Hydralazine and Nitrates

Q: Hydralazine is? - select one

A) an arterial vasodilator

B) a venous vasodilator

Answer: A

Hydralazine is an arterial vasodilator. That's why it is an integral part of managing Congestive Heart Failure (CHF). It is often used in combination with nitrate, which is venodilator. The combination reduces the cardiac preload and the аftеrlоаd by simultaneous venous and arterial vasodilation. The overall decrease in intracardiac filling pressures decreases the pathologic cardiac remodeling. 

Another vital aspect seldom described of the combined use of hydralazine and nitrates is the enhanced bioavailability of nitric oxide. Since ոitrates serve as nitric oxide donors, hуԁralazine is an antioxidant that reduces the consumption of nitric oxide. This independent protective effect remains intact even in neurohormonal blockades, such as when using angiotensin-converting enzyme inhibitors (ACE-I).

#cardiology

#pharmacology

References:

1. Taylor AL, Ziesche S, Yancy C, et al. Combination of isosorbide dinitrate and hydralazine in blacks with heart failure. N Engl J Med 2004; 351:2049.

2. Taylor AL, Ziesche S, Yancy CW, et al. Early and sustained benefit on event-free survival and heart failure hospitalization from fixed-dose combination of isosorbide dinitrate/hydralazine: consistency across subgroups in the African-American Heart Failure Trial. Circulation 2007; 115:1747.

3. Cole RT, Kalogeropoulos AP, Georgiopoulou VV, et al. Hydralazine and isosorbide dinitrate in heart failure: historical perspective, mechanisms, and future directions. Circulation 2011; 123:2414.