TUESDAY, Dec. 2, 2003 (HealthDayNews) -- A large new study should remove doubts about the benefits of calcium channel blocker drugs in controlling high blood pressure, but another expert says no end is near for the ongoing debate about which drugs are best for which patients.
The study compared a drug regimen that included a calcium channel blocker (sometimes called calcium antagonist) with one that included a beta blocker in more than 22,000 patients with coronary artery disease and high blood pressure. Both drugs lower blood pressure by relaxing arteries through different molecular mechanisms.
The percentage of patients suffering what is formally called "a primary outcome event" -- death, a nonfatal heart attack, or nonfatal stroke -- during an average 2.7-year follow-up was almost identical in both groups, says a report in the Dec. 3 issue of the Journal of the American Medical Association.
That finding directly contradicts results of some earlier and much smaller studies suggesting that calcium channel blockers were not as safe and effective as other blood pressure drugs, says study author Dr. Carl J. Pepine, chief of cardiovascular medicine at the University of Florida School of Medicine.
"What was apparent was that there was not enough data to reach conclusions," Pepine says. "What was clearly needed was a study of this magnitude."
And so his way of treating high blood pressure is to start with either a calcium channel blocker or beta blocker "and build on that until you get blood pressure under control," Pepine says.
It's clear that combined treatment is needed because single-drug therapy is not enough to achieve blood pressure control, Pepine says.
Most physicians would agree on that, says Dr. Michael J. Alderman, professor of medicine and epidemiology at Albert Einstein College of Medicine and author of an accompanying editorial, but he has a different recipe.
Alderman would start with a diuretic, a drug that lowers blood pressure by removing fluid from the body, and then add an artery-relaxing medication -- a calcium antagonist, beta blocker, or an ACE inhibitor, which has a different mode of action.
But Alderman says debate about which drug combination is best should take second place to the fact that "the most important thing is to treat high blood pressure." Studies indicate that less than a third of Americans with high blood pressure are getting drug therapy to reduce their risk of heart attack and stroke, he says.
"Everyone would agree that the choice of drugs is a secondary issue," Alderman says.
And no single regimen is best for all patients, since there is no single cause of high blood pressure, he says. About a third of all patients have high blood pressure simply because there is too much fluid in their arteries, Alderman says, and they will do best with a diuretic. But they will also require some sort of medication that reduced blood pressure by widening blood vessels.
It may be possible to do exquisite tailoring of drug therapy, using tests to see which mechanism of high blood pressure is most important in a given patient, Alderman says. But money can't be ignored, he says, and diuretics, which are older drugs available as generics, win on that point.
"A diuretic costs a penny or day or so," Alderman says. "A calcium antagonist is a buck a day. I wouldn't base a medical decision on cost alone, but before we make the more expensive drug the first choice, we need better evidence that it is more effective."
And he comes back to his main point: "If we can just get the message out about controlling blood pressure, there are lots of ways to do it."