title: Combination therapy for pulmonary arterial hypertension: still more questions than answers.
authors.forename: M M
authors.initials: MM
authors.lastname: Hoeper
authors.forename: A T
authors.initials: AT
authors.lastname: Dinh-Xuan
mesh_terms: D004359:Drug Therapy, Combination; D065128:Endothelin Receptor Antagonists; D006801:Humans; D006976:Hypertension, Pulmonary / Q000188:drug therapy*; D010726:Phosphodiesterase Inhibitors / Q000627:therapeutic use*; D011453:Prostaglandins / Q000627:therapeutic use*
chemical_list: D065128:Endothelin Receptor Antagonists; D010726:Phosphodiesterase Inhibitors; D011453:Prostaglandins