Vasodilating antihypertensive agents peripheral

The vasodilators decrease total peripheral resistance and thus correct the hemodynamic abnormality that is responsible for the elevated blood pressure in primary hypertension. In addition, because they act directly on vascular smooth muscle, the vasodilators are effective in lowering blood pressure, regardless of the etiology of the hypertension. Unlike many other antihypertensive agents, the vasodilators do not inhibit the activity of the sympathetic nervous system therefore, orthostatic hypotension and impotence are not problems. Additionally, most vasodilators relax arterial smooth muscle to a greater extent than venous smooth muscle, thereby further minimizing postural hypotension. 

MecfMnism of Action An antihypertensive and antianginal agent that inhibits calcium movement across cardiacandvascular smooth-musclecell membranes. Potent peripheral vasodilator (does not depress SA or AV nodes). Therapeutic Effect Increases myocardial contractility, heart rate, and cardiac output decreases peripheral vascular resistance and BP. 

Mechanism of Action An antihypertensive and antianginal, antiarrhythmic, and antihypertensive agent that inhibits calcium ion entry across cardiac and vascular smooth-muscle cell membranes. This action causes the dilation of coronary arteries, peripheral arteries, and arterioles. Therapeutic Effect Decreases heart rate and myocardial contractility and slows SA and AV conduction. Decreases total peripheral vascular resistance by vasodilation. 

Fenoldopam is a Di receptor agonist that selectively leads to peripheral vasodilation in some vascular beds. The primary indication for fenoldopam is as an intravenously administered drug for the treatment of severe hypertension (Chapter 11 Antihypertensive Agents). Continuous infusions of the drug have prompt effects on blood pressure. 

It is a potent antihypertensive agent which exerts its action mainly by causing direct peripheral vasodilation. It has been observed that its effect on diastolic pressure is more marked and pronounced than on systolic pressure. It is employed in the treatment of essential and early malignant hypertension usually in conjunction with thiazide diuretics or rauwolfia alkaloids. 

Mechanism of Action An antihypertensive and benign prostatic hyperplasia agent that blocks alpha-adrenergic receptors. Produces vasodilation, decreases peripheral... 

The required properties of such an agent Included (1) selectivity for peripheral vascular dopaminergic receptors versus < -and 6-adrenerglc receptors which could mediate pressor and cardiac effects, (2) absence of central dopaminergic and emetic effects, and (3) potent oral renal vasodilator effects. Dopamine has been associated with diuresis and natriuresls. Possible mechanisms include a direct tubular effect on sodium transport, indirect effects produced by changes in total or regional renal blood flow, or effects resulting from a dopamine Induced decrease in aldosterone release from the adrenal (9). Since diuretics play a key role in antihypertensive therapy, the addition of a natriuretic/diuretic component to the renal vasodilator profile would be valuable and appeared to be feasible. 

Antihypertensive Vasodilators - A common characteristic of hypertensive patients, regardless of the etiology of their disease, is abnormally high peripheral vascular resistance. Drugs that act directly on peripheral vasculature to decrease resistance are, therefore, logical agents for the treatment of hypertension. Unfortunately, sympathetic reflex actions leading to cardiac stimulation, hyperreninemia and fluid retention limit the hypotensive action of vasodilators and they are used mainly in combination with 6-blockers and diuretics for the treatment of more severe hypertension. A vasodilator that may not cause undesirable reflex... 

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