Adverse drug events (ADEs) cause an estimated 100,000 emergency hospitalizations for seniors every year, yet two-thirds involve just a handful of anticoagulants and diabetes medications, according to a new study in the New England Journal of Medicine.

Researchers from the Centers for Disease Control and Prevention (CDC) conducted the study and singled out four drugs and drug classes as the cause of most emergency visits. They are warfarin, oral antiplatelet medications, insulins, and oral hypoglycemic agents. Alone or together, they account for 67 percent of emergency ADE hospitalizations of adults 65 years and older. Warfarin was implicated in 33 percent of cases, lead author Daniel Budnitz, MD, director of CDC’s medication safety program, said.

In contrast, medications red-flagged as high risk or inappropriate by health authorities explained only 1.2 percent and 6.6 percent, respectively, of such hospital admissions.

“These data suggest that focusing safety initiatives on a few medicines that commonly cause serious, measurable harm can improve care for many older Americans,” Budnitz said.

“Doctors and patients should continue to use these medications but remember to work together to safely manage them.”