Blood pressure drug combo cuts deaths in elderly

NEW YORK (Reuters Health) - Using two drugs rather than one to combat high blood pressure in elderly individuals can reduce their chances of dying over a given period of time, according to a report in the Journal of the American Society of Hypertension.

Current guidelines recommend using a "thiazide" water pill, such as hydrochlorothiazide, as the initial treatment for high blood pressure. Although these drugs effectively reduce blood pressure, prior research has suggested that they do not actually decrease the risk of death compared to no treatment.

This may be, in part, because they cause loss of potassium, which can increase the risk of serious, even fatal heartbeat disturbances. Thus, the potential survival benefits of reduced blood pressure may be offset by the increased risk of these heartbeat disturbances.

A way to combat this problem is to combine thiazide diuretics with potassium-sparing drugs called ENaC inhibitors. In the current study, when a thiazide water pill was combined with an ENaC inhibitor, such as amiloride, the risk of death from heart-related causes fell by about 40 percent.

Guideline recommendations "can now be re-examined in light of these new findings," senior author Dr. John Oates, from Vanderbilt University Medical Center in Nashville, Tennessee, said in a statement.

The results come from a review and analysis of data from studies that compared the benefits of thiazide or thiazide/ENaC inhibitor therapy with that of other treatments. Three trials, which included a total of nearly 6000 patients, looked at use of a thiazide water pill plus an ENaC inhibitor and 14 trials, which included over 60,000 patients, focused primarily on thiazide use alone.

Compared to other blood-pressure treatments, use of hydrochlorothiazide plus an ENaC inhibitor reduced deaths from heart causes by 40 percent. By contrast, treatment with only thiazide water pills did not reduce the risk of death.

The results support the use of the thiazide/ENaC inhibitor combination as initial treatment for high blood pressure in elderly adults, the research team concludes. Whether this approach should also apply to younger patients will require further study, they add.

SOURCE: Journal of the American Society of Hypertension, September/October 2008.