Clinical outcomes of dose modification during pirfenidone treatment for IPF: A nationwide post-marketing surveillance study

Pirfenidone, an antifibrotic medication approved for the treatment of idiopathic pulmonary fibrosis (IPF), often requires dose reduction owing to adverse events. In this study, we evaluated if pirfenidone's reduced dose has any impact on clinical outcomes in patients with IPF. We used the data of a prospective post-marketing study of pirfenidone conducted at 10 hospitals in South Korea from 2014 to 2017. Dose reduction was defined when the pirfenidone dose was temporarily or permanently reduced to manage adverse events or when the treatment dose failed to reach the standard dose. Study patients were classified based on the most frequently administered dose during 48-week follow-up-1800 mg, 1,200 mg, and