For patients who continue to have asthma symptoms while using an inhaled steroid medication, "the addition of long-acting beta-2 agonist is superior to remaining on similar doses of inhaled steroids alone," Ni Chroinin says.
In a second review, Ilana Greenstone, M.D., of McGill University Health Center in Canada and colleagues concluded that a double dose of inhaled steroids worked just as well as combination therapy in reducing the rate of severe asthma attacks.
But the combination therapy "clearly leads to greater improvement in lung function and symptoms than a two- to two-and-a-half-fold higher dose of inhaled corticosteroids," according to Greenstone. There was a 12 percent increase in symptom-free days among patients taking LABA and steroids, compared to those taking the higher steroid dose. Patients on the combination therapy also reduced their rescue inhaler use by as much as one less "puff" per day.
There were no significant differences in side effects between the combination therapy and higher steroid doses except for a three-fold increase in the rate of tremor, or uncontrolled muscle contractions, in the patients taking LABA medications, the researchers found.
Ni Croinin and colleagues reviewed 26 studies that included 8,147 patients. Greenstone and colleagues analyzed 30 studies that included 9,509 patients. Only eight of the studies in the Ni Croinin review and three studies in the Greenstone review focused on children with asthma.
"I think the lack of data for pediatrics is certainly a problem which may limit the use of LABA in that age group. There just aren't enough studies to make evidence-based clinical decisions," Greenstone says.
The Cochrane reviewers say their work may help physicians decide when or if to prescribe LABA medications to asthma patients already taking inhaled steroids.
"My sense is that there is a tendency to initiate combination therapy wi
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Contact: Muireann N Ni Chroinin
muireann.nichroinin@nnuh.nhs.uk
Center for the Advancement of Health
18-Oct-2005