New oral treatments are likely to play a more central role in limiting the impact of COVID-19, but health authorities are still evaluating how this will shape up.
What is being done to raise the public profile of the two new COVID-19 oral antivirals? What do we really know about the difference they make?
What more can be done to ensure they reach the right people at the right time? And what is their long-term role in the fight against COVID-19 as the virus becomes more endemic?
These are the questions, among many others, that primary care health professionals involved in the response to COVID-19 have been asking themselves for several weeks.
But while much still remains unknown, one thing is clear; the role of the two oral antivirals approved for use in Australia – molnupiravir (sold as Lagevrio) and nirmatrelvir plus ritonavir (sold as Paxlovid) – are likely to develop further in the coming months.
Registration on the Pharmaceutical Benefits Scheme (PBS) has been approved for both: molnupiravir can already be dispensed by general practitioners, while general practitioners will be able to prescribe the treatment nirmatrelvir plus ritonavir on the PBS from the beginning of May .
The additions came at the same time as clinicians noted an apparent decrease in the efficacy of sotrovimab against the current dominant subvariant of SARS-CoV-2, which will only heighten the focus on the two new oral treatments. .
Until recently, the monoclonal antibody, which is administered intravenously, was one of the most widely used treatments to reduce the risk of severe COVID-19 in vulnerable patients.
However, according to the National COVID-19 Clinical Evidence Task Force, it is now only recommended for use when the Omicron BA.2 subvariant is suspected when “other treatments are not suitable or unavailable. “.
Professor Brendan Murphy, Secretary of the Department of Health (DoH), explained a shift in dynamics in the COVID response during the ‘COVID-19 Treatments Forum’ webinar last week, as official policy shifts to a policy of minimization damage.
“While vaccination remains a crucial part of this approach, and we cannot neglect to keep pushing those extra doses that are needed, the role of treatments is now increasingly important,” he said.
“Oral treatments… are going to have [an] important and growing role over the next 12 months.
But while transmission is still mainly among young people, Professor Murphy said the use of antivirals will remain focused on older people and those with underlying disease.
“These are the people we need to have these treatments given early enough in their infection to be effective,” he said. “We believe we have purchased enough to meet the needs of clinically indicated populations.”
Between them, the projected supply of oral antivirals is currently sufficient to treat more than one million people with COVID-19.
The federal government confirmed 300,000 courses of molnupiravir last year, while a million courses of nirmatrelvir plus ritonavir were also ordered – although molnupiravir currently remains the most accessible and available.
The target groups are people aged 65 and over – or 50 and over in Aboriginal or Torres Strait Islander patients – with two or more risk factors for severe disease, as well as people aged 75 and over. more presenting a risk factor. All moderate to severe immunocompromised patients over the age of 18 are also included.
And although the drugs are not yet widely recognized by the general public, their use is increasing, with Deputy Chief Medical Officer Professor Michael Kidd recently reporting a “significant increase” in molnupiravir PBS prescriptions.
Of the 5,386 prescriptions reported last week, most were in the past few days, with the majority issued by GPs.
On Saturday April 9, the DoH reported that 42,867 courses of oral antivirals had been issued so far through the National Medical Stockpile, which GPs will need to continue to use until the PBS list goes live. next month.
Barriers to use
However, general practitioners report difficulties in prescribing treatment in a timely manner.
Oral antivirals are considered most effective if taken within five days of the patient’s diagnosis or the onset of symptoms. For GP Dr Chris Moy, this is a difficult schedule to meet, especially with the current volume of cases.
“The problem is trying to join the dots in time,” he told the COVID-19 Treatment Forum.
“Unfortunately, we’re not getting a very high success rate at the moment – I’d be surprised if it was above 30 or 40 percent.”
He said overly complex guidelines and inconsistency between approaches in different states were other potential barriers that could limit the use of antivirals.
The use of COVID oral antivirals may not be limited to those with comorbidities as supplies increase later in the year. (Image: AAP)
Meanwhile, Professor Kidd urged healthcare professionals to be aware of the long list of people classified as immunocompromised.
“It is very important that people become familiar with the people on this list,” he told those watching the webinar on COVID-19 treatments, highlighting the wide range of conditions included, people living with HIV/AIDS to those with intellectual and physical disabilities.
“Please make sure you know who is on this list. Because many of your patients may be eligible to prescribe molnupiravir on the PBS if they are 18 years of age or older.
Drug interactions are particularly complex with Paxlovid, with reports of prescriptions taking up to 90 minutes in a hospital setting. However, Dr Moy and Prof Kidd said GPs are ideally placed to navigate the contraindications given their knowledge of their patients and their treatments.
Australia’s Chief Medical Officer, Professor Paul Kelly, also agreed that the profile of antivirals needs to be raised within the wider community.
“We need to do more work in this area and we are doing it,” he said.
He declared his support for widespread pre-testing so that vulnerable people who contract COVID-19 can transparently receive appropriate treatment.
“I have this view that anyone in one of these high-risk groups has a treatment plan before they get COVID, not after they get COVID,” Professor Kelly said.
Clinical evidence to date
Assistant Professor John Skerritt, head of the Therapeutic Goods Administration (TGA), reiterated that there was not yet conclusive evidence on the relative effectiveness of antiviral treatments, pointing out that clinical trials were taking place under very distinct.
“They were tested against different circulating strains, different disease pressures, different hospitalization criteria and different patient inclusion criteria,” he said. “I don’t believe there is a valid back-to-back comparison of the two treatments.”
Professor Skerritt also pointed to the practical constraints in assessing the real effectiveness of treatments, although he believes evidence will emerge in about the same time as it took for detailed data on the vaccine efficacy are published.
He also thinks the treatments are likely to become more widely used among the general population.
“With COVID endemic, we could well see ourselves in a position where these drugs are very widely available in six or 12 months and we don’t need to limit ourselves to people with comorbidities,” he said.
“If the drug prevents disease progression in someone with comorbidities, it would be hard to imagine that it wouldn’t also prevent viral replication in someone who doesn’t have comorbidities.”
The RACGP produced a list of COVID-19 resources with relevant information for each state and territory.
A guide presenting information GPs need to know about oral antivirals was also published by newsGP.
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