy, supporting safe oral switch and ensuring that OPAT capacity is reserved for patients who genuinely require parenteral treatment.
Dr Pybus emphasised that measuring and monitoring these outcomes is essential for a high-quality OPAT service, noting the embedded stewardship benefits that vetting delivers.
‘We need to be able to deliver antimicrobial stewardship through the OPAT model and also recognise the impact that we’re having not just in those completing OPAT episodes,’ he said.
Conclusion
The BSAC National OPAT Conference 2025 illustrated how outpatient antimicrobial therapy is evolving into a more complex and therapeutically diverse field, with an increasing need for data-informed practice.
Across the sessions, speakers highlighted how OPAT now aligns with key UK health system priorities, including improving patient flow, addressing inequities in access and reinforcing AMS.
Now, with OPAT broadening in ambition, the hospital pharmacy professions must engage not only with expanding contexts of care but also the frameworks that ensure its safe and effective use.
