Rationale: Idiopathic Pulmonary Fibrosis (IPF) is a progressive fibrotic lung disease of unknown cause with a median survival of 3-5 years. No curative treatment exists, though in 2011 Pirfenidone was approved for the treatment of IPF as it appeared to slow down the decline in lung function. In patients with IPF, the most common symptoms are cough and breathlessness. Cough is not only a major distressing and disabling symptom but also an independent predictor of disease progression and death in IPF. Recent preliminary data suggest a possible effect of Pirfenidone on cough.