For Australians at high risk of developing severe COVID-19, getting access to potentially lifesaving treatment recently became easier — but experts say some are still missing out.
On May 1, COVID-19 antiviral drug Paxlovid — the most effective oral treatment to date — was listed on the Pharmaceutical Benefits Scheme (PBS), which means it can now be prescribed by a GP or nurse and dispensed at a community pharmacy.
It's the second antiviral drug to be listed on the PBS for people at high risk of severe COVID-19, following the addition of molnupiravir (also known as "Lagevrio") back in March.
Both drugs, while no substitute for vaccination, help head off the worst effects of the virus and reduce the risk of hospitalisation, said Royal Australian College of General Practitioners vice-president Bruce Willett.
"They don't cure COVID-19 completely, but they do decrease the severity of it, so they have a really important role to play in keeping people safe," he said.
The addition of oral antiviral treatments to the PBS means that many high-risk Australians are now able to receive COVID-19 treatment at home, instead of in hospital.
"Before, we were sending our patients with a significant risk of developing severe disease into emergency departments to have intravenous medications," Dr Willett said.
"So this is really helping to get these medications to people, and to get them to people quickly."
Despite increased availability, Dr Willett said many high-risk Australians were unaware they could potentially access COVID-19 antivirals through their GP.
"So increasing awareness and increasing our ability to get these medications to people when they need them is going to really save lives."
Who is eligible for prescription antivirals?
Adults who have mild to moderate COVID-19 — which is confirmed by a PCR or a rapid antigen test — can be considered for an oral antiviral treatment if they are:
- aged 65 or older, with two other risk factors for severe disease
- aged 75 or older, with one other risk factor
- aged 50 or older and identify as Aboriginal or Torres Strait Islander, with two other risk factors
- aged 18 or older and moderately to severely immunocompromised
To be considered for treatment, patients must have at least one sign or symptom of COVID-19 (eg. fever, cough, or headache) and be able to start treatment within five days of the onset of symptoms.
"These [medications] are aimed at people who are at risk of getting severe symptoms and who are unwell, but who do not require hospitalisation or supplemental oxygen," Dr Willett said.
Risk factors for severe disease — which are listed here — include being unvaccinated, living in residential care, having respiratory problems, heart failure, obesity, diabetes, and neurological conditions such as stroke and dementia.
The list of immunocompromising conditions has been expanded to include conditions such as Down syndrome and cerebral palsy, as well as severe intellectual and physical disabilities.
While not everyone will qualify for antiviral treatment, Dr Willett says it is "certainly worth asking the question" of your GP if you believe you're at increased risk.
They will look at your individual circumstances, medical history, age, and vaccination status (including time since vaccination).
You can also use the government's COVID-19 Symptom Checker or call the National Coronavirus Helpline, both of which will advise you of your eligibility, Australian Medical Association vice-president Chris Moy said.
"They will take you through the algorithm to work out not only if you should go to hospital or not, but also whether you're at risk [and therefore eligible for antivirals]," Dr Moy said.
How do I access antiviral medicines?
Like all antivirals, Paxlovid and molnupiravir work best early in the course of an infection, which is why they must be taken within five days of symptoms appearing.
Because of the short time frame, it's important to get tested for COVID-19 as early as possible, and if you return a positive result, to get in touch with your GP.
"In the past, there have been issues because people aren't aware of the medications, or if they are, they don't go through the process of getting a test and following through with a doctor in those five days," Dr Moy said.
"The hit rate has been quite low, although it's been improving, and hopefully will improve more."
GP practices are often busy or booked out, so make sure you let them know you are seeking COVID-19 antiviral treatment and that it's time sensitive.
If you don't have a regular GP or are unable to make a telehealth appointment, Dr Moy recommends calling the National Coronavirus Helpline.
"They will give you some other options," he said.
If you qualify for treatment, it's recommended that you ask your pharmacy to arrange for the medication to be delivered to your home, or get someone to collect it on your behalf.
"There are still some issues around the country with availability in pharmacies," Dr Willett said.
"But as more people become aware … we're seeing pharmacies really ramping up their supply."
What if I'm not technically eligible?
GPs are being discouraged from prescribing COVID-19 antivirals to people who are not eligible on the PBS, due to limited supply.
"We are being requested to restrict these medications for people who qualify to make sure those people who are at risk of developing severe disease are able to get them," Dr Willett.
"It's very difficult for GPs to bend the rules on this because of the short supply."
How effective are antiviral treatments?
Clinical trials have found both oral treatments reduce the risk of hospitalisation and death. However, Paxlovid appears to be more effective — but is not always suitable to prescribe (more on that below).
The drug, developed by Pfizer, is made of two different antiviral medicines: nirmatrelvir and ritonavir.
Nirmatrelvir is a COVID-19-specific-drug designed to interfere with the virus's ability to multiply. Ritonavir — once used as a HIV/AIDS treatment — slows the body's metabolism so the medication remains active in the body for longer and at higher concentrations.
A phase-three clinical trial of Paxlovid found it reduced the risk of hospitalisation and death by 89 per cent when unvaccinated COVID-19 patients were treated within five days of symptom onset.
"The problem is that you can't have Paxlovid if you have significant liver impairment or renal disease, so it really rules out a lot of elderly patients," Dr Moy said.
"It also has major interactions with commonly used medications like cholesterol tablets, so certain people just can't take it."
When Paxlovid isn't suitable, patients may be prescribed molnupiravir or sotrovimab (sold as "Xevudy") — a monoclonal antibody treatment given via intravenous drip.
"When molnupiravir first came along, initial effectiveness was 50 per cent, but then it dropped down to about 30-35 per cent effective," Dr Moy said.
"There is some new data coming out that may change that — some emerging evidence that it may be more effective than those initial numbers."
Sotrovimab was initially found to cut the risk of hospitalisation and death by 79 per cent, but emerging preliminary data suggests the drug may be less effective against the Omicron BA.2 variant.
Who are antiviral treatments not recommended for?
As noted by Dr Moy, Paxlovid is not recommended for people with severe liver or kidney impairment.
It also has a long list of medications that it can't be taken with, including some common drugs used to treat hypertension, heart arrhythmias, arthritis, psychosis, and cancer, among other things.
Both Paxlovid and molnupiravir are not recommended during pregnancy or breastfeeding, and it's advised that people of "childbearing potential" use contraception during the course of treatment (and for several days afterwards).
Identifying vulnerable people ahead of time
While high vaccination rates mean the majority of Australians are well protected against severe COVID-19, Dr Moy said there were still many people who remained at risk, including significantly immunocompromised and undervaccinated people.
"COVID-19 is not a cold. It's a serious multi-system disorder which can, particularly in high-risk people, still cause them to end up in hospital and die," he said.
"With antivirals, we're trying to stop people dying, but also stop people getting sick enough to end up in hospital, and potentially end up with major long COVID as well."
Ideally, Dr Moy says, health authorities will soon be able to identify all high-risk individuals so they can be notified ahead of time.
"Then we can tell them they will need to get treatment if they get COVID-19, and expedite testing and so on."
He stressed that vaccination continued to "beat antivirals any day", but that drug treatments were a key part of Australia's COVID-19 armoury.
"The main emphasis should quite rightly be vaccination, because prevention is better than cure," he said, noting Australia's lagging booster rollout.
"But this is a great second stop."
