'Roids not the rage

New research adds to the evidence that inhaled corticosteroids have unclear benefits in COPD patients

By Chris Lipowski

There's been a lot of controversy in medical circles over the therapeutic value of inhaled corticosteroids for patients with chronic obstructive pulmonary disease (COPD). Some of the fog has been cleared by a new prospective cohort study published in the December 2003 issue of the American Journal of Respiratory Critical Care Medicine, which has found that inhaled corticosteroids are of little benefit to COPD patients.

Characterized by degeneration and destruction of the lung and supporting tissue, COPD can lead to emphysema, chronic bronchitis or both. Because no curative therapy is available, management of severe exacerbations of COPD should be directed at relieving symptoms and restoring functional capacity. But compared with patients who have asthma, COPD patients have had unclear benefits from corticosteroids. Although observational studies of these drugs have reported improved mortality in COPD, randomized trials have not. According to lead author Dr Vincent S Fan, of the University of Washington, Seattle, the discrepancy stems from immortal time bias, a problem that's due to an inappropriate evaluation of exposure to inhaled corticosteroids and analysis of immortal time. The study attempted to avoid this problem by using time-dependent methods to examine whether patients using inhaled corticosteroids had reduced mortality and COPD exacerbations.

The authors did not find any reduced risk of death or prevention of COPD flare-ups after evaluating 2,686 patients who were using an inhaled steroid for at least 80% of the time over a three-month period. And these results were the same for groups on low, medium or high dosages of the drug. Although this is refreshing news, some confusion will remain until large clinical trials are done to look at mortality and flare-up in COPD patients who are randomly administered an inhaled corticosteroid or placebo. In the meantime, COPD sufferers can expect benefits from long-acting inhaled beta-2 agonists, which have been proven to control symptoms and prevent exacerbations.

(For more on corticosteroids, see Don't double the drug dosage)