title: Sildenafil for COPD: a randomized crossover trial.
authors.forename: Todd
authors.initials: T
authors.lastname: Bull
authors.forename: David B
authors.initials: DB
authors.lastname: Badesch
mesh_terms: D005080:Exercise Test / Q000187:drug effects*; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000187:drug effects*; D010879:Piperazines / Q000627:therapeutic use*; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000188:drug therapy*; D011687:Purines / Q000627:therapeutic use; D000068677:Sildenafil Citrate; D013450:Sulfones / Q000627:therapeutic use*; D014665:Vasodilator Agents / Q000627:therapeutic use*
chemical_list: D010879:Piperazines; D011687:Purines; D013450:Sulfones; D014665:Vasodilator Agents; D000068677:Sildenafil Citrate