|Mood Drugs Curl Brain
Cells in Rat Study
PHILADELPHIA, March 1 (UPI) -- Extreme doses of popular
prescription diet and depression drugs made lab rats' brain cells
shrivel or curl into corkscrews.
While the researchers said the
study raises questions about long-term use of such medicines, a
spokeswoman for the company that makes Prozac, one of the drugs
studied, said people would have to swallow hundreds of pills to
reach the kinds of doses given to rats in the experiment.
In the research, investigators
from Philadelphia's Jefferson Medical College over four days fed
rats toxic amounts -- up to 100 times the normal dose -- of the
depression-fighting drugs Prozac and Zoloft, or the obesity
treatments Meridia and Redux.
Three of the drugs -- Prozac,
Zoloft and Meridia -- are on the market. Redux was removed from the
market in 1997.
At the highest doses, nerve
endings suddenly swelled and started to curl, said lead author Madhu
Kalia, a Jefferson professor of biochemistry, molecular
pharmacology, anesthesiology and neurosurgery. Similar abnormalities
were seen in studies with the street drug Ecstasy, which has been
shown to destroy brain cells.
The study is published in the
March 6 issue of the journal Brain Research. Laura Miller, a
spokeswoman for Indianapolis-based Eli Lilly & Co., makers of
Prozac, said the doses given to the rats were too high to be
meaningful. Miller said it would be like a person taking 300
capsules a day of Prozac. "That's an extraordinary high dosage," she
Prozac has been on market about 12
years. Miller said no similar effects were seen in research leading
up to the drug's approval.
The drugs belong to a class of
medications called selective serotonin reuptake inhibitors and they
are designed to boost levels of the mood lifting chemical serotonin.
Kalia said it is unknown whether
therapeutic doses of the drugs over the long-term can produce the
same effects and what impact these shape changes have on behavior.
She plans other studies to answer these questions.
Kalia said that even though the
drugs have been rigorously tested, doctors should still be cautious
about their use. The changes in the rat brains were subtle and
similar effects would be difficult to pin down in humans.
"You can't assume it won't have an
effect on the structure of the brain," she said.
(c) 2000 UPI All rights reserved. Copyright 2000 by United Press
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