By William J. Cromie

Gazette Staff

Asthma is on the attack. It sends 1.6 million people to the emergency room each year, and is the leading cause of hospitalization among children.

That toll could be significantly reduced by the use of inhaled steroids, according to a study by researchers at the Medical School and Brigham and Women's Hospital. These steroids treat inflammation of air passages from the windpipe to the lungs.

"Anti-inflammatory [drugs], particularly inhaled steroids, appear to confer significant protection against acute exacerbations of asthma leading to hospitalization," says Jim Donahue, instructor in medicine at Channing Laboratory. "This effect was most pronounced when there was moderate or greater use of beta-agonists," which open up airways in the lungs.

Inhaled steroids were associated with a 50 percent decrease in the risk of hospitalization relative to people who took no inhaled steroids. The greatest reduction in risk came to those who had filled more than eight prescriptions a year for beta-agonists. This group enjoyed a 70 percent reduced risk of hospitalization.

Relief from mild asthma attacks often can be obtained with beta-agonists alone, taken on an as-needed basis. But as asthma progresses, requiring more and more medication, the risk of severe attacks that send a person to the hospital increases.

Those not using inhaled steroids and receiving more than eight beta-agonist prescriptions a year "were at least four times more likely to be hospitalized than those not receiving beta-agonists," the researchers reported in yesterday's Journal of the American Medical Association. Their study supports use of inhaled steroids by those who suffer from moderate to severe asthma.

Three-Year Study

Donahue and his colleagues tracked drug use and hospitalization among 16,941 asthmatics for three years, between October 1991 and September 1994. During that time, 1,610 of them made 2,245 visits to emergency rooms. Another 742 were hospitalized because of their condition. All those in the study were members of Harvard Pilgrim Health Care, a large health maintenance organization (HMO).

Eighty-eight percent, or 14,941 patients, took prescriptions for medications that included inhaled beta-agonists such as albuterol, inhaled steroids, inhaled cromolyn (an anti-inflammatory), and an oral bronchodilator. Beta-agonists were the most frequently dispensed drug, and inhaled steroids were second.

Cromolyn was used mainly by children. "It is only clearly protective for those under 18 years old," Donahue notes.

The study was done before the Food and Drug Administration approved a new type of asthma medication late last year. Called anti-leukotrienes, these drugs (Accolate and Zyflo) block powerful leukotrienes which cause the inflammation that contributes to blocking of airways. Thus, they treat the cause rather than the symptoms of asthma.

Patients can ask their doctors about these new drugs. Accolate, developed by Harvard researchers, is designed to be taken twice a day by asthmatics 12 years old and older. K. Frank Austen, Bayles Professor of Medicine, thinks it could help 70 to 80 percent of the 14.6 million people in this country who have the disease.

Anti-leukotrienes might avoid a possible problem with prolonged use of inhaled steroids. A study of 50,000 elderly people in Canada found that use of high doses of these steroids over many years increases a person's risk of glaucoma, the leading cause of blindness.

"We didn't look into glaucoma," Donahue says. "But it's certainly something to take into consideration."

Samy Suissa of McGill University in Montreal, who did the glaucoma study, cautions against abandoning inhaled steroids because they remain the best way to prevent asthma attacks that can be fatal. Deaths from the disease have more than doubled in the U.S. since 1979. He advises older adults who have used high-dose inhaled steroids for many years to consult with their doctors and have their eyes checked regularly.