Evaluating the Effectiveness of Prednisone, Azathioprine, and N-acetylcysteine in Patients With IPF

IPF is a disease with widespread and permanent scarring of lung tissue which eventually results in death. Individuals with IPF may experience breathing difficulties, cough, chest pain, and a decreased exercise capacity. Although the cause of IPF is unknown, it may be a result of an inflammatory response to an unknown substance. NAC, an antioxidant that is effective at loosening up mucus that forms in the lungs, may improve lung function. The purpose of this study is to evaluate the effectiveness of NAC at preventing the loss of lung function in people with IPF. In the initial double-blind, placebo-controlled trial, subjects who have idiopathic pulmonary fibrosis with mild-to-moderate impairment in pulmonary function are randomly assigned to receive a three-drug regimen of prednisone, azathioprine, and acetylcysteine; acetylcysteine alone; or placebo. After safety concerns were identified by the data and safety monitoring board, the three-drug regimen was stopped by the National Heart, Lung, and Blood Institute (NHLBI) on October 14, 2011, and a clinical alert was issued. After a brief period of interruption for modification of the protocol and approval by the institutional review boards, patients continued to be recruited for the acetylcysteine group and the placebo group and were followed for the pre-specified duration of 60 weeks. Study visits will occur at baseline and Weeks 4, 15, 30, 45, and 60. At all study visits, a physical exam and blood collection will occur. At selected visits, the following study procedures will occur: lung function testing; urine collection; a 6-minute walk test, and questionnaires to assess health status, breathing, and quality of life. Participants will record medication usage and symptoms in a daily diary.