This multicentre, randomised, double-blind placebo-controlled trial was designed to address the effectiveness of the antioxidant, N-Acetylcysteine (NAC), alone and in ‘triple’ therapy (prednisolone, azathioprine and NAC) in idiopathic pulmonary fibrosis (IPF). Patients with IPF and mild to moderate lung function impairment (FVC≥50% and TLCO≥30%) were assigned to receive triple therapy, NAC alone or matched placebo …