Dilates arterioles by relaxing arteriolar smooth muscle. Relax smooth muscle of arterioles , thereby decreasing systemic vascular resistance and afterload. Increase in cardiac output due to marked arteriolar dilation. This syndrome is reversible and not associated with any renal damage. The vasodilators are usually reserved for combination therapy in advanced hypertension.
Parenteral hydralazine is used to lower blood pressure rapidly.
By reducing afterload and heart volume, vasodilators improve cardiac function in chronic heart failure. Hydralazine use may lead to reflex tachycardia and sympathetic stimulation, provoking angina or ischemic arrhythmias. The vasodilator drugs are usually reserved for combination therapy with a diuretic and a beta-blocker in resistant or advanced hypertension.