Battle of the High Blood Pressure Drugs
April 18, 2000 -- If you're among the one million Americans who use what's called an alpha-blocker to treat your high blood pressure, this story concerns you.
A preliminary result from a large national study looking at blood pressure medications finds the alpha-blocker Cardura is less effective in treating high blood pressure than the less costly and more conventional treatment, a diuretic. Diuretics decrease blood pressure by increasing urination.
There is nothing in the findings that state Cardura is harmful in any way, just that it is not as effective as a diuretic for treating high blood pressure.
The primary goal of the study was to evaluate heart disease, both fatal and non-fatal, and there was essentially little difference between the two drugs, one of the researchers, Charles Ford, PhD, tells WebMD.
An advisory committee from the National Heart, Lung, and Blood Institute (NHLBI), the sponsor of the study, recommended halting the part of the study that involved Cardura in late January. The basis of that decision is outlined in the April 19 issue of TheJournal of the American Medical Association.
The Cardura portion of the study involved just under 25,000 patients. Compared to the diuretic chlorthalidone, patients in the study using Cardura had 25% more heart problems and were twice as likely to be hospitalized for heart failure. The patients had slightly higher systolic blood pressures than the chlorthalidone group, and were less likely to take their medicine. Both drugs were similarly effective in preventing heart attacks.
The higher incidence of heart attacks and heart failure was "foremost", says lead author Barry R. Davis, MD, PhD, in deciding to discontinue with Cardura. Davis is with the University of Texas-Houston School of Public Health.
Gerald Payne, MD, NHLBI scientific project officer for the study, tells WebMD, "we can't say that [Cardura] causes these events ... It just doesn't prevent them as much as the diuretics. That's as far as we can state from this study," he says.
"Clearly, the diuretic was superior to [Cardura] in preventing ... heart failure and [Cardura] did not seem to be any better at preventing the other kinds of outcomes that we were looking at," Ford tells WebMD. He suggests that it might be a good idea to start with the diuretic and then keep Cardura "as a step two or step three drug to be added as needed." Ford is an associate professor of biometry at University of Texas-Houston School of Public Health.