Inhaled Corticosteroids Get Mixed Reviews in Kids' Asthma Studies

WEDNESDAY, May 10, 2006 (HealthDay News) -- Two new studies report mixed results on the use of inhaled corticosteroids for the treatment or prevention of asthma in babies and young children.

One study found that inhaled corticosteroids were effective in treating asthma symptoms, but once the therapy was stopped, it had no long-lasting effects on the course of the disease.

The second study looked at the initiation of inhaled corticosteroid therapy in 1-month old infants who had one episode of wheezing, but weren't necessarily diagnosed with asthma. That study found the medications weren't particularly effective at treating either the symptoms or altering the course of the disease.

"Both studies together strengthen the evidence that treatment with inhaled corticosteroids doesn't alter the natural course of asthma," said Dr. Diane Gold, an associate professor of medicine at Harvard Medical School and Brigham and Women's Hospital, both in Boston.

"That doesn't mean that steroids shouldn't be used very selectively with young kids who are having frequent symptoms," she added. Gold is also the co-author of an accompanying editorial. Both studies and the editorial appear in the May 11 issue of the New England Journal of Medicine.

Because the airway inflammation that causes asthma symptoms has also been associated with damage to the lungs, it's been theorized that if the inflammation was controlled with the use of inhaled corticosteroids, worsening of the disease might be avoided. And, according to the Danish study, experts have suspected that for such therapy to be effective, it would need to be initiated in the first year of life when the lungs are still developing and the damage from asthma begins.

The study included 411 babies with physician-diagnosed asthma. The babies were enrolled at 1 month of age, but weren't assigned to a treatment group until they had experienced their first episode of wheezing.

Then the babies were randomly assigned to receive a two-week course of the inhaled corticosteroid budesonide or an inhaled placebo when they had wheezing episodes. Parents in both groups were also instructed to give fast-acting asthma relief medication when needed. Intermittent treatment when wheezing occurred continued for three years.

The corticosteroid group had a symptom-free day rate of 83 percent, while the placebo group had an 82 percent rate. Twenty-four percent of babies in the treatment group had persistent wheezing, compared to 21 percent in the placebo group.

"Intermittent inhaled corticosteroid therapy had no effect on the progression from episodic to persistent wheezing, and no short-term benefit during episodes of wheezing in the first three years of life," said study author Dr. Hans Bisgaard, a professor of pediatrics at Copenhagen University Hospital and head of the Danish Pediatric Asthma Centre.

Bisgaard said he was very surprised by the results and added, "The findings may serve as a warning to treatment practices extrapolated from adult studies and emphasizes the need to provide evidence on medicine in children."

But in contrast to Bisgaard's research, a second study did find a benefit to using inhaled corticosteroid therapy for symptom control, though this study also found no long-term effects from the medications on the course of children's asthma.

Two hundred eighty-five 2- and 3-year-olds at very high risk for asthma were randomized to receive continuous treatment with the inhaled corticosteroid, fluticasone propionate or an inhaled placebo. The youngsters took the medications twice daily for two years, and then the researchers followed them for another year while they were off the treatment.

During the treatment years, the proportion of episode-free days was 93 percent for the treatment group and 88 percent for the placebo group. During the observation year, the proportion of episode-free days was 87 percent for the former treatment group and 86 percent for the placebo group.

The biggest side effect from the long-term use of inhaled corticosteroids was a 1.1 centimeter difference in height in the treatment group vs. the placebo group. During the observation year, that difference began to even out and was 0.7 cm at the end of the study.

"In this high-risk group, they did respond nicely to inhaled steroids while they were on them. But starting them early didn't prevent anything," said study author Dr. Theresa Guilbert, an assistant professor of pediatrics at the Arizona Respiratory Center at the University of Arizona.

In her editorial, Gold points out that one possible reason the Guilbert study found symptom relief while the Bisgaard study didn't is the difference in the study populations. The Bisgaard study included a much more diverse group of children, including youngsters who may not go on to have asthma. Also, asthma is notoriously hard to diagnose in children under 2, and wheezing can be a sign of some viral infections that typically don't respond to inhaled corticosteroids. Additionally, the editorial noted that many children in the Bisgaard study were exposed to maternal smoke or environmental smoke in the home, which could adversely affect any treatment plan.

Both Gold and Guilbert emphasized that clinicians should follow the U.S. National Asthma Education and Prevention Program Guidelines, and use their clinical judgment about the need for inhaled corticosteroids. Guilbert added that she would encourage physicians to step down the dose once asthma control has been achieved.

More information

To learn more about asthma and ways to prevent flare-ups, visit the National Heart, Lung, and Blood Institute.