<s>[INST] context: alpha blockers Pulmonary hypeension General management Diuretic therapy may be useful as it relieves pulmonary edema. Anticoagulant therapy is advocated for all patients. Specific management Calcium channel blockers Patients who have substantial reductions in pulmonary aerial pressure in response to sho acting vasodilators at the time of cardiac catheterization should he initially treated with calcium channel blockers. Endothelin receptor antagonist Bostenan is a non-selective endothelium receptor antagonist, is an approved t/t ,for patients who are NYHA .functional classes III and IV. Phosphodiesterase-5 inhibitors Slidenafil is used for patients who are NYHA functional classes II and Prostacyclins Iloprost is a prostacyclin analogue used in PAH patients who are NYHA functional classes III and IV. Pulmonary circulation is unique in that it accommodates a blood flow that is almost equal to that of all the other organs of body but still maintains low pressure. The factors responsible for low pressure in pulmonary circulation (even with large volume of blood) are:- - Larger diameter of pulmonary vessels due to thin wall of pulmonary aery and aerioles. [/INST] question: Drug NOT used in pulmonary hypeension is? | options: A: Calcium channel blocker B: Endothelin receptor antagonist C: Alpha blocker D: Prostacyclin | answer: C </s>