One in four Americans has hypertension, or high blood pressure, defined as a blood pressure of 140/90 millimeters of mercury or greater. That translates to about 50 million Americans, not to mention the hundreds of millions of hypertensive patients worldwide. We spend almost $20 billion dollars annually for the medications to lower blood pressure. Yet the results from the National Institutes of Health's ALLHAT (Antihypertensive and Lipid-Lowering Treatment to Prevent Heart Attack Trial) program comparing the results of several classes of blood pressure medications suggest that the tried, true and cheapest of the interventions also may have been the most effective. The dollar savings to the American health system may be enormous. But are these initial conclusions correct, or are there other considerations?

ALLHAT had approximately 33,000 subjects aged 55 years or older in this federally funded clinical trial comparing a representative blood pressure lowering drug from four different classes. Large numbers of patients strengthen the validity of the conclusions. One medication class was the ACE inhibitor, another was the calcium channel blocker, then a representative from the alpha-blocker class, and finally the oldest class of all, the diuretic. There were no placebo patients, so this was a head to head comparison of these medications to determine whether they were comparable in the prevention of complications of long standing high blood pressure such as coronary disease, heart failure or stroke.

Midway through the trial, the alpha-blocker was dropped when it became apparent that patients on that treatment had a higher incidence of stroke and heart failure. The three remaining classes made it to the end of the study which lasted eight years and cost taxpayers $120 million. Money well spent as it turns out.

In all the major endpoints of this program, occurrence of heart failure, coronary events and strokes, the lowly and least expensive diuretic, the water pill, did at least as well, if not somewhat better, than the newer and more expensive classes of medications. This is certainly great news, but in my estimation represents only part of the considerations we must ponder.

When we look at outcomes, such as the endpoints of ALLHAT, we must remember that the other medication classes also showed reductions in those cardiovascular events. Indeed, the inexpensive beta-blockers, not included in ALLHAT, have shown similar benefits. A key consideration physicians must keep in mind is that some of these medications may have benefits not directly measured in ALLHAT, but that have been demonstrated in other large clinical trials. For example, ACE inhibitors, such as ramipril, have been shown to protect heart function, protect kidney function and reduce the development of diabetes, independent of their effect on blood pressure. Beta-blockers have been shown to prevent the development of second heart attacks and delay the progression of heart failure, again independent of their effects on blood pressure.

Undoubtedly, and appropriately, pressure will be applied to healthcare providers to use the cheap diuretic as first line therapy for simple high blood pressure. Although in most cases the diuretic may be the first drug utilized, we must keep in mind that other drug classes may actually be preferred. Recommendations must be individualized. And the fact that generic medications in all of these classes have now become available may obviate the cost advantages of always using diuretics first.

Finally, the conclusion doctors and patients should reach as a result of ALLHAT is that most patients can be started on a simple diuretic if lifestyle changes such as weight loss, exercise and salt restriction do not normalize the blood pressure. If needed, other classes of medications such as the ACE inhibitors, beta-blockers, angiotensin receptor blockers and perhaps calcium channel blockers can be added. Ultimately, there simply is no substitute to asking the doctor what is the best treatment course, factoring in cost, effectiveness and specific considerations for the patient.