Escalating the dose of inhaled steroids for exacerbations could stunt growth
Increasing the dosage of inhaled steroids at the first sign of an asthma flare-up in children doesn’t change the outcome, and should not be recommended on paediatric asthma plans, Australian experts say.
Emeritus Professor Craig Mellis, a paediatrician and respiratory physician, said that there were likely many in the community who were still following outdated guidelines that had recommended escalating the dose of inhaled steroids at the early signs of an asthma flare-up.
However, new US research showing that temporarily increasing the dose even fivefold had no benefit, and might stunt growth, would likely be the “nail in the coffin” for the practice, he said.
Researchers tracked 254 children aged 5 to 11 with mild-to-moderate asthma and a daily regimen of low-dose inhaled corticosteroids for a year, randomly allocating participants into either a group that maintained their same dosage or increased it to a high-dose at the earliest signs of a flare-up.
Quintupling the dose, from two inhalations twice daily of 44 µg per inhalation to 220 µg, had no significant bearing on asthma symptoms, time to first exacerbation, the need for systemic steroids, or use of the rescue medication albuterol, they found.
Total glucocorticoid exposure was 16% higher on average over the year however, and this was tied to a height gap of 0.23cm per year between the high and low-dose groups.
“These findings suggest that a short-term increase to high-dose inhaled steroids should not be routinely included in asthma treatment plans for children with mild-moderate asthma who are regularly using low-dose inhaled corticosteroids,” said lead author and paediatrician Associate Professor Daniel Jackson, from the University of Wisconsin School of Medicine and Public Health.
“Low-dose inhaled steroids remain the cornerstone of daily treatment in affected children.”
Parents of children diagnosed with asthma a decade or more ago may have been advised to increase or double the dose of their inhaled steroids at early signs of an exacerbation. But in the years since, doubt has been cast on that advice, culminating in a recent Cochrane review which concluded there was no evidence to support the practice.
Professor Mellis said the findings of this new study would be uncontroversial to Australian specialists, as guidelines do not currently recommend it here either.
Nevertheless, recent research into higher doses and their possible effectiveness in adults prompted the authors of this new study to examine the question of higher doses in children.
In an accompanying article, Australian asthma expert Professor Philip Bardin said the findings were “compelling” and indicated that “escalating the dose of inhaled glucorticoids is a failed strategy to prevent exacerbations in children with early symptoms of asthma instability”.
The study was published alongside another trial into escalating medication dosages in adult patients, which found a modest, but not substantial improvement in exacerbations.
Taken together, the trials indicate exacerbations are “highly heterogenous, and interactions between the underlying asthma phenotype and provoking factors are not understood”.
“Evidence indicates that substantial escalation of regularly used inhaled glucorticoids, even by a factor of 4 or 5, fails to prevent most asthma exacerbations,” Professor Bardin said.
Associate Professor Paul Robinson, respiratory paediatrician at the Children’s Hospital at Westmead, agreed that a blanket approach to exacerbations had not been effective. “We need to better understand exacerbations, what drives them and how they develop, to better target therapy.”
In children, the nature of the exacerbation was different, with viral causes much more common than in adults, he explained.
For this reason, the study was useful in showing that an adult-style approach did not help children and could expose them to harm, Professor Robinson said.
The study found that children’s growth was affected even with the relatively small number of exacerbations over the study period, and the impact was dose-dependent in children under age eight years.
Australian guidelines recommend children with asthma adhere to their preventer dose, and in the case of exacerbations, use a rapid-acting reliever as directed by their asthma action plan.
NEJM 2018; online 3 March
