Heart Attack Drugs Often Misprescribed
Powerful anti-clotting meds aren't adjusted for patient size, study finds
TUESDAY, Dec. 27, 2005 (HealthDay News) -- Emergency room doctors treating heart attack patients often fail to administer powerful clot-preventing drugs in the proper doses, a new study finds.
One common error is to overprescribe -- giving doses large enough to cause potentially dangerous bleeding, according to researchers reporting in the Dec. 28 issue of the Journal of the American Medical Association.
The problem is that the doctors tend to follow the rules too closely, said study author Dr. Karen Alexander, an associate professor of medicine at Duke University.
"In many cases they resort to standard dosing, which is appropriate for middle-aged men of normal body size and normal renal [kidney] function," she said. "But one size doesn't fit all."
For many patients -- the elderly, women, thin people, those with kidney problems -- "certain calculations are required to make sure the doses are in the clinical range," said Alexander. She believes that too often those calculations aren't being made.
Her team analyzed data from an ongoing study that is tracking treatment guideline adherence for more than 400 U.S. hospitals. The researchers identified more than 30,000 patients rushed to hospitals with heart attack symptoms during a nine-month period in 2004.
Such patients often get anti-clotting drugs, most notably heparin, within the first 24 hours, to help open arteries or keep them open. The analysis showed that 42 percent of those patients got doses outside the recommended range.
Patients who got too-large doses were more likely to have bleeding episodes, and they were also more likely to have extended stays in the hospital or to die. About 15 percent of major bleeding episodes in this group of patients could be attributed to excess dosing, the report said.
Alexander stressed that anti-clotting drugs are unquestionably helpful in the treatment of heart attacks and are safe when dosed correctly. "There are a lot of data encouraging physicians to use these medications because they are beneficial," she said. "There haven't been much data looking at how they are given."
The study on which the report is based is funded by four drug companies, the journal noted. "The message in this paper is not a particularly good one for drug companies, the idea that these drugs might be harmful," Alexander said. "It may not be a comfortable message, but it may be an important one."
There is a clear message for doctors in the report, she said.
"Hopefully, this will begin to get providers to be aware that it is important to consider dosing adjustments, particularly among high-risk populations such as women, the elderly, and those who are small," she said.
For more on heparin, head to the National Library of Medicine.