|By DAWN WALTON
Wednesday, March 20,
2002 - Print Edition,
Patients taking drugs to treat psychiatric
disorders including schizophrenia, depression and
dementia may be taking too much medication, a
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
"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
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
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.
The implications are far-reaching but are being
viewed skeptically by some physicians, the
"Historically we wag our fingers and tell
people to take their medication every day and
don't forget it," Dr. Remington said. "This is a
kind of reverse of what we've been saying for many
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
The research was financed in part by a grant
from pharmaceutical company Eli Lilly Canada.