“Treatment of mild to severe hypertension”
Antihypertensive agents include angiotensin-convertingenzyme inhibitors, angiotensin II–receptor blockers, calcium channel blockers, vasodilators, and other antihypertensive agents, including diuretic agents, ganglionic receptors, renin inhibitors, and sympathetic nervous system drugs. See following table for a complete list of Antihypertensive agents.
Groups of medications used in the treatment of hypertension.
Decrease conversion of angiotensin I to angiotensin II, a potent vasoconstrictor, reducing peripheral vascular resistance and B/P.
Alpha agonists (central action):
Stimulate alpha2- adrenergic receptors in the cardiovascular centers of the CNS, reducing sympathetic outflow and producing an antihypertensive effect.
Alpha antagonists (peripheral action):
Block alpha1- adrenergic receptors in arterioles and veins, inhibiting vasoconstriction and decreasing peripheral vascular resistance, causing a fall in B/P.
Angiotensin receptor blockers:
Block vasoconstrictor effects of angiotensin II by blocking the binding of angiotensin II to AT1 receptors in vascular smooth muscle, helping blood vessels to relax and reduce B/P.
Decrease B/P by inhibiting beta1- adrenergic receptors, which lowers heart rate, heart workload, and the heart’s output of blood.
Calcium channel blockers:
Reduce B/P by inhibiting flow of extracellular calcium across cell membranes of vascular tissue, relaxing arterial smooth muscle.
Inhibit sodium (Na) reabsorption, increasing excretion of Na and water. Reduce plasma, extracellular fluid volume, and peripheral vascular resistance.
Directly inhibit renin, decreasing plasma renin activity (PRA), inhibiting conversion of angiotensinogen to angiotensin, producing antihypertensive effect.
Directly relaxe arteriolar smooth muscle, decreasing vascular resistance. Exact mechanism unknown.