1. A drug containing an effective amount of a P2Y receptor antagonist with a reversible effect, suitable for the treatment or prevention of pulmonary hypertension in a subject. A drug containing an effective amount of a P2Y receptor antagonist with a reversible effect, suitable for reducing mortality in a subject with pulmonary hypertension. 3. A drug containing an effective amount of a P2Y receptor antagonist with a reversible action, suitable for inhibiting ADP-mediated pulmonary artery vasoconstriction in a subject. A medicament according to any one of claims 1 to 3, characterized in that the P2Y receptor antagonist with a reversible action is a fast acting antagonist. A medicament according to any one of claims 1 to 3, characterized in that the P2Y receptor antagonist with a reversible action is kangrelor. The drug according to claim 5, characterized in that the drug comprises 0.1-100 mg / ml kangrelor. A medicament according to any one of claims 1 to 3, further comprising a pharmaceutically acceptable carrier or diluent. A medicament according to any one of claims 1 to 3, additionally containing an active substance selected from the group consisting of pulmonary vasodilators, digoxin, diuretics, anticoagulants, diuretics, beta-blockers and ACE inhibitors. The drug of claim 8, wherein the pulmonary vasodilator is selected from the group consisting of prostaglandins, endothelin receptor antagonists, type 5 phosphodiesterase inhibitors and soluble guanylate cyclase (sGC) activators. 10. Drug by1. Лекарственное средство, содержащее эффективное количество антагониста рецептора P2Yс обратимым действием, пригодное для лечения или предотвращения легочной гипертензии у субъекта.2. Лекарственное средство, содержащее эффективное количество антагониста рецептора P2Yс обратимым действием, пригодное для снижения смертности у субъекта с легочной гипертензией.3. Лекарственное средство, содержащее эффективное количество антагониста рецептора P2Yс обратимым действием, пригодное
