Some adults with mild persistent asthma may be able to adequately control their asthma by taking corticosteroids only when needed, instead of taking anti-inflammatory medication daily, according to new results from the Improving Asthma Control Trial (IMPACT). Conducted by the National Heart, Lung, and Blood Institute's (NHLBI) Asthma Clinical Research Network, the one-year, multi-center study found that participants who were treated with corticosteroids intermittently based on symptoms had about the same rate of severe exacerbations and of asthma-related lung function decline as those treated with the standard recommendation of daily long-term control medication.
Asthma is considered mild and persistent when individuals have acute symptoms such as wheezing, coughing, or chest tightness more than twice a week, but not daily, or they have night-time awakenings due to asthma more than two nights a month. The researchers caution that the new findings might not apply to people who have recently developed asthma. In addition, they do not apply to patients with more frequent symptoms or more severe asthma. The results are published in the April 14 issue of the New England Journal of Medicine.
"This study provides evidence of another possible way to treat adults with long-standing mild persistent asthma," stated Elizabeth G. Nabel, MD, director of the NHLBI, part of the National Institutes of Health. "If additional research confirms these findings, then some of these patients may be able to safely treat their asthma with intermittent medication and avoid the added expense and inconvenience of daily therapy. As for all asthma patients, however, individuals should work closely with their healthcare providers to develop and follow the treatment plan that suits them best."
More than 20 million Americans have asthma. For those with mild persistent asthma, guidelines from the National Asthma Education and Prevention Program (NAEPP) currently recommend daily long-term control medication to prevent symptoms and quick-relief medication (inhaled bronchodilator) to treat acute asthma symptoms if they occur.
The recommendation for daily long-term control medication for mild persistent asthma was based largely on clinical trials that showed that anti-inflammatory therapy improves lung function and measures of asthma control. However, participants in these earlier studies had asthma that ranged in severity from mild to moderate, according to the IMPACT authors. The IMPACT study strictly adhered to the guidelines' definition.
James Kiley, PhD, director of the NHLBI Division of Lung Diseases, commented, "By focusing exclusively on mild persistent asthma, the IMPACT study has added to our understanding of possible treatment options for different levels of asthma severity."
NAEPP is expected to release updated guidelines in 2006. An expert panel will consider the results of IMPACT and other studies to determine if changes in treatment recommendations for adults with mild persistent asthma are warranted.
IMPACT was designed to identify the best long-term treatment strategy for adults with mild persistent asthma. Researchers compared changes in lung function, frequency and severity of asthma symptoms, and quality-of-life scores in 255 adult patients. Participants were randomly selected to one of three treatment groups. Two groups were assigned to long-term control medication taken twice daily -- either an inhaled steroid (budesonide) or a leukotriene modifier (zafirlukast) taken in pill form. The third group received placebo (inactive) medication. All participants were given medications for asthma symptoms -- inhaled bronchodilator (albuterol), inhaled corticosteroid (budesonide), and oral corticosteroid (prednisone) -- with explicit instructions on when and how to use these treatments depending on the severity and duration of the individual's symptoms.
After one year, changes in lung function and the number of severe attacks did not significantly differ among the three groups. In addition, participants scored similarly on quality-of-life tests regardless of treatment group. Those in the daily inhaled steroid group, however, reported significantly more symptom-free days (equivalent to about 26 additional symptom-free days per year) than participants in the other two treatment groups.
"Although some reports of symptoms differed between those taking budesonide daily and the other participants, these differences were not reflected in the quality-of-life scores," noted Homer Boushey, M.D., Principal Investigator at the University of California San Francisco, and a lead author of the study. "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."
Other reports have noted that many asthma patients do not follow recommendations for daily controller medication. "The results of IMPACT suggest that for some adults with long- standing mild persistent asthma, choosing not to take daily medications might be okay,' added Elliot Israel, M.D., Principal Investigator at Brigham and Women's Hospital in Boston and the co-lead author. 'But this choice should be made in consultation with the patient's healthcare provider. It's critical that individuals with more severe asthma follow recommendations for daily long-term control medications and that all asthma patients -- even those with mild asthma -- be aware of signs of worsening asthma and adequately treat their symptoms."
Asthma treatment guidelines also recommend written action plans as part of an overall effort to educate patients in self-management. The plans provide guidance for patients on how to monitor and treat their asthma, including how to recognize when their condition worsens. In general, action plans are based on the patient's symptoms or on "peak flow" measurements of lung function, which can be taken by patients using a hand-held device.
"One of the most important things we did during this study was to work closely with the participants to help them effectively manage their asthma," noted Boushey. "Patients need to know how to recognize asthma symptoms, what to do when symptoms begin, and -- perhaps most essential -- they must have at hand the means to treat their symptoms quickly."
Clinical centers for the Improving Asthma Control Trial were
- Brigham and Women's Hospital and Harvard Medical School, Boston, MA
- Columbia Presbyterian Medical Center and Harlem Lung Center, New York, NY
- National Jewish Medical and Research Center, Denver, CO
- University of Wisconsin, Madison
- Thomas Jefferson Medical College, Philadelphia, PA
- University of California, San Francisco
The data coordinating center is at Penn State College of Medicine, Penn State Milton S. Hershey Medical Center, Hershey, PA.
The medications for IMPACT were donated by Astra-Zeneca Pharmaceuticals, headquartered in Wayne, Pennsylvania.
To interview an NHLBI expert, please contact the NHLBI Communications Office at (301) 496-4236. To interview Dr. Boushey, please contact Wallace Ravven, at the University of California, San Francisco Department of Public Affairs at 415-476-2557. To interview Dr. Israel, please contact Melanie Franco at the Brigham and Women's Hospital Department of Public Affairs at (617) 534-1600.
- Guidelines for the Diagnosis and Management of Asthma Update on Selected Topics 2002, http://www.nhlbi.nih.gov/health-pro/guidelines/current/asthma-guidelines
- National Asthma Education and Prevention Program, http://www.nhlbi.nih.gov/about/org/naepp