Drugs often used to treat elderly patients with dementia-related aggression and delusions can raise their risk of death, according to a study that reinforces new warning labels required on the medications.

The researchers pooled results of 15 previous studies on drugs known as atypical anti-psychotics and sold under the brand names Zyprexa, Risperdal, Seroquel and Abilify.

Among more than 5,000 elderly dementia patients, those taking any of the drugs faced a 54 percent increased risk of dying within 12 weeks of starting the medication, compared with patients taking dummy pills.

There were 118 deaths among the 3,353 drug users versus 40 in the 1,757-patient placebo group, or 3.5 percent compared with 2.3 percent. The risks were similar for each of the drugs.

The drugs are approved for treating schizophrenia and bipolar disease, not elderly dementia. But because schizophrenia-like symptoms are common in elderly patients with Alzheimer's disease or other dementia, doctors frequently prescribe the drugs to these patients, too. Such "off-label" uses are legal.

The study gave no information on the causes of death, but the Food and Drug Administration warned in April that the drugs have been linked to deaths from heart failure and pneumonia in elderly dementia patients. At the FDA's request, manufacturers recently revised their drug labels to include strong warnings of the increased risk of death.

Dr. Lon Schneider, a University of Southern California psychiatrist and the study's lead author, said the results should instill caution "but not a great sense of fear."

"These drugs are clinically needed and there are actually few alternatives" for elderly dementia patients, Schneider said.

Withholding the drugs from patients who need them could also prove dangerous, by increasing the chances they might harm themselves and others, he said.

The study appears in the Journal of the American Medical Association.

Dr. Ronald Landbloom of Zyprexa maker Eli Lilly & Co. said the drugs "can be very helpful with aggressive psychotic patients who are beating up caregivers and nursing home staff, and hurting themselves," but doctors need to be aware of the risks.

William Thies, scientific director of the Alzheimer's Association, said up to about half of all Alzheimer's patients develop problems the drugs can treat.

"The trade-off is clearly going to be this small risk," and for some patients, the risk is worth taking, Thies said.

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