Hospital pharmacists' role in COVID-19 treatments

The recent introduction of oral antiviral treatments has shaken up the COVID-19 healthcare landscape, once again calling on the expertise and services of Australian hospital pharmacists as we progress towards the endemic stage of this pandemic.

Medicine information centres led by clinical pharmacists are key hubs in this knowledge network and must be supported to ensure accurate and timely information reaches pharmacists and their healthcare colleagues handling novel COVID-19 treatments.

Secured by the Australian Government at the end of 2021, nirmatrelvir/ritonavir (PaxlovidR) and molnupiravir (LagevrioR) were recently distributed via the National Medical Stockpile to public hospitals, residential aged-care facilities and Aboriginal Community Controlled Health Organisations (ACCHOs). On 1 March 2022, molnupiravir (LagevrioR) was listed on the Pharmaceutical Benefits Scheme. This has broadened treatment accessibility beyond the realms of acute healthcare facilities, but has exposed safety gaps which clinical pharmacy support and services are needed to fill.

Throughout this pandemic, hospital pharmacists have been essential in overseeing the safe management and supply of COVID-19 vaccines and intravenous medicines. The new oral antivirals mitigate the progression of COVID-19 infection, reducing hospital admission or death from any cause by up to 89%; while this data pertains to earlier variants, there is demonstrated efficacy with Omicron.

A recently published article in SHPA’s flagship peer-reviewed journal has outlined the ‘Pandora’s box’ relating to oral COVID-19 treatments, authored by expert pharmacist representatives from the National COVID-19 Clinical Evidence Taskforce.

The safe use of PaxlovidR requires a thorough medication history and individual patient assessment of all medications, including those bought over the counter. Careful clinical consideration needs to determine if concurrent medicines can be temporarily withheld, appropriately dose-reduced or avoided altogether in light of clinical factors such as significant renal impairment.

Many medications with narrow-therapeutic and high toxicity ranges are known to be affected by these interactions including some antipsychotics and anticoagulants, while other interactions render PaxlovidR ineffective altogether.

Clinical assessment of medicine interactions is a core function of all expert clinical pharmacists who are essential to advising on the quality and safety of these new treatments. A recent 3-year (unpublished) review of over 11,000 immunocompromised patients from Melbourne’s Alfred Hospital found a third of patients would not have been able to receive PaxlovidR due to such interactions. A similar review of COVID-19 positive patients found 37% of patients would have also been excluded from PaxlovidR therapy, highlighting the significant extent to which expert input is required in key patient populations.

It is into this breach that medicine information centres, led by expert clinical pharmacists, step in. Specialist medicines information pharmacists are trained to deal in the complex clinical assessment of medicines, and therapeutic recommendations can be tailored to the individual patient and their specific clinical factors. Not supporting widespread access to specialist medicine information centres to deal with these newly introduced oral treatments leaves wide knowledge gaps that product information and standard consensus guidelines are simply unable to fill. Even one of the most widely shared drug interaction checkers for PaxlovidR among the clinician community, the University of Liverpool’s COVID-19 Drug Interactions Checker, currently omits many medicines including chemotherapy medicines and some HIV antivirals.

It therefore comes as no surprise that some jurisdictions are centralising distribution models within designated public hospitals, where specialist COVID-19 teams — with expert clinicians and specialist clinical pharmacists — review and assess individual patients and their medications before commencing COVID-19 treatments. Many of these specialist teams have been in place since 2021 for COVID-19-positive inpatients being treated with intravenous remdesivir and sotrovimab, also accessed from the National Medical Stockpile.

Some states are using this model to support GPs and patients in the community. However, this level of clinical pharmacy review is not currently embedded in residential aged care facilities or as part of ACCHOs, nor are expert clinical pharmacist reviews or medicines information pharmacists available, meaning GP prescribers are unable to have their patients access a clinical pharmacist review and dispensing service.

Specialist hospital pharmacists are fundamental to bridge these care gaps, supporting treating clinicians in the next phase of this pandemic to improve patient outcomes and reducing pressures faced by hospitals.

The new oral COVID-19 therapies are rightly receiving an enthusiastic welcome, and they provide a much-needed rapid response to COVID-19 infection for those in the wider community. Clinical hospital pharmacy expertise is needed to support the safe, timely and quality use of new oral COVID-19 therapies to reduce related hospital admissions.

Put simply, hospital pharmacists are crucial to their success.

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