When her mum's RAT was positive, Christie thought she'd be able to get COVID antiviral drugs easily: her mum, who is in her 80s, has a condition called cardiomyopathy that can lead to heart failure.
So, Christie was surprised when a nurse at her mum's cardiologist office, which is based at a major Melbourne hospital, said she wasn't eligible.
"My sister [rang the cardiologist's office and] asked if mum could have a prescription for antivirals because she'd just tested positive for COVID," Christie says.
"The nurse said, 'Oh, no, they're just for immunocompromised people.'"
Yet when Christie looked online, she found criteria stating her mum's age and heart condition meant she did, indeed, fall under the antiviral eligibility umbrella.
Confusion and lack of awareness around who qualifies for COVID antivirals — and who doesn't — may be why some eligible patients aren't getting the COVID medicines, according to Adelaide GP and Australian Medical Association vice president Chris Moy.
"Awareness was very poor, even from GPs initially, but it's gotten better.
"And this is a very difficult area when everything's moving all the time and the science keeps changing.
For people like Christie looking for clear, simple antivirals eligibility information, navigating the plethora of different guidelines and recommendations can be a frustrating task.
Alongside Pharmaceutical Benefits Scheme (PBS) eligibility criteria, other organisations such as the National COVID-19 Clinical Evidence Taskforce have published their own guidance, and depending on where you live, your state health authority might have its own priority groups too.
So who can get COVID antivirals, how do you get them, and who determines eligibility?
But first, let's take a look at what antivirals are available in Australia and how they work.
What antivirals are on offer?
There are two antiviral COVID drugs currently available on the PBS in tablet form: molnupiravir (sold as Lagevrio and made by Merck) and a combination of nirmatrelvir and ritonavir (known as Paxlovid and made by Pfizer).
(Another approved antiviral is remdesivir, but it's an intravenous drug and only given in hospital.)
Molnupiravir and Paxlovid are prescribed to people with mild to moderate COVID-19 who have a high risk of progressing to severe disease.
In short, the goal is to keep people out of hospital.
They work by throwing a spanner in the SARS-CoV-2 virus replication process in our cells, thus curbing its spread through our body.
And for this reason, time is of the essence when it comes to molnupiravir or Paxlovid.
The five-day course must be started before the virus has well and truly taken hold, so within five days of first symptoms appearing, Dr Moy says.
A phase-three clinical trial found Paxlovid reduced the risk of hospitalisation and death by 89 per cent when unvaccinated COVID-19 patients were treated within five days of symptom onset.
But they're not suitable for everyone. Paxlovid interacts with a whole range of other drugs — including herbal supplements — which can cause severe or life-threatening reactions, or stop Paxlovid doing its job.
Neither Paxlovid nor Molnupiravir are recommended for use during pregnancy or breastfeeding.
Who's eligible for COVID antivirals?
To get PBS-subsidised antivirals, you must meet PBS criteria. (Given limited supply, this is the only way GPs are supposed to prescribe antivirals.)
First, you must test positive for COVID on a RAT or PCR test, have at least one COVID symptom, and, at the time of prescribing, not be so sick that you're in hospital.
Then depending on factors such as your age, immunocompromised status and if you identify as Aboriginal or Torres Strait Islander, you may qualify as "high risk" of progressing to severe disease if you, say, have other conditions, live in residential care, or are not fully vaccinated.
(For a full breakdown of PBS eligibility criteria, tap or click on "Authority Required (STREAMLINED)" on the molnupiravir and Paxlovid pages.)
A reason these antivirals aren't given to low-risk people is because they're not without potential side effects, says Mark Morgan, a professor of general practice at Bond University and chair of the Royal Australian College of GP's Expert Committee for Quality Care.
Paxlovid can cause diarrhoea in 3 per cent of people, and in 6 per cent, a condition called dysgeusia, where all food tastes sour, sweet, bitter, or metallic.
"In low-risk people, any harms, any risks of side effects start to become a bigger factor," Professor Morgan says.
The Pharmaceutical Benefits Advisory Committee, which advises the government on which medicines should be subsidised on the PBS, also takes into account value for money compared to other available therapies.
And these drugs are expensive. A five-day course costs more than $1,000 (but with the PBS subsidy, you only pay $42.50, or $6.80 with a Health Care Card).
Then there's the issue of supply. The Morrison government "secured access" to 300,000 treatment courses of molnupiravir and a million courses of Paxlovid to be distributed across 2022.
