Blood pressure, as defined by MedLine Plus of the National Institutes of Health, is the measure of the force against your artery walls as your heart pumps blood. Hypertension occurs when blood pressure measures at or above 140mmHg systolic and at or above 90mmHg diastolic, with the former representing the pressure when your heart pumps blood, and the latter representing the pressure between pumps. Those with hypertension are advised to follow a low-sodium diet and take medications such as diuretics if necessary.
Choosing a Medication Treatment
Various medications are used to treat hypertension, depending on the primary cause of the condition. Renal disease and problems with the fluid balance in cells, as well as genetics, stress and obesity can all contribute to hypertension, according to the Merck Manuals online medical library. Therefore, one or more medications such as diuretics, beta blockers, ACE inhibitors, angiotensin II receptor blockers or calcium channel blockers may be prescribed. But diuretics are usually the first medication to be prescribed, because they are usually the least expensive and may be taken in small doses, according to the Merck Manuals.
About Diuretics
Diuretics reduce plasma volume and vascular resistance in the body. According to the European Society of Cardiology, they also decrease extracellular fluid volume. A reduction in extracellular fluid places less pressure on the blood vessels, which causes a decrease in blood pressure.
Thiazide Diuretics
Thiazide diuretics are the most commonly used diuretics in treating arterial hypertension, according to the European Society of Cardiology. Hydrochlorothiazide, also known as HCTZ, and chlorthalidone are the most commonly studied thiazide diuretics. Chlorthalidone has been shown to have greater potency and duration of action than HCTZ, thus having great effectiveness in lowering systolic blood pressure. Though effective, thiazide-type diuretics have some safety concerns. Thiazide diuretics, according to the European Society of Cardiology, reduce the excretion of calcium and uric acid, which causes these compounds to build up, in turn increasing the risk of kidney stones. In addition, thiazides can increase excretion of potassium and magnesium, which can lead to electrolyte imbalances. A 2010 study in the American Heart Association journal "Hypertension" found that thiazides increase the risk of onset diabetes associated with low potassium.
Loop Diuretics
Loop diuretics such as bumetanide and furosemide are usually prescribed only to those who have less than 50 percent kidney function, such as those with renal disease, according to the Merck Manuals. Loop diuretics are used to excrete water and salt from the kidneys, thus decreasing pressure in the blood vessels.
Potassium-Sparing Diuretics
Potassium-sparing diuretics act similarly to other diuretics, except that potassium excretion is decreased. Potassium-sparing diuretics, such as spironolactone, aid in closing potassium channels in arterial walls. Although the diuretics are effective in decreasing potassium excretion, the Merck Manuals advises that this may lead to constriction, or stiffening, of blood vessels, thus making the medication ineffective in decreasing blood pressure. Potassium-sparing diuretics are used only when someone is at risk of experiencing a cardiovascular event, in which case potassium preservation can decrease the risk of arrythmia.
Nutrition Needs While Using Diuretics
Because of electrolyte excretion caused by diuretic use, those taking diuretics need to supplement their diets to avoid electrolyte imbalances. Minerals most at risk of becoming deficient include potassium, magnesium, and calcium. The Cleveland Clinic recommends a variety of "power foods" that provide an abundance of nutrients to aid in treating those with hypertension and heart disease.They include squash and leafy greens such as spinach and romaine, which provide calcium, potassium and magnesium. In addition, salmon, citrus fruits, berries and bananas are rich sources of potassium, while low-fat dairy sources such as soy milk, cheese and oatmeal are rich sources of magnesium.
References
- MedLinePlus: National Institutes of Health: Hypertension
- The Merck Manuals Online Library: Arterial Hypertension
- "Hypertension"; Impact of Abdominal Obesity on Incidence of Adverse; Cooper-DeHoff et al.; 2010
- "European Society of Cardiology"; Thiazide diuretics in hypertension; Ferreira R.; June 2010
- Cleveland Clinic: 35 Power Foods
