Each year in the U.S., there are nearly 100,000 emergency hospitalizations for adverse drug events in adults 65 and older, says researcher Daniel S. Budnitz, MD, MPH, director of the CDC's Medication Safety Program.
"The most significant finding of this study was [that] of the thousands of medicines available to older adults, it's really a small group ... that causes two-thirds of the hospitalizations," he tells WebMD.
The blood thinner warfarin, insulin, oral anti-platelets such as aspirin, and oraldiabetes drugs led the list.
"Both blood thinners and diabetes medicines are critical drugs that can be lifesaving," Budnitz says. However, he says that ''these are medications that you do need to pay attention to," being sure the dose and timing are correct, among other measures.
High-risk medications, such as narcotics, only accounted for about 1% of the hospitalizations, the researchers found.
The study is published in The New England Journal of Medicine.
Tracking Bad Events From Drugs
The researchers used data collected between 2007 and 2009 from 58 hospitals around the country. The facilities participate in the CDC's drug event surveillance project.
The researchers looked at how often an adult 65 or older was hospitalized after emergency department visits for adverse drug events.
The researchers estimated that 265,802 visits to emergency departments for adverse drug events occurred from 2007 to 2009 for adults 65 or older.
Over a third of these visits, or nearly 100,000, required hospitalization. About half of the patients hospitalized were age 80 or older.
Unintentional overdose of medication was the most common reason, accounting for nearly two-thirds of hospitalizations.