Eligibility for Paxlovid and Lagevrio remains unclear as the eighth wave of covid washes across the nation.
GPs need clear, consistent guidance on antiviral eligibility, as continued “to-ing and fro-ing” is causing “unrest and confusion”, says expert.
This summer has seen an increase in covid hospitalisations amid the rise of two strains, EG.5 and the emerging JN.1, which is said to be one of the most infectious yet.
Unsurprisingly, there has been a matching spike in PBS antiviral scripts, with around 90,000 scripts issued in December according to DoHAC.
But, according to the latest data available , cases are vastly outnumbered by antiviral scripts issued.
Speaking to The Medical Republic, infectious disease expert from the University of Sydney Professor Robert Booy said there was “no doubt” about the mismatch between recorded case numbers and script numbers.
Although in general the recommendation is to issue antivirals on the basis of a positive PCR result, many doctors may “not unreasonably” prescribe the medication based on positive RATs, Professor Booy told TMR, meaning some cases may be going unrecorded.
According to Professor Booy, waiting for a PCR test “could lead to a poorer outcome”.
Health outcomes are best for people who start the antivirals within two or three days of infection, he added.
Currently in Australia, there are two antiviral treatments on offer through the PBS: nirmatrelvir-ritonavir (Paxlovid, Pfizer) and molnupiravir (Lagevrio, MSD Australia).
Studies suggest that Paxlovid is effective at reducing risk of hospitalisation for people at high risk of severe covid.
Lagevrio may reduce covid deaths, but a recent, larger study suggested it did not significantly reduce death or hospitalisation.
According to Professor Booy, “both drugs are effective”.
But Paxlovid, while it may be more effective for those at risk of more severe disease, “is harder to prescribe because it interacts with a number of routine medications to the point where some medications have to be stopped or halved before it can be prescribed”.
This creates a tricky situation for GPs, who must make a clinical decision about whether to alter patients’ medications in favour of Paxlovid. “If you’re particularly high risk [this] is probably the better option,” Professor Booy said.
While the list of interactions is long, Professor Booy suggested a tool like the Liverpool tracker may be useful for GPs.
“You need quality GPs making assessments and decisions,” he said, adding that this was tough when criteria kept changing.
Related
In Australia, Paxlovid is preferred over Lagevrio and is available through the PBS for patients over 70, anyone who is immunocompromised, 50-69-year-olds with one risk factor for severe illness, and Aboriginal and Torres Strait Islander people aged 30 or older with one risk factor for severe illness.
But earlier this month, the PBAC recommended that eligibility for PBS subsidised Paxlovid be tightened for adults aged 50-69.
“The PBAC recommended that, at its current price, there should be a change to the restriction for patients aged 50-69 years, which currently allows access for patients with one or more additional risk factors, to revert to the requirement for two or more risk factors, due to reduced cost-effectiveness in this lower-risk population,” the PBAC stated in its recommendation.
While some argue this is “short-termism”, Professor Booy said he could “see the logic” for the change given the evidence.
The Australian PBAC wants to tighten Paxlovid eligibility because it is not 'cost effective' to make criteria wider.
— Prof Deborah Lupton Master of Public Health, PhD (@DALupton) January 10, 2024
Money over people's health (and short-termism, because long COVID will impact the economy if not prevented)https://t.co/8pW2dQlBrn
“The evidence is clear that the likelihood of a severe outcome from covid is much higher if you’ve got two or more risk factors than one,” he told TMR.
“With any medication, we have to take an economic approach.
“It’s not anything new. It’s just the reality.”
But at present, “we don’t even know when the change is actually happening”, resulting in “unrest and confusion among GPs – who are busy enough as it is”, added Professor Booy.
“It’s reminiscent of the time when there was quite a lot of to-ing and fro-ing about who should get the vaccine,” he said.
“I think what we need is clarity for GPs, not fiddling around the edges with altering risk factors every few months.”
According to Professor Booy, patients in need are getting access to antivirals, but “the problem is that people who need a vaccine who are vulnerable haven’t had one”.
“So that’s what we should be focusing our efforts on – making sure that the public and the professionals know what to do and have a practical means to achieve that,” he said.
Professor Booy added that while it was “too soon to say conclusively” whether antivirals remained effective against the current prominent strains, they were still effective against the many subvariants they had been tested on so far.
