ORLANDO – Dementia patients who have taken atypical and conventional antipsychotic medications have more adverse events than do patients with a history of only one medication, new research shows.
“It's hard to say there is a strong causal connection, but there is an association, and it gives physicians something to think about when they are prescribing–and perhaps overprescribing–drugs for dementia,” said Frank M. Ahern, Ph.D., one of the authors of the study, which was presented as a poster at the annual meeting of the Gerontological Society of America.
“These individuals are likely to be those whose behaviors do not respond to initial pharmacological therapy,” added the lead author, Ann Kolanowski, Ph.D., of the Pennsylvania State University in University Park.
Up to 90% of people with dementia (PWD) exhibit behavioral and psychological symptoms of dementia (BPSD) that can be controlled with antipsychotic medications. But although the newer atypical antipsychotics seem to have a better side-effect profile, little is known about how these drugs are used in community-dwelling PWD, said Dr. Ahern, professor of biobehavioral health at the university.
The retrospective study used the database of a managed care organization to identify 3,231 community-dwelling PWD who had at least one claim in the preceding 3 years.
A total of 260 (8%) had taken antipsychotic drugs, with most of this group (62%) having taken atypical medication. The remaining patients had taken either conventional medication (24%) or both (14%) during that time period.
In comparing this prescription information with claims data, the researchers found that not only was the use of any antipsychotic medication associated with more adverse events than no use, but that generally, atypical antipsychotics were associated with more problems than conventional antipsychotics. Patients who had a history of taking both types of medication over the study period had the most problems.
“More often than not, it looks like combination therapy–which really means more drugs–might be more risky,” said Dr. Ahern in an interview.
Combination therapy refers to the use of both types of drugs, but not necessarily at the same time, during the 3-year study period, Dr. Kolanowski said. “Because the data were taken from an administrative database, we had no way of determining whether these two different types of medication were actually taken together,” she said in an interview.
Specifically, compared with no medication use, the use of both types of medication had the highest risk for delirium (odds ratio 3.6), followed by atypical medications alone (OR 1.5). There was a reduced risk associated with conventional medication alone (OR 0.8).
Similarly, the use of both medication types carried more risk for depression (OR 3.6), compared with atypical medications alone (OR 2.73).
For falls, the use of both types of medication again carried the highest risk (OR 2.8), with similar risks for conventional therapy alone (OR 2.2), and atypicals alone (OR 2.1).
For femur fracture, a history of both types of medication had the highest risk (OR 3.7), followed by atypicals alone (OR 2.5), and conventional medications alone (OR 1.6).
And finally, for syncope, use of both medication types increased the risk (OR 2.8) while either medication alone decreased it.