Effect of pirfenidone on cough in patients with idiopathic pulmonary fibrosis

To the Editor:
Idiopathic pulmonary fibrosis (IPF) is a progressive, fatal lung disease. In patients with IPF, cough is one of the most disabling symptoms and is an independent predictor of disease progression. Cough in IPF is often non-responsive to antitussive therapy, and studies on cough are scarce and have unfortunately not yet resulted in effective treatments. Several observations suggest that pirfenidone, an anti-fibrotic drug, might decrease cough. We aimed to measure objectively the effect of pirfenidone on cough in patients with IPF and substantial cough. In addition, we assessed the effect of pirfenidone on subjective cough and quality of life (QoL) measures. [...]