More than 56,000 people died in 2006 due to complications of hypertension, according to the American Heart Association, and almost 75 million Americans suffer from the disease as of 2010. Although lifestyle changes, such as regular exercise and weight loss, are first-line therapy for blood pressures above 140/90, you may also need to take one or more medications to lower your blood pressure to normal levels. A variety of drugs are available for treating hypertension.
No Single Cause for Hypertension
Several factors can contribute to the development and maintenance of elevated blood pressure including hormonal imbalances, deficiencies of vasodilators, which normally expand blood vessels, abnormal sodium metabolism and inappropriate stimulation of the sympathetic nervous system. Once you develop hypertension, it is likely that several factors conspire to sustain the condition. Current drug therapies for hypertension target one or more of these factors.
Calcium Channel Blockers
The movement of calcium across cell membranes is a major determinant of how your cells function. Muscle contraction, blood vessel constriction and dilation, inflammation and nerve conduction are just a few of the many physiologic activities that are governed by calcium flux. According to a February 2011 article in "Current Drug Targets," several different kinds of cell membrane channels, or "pores," control calcium flux into cells, and the blocking of these channels exerts a variety of effects on cell function. For example, blocking calcium channels can slow your heart rate and dilate your blood vessels, both of which lead to a reduction in your blood pressure.
ACE Inhibitors
According to a September 2007 review in "Clinical Therapeutics," your kidneys are intimately involved in controlling your blood pressure. Optimal kidney function depends on good blood flow through the vessels of the kidneys themselves, and the kidneys can enhance this flow by releasing an enzyme called renin. Renin converts another protein in your bloodstream to angiotensin I, which then travels to your lungs where it, in turn, is converted by angiotensin converting enzyme, or ACE, to angiotensin II. Angiotensin II increases your blood pressure, which improves blood flow to your kidneys. If this renin-angiotensin system is too active, your blood pressure rises too high. Drugs called ACE inhibitors interfere with the activity of ACE, thereby decreasing the levels of angiotensin II in your bloodstream.
Combination Therapy
Doctors frequently have to use two or more medications to control a patient's blood pressure, because the human body has compensatory mechanisms that thwart the activity of a single drug. By using one medication to reduce calcium flux into your cells and another that inhibits the production of angiotensin II, your blood pressure may be easier to control. The use of multiple medications at lower dosages sometimes helps to reduce side effects, too.
References
- American Heart Association: High Blood Pressure Statistics
- "The Merck Manual of Diagnosis and Therapy, 18th Edition: Arterial Hypertension"; Mark H. Beers, M.D., Editor-In-Chief; 2006
- PubMed.gov: and Therapeutic Potential of Transient Receptor Potential Channels and Putative Properties Roles in Adversity: Focus on TRPC5, TRPM2 and TRPA1; L.H. Jiang, et al.; February 2011
- PubMed.gov: Effects of Renin-Angiotensin System Inhibition on End-Organ Protection: Can We Do Better?; M.R. Wier; September 2007
