More than a quarter of Australians who use inhaled corticosteroids (ICS) to control their asthma are dispensed high and potentially toxic cumulative levels of oral corticosteroids (OCS), a new study suggests.
An analysis of a 10% random sample of PBS dispensing data between 2014 and 2018 identified 124,011 people aged 12 years and above who had been dispensed at least two prescriptions of ICS or ICS/LABA and met the study definition of asthma.
The data showed 51.7% of the study group were also dispensed OCS during the five-year period and 27.9% were cumulatively dispensed a potentially toxic level of 1000 mg prednisolone-equivalent or more.
The study, published in the MJA, also found the proportions of people dispensed medications for managing diabetes or osteoporosis were significantly higher for patients cumulatively dispensed 1000 mg prednisolone-equivalent or more than for those with lower cumulative exposure.
“We estimate that almost 350 000 people with asthma were cumulatively dispensed 1000 mg oral prednisolone-equivalent or more during 2014–2018, a level associated with long term systemic toxicity,” the study authors said.
Using data from the final year of the study period, they found about half (49%) of people prescribed oral steroids at 1000 mg prednisolone-equivalent or more were infrequent users of high dose ICS/LABA.
This suggested OCS use could be reduced by improving adherence to ICS therapy.
“Overall, better approaches are needed to improve asthma outcomes whilst minimising OCS use and toxicity,” the authors said.
The major prescribers of OCS during 2018 were GPs (76%).
“Patients for whom OCS therapy is needed should undergo a comprehensive asthma review by their general practitioners, focussing on education and medication adherence,” the study authors suggested.
Lead investigator Associate Professor Mark Hew, head of allergy, asthma and clinical immunology at Alfred Hospital, told the limbic that the study was not about denigrating GPs or oral steroids per se.
“This is the first time we have actually had data on this question – quantifying the amount of steroids being used as treatment for asthma. Of note, we don’t actually know if the steroid dispensing is appropriate or not.”
He said that the data would also serve as a useful baseline from which to examine the impact of guideline changes recommending asthma patients begin on ICS-LABA as a reliever strategy.
“It will be really useful to know in a year or two whether, in that environment, the use of oral steroids is any lower.”
Associate Professor Hew said the association between a higher cumulative dose of oral steroids and increased dispensing of OCS of diabetes and osteoporosis medications, suggested OCS were being taken at a level that caused complications.
“We do not want to create steroid-phobia in the community or with patients or GPs. That’s not the point.”
However the need for prescribing oral steroids for an exacerbation of asthma should be a red flag to the treating doctor to re-evaluate the whole care of the patient and control of their asthma, he said.
He added that there was a systems problem in that clinicians currently have no way to know if the patient was taking their prescribed ICS or not.
“In some other health systems it is easier for a GP or a health practitioner to access dispensing data. In Australia, we can only do that for drugs of addiction. We’ve got fantastic ways of picking up the use of drugs of addiction – methods which we could potentially apply to other medications as well. It’s not a new idea, but one that has not gained much traction – as yet.”