Big fluctuations in PBS antiviral use by state

Significant differences have been revealed across Australian jurisdictions in the prescribing patterns of COVID-19 oral antiviral pills.  
 
In some states, such as Victoria, prescribers including GPs have been getting treatments to almost two in every 100 of the official cases registered since the beginning of March, when the oral antivirals first came onto the Pharmaceutical Benefit Scheme (PBS). 
 
Elsewhere, such as Queensland, the rate has been much lower. When compared to overall case numbers, prescribers there have issued prescriptions at less than half the rate of the nationwide average. 
 
Molnupiravir (sold as Lagevrio) was the first of the new oral treatments to come onto the PBS on in March, while nirmatrelvir and ritonavir (known as Paxlovid) was added at the beginning of May.
 
The figures emerge at a time when there is a significant push to increase prescriptions of the antivirals, including from the Federal Minister for Health and Aged Care Mark Butler.  
 
The Department of Health (DoH) supplied newsGP with prescription figures for each state and territory from the time oral antivirals first became available on 1 March until 26 June this year.  
 
To compare the prescription rates, newsGP extracted the case numbers for each jurisdiction in the same timeframe using covid19data.com.au, then calculated the number of treatments issued via the PBS as a percentage of those cases.  
 
Of all the jurisdictions, the Northern Territory had the lowest prescription rate at just 0.41% – in other words, oral antivirals were prescribed on the PBS for fewer than one in every 200 officially recorded cases.  
The highest rate in the meantime was in the Australian Capital Territory, where the prescription tally reached 2.33% of the total number of cases.  
 
Among the states, the PBS prescription rate in Queensland was significantly lower than any other at 0.57% of the 890,626 cases recorded. That is less than a third of the rate of the highest, Victoria, where there was a total of 18,571 prescriptions for the 1,029,855 cases recorded from March 1 to June 26 – which equates to around 1.8%. Nationally, the average was 1.23%.
 
While the figures are an imperfect measure as they cannot take into account the different ways jurisdictions register COVID-19 cases, nor the varying age and clinical profiles, they are the clearest indication yet of the significant variations across different states. 
 
Last week, RACGP Vice President and Queensland Faculty Chair Dr Bruce Willett said earlier variations in the Health Direct pathways could have played a part in the different prescribing rates. 
 
Previously, GPs in the state were reportedly told that prescriptions needed to go through hospital health services. 
 
This week, Minister Butler told reporters he had put a ‘strong case’ to the Pharmaceutical Benefits Advisory Committee requesting an expansion in access to the treatments, which he said could ‘dramatically reduce the risk of severe disease, particularly for older Australians’. 
 
Prominent health professionals have also called for more flexibility, including Professor Mark Morgan, Chair of RACGP Expert Committee – Quality Care. 
 
‘If a patient has a particularly severe co-morbidity there should be an opportunity to prescribe antiviral treatments,’ he said last week.
 
Currently those aged over 65 need two risk factors to be prescribed the treatments under the PBS, while those over 75 require one.   
 
Similarly, this week the Pharmaceutical Society of Australia (PSA) National President Dr Fei Sim called on state and federal governments to improve access to antiviral medicines. 
 
The treatments’ cost – quoted at $1200 – has been cited as a barrier by some pharmacists to keeping them in stock, particularly in more remote communities. The DoH confirmed to newsGP that it acts as ‘the responsible person’ for nirmatrelvir and ritonavir and that by supporting wholesalers through the Community Service Obligation (CSO) Funding Pool, it aims to ensure access regardless of location ‘usually within 24 hours’. 
 
The treatments issued via PBS prescriptions also form a minority of those used since they became available, with the DoH stating that most so far have been dispensed using the National Medical Stockpile (NMS). It reports 125,378 packets of molnupirivir and 150,812 packets of nirmatrelvir and ritonavir have been deployed up until 6 July.  
 
The number used in different jurisdictions via the NMS was not supplied, and only the Western Australia Department of Health gave a specific answer (2168) to newsGP inquiries to state authorities about the amount they had used via that route. 
 
The push to expand access to oral antivirals via the PBS has gained momentum since 26 June, the latest date for the figures supplied by the DoH.  
 
In the COVID-19 response update for primary care webinar this week, the Deputy Chief Medical Officer Professor Michael Kidd said more than half of the treatments have been prescribed for people aged 75 years and older. He also reported a recent rise in the number of antivirals supplied via the PBS, saying the number of prescriptions has doubled in the past two weeks.  
 
The DoH figures broke down the specific number of prescriptions dispensed for each oral antiviral, showing more than six times more molnupirivir prescriptions. Nirmatrelvir and ritonavir has been on the PBS a shorter time, and the treatment comes with a much longer list of contraindications – although early efficacy studies suggest it may have more success in preventing vulnerable patients from progressing to serious illness or death.
 
This week, a statement from the Australian Technical Advisory Group on Immunisation (ATAGI) suggested that the oral antivirals are likely to make more of a difference than the recently expanded winter COVID-19 vaccine dose program.  
 
It also hinted at the likelihood of expanding access to a broader age group.  
 
While ATAGI said that greater coverage of winter booster doses is likely to reduce hospitalisations in the coming months, it expects the effect of that recommendation on its own to be ‘limited’.  
 
‘ATAGI advises that other public health and social measures, in addition to vaccination, will have the greatest impact against the Omicron BA.4 and BA.5 surge in infections,’ the recent statement reads.   
 
‘This includes increased use of masks and increasing the use of antiviral treatment in people diagnosed with COVID-19, including in people aged 50 years and above.’ 
 
In the meantime, evidence for the oral antivirals suggests their impact may be limited among younger, healthier people.  
 
Another pre-print study released this week indicates there may be some over-subscribing risks too, with authors suggesting that mutations of the main protease of SARS-CoV-2 could result in resistance to nirmatrelvir and ritonavir treatments.
 
The RACGP’s COVID-19 resources includes information relevant for every state and territory.
 
A guide with details relevant to general practice about the COVID-19 oral antivirals has also been published by newsGP.
 
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