Thiazide-type diuretic shown to be best first-choice drug for hypertensive patients

May 19 2008

A study based at The University of Texas Health Science Center at Houston provides added justification that a thiazide-type diuretic is the best first-choice drug for hypertensive patients. The findings, published in the American Heart Association's Circulation, Volume 117, Issue 20, evaluate the results of a previous trial coordinated by researchers at The University of Texas School of Public Health, along with other recent studies.

According to the American Heart Association, about one in three U.S. adults has high blood pressure. Uncontrolled high blood pressure can lead to stroke, heart attack, heart failure or kidney failure. A joint national committee (JNC) on the prevention, detection and evaluation of high blood pressure meets on a regular basis to summarize suggested guidelines for doctors on treating hypertension based on medical research. The study, titled "Thiazide-type diuretics and beta-adrenergic blockers as first-line drug treatments for hypertension," analyzes the guidelines of the committee based on previous and recent research.

The findings of the JNC are based on information stemming from a landmark investigation at the UT School of Public Health, which in 2002 established that diuretics were "as good or better" than three other classes of medications for high blood pressure. The original investigation was called ALLHAT - Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial.

"We found that further analyses of the original ALLHAT trial and information from more recent studies confirmed the original findings that diuretics are the preferred choice for antihypertensive therapy, alone or in combination with other drugs," said Barry Davis, M.D., Ph.D., professor of biostatistics and the director of the Coordinating Center for Clinical Trials at the UT School of Public Health.

"Five years after the ALLHAT results were published, the JNC recommendation still holds," added Davis, who co-authored the study with Jeffrey A. Cutler, M.D., MPH, a consultant to the National Heart, Lung and Blood Institute (NHLBI).

The most recent committee highlighted ALLHAT's findings in the revision of its guidelines, meaning the information will now be used for practical treatments. The committee states that when compared to calcium channel blockers, ACE inhibitors and alpha blockers, thiazide-type diuretics are better first-line drug treatments for hypertensive patients. The diuretics excelled in controlling blood pressure, preventing cardiovascular events, are well tolerated by patients and are relatively inexpensive.

Original ALLHAT findings appear in two articles in a 2002 issue of The Journal of the American Medical Association (JAMA). The project consisted of two clinical trials: one compared a diuretic with newer and more expensive antihypertensive drugs to start blood pressure-lowering treatment to ascertain which was best at preventing cardiovascular outcomes; the other compared a statin drug to usual care in lowering cholesterol levels to determine if treatment would lower the occurrence of deaths over the study period. The articles and details of the study and its findings can be found on the study's web site, www.allhat.org.