Older adults in the United States are popping prescription pills, over-the-counter drugs and dietary supplements in record numbers, and in combinations that could be deadly, according to researchers.
More than half of U.S. adults aged 57 to 85 are using five or more prescription or non-prescription drugs, and one in 25 are taking them in combinations that could cause dangerous drug interactions.
"Older adults in the United States use medicine and they use a lot of it," said Dr. Stacy Tessler Lindau of the University of Chicago Medical Center in Illinois, whose study appears in the Journal of the American Medical Association.
"While medications are often beneficial, they are not always safe," she said. She noted a recent report that estimated U.S. adults over 65 make up more than 175,000 emergency department visits a year for adverse drug reactions, and commonly prescribed drugs accounted for a third of these visits.
Nearly half of the potential drug-to-drug interactions could cause bleeding problems.
The blood thinner warfarin, often sold by Bristol-Myers Squibb Co. under the brand name Coumadin, was most commonly cited in potentially dangerous combinations. Some 2 million Americans take warfarin after a heart attack, stroke or major surgery. The team found warfarin was commonly teamed up with aspirin, a drug often taken to prevent heart attacks that also interferes with clotting.
Warfarin and the cholesterol-lowering statin drug simvastatin, which is sold by Merck & Co under the brand name Zocor, was another combination that could cause potential bleeding risks.
Among non-prescription drugs, they found many people were taking the popular nutritional supplement Ginkgo biloba in combination with aspirin, another potential cause of bleeding.
The team was reassured that they found no instances of people taking absolutely forbidden drug combinations, but the finding of widespread use of drugs that could cause major drug reactions was worrisome.
"We think the patient needs to know about these risks," one researcher said.