According to Brian Hoffman, M.D., Professor of Medicine at Harvard Medical School, the most common cardiovascular disease in America is high blood pressure. The Centers for Disease Control and Prevention states that as of 2006, 32 percent of American adults who are 20 years old and older have been diagnosed with hypertension. Physicians do have several categories of anti-hypertensive medications available to lessen your blood pressure.
Vasodilators
The term vasodilator means this medication dilates, or enlarges, your blood vessels. It does this by relaxing the smooth muscle in your blood vessels, primarily in your arteries and arterioles. This decreases what is called your total peripheral resistance, or the resistance of the blood vessels outside of your heart, which then lowers your blood pressure. Hydralazine and minoxidil are vasodilators.
Diuretics
Diuretics lower your blood pressure by lowering your volume of blood. They do this by making your kidneys increase the amount of salt and water they excrete. According to Neal Benowitz, M.D., Professor of Medicine, Psychiatry and Biopharmaceutical Sciences at the University of California, there are two types of medications within the category of diuretics that are important in lowering your blood pressure: the thiazides and the loop diuretics. Hydrochlorothiazide is an example of a thiazide, while furosemide is an example of a loop diuretic.
Alpha Blockers
The smooth muscle in your blood vessels has protein molecules called receptors. Your nervous system sends substances, called neurotransmitters, to attach to these receptors. They attach to the alpha receptors, and this causes your blood vessels to constrict; this will raise your blood pressure. Alpha blockers are also called alpha-receptor antagonists because they block, or antagonize, these alpha receptors, prevent your blood vessels from constricting and make them dilate. Prazosin and phenoxybenzamine are examples of alpha blockers.
Beta Blockers
Your heart has beta receptors. The neurotransmitters that attach to these beta receptors make your heart beat faster. Beta blockers are also called beta receptor antagonists because they block (antagonize) these beta receptors. They make your heart beat slower. Propanolol and metoprolol are examples of beta blockers.
Calcium Channel Blockers
Elizabeth Corwin, PhD writes in "Handbook of Pathophysiology," that your heart and the smooth muscle in your blood vessels need calcium to be able to contract. Calcium channel blockers are the category of blood pressure medication that blocks the flow of calcium. This lowers your heart rate and its contractions and relaxes your blood vessels. Diltiazem and verapamil are examples of calcium channel blockers.
ACE Inhibitors
ACE inhibitor stands for angiotensin converting enzyme inhibitor. The angiotensin converting enzyme converts, or changes, a protein called angiotensin I to a protein called angiotensin II. The angiotensin II protein makes your blood vessels constrict and helps to increase your blood volume. Thus, the ACE inhibitor blocks the enzyme that is needed for this to happen. Captopril and lisinopril are examples of ACE inhibitors.
Angiotensin II Receptor Blockers
Angiotensin II Receptor Blockers block the angiotensin II receptors (instead of the enzyme that is needed to make the angiotensin II protein.) It blocks the receptor where the angiotensin II protein would normally attach. Losartan and valsartan are examples of this category of medication.
Centrally Acting
Your central nervous system is made up of your brain and spinal cord. Centrally acting medications interfere with the sympathetic nervous system of your brain. It is the sympathetic nervous system that takes care of "fight or flight" and makes your heat beat faster. Clonidine and methyldopa are examples of this category of medication.
References
- "Basic & Clinical Pharmacology"; Bertram Katzung, M.D., PhD, Susan Masters, PhD, Anthony Trevor, PhD; 2009
- Centers for Disease Control and Prevention: Hypertension
- "Goodman & Gilman's The Pharmacological Basis of Therapeutics"; Laurence Brunton, PhD; 2006
- "Handbook of Pathophysiology"; Elizabeth Corwin, MSN, PhD, FNP; 2000
