TUESDAY, March 1 (HealthDay News) -- Older adults carefully weigh the benefits and risks of cardiovascular disease prevention drugs before they decide whether to take them, finds a new study.

And if the benefits don't greatly outweigh the risks, they aren't that interested.

Researchers interviewed 356 people with an average age of 76 about their willingness to take medication that would reduce the risk of a heart attack over the next five years, but caused various side effects, including fatigue, dizziness, nausea and fuzzy or slowed thinking.

Eighty-eight percent of the participants said they would take the medication if it had no adverse effects and led to six fewer heart attacks per 100 people. That's the average risk reduction of current medications to prevent cardiovascular disease.

"In contrast, large proportions (48 percent to 69 percent) were unwilling or uncertain about taking medication with average benefit causing mild fatigue, nausea, or fuzzy thinking, and only three percent would take medication with adverse effects severe enough to affect functioning," wrote Dr. Terri R. Fried of Yale University School of Medicine and the VA Connecticut Healthcare System, and colleagues, in a news release.

The greater the benefit offered by the drug, the more willing people were to take medication.

"The central finding of this study was the large influence exerted by the presence of adverse effects on older persons' decisions about whether to take a medication," they noted.

The results suggest that clinical guidelines and decisions about prescribing these medications to older persons need to emphasize both benefits and harms, the researchers added.

"Guideline-directed therapy may be at odds with the preferences of the patients who are targeted by the guidelines," they concluded.

The study appears online Feb. 28 and in the June 27 print issue of the Archives of Internal Medicine.

More information

The U.S. National Institute on Aging has more about heart health.