Many adults with mild persistent asthma may not need daily inhaled steroid treatments to adequately control the condition, according to findings from a new government study.

The surprising results could lead to a change in treatment guidelines for asthma, which currently call for daily therapy with inhaled steroids even in those that do not have daily symptoms.

Studies have supported the current guidelines. Researchers have shown that daily treatment with inhaled steroids leads to the control of asthma and may stabilize the disease and prevent its progression. But the newly reported Improving Asthma Control Trial (IMPACT) found that this daily treatment approach was no better than treating only when asthma symptoms occur in adults with mild persistent asthma.

The findings are published in the April 14 issue of The New England Journal of Medicine.

"Using these drugs in an intermittent fashion [to control symptoms] rather than on a regular basis does seem to be an appropriate option for many asthma patients," James Kiley, PhD, tells WebMD. Kiley is director of the National Heart, Lung, and Blood Institute's division of lung diseases, which oversaw the study.

But Kiley also offered several large caveats to the findings. Most study participants had asthma for a long time. It's not clear that, if there is a treatment advantage to daily inhaled steroids, whether this translates to treatment for newly diagnosed patients with mild, but chronic, asthma.

And it is also not clear if children with mild asthma benefit from daily treatment. Similar studies are now under way in children to address this question.

Patients Aren't Following Asthma Guidelines

Persistent asthma is generally considered mild when symptoms such as wheezing, coughing, or chest tightness occur more than twice a week, but not daily, or when patients awaken during the night due to symptoms more than two nights a month.

While daily inhaled steroids have been recommended for mild asthma for more than a decade, there is a good deal of evidence that patients aren't following this advice.

Kiley says prescription reviews and patient surveys indicate that people with mild asthma often use inhaled steroids only when bothered by symptoms. The newly published study was designed to determine whether this approach resulted in poorer asthma control.

Researchers compared changes in tests of lung function, frequency and severity of asthma symptoms, and quality-of-life variables in 255 adult patients with mild symptoms assigned to one of two daily treatment regimens or to treatment only when symptoms occur.

Participants received one of the following treatments: Oral asthma medication and an inhaled placebo; inhaled asthma medication and an oral placebo; or both oral and inhaled placebos.

After a year on the respective treatments, no differences lung function and frequency of severe attacks were seen among any of the three treatment groups. Quality of life was also similar.

The patients taking daily inhaled steroids did report more symptom-free days than those who took the oral, nonsteroid asthma drug every day and those who treated only their asthma symptoms. But this did not translate into an overall difference in perceived quality of life.

"Combined with the fact that there were no significant differences in lung function changes or in the frequency of severe attacks among the treatment groups after a year of treatment, we conclude that, overall, the three treatments had similar clinical effects in this study of mild asthma," says study researcher Homer A. Boushey, MD.

Long-Term Impact Not Known

In an editorial accompanying the study, asthma specialist Leonardo M. Fabbri, MD, acknowledged that intermittent treatment is a more appealing approach to controlling mild persistent asthma than daily treatment.

But he adds that the yearlong study by Boushey and colleagues was not long enough to determine if daily treatment to suppress airway inflammation is associated with better long-term lung function.

Kiley says all of the evidence on the treatment of mild persistent asthma is being reviewed by the NHLBI's National Asthma Education Program, and updated guidelines should be released sometime next year.

But even if the guidelines are changed, Kiley says no single approach to asthma treatment will be right for all patients.

"Patients really do need to work with their physician to make sure they are getting the therapy they need to maintain good asthma control," he says.

Salynn Boyles, reviewed by Brunilda Nazario, MD

SOURCES: Boushey, H. The New England Journal of Medicine, April 14, 2005; vol 352: pp 1519-1528. Homer A. Boushey, MD, University of California at San Francisco. Leonardo M. Fabbri, MD, professor, respiratory medicine, department of respiratory diseases, University of Modena & Reggio Emilia, Modena, Italy. James Kiley, PhD, director, division of lung diseases, National Heart Lung and Blood Institute, National Institutes of Health, Bethesda, Md.