Inhaled corticosteroids and risk of pneumonia: evidence for and against the proposed association.

Inhaled corticosteroids (ICS) are commonly used in the treatment of chronic obstructive pulmonary disease. Recent large prospective trials have reported an increased incidence of pneumonia in patients treated with ICS. Despite this, the link between ICS and pneumonia remains controversial. In this review, pro and con arguments for the association between ICS and increased pneumonia risk are discussed, drawing on evidence from experimental and clinical research.