More than one-in-three patients undergoing treatment for asthma have been exposed to toxic cumulative doses of oral corticosteroids, an Australian registry study has concluded.
Drawn from the Australasian Severe Asthma Registry, the data also reveal that steroid-sparing were employed only infrequently, reinforcing the need for urgent oral corticosteroid (OCS) stewardship initiatives, the investigators say.
The study included 924 patients enrolled in the registry between 2013 and 2021, 23% of whom were taking OCS at baseline, with 44% and 32% of participants having exposure to ≥500 or ≥1000 mg of OCS respectively in the prior year.
Twelve months later, an additional 10% and 9% of participants reached cumulative doses of 500 or 1000 mg, the researchers reported in IMJ (link here).
This ‘disturbingly high’ use of OCS underscored proposals for action on stewardship, as recently promulgated by TSANZ, they wrote.
Troublingly, many of those exceeding OCS thresholds also had poor asthma control, according to the team.
They noted that, at baseline, only 26% of participants were treated with asthma biological therapy, with an additional 12% participants identified as potentially benefiting from this steroid-sparing medication.
“Of these patients, only 23% commenced a biologic agent in the next 12 months,” they wrote.
And while it was arguable that the registry may reflected a biased selection of patients with severe asthma, there was compelling evidence the findings may mirror widespread OCS use in clinical practice, the researchers said.
To that end, they pointed to comparable data from registries overseas, as well as recent local research using PBS data which found that greater than 50% of participants prescribed combination ICS/LABA treatment also received OCS over a 5-year period, and about 25% received cumulative doses above 1000 mg.
“There is now persuasive evidence that cumulative doses of OCS are associated with significant long-term adverse side-effects,” they wrote.
“Patients who have received >1000 mg of lifetime OCS appear to exceed a ‘threshold’ that is associated with increasingly severe toxicity reflected by obesity, depression, osteoporosis, diabetes, cardiac disease and other morbidities.”
“In this context, the findings were concerning: approximately one-third of people had already exceeded 1000 mg of OCS on entry into the registry, and this increased approximately 40% over the next 12 months.”
Stewardship should involve patients, prescribers, pharmacists and regulators and ought to emphasis treatment adherence, correct inhaler techniques, appropriate prescription and alternative therapies to OCS, added the team.
Beyond that, the fact that eosinophil counts were significantly elevated in at least one-third of people taking regular OCS, but only about a quarter of those patients were treated with a biologic agent highlighted another potential avenue for reducing OCS use.
“There may be several reasons for this including patients not (yet) achieving funding criteria for subsidised treatment, doctors not being aware of the benefits and indications for this therapy and lack of ongoing access to specialist care,” the authors said.
“The findings reinforce the potential to reduce OCS use by leveraging treatment of this key ‘treatable trait’.”