Combination therapy for asthma is “overkill”

TWO leading paediatric respiratory physicians have urged medical practitioners to use greater caution when prescribing inhaled corticosteroid (ICS) and long-acting beta-agonist (LABA) combination therapy for children, reminding doctors that such therapy is costly and rarely appropriate.

The call comes in the wake of Australian findings, reported in Pediatric Drugs, that many children appeared to have been prescribed high-dose ICS and expensive ICS/LABA combination inhalers inappropriately. (1)

Professor Craig Mellis, professor of medicine at the University of Sydney, said prescribing ICS/LABA combination inhalers for children was overkill.

In most cases, children recovered quickly from asthma, he said, and the combination therapy was just an expensive way to give salbutamol, which was all they required.

“Combined aerosols shouldn’t be used as first-line treatment”, Professor Mellis said. “Most children don’t need preventers full stop, and if they need a bronchodilator, why not use the ones that we know about and that we’ve been using for 50 years — salbutamol or terbutaline?”

Professor Peter Van Asperen, head of the department of respiratory medicine at The Children’s Hospital at Westmead and Macintosh professor of paediatric respiratory medicine at the University of Sydney, said education had helped to curb the use of high-dose ICS. “The high-dose ICS prescribing in children has improved and I think that relates to education.”

He said the real concern was the over-prescription of combination therapy, which is now the number one prescribed preventer in children.

“It should be the lowest prescribed preventer therapy and is not currently recommended for children 5 years or younger because no clinical trial data is available in this age group”, he said.

“The vast majority of children (75%) require only a short-acting beta-agonist for their intermittent asthma. Of the other 25%, most can be well controlled on a non-steroidal preventer, such as montelukast, or low-dose inhaled corticosteroids, so only a very small number might require a combined ICS/LABA.”

Professor Van Asperen said education was important in highlighting the indications for ICS/LABA combination therapy.

Given the higher cost of this therapy to government, if education did not lead to more appropriate prescribing, there could be an argument that ICS/LABA therapy for children under 12 should only be available on authority prescription.

“Authority prescribing is a way to re-educate and remind medical practitioners of the indications for the use of combination therapy”, Professor Van Asperen said.

However, he said it was not a fail-safe way of improving prescribing habits. “Sometimes people still prescribe on authority without meeting the guidelines.”

Using unpublished Medicare Australia data, the study found that more than half of the children prescribed either an inhaled corticosteroid or a combined ICS/LABA were dispensed only one prescription a year, falling far short of the 6-weekly prescriptions required for regular preventer use.

Professor Mellis said this was one area in which parental non-adherence was a “huge advantage”, helping to ameliorate inappropriate prescribing.

While the researchers attributed non-compliance to cost barriers to patients, Professor Mellis said parents also tended to stop using medications once their children were well.

Professor Van Asperen said medical practitioners sometimes advised patients to use ICS/LABA therapy on an as-needed basis.

“Some patients are being told only to use the ICS/LABA during an acute episode, but LABAs, particularly salmeterol, have a delayed onset of action and there is no evidence for their use intermittently at the time of acute symptoms”, he said.

“While formoterol does have an onset of action similar to short-acting beta-agonists, it is not approved for use in children under 12 years.”

- Nicole Mackee

1. Pediatric Drugs 2012; 14: 211-220

Posted 30 July 2012

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