A majority of the emergency hospitalizations for bad events related to medication use in old U.S. adults stem from four common medications, according to a new study in the New England Journal of Medicine Monday.

The study was conducted by researchers from the Centers for Disease Control and Prevention of U.S.

There are nearly 100,000 emergency hospitalizations for adverse drug events in older Americans, says researcher Daniel S. Budnitz, MD, MPH, director of the CDC's Medication Safety Program.

And the four types of medication -- two for diabetes and two blood-thinning agents -- account for two-thirds of those drug-related emergency hospitalizations. They most often cited: warfarin (Coumadin, Jantoven); insulin; antiplatelet drugs such as aspirin and clopidogrel (Plavix); oral hypoglycemic agents.

"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.