What is "hydralazine"

n. A direct-acting smooth muscle relaxant used to treat hypertension by acting as a vasodilator primarily in artery and arterioles.

n. an antihypertensive drug (trade name Apresoline) that dilates blood vessels; used (often with a diuretic) to treat hypertension and congestive heart failure [syn: Apresoline]

Hydralazine (Apresoline) is a direct-acting smooth muscle relaxant used to treat hypertension by acting as a vasodilator primarily in arteries and arterioles. By relaxing vascular smooth muscle, vasodilators act to decrease peripheral resistance, thereby lowering blood pressure and decreasing afterload.

However, this only has a short term effect on blood pressure, as the system will reset to the previous, high blood pressure needed to maintain pressure in the kidney necessary for natriuresis. The long-term effect of antihypertensive drugs comes from their effects on the pressure natriuresis curve. It belongs to the hydrazinophthalazine class of drugs.

It is on the World Health Organization's List of Essential Medicines, the most important medications needed in a basic health system.