Inhaled Corticosteroids in Chronic Obstructive Pulmonary Disease: How Significant is the Risk of Pneumonia and Should It Impact Use of Inhaled Corticosteroids?

Patients with chronic obstructive pulmonary disease (COPD) are at an increased risk of infections such as pneumonia. Pneumonia among patients with COPD carries a higher risk of mortality. Inhaled corticosteroids are among the most widely used agents in patients with COPD. They are usually indicated in patients with severe COPD in combination with a long-acting β-agonist to reduce the frequency of exacerbations. Apart from their local effects in the lungs, inhaled corticosteroids may be systemically absorbed and have immunosuppressive effects. Although, the strength of the association between inhaled corticosteroids and pneumonia is modest (≈ 60% increased relative risk), this effect is consistent across clinical trials, meta-analyses of clinical trials, and observational studies. Observational studies also confirm a dose-response effect. Whether this increased risk of pneumonia translates into an increased risk of mortality is unknown. Although all the links in the causal chain have yet to be elucidated, converging lines of evidence suggest that clinicians should carefully balance the risk of pneumonia associated with inhaled corticosteroids, along with their benefits on exacerbations, in determining the optimal choice of therapy for patients with COPD.