CHICAGO Strong warnings about the dangers of giving antipsychotic drugs to patients with dementia have reduced use of the drugs in these patients by a "modest" 19 percent, U.S. researchers said on Monday.
Studies have shown that using antipsychotic drugs shortens the lives of elderly patients with dementia. The U.S. Food and Drug Administration issued a warning about the drugs in 2005.
"We concluded that it resulted in a modest reduction," said Dr. Ray Dorsey of the University of Rochester Medical Center in New York, who conducted a six-year study along with colleagues, said of the warning.
Dorsey said the group does not have enough data to say how many people benefited from the warning, and he did not cast the results as a sign of its success or failure.
"It's hard to say whether 20 percent is the right number," Dorsey said. He said previous health warnings have had mixed results.
The team analyzed nationally representative data on the use of atypical antipsychotic drugs between January 2003 and December 2008.
Dr. Paula Rochon of the Women's College Research Institute in Toronto suggested the warning did little to decrease use.
"Regulatory agency messages about the risks and benefits of antipsychotic therapy in the care of older people with dementia appear to have little effect on prescribing," she wrote in a commentary.
Antipsychotic drugs have been used widely to control behavioral problems in elderly dementia patients such as those with Alzheimer's disease.
Common antipsychotic drugs include Johnson & Johnson's Risperdal, known generically as risperidone; Eli Lilly and Co's Zyprexa or olanzapine; Bristol-Myers Squibb's Abilify or aripiprazole; and AstraZeneca's Seroquel or quetiapine.
Rochon and colleague Dr. Geoffrey Anderson said the warnings for antipsychotic drugs were not specific and should more clearly state the dangers of giving the drugs to older patients.
In the United States, once a drug is approved, doctors are free to use it in patients as they see fit, but companies are only allowed to market the drug for the approved use.
(Editing by Maggie Fox and Steve Gutterman)