DURHAM, N.C. Older heart patients present unique challenges for determining the optimal dosages of medications, so a new study from researchers at Duke Medicine offers some rare clarity about the use of drugs that are used to treat patients with heart attacks.
For certain heart patients older than age 75, a half-dose of the anti-platelet drug prasugrel works about as well as the typical dosage of clopidogrel, according to a team led by the Duke Clinical Research Institute that looked at a sub-study of a large clinical trial.
"As people live longer throughout the world, it's increasingly important to establish appropriate treatments for conditions such as acute coronary syndromes that commonly occur later in life," said Matthew T. Roe, M.D., MHS, associate professor of medicine at Duke and lead author of a study published Aug. 20, 2013, in the journal Circulation.
"These patients are very vulnerable to side effects, including bleeding, if therapies are not properly dosed," Roe said. "Additionally, existing practice guidelines have few specific recommendations for older patients with acute coronary syndromes as little evidence has been accrued from prior clinical trials in this population."
People older than age 75 comprise less than 10 percent of the U.S. population, but account for 35 percent of patients with acute coronary syndrome (ACS), which includes a recent heart attack or unstable chest pain. ACS is typically treated with anti-platelet therapies.
Earlier studies, for example, had shown that the platelet inhibitor prasugrel reduced the risk of adverse outcomes compared with clopidogrel in ACS patients undergoing coronary stent implantation. Those studies used a 60-mg initial dose followed by a 10-mg/day maintenance dose.
At that dosage level, however, patients older than age 75 had an increased risk of intracranial and fatal bleeding, as did younger patients weighing 132 pounds or less. The r
|Contact: Sarah Avery|
Duke University Medical Center