A new study has raised concerns that Botox injections may reach the brain, but the anti-wrinkle treatment's manufacturer has disputed the study's findings and the FDA says it's too early to draw conclusions.
Botox is made from a diluted form of botulinum toxin A. The Food and Drug Administration approved Botox in 1989, after testing in animals showed that the toxin did not travel to the brain. The approval was for treating uncontrollable blinking and misaligned (''lazy'') eyes.
By 2002, the FDA approved Botox for cosmetic reasons, including injecting the substance into facial muscles to minimize wrinkles and frown lines.
In the latest study, in the April 2 edition of the Journal of Neuroscience, researchers at Italy's Institute of Neuroscience injected rats and mice with botulinum toxin A in doses comparable to those given to humans. They noticed that within three days, neurons at the injection area -- the whisker muscles -- had passed on the toxin to the brain stem, where it disrupted normal brain activity.
''It is too early, based on these animal studies, to extrapolate to activity of the drug in humans,'' said Sandy Walsh, an FDA spokeswoman.
A spokeswoman for Allergan, Botox's manufacturer, said the study did not actually test Botox and said other studies have contradicted these findings.
''Data suggest that different preparations of botulinum toxin type A react differently in both the laboratory and in clinical practice,'' Leslie Bryant said.
The FDA, as a result of receiving adverse incident reports about Botox, has recently launched a safety review of the product.
-- JAWEED KALEEM
