Study to Test the Validity of the Treatment of Idiopathic Pulmonary Fibrosis With Cotrimoxazole

First study to test the validity of the treatment of idiopathic pulmonary fibrosis, which causes inflammation and fibrosis (scarring) of the lung tissue, with cotrimoxazole. Cotrimoxazole may improve the clinical course of the disease through eradication of Pneumocystis jiroveci colonization and other mechanisms as inhibiting the activation of alveolar macrophages and producing alterations in the surfactant system which favours the persistent activation of the inflammatory response and the development of pulmonary fibrosis.