The independent IPFnet protocol review committee, the IPFnet data and basic safety monitoring board, and local institutional review boards accepted the protocol. All individuals provided written informed consent. Study Patients Eligibility requirements included a diagnosis of idiopathic pulmonary fibrosis, while defined by consensus requirements , in an advanced stage, that was defined as a diffusing convenience of carbon monoxide of less than 35 percent of the predicted value. Key exclusion criteria were a 6-minute walk distance of less than 50 m ; a notable difference of more than 15 percent in the 6-minute walk range between two prerandomization walks; an extent of emphysema greater than the extent of fibrotic modify, as dependant on high-quality computed tomography ; treatment with medications containing nitrates ; the presence of aortic stenosis or idiopathic hypertrophic subaortic stenosis; the initiation of pulmonary rehabilitation within 30 days after screening; the initiation or change in the dosage of any investigational treatment for idiopathic pulmonary fibrosis within thirty days after screening; treatment for pulmonary hypertension with prostaglandins, endothelin-1 antagonists, or additional phosphodiesterase inhibitors within thirty days after screening; a resting oxygen saturation of less than 92 percent while inhaling and exhaling 6 liters of supplemental oxygen; and being listed on an active waiting list for lung transplantation.Among 363 patients signed up for the trial, by June 4 44 had left the study, 2009: 16 of 176 in the ezetimibe group and 28 of 187 in the niacin group . Among these 16 and 28 individuals, for whom there were laboratory values at 2 months, the modification in the LDL level from baseline in the ezetimibe group and the modification in the HDL level from baseline in the niacin group were similar to the corresponding changes among the patients who completed the study. Adverse drug effects were cited because the reason for withdrawal in 3 of 9 patients receiving ezetimibe and 17 of 27 patients receiving niacin .