Pharmacology

They work by promoting excretion of sodium and water in the urine. Diuretic drugs decrease the total blood volume, which lowers blood pressure.

Beta-Blockers block the action of epinephrine at all beta receptors to decrease heart rate and dilate the blood vessels.

Suffix ending olol

They block the action of epinephrine at the Beta-1 receptor (in the heart) and Beta-2 receptors (in the blood vessels). They do not block the action of Beta-2 receptors in the bronchi. (good for pt's with asthma)

Block both Alpha and Beta receptors in the smooth muscle of blood vessels.

Only Apha-1 receptors are blocked. Receptors are located in the peripheral blood vessels in both arteries and veins. This causes dilation in veins and arteries.

Suffix ending- azosin

Block the movement of calcium ion into the heart muscle and smooth muscles in the blood vessels.

Suffix ending-dipine

Blocks the enzyme in the blood that converts angiotensin 1 to angiotensin 2. Angiotensin 2 is a vasoconstrictor. When the enzyme is blocked angiotensin 2 is not produced, thus the blood vessels dilate.

Suffix ending- pril

Keeps angiotensin 2 from binding to and activating receptors on smooth muscle of the blood vessels. This allows the smooth muscle to relax (vasodilation).

These drugs relax the smooth muscle in the blood vessels and cause the blood vessels to dilate.

• Hydralazine (Apresoline)
• Minoxidil

These drugs stimualte Alpha 2 receptors in the vasomotor center of the brain. Stimulating these repectors decrease the number of nerve impulses sent by the SNS to the adrenal medulla. Causes less epinephrine to be secreted.