Several classes of drugs are used to treat hypertension.
Diuretics help the kidneys get rid of excess salt and water. They are the mainstays of anti-hypertensive therapy and are often the first type of drug selected for most people with hypertension. They are also especially helpful for treating patients with heart failure, patients with isolated systolic hypertension, the elderly, and African-Americans. (African-Americans are more likely to be salt-sensitive, so they respond well to these drugs.) They also work well for patients with diabetes. Diuretics are often used in combination with other antihypertensive drugs.
There is strong evidence that diuretics work just as well as newer drugs in lowering blood pressure and are more effective in preventing heart failure, heart attack, and stroke.
Diuretic Types and Brands. The three main types of diuretics include:
- Thiazide diuretics. These include chlorothiazide (Diuril), chlorthalidone (Hygroton), indapamide (Lozol), hydrochlorothiazide (Esidrix, HydroDiuril), bendroflumethiazide (Naturen), methylclothiazide, (Edduran), and metolazone (Mykrox, Zaroxolyn). In most cases, thiazides are preferred to other diruetics for treatment of high blood pressure.
- Potassium-sparing diuretics. These include amiloride (Midamor), spironolactone (Aldactone), and triamterene (Dyrenium).
- Loop diuretics. Because loop diuretics act faster than other diuretics it is important to avoid dehydration and potassium loss. Loop diuretics include bumetanide (Bumex), furosemide (Lasix), ethacrynic acid (Edecrin), and torsemide (Demadex).
Problems with Diuretics.
- Loop and thiazide diuretics reduce the body's supply of potassium, which, if left untreated, increases the risk for arrhythmias. Arrhythmias are heart rhythm disturbances that can, rarely, lead to cardiac arrest. If you experience reduced potassium, your doctor will prescribe a lower dose of the current diuretic, recommend potassium supplements, or switch to a potassium-sparing diuretic either alone or in combination with a thiazide.
- Potassium-sparing drugs have their own risks, which include dangerously high levels of potassium in people with existing elevated levels of potassium or in those with damaged kidneys. However, all diuretics are generally more beneficial than harmful.
- Thiazide diuretics may increase blood sugar levels.
- Erectile dysfunction (impotence) may be a side effect of thiazides.
- Elevated uric acid levels, and possibly gout, may be caused by thiazide diuretics.
Review Date: 04/06/2010
Reviewed By: Harvey Simon, MD, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.