How much is available in the country right now, though, is unclear, and a Department of Health spokesperson said the department "does not traditionally reveal the number of products or volumes of each product in the National Medical Stockpile".
How can I get them?
If you think you may be eligible for COVID antiviral treatments under the PBS, get tested as soon as you notice any symptoms, says Josh Davis, an infectious diseases physician in Newcastle.
"I think it's tempting for people now to sometimes not even worry about doing a test, because they think, 'Oh, well, I could just have a cold or the flu, and I might get better in the next few days.'
If the test is positive, make a phone or video appointment with your GP, or at a GP respiratory clinic, if there's one in your area.
Your GP is your best option, Dr Moy says, because they know your medical history and medications. Just let them know you're seeking COVID antivirals and the appointment is time-sensitive.
There, your GP will (among other things) assess your risk factors for severe COVID, see if you fit the PBS criteria, and check your medications won't clash with an antiviral.
And if you are prescribed COVID antivirals, it's recommended you ask your pharmacy to arrange home delivery for your medication, or ask someone to collect it on your behalf and drop it off.
If you don't have a GP or have trouble making a telehealth appointment, Dr Moy recommends calling the National Coronavirus Helpline.
But even before you are infected with COVID, it's worth having a chat with your GP about antivirals. Don't leave it until the day you test positive, Professor Morgan says.
"I would very much like GPs to have that discussion when patients come in for routine health checks, monitoring their long-term medical conditions, or when they come in for their influenza vaccination, to be using that opportunity to highlight if you ever get COVID, contact us straight away, because we have a treatment that might help — but only if we catch it at the beginning."
What are all the other recommendations and guidelines?
While the PBS eligibility criteria help GPs ascertain who can be prescribed subsidised COVID antivirals, a quick look online turns up other recommendations too.
These non-PBS sets of guidelines might help the Pharmaceutical Benefits Advisory Committee make its decisions, but aren't used by GPs to determine who qualifies for antivirals.
One major set of recommendations for molnupiravir and Paxlovid are from the National COVID-19 Clinical Evidence Taskforce, a federal-government-funded group comprising clinicians from major health bodies across Australia.
As its name suggests, it develops guidelines based on clinical evidence, says Professor Davis, who also co-chairs the taskforce's drug treatments panel.
Expert panels trawl the latest clinical trial results and meet every week or month, depending on need, to adjust their recommendations accordingly, which are then approved by other committees.
This evidence-based process is reflected in the taskforce's antiviral recommendations that mostly focus on unvaccinated people.
"We labour the point about vaccination because in all of the randomised trials [run by drug companies to test drug effectiveness], you had to be unvaccinated to get into them," Professor Davis says.
"As the taskforce, we don't have inside knowledge and visibility about supply and cost and government budgets. That's outside our brief.
But in the end, it's the PBS criteria that dictate if a person is prescribed COVID antivirals. And sometimes, GPs don't have up-to-date information at hand, Professor Morgan says.
"In our usual work as a GP, the most accessible information is the information that's embedded in our prescribing software … but those databases get updated periodically, rather than in real time, so there's a lag between something changing and those databases catching up.
"Normally, that lag doesn't matter much, because things don't change quickly. But COVID-19 is a situation that's changing all the time.
"I would certainly like to see some enhancements come out of the pandemic where that sort of database, including availability and cost information, is available at a GP's fingertips."
Will more people be eligible?
More people might qualify for COVID antivirals down the track.
A Department of Health spokesperson said the Pharmaceutical Benefits Advisory Committee "will continue monitoring the eligibility criteria for PBS access" to molnupiravir and Paxlovid and, "may recommend changes to the eligibility criteria as needed, considering new evidence for the effectiveness and safety of these antivirals in other patient groups. as well as the evolving epidemiology of COVID-19."
That criteria may one day include people like Christie's dad, who tested positive for COVID a couple of days after his wife.
He's also over 80, and had heart surgery in 2019, but he did not qualify for COVID antivirals under the PBS.
Luckily, Christie says, both parents have since largely recovered, although her mum still has bouts of muscle weakness during the night.
"Those sorts of nights are happening more frequently. She's struggling more than she normally does."
Being fully vaccinated is the best way to stave off severe disease, no matter your age, Professor Davis says.
For those who'll need them, there are more antivirals in development too.
In an ideal world, Dr Moy says, "we'd get an effective, safe medication with few or no interactions that won't be affected by variants, which is the main thing.
"That's the goal with medication. That would change everything."
