20 Isosorbide dinitrate 與下列那一種藥品合併使用於治療心臟衰竭時，有相輔相成之效果？
(A) Clonidine
(B) Hydralazine
(C) Prazosin
(D) Propranolol

Nitrate和hydralazine可在治療 HFrEF時併用，因為它們具有互補的hemodynamic actions。
Nitrate：提供NO—>活化guanylate cyclase—>增加血管平滑肌中的cGMP—>使靜脈擴張—>前負荷降低。
hydralazine：動脈的直接擴張劑—>使 SVR 降低—>進而導致 SV 和 CO 增加。
*作為ACEi或ARB的替代用藥

Dipro 12e的原文：
「Nitrates and hydralazine were originally combined in the treatment of HFrEF because of their complementary hemodynamic actions. Nitrates, by serving as nitric oxide donors, activate guanylate cyclase to increase cyclic guanosine monophosphate (cGMP) in vascular smooth muscle resulting in venodilation and decreased preload. Hydralazine is a direct-acting arterial vasodilator causing a decrease in SVR and resultant increases in SV and CO. However, the beneficial effects of hydralazine and nitrates extend beyond their hemodynamic actions and are likely related to attenuating the biochemical processes driving HF progression.」
「Hydralazine and nitrates should be used in Black patients with persistent symptoms despite GDMT. Hydralazineand a nitrate might be reasonable in patients unable to tolerate either an ACE inhibitor or ARB because of renal insufficiency, hyperkalemia, or possibly hypotension.」