The U.S. Food and Drug Administration on Monday warned physicians that prescribing certain types of antipsychotic drugs to seniors suffering from dementia could expose them to an increased risk of death.

Dr. Thomas Laughren, director of the FDA’s Division of Psychiatry Products at the Center for Drug Evaluation and Research said the announcement was an update to a 2005 action, when the agency added warnings about increased heart attacks and pneumonia to drugs called atypical antipsychotics, which include Eli Lilly & Co.’s Zyprexa and Johnson & Johnson’s Risperdal, Reuters reports.

On Monday, the FDA said 11 other older drugs known as typical antipsychotics should carry the same warning. They include Pfizer Inc.’s Navane, Johnson & Johnson’s Haldol and Endo Pharmaceutical Holding Inc.’s Moban, as well as Loxitane, Mellaril, Orap, Prolixin, Stelazine and Trilafon, some of which have been discontinued, according to the FDA’s online database.

Under the FDA’s order both atypical antipsychotics and typical antipsychotics will now carry boxed warnings, the most serious a drug can carry, saying their use “is associated with an increased risk of death when used in elderly patients treated for dementia-related psychosis.”

The measure follows the results of two recently published epidemiological studies, involving more than 64,000 patients age 65 and older, which showed that mortality rates were great with both typical and atypical antipsychotics, if not higher with atypicals. Overall, the studies found that roughly 4.5 percent of patients with dementia taking these drugs died after 10 week of treatment, compared with 2.6 percent of patients receiving a placebo.

Antipsychotics are approved to treat schizophrenia and bipolar disease and not dementia, but doctors can use their discretion in prescribing them.