The National Asthma Education and Prevention Program advises people who I have mild persistent asthma to use inhaled corticosteroids daily. This advice relies on previous studies that suggested daily use could reduce symptoms, improve quality of life and perhaps prevent a decline in lung function. But a new study questions this long-held belief.
The Study
Researchers from across the United States recruited 225 adults who had mild persistent asthma to participate in a randomized, double blind, placebo-controlled study-The Improving Asthma Control Trial (IMPACT). Mild persistent asthma is defined as asthma that causes symptoms more than twice a week but less frequently than daily, nighttime symptoms more than twice a month and sometimes severe episodes that limit activity, according to the American College of Allergy, Asthma & Immunology (ACAAI).
For one year, one-third of the volunteers were given inhaled corticosteroids; one-third were given a placebo; and one-third were instructed to take oral, zafirlukast twice daily.
Zafirlukast, sold under the brand name Accolate, is one of a new class of nonsteroidal medications that are known as leukotriene receptor antagonists. Like corticosteroids, leukotriene receptor antagonists are long-term controller medications and should not be used to treat an asthma attack.
Study volunteers were given a 1O-minute education session, instructed to use a rescue medication (albuterol) if their symptoms worsened, and were told to use either an inhaled corticosteroid for 10 days or an oral steroid for five days after an asthma exacerbation.
The researchers evaluated the lung health of the study participants using common asthma assessment tools, including the number of asthma flare-ups, the number of symptom-free days and reports of quality of life.
The researchers found little difference in lung function and quality-of-life scores between the three groups. Although the people taking daily inhaled corticosteroids reported approximately 26 more symptom-free days than the placebo or zafirlukast groups, that difference did not translate into a difference in quality of life between the groups.
Implications
Despite recommendations, physicians find that many people who have mild asthma do not refill their prescriptions for long-term controller medications, such as corticosteroid inhalers, because their symptoms are mild and they don't want to take a daily medication.
"The results of IMPACT suggest that for some adults with long-standing mild persistent asthma, choosing not to take daily medications might be OK," says study author Dr. Elliot Israel of Brigham and Women's Hospital in Boston.
"It may be possible to treat mild persistent asthma with short, intermittent courses of inhaled or oral corticosteroids taken when symptoms worsen," the study authors conclude.
This study "provides an interesting therapeutic option-prompt treatment of mild exacerbations with inhaled steroids-that is likely to provide benefits with low risk," says Dr. Leonardo Fabbri, a professor of respiratory medicine at the Universita degli Studi di Modena e Reggio Emilia-Policlinico di Modena in Modena, Italy.
The most important thing, says Fabbri, is for patients "to learn to recognize exacerbations of symptoms and then to treat them promptly with a short course of inhaled steroids."
