Antipsychotics Stay in Brain - Beware of Overmedication
Wednesday, March 20, 2002
Psychiatric drugs targeted- Researchers warn overmedication possible
after finding medications linger in brain
Patients taking drugs to treat psychiatric disorders including schizophrenia,
depression and dementia may be taking too much medication, a study suggests.
A report published yesterday in the journal Molecular Psychiatry found
that some antipsychotic medications linger in the brain longer than is
indicated by blood samples.
The findings by a team of researchers affiliated with the University
of Toronto raise questions about traditional prescribing procedures that
are based on medication levels found in the blood.
"The drugs that were sometimes being prescribed twice a day, even
three times a day, may be able to be given less frequently, based on these
findings," said study co-author Dr. Gary Remington, who is director
of the schizophrenia and continuing-care medication-assessment program
at the Centre for Addiction and Mental Health.
"It would mean that people could take their medication less frequently
and still maintain the same response."
Using positron-emission tomography, or PET scans, the scientists tracked
olanzapine and risperidone -- North America's most commonly used antipsychotic
drugs -- in the brains of 10 healthy volunteers and five patients being
treated for schizophrenia.
The researchers found that medication in a pill taken on a Monday could
be detected in the brain on Friday, although there was no trace of the
drug in the blood.
Beyond prescribing practices, the findings could have implications for
drug development, with a focus on what's happening in the brain rather
than in the blood, Dr. Remington said.
And the findings could lead to cost cuts for patients and health-care
insurers if less medication is prescribed, he added.
Dr. Remington is among a group of researchers examining whether antipsychotic
medications taken once every few days could be as effective as medications
taken daily. While preliminary results suggest it's possible to cut dosages,
Dr. Remington said, it is too soon for patients to request that their
medications be changed.
The research was financed in part by a grant from pharmaceutical company Eli Lilly Canada.