Inhaled Corticosteroids in Chronic Obstructive Pulmonary Disease: New Trials and Old Practices

Abstract

The practice of using inhaled steroids (ICS) in chronic obstructive pulmonary disease (COPD) is common but controversial. Four large randomized controlled trials provide an objective assessment of this practice. An examination of the design of these studies is useful to explaining some of the differences between their results but may also help to appropriately integrate the findings of these studies into clinical practice. All studies agree that the early introduction of the inhaled corticosteroids (ICS) does not appear to affect the rate of decline in FEV1. Thus, the routine prescription of these agents to asymptomatic patients with well-preserved lung function is not indicated. However, more selective use of ICS in patients with moderately severe disease (FEV1 < 50% predicted) may produce clinical benefit as measured by an increase in FEV1, reduced symptoms and fewer exacerbations. The effectiveness of ICS in patients with severe disease (FEV < 800 mL, or chronic respiratory failure) has not been studied due to practical difficulties of enrolling and maintaining such patients in clinical trials. Similarly patients with evidence of chronic bronchitis and emphysema who demonstrate high degrees of reversibility (>10% predicted FEV1) are usually excluded from both COPD and asthma trials, and the effectiveness of ICS in this population is also not known. Neither responsiveness to a single dose of beta₂-agonist nor to a 14-day trial of systemic steroids has been shown to be a reliable predictor of response to ICS. For individual patients with moderate or severe symptomatic COPD, an 8-week therapeutic trial with ICS may be needed to assess clinical benefit.