Study: Diuretics Best For Treating Hypertension

Treating high blood pressure may be as simple as popping an inexpensive diuretic, according to a major new study.

Researchers found that a diuretic, or water pill, is more effective in treating high blood pressure and preventing cardiovascular disease than newer, more expensive medications.

The eight-year study, led by a doctor at Wake Forest University Baptist Medical Center, included 623 clinical sites in North America.

The study compared high blood pressure drugs among more than 33,000 participants age 55 or older, all of whom had hypertension and at least one other coronary heart disease risk factor. About 50 percent of the participants were women and 35 percent were black.

The study, which is published in Wednesday's issue of the Journal of the American Medical Association, was supported by the National Heart, Lung and Blood Institute.

The researchers found that most patients will need more than one drug to adequately control their blood pressure and one of the drugs should be a diuretic.

"The preferred drug is the diuretic for three reasons," said lead researcher Dr. Curt Furberg. "It provides better control of hypertension; it reduces complications from hypertension -- particularly heart failure -- more effectively; and it is 10 to 20 times less expensive than the other drugs used in the trial."

Participants in the study were randomly assigned to receive the diuretic chlorthalidone, amlodipine (a calcium channel blocker sold under the name Norvasc) or lisinopril (an angiotensin-converting enzyme -- ACE -- inhibitor sold under the names Prinivil and Zestril.)

In 2000, another drug used in the trial, doxazosin (an alpha-blocker sold under the name Cardura) was pulled from the trial because researchers realized early on that it was not as effective as the less expensive diuretic medication.

"Many of the newer drugs were approved because they reduce blood pressure and the risk of heart disease compared with a placebo," said Dr. Claude Lenfant, NHLBI director. "But they were not tested against each other. Yet, these more costly medications were often promoted as having advantages over older drugs, which contributed to the rapid escalation of their use. Now, at last, we can make those needed comparisons and know which blood pressure drug to choose to begin therapy."

About 24 million Americans take drugs to lower high blood pressure, at an estimated annual cost of about $15.5 billion, according to the article.

The study does not recommend that patients stop taking their medication if they are using a drug other than a diuretic. But they are encouraged to speak with their physicians about adding or switching to a diuretic for their treatment.