Methods of treating pulmonary hypertension

A method of treating pulmonary hypertension, which comprises administering to a patient in need thereof therapeutically effective amounts of a prostacyclin and a compound of the formula:

• or a pharmaceutically acceptable salt thereof, wherein:
• A is optionally substituted cycloalkyl, aryl, or heterocycle;
• X is a bond, —O—, —S—, —C(O)—, —C(R4)═, ═C(R4)—, —C(R3R4)—, —C(R4)═C(R4)—, —C≡C—, —N(R5)—, —N(R5)C(O)N(R5)—, —C(R3R4)N(R5)—, —N(R5)C(R3R4)—, —ONC(R3)—, —C(R3)NO—, —C(R3R4)O—, —OC(R3R4)—, —S(O2)—, —S(O2)N(R5)—, —N(R5)S(O2)—, —C(R3R4)S(O2)—, or —S(O2)C(R3R4)—;
• D is optionally substituted aryl or heterocycle;
• E is optionally substituted aryl or heterocycle;
• R1 is hydrogen or optionally substituted alkyl, alkyl-aryl, alkyl-heterocycle, aryl, or heterocycle;
• R2 is hydrogen or optionally substituted alkyl, alkyl-aryl, alkyl-heterocycle, aryl, or heterocycle;
• R3 is hydrogen, alkoxy, amino, cyano, halogen, hydroxyl, or optionally substituted alkyl;
• R4 is hydrogen, alkoxy, amino, cyano, halogen, hydroxyl, or optionally substituted alkyl or aryl;
• R5 is hydrogen or optionally substituted alkyl or aryl;
• and
• n is 0-3.