MONDAY, Nov. 11, 2003 (HealthDayNews) -- A newer, more expensive drug that blocks the action of a heart-threatening protein is almost as effective as an older class of medications in preventing problems for people who have had heart attacks, but combining the two seems to do more harm than good, a major study finds.
Both drugs act against angiotensin II, which causes the narrowing of blood vessels and raises blood pressure. The older class of drugs, available as lower-cost generic products, are called ACE inhibitors because they block the action of an enzyme that produces angiotensin II.
The newer drug, valsartan, available under the brand name Diovan, blocks the cell receptors on which angiotensin II acts. Both drugs are commonly prescribed after heart attacks.
A study of nearly 10,000 heart attack survivors finds that both drugs are equally effective in preventing adverse events in those patients, but that combined treatment increased the risk of adverse side effects without improving survival, says Dr. Marc A. Pfeffer, a professor of medicine at Harvard Medical School and leader of the study reported Nov. 10 at the American Heart Association's annual conference in Orlando, Fla.
In a two-year follow-up, the number of deaths among patients given the ACE inhibitor captopril was virtually identical to those given valsartan, Pfeffer reports. Overall survival in both groups and among patients who got combined therapy was better than 80 percent.
The incidence of side effects such as cough, taste disturbance and rash was higher among those given both drugs together, and people getting the combined treatment were more likely to stop taking the medications.
A report of the results will appear in the Nov. 13 issue of the New England Journal of Medicine.
The good news of the study is that cardiologists can prescribe either drug with confidence, Pfeffer says. "Because both work, hopefully more patients will be getting these lifesaving benefits," he says.
"It's never been proven that using a receptor blocker gives all the benefits of an ACE inhibitor," he says. "This provides one more option in our armamentarium."
But cost is an issue that can influence treatment, says an accompanying editorial by Dr. Douglas L. Mann, a professor of medicine at Baylor College of Medicine.
Because valsartan costs from four to six times more than generic captopril, "ACE inhibitors remain the logical first-line therapy for high-risk patients after acute myocardial infarction [heart attack]," Mann writes.
But the trial does show that valsartan is "a safe and equally effective alternative" for patients who have problems with ACE inhibitor treatment, Mann writes. People with kidney problems, for instance, are usually kept away from these drugs.
That is a cheering finding, Pfeffer agrees, since therapy aimed at angiotensin II will continue indefinitely after a heart attack. "When you are on something for life, it's nice to know that you have an equally effective alternative," he says.
Pfeffer says he will give first consideration to ACE inhibitors for heart attack patients, but he declines to comment on the economics of the decision. "That's not my area," he says.