Published: January 20, 2008 11:13 pm         

Diuretics tried and true for blood pressure

Looking at the scale, Vic thought, “What could I possibly have eaten that would cause me to gain four pounds in one day?”

On taking inventory, he found he could not possibly have eaten enough extra calories (14,000) to gain that much weight in such a short period. He had consumed more than his share of sodium — a corned beef sandwich with potato chips and two large dill pickles. That meal undoubtedly contributed to the extra four pounds of water weight he was carrying.

Later, Vic was diagnosed with high blood pressure, put on a diuretic medication and advised to limit his sodium intake.

An estimated 65 million Americans have high blood pressure; nearly a third of them don’t know it. One major cause is salt sensitivity that causes the body to retain fluids, increasing blood volume and making the heart work harder.

Salt is everywhere — in restaurant meals, prepared and canned foods — and most Americans consume three or four times more salt than they need. When blood pressure is elevated, doctors usually recommend limiting sodium intake (less than 1,500 milligrams per day).

In addition to that and other lifestyle measures, diuretic medication is recommended as first-line treatment by the Joint National Commission on Prevention, Detection, Evaluation and Treatment of High Blood Pressure. Also known as water pills, diuretics work by causing the kidneys to flush excess sodium and water from the body, which in turn helps relax blood vessel walls.

Although there are many newer and more expensive blood pressure medications available, the guidelines are based in part on the large ALLHAT study (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial) published in 2002 in the Journal of the American Medical Association.

More than 33,000 ALLHAT subjects treated for an average of five years, those taking diuretics were less likely to suffer a stroke, develop congestive heart failure or be hospitalized for heart problems compared to subjects taking calcium channel blockers or ACE inhibitors. They had about the same rate of suffering heart attacks or dying from heart disease.

The good news is diuretics are not only considerably less expensive than other hypertension drugs (costing pennies a day rather than dollars) but have a long-term safety record established over 40 years of use.

Most commonly prescribed for early hypertension are thiazide diuretics. Chlorthalidone was used in ALLHAT, but a more common choice today is hydrochlorothiazide (HCTZ), which has fewer side effects.

Thiazide diuretics can cause the body to flush out potassium as well as sodium, and potassium is needed for muscles and to keep the heart working properly. As a result, thiazide diuretics often are prescribed along with a potassium supplement or with a potassium-sparing diuretic such as triamterene.

Loop diuretics are more powerful and often prescribed for congestive heart failure, liver disease or emergency situations involving fluid retention. Loop diuretics include furosemide and bumetanide.

The major side effect of diuretics is frequent urination that usually continues for about four hours after the medication is taken.

Most men are aware of the potential for erectile dysfunction with diuretics. This effect is probably not as common as believed. Erection problems are associated with hypertension itself. Whatever the cause, ED responds readily to Viagra.

Diuretics also can raise cholesterol and increase the risk of gout and diabetes but ordinarily only at doses higher than those recommended today.

Many patients, particularly those with high readings or blood pressure that’s resistant to treatment, may need another medication, along with a diuretic.

Edema, or swelling caused by accumulation of fluid in body cells, is associated with a number of serious illnesses such as congestive heart failure, enlarged left chamber of the heart, kidney disease, cirrhosis of the liver and thyroid problems. These illnesses usually require more powerful diuretics and in higher doses. Congestive heart failure and kidney disease can occur as late effects of uncontrolled hypertension.

When the late President Franklin D. Roosevelt was diagnosed with hypertension, in the days before good treatments were available, he progressed within a decade to severe cardiovascular problems that led to his death. Vic has kept his blood pressure under tight control for 14 years through exercise, diet and one water pill a day.



Rupp is information and assistance case manager with the Northern Oklahoma Development Authority Area Agency on Aging.