Together your heart and blood vessels comprise the cardiovascular system. Substances you ingest daily such as caffeine, nicotine, over-the-counter preparations for flu and cold symptoms, weight loss and increased stamina affect your cardiovascular system. These substances, including prescription medications used specifically for the cardiovascular system, are classed according to the effect they have on your heart and blood vessels. It is important to realize that effects on the heart cause changes in the blood vessels and vice versa.
Cardiac Glycosides
Cardiac glycosides are a class of medications that perform the same action: control of heart rate and rhythm. Digoxin is a cardiac glycoside. The National Institutes of Health explains how digoxin works on the conduction system of the heart and in proper doses slows the heart rate. However, too much digoxin can either cause a complete heart block or a very rapid heart rate called tachycardia. Cardiac glycosides like digoxin are used to treat congestive heart failure and irregular heart rhythms such as atrial fibrillation.
Vasodilators
Vasodilators are a class of drugs that cause blood vessels to relax and widen. These medications are used to treat high blood pressure, called hypertension. According to "Pearson Nurse's Drug Guide 2010," some vasodilators work specifically on the blood vessels in the heart and are called coronary vasodilators. These medications are used to improve blood flow to the heart muscle during or after a heart attack. Nitroglycerine is an example of a coronary vasodilator. Nifedipine is another example of a vasodilator used to treat hypertension.
Vasoconstrictors
Vasoconstrictors do the opposite of vasodilators; they narrow blood vessels. Vasoconstrictors are used to treat low blood pressure. An example of such a drug is enalapril. Caffeine and nicotine have vasoconstricting effects on the cardiovascular system.
Beta Blockers
This class of medication affects the heart by slowing the heart rate. A common beta blocker is atenolol. The American Heart Association explains that beta blockers are used alone or in combination with other drugs like vasodilators to improve heart rate and blood pressure.
Sympathomimetics
Sympathomimetics are medications whose effects mimic the branch of the central nervous system called the sympathetic nervous system. The effects of this class of drugs include an elevated heart rate and vasoconstriction, which increases blood pressure. Norepinephrine is an example of a sympathomimetic medication that is used in emergency situations to sustain heart rate and blood pressure.
References
- National Institute of Health DailyMed: "Digoxin tablet"
- "Pearson Nurse's Drug Guide 2010"; Wilson, B. A., Shannon, T. M., & Shields, K. M.; 2010
- American Heart Association: "Blood Pressure Lowering Drugs"
