London, Nov. 22: The long-term effects of Botox, the anti-wrinkle drug favoured by ageing celebrities, are unknown, a leading neurologist has warned.
According to Dr Peter Misra, of the National Hospital for Neurology and Neurosurgery in London, Botox is being used “ahead of clear scientific evidence”.
In an editorial in the British Medical Journal, he says the drug, a derivative of the deadly botulism toxin, is used to treat conditions based on anecdotal evidence and small-scale studies.
The fastest growing cosmetic treatment, Botox injections are used to reduce wrinkles. The toxin affects nerve endings, preventing the brain from sending messages that make muscles contract. Sir Cliff Richard, Lulu and Christine Hamilton are among the celebrities known to have used the treatment. Madonna, Kylie Minogue and Liz Hurley are also rumoured to have used it.
Studies suggest that the drug can also help with migraines and Parkinson’s disease. Dr Misra said the toxin was licensed only for a few specific conditions in Britain, “based on clear scientific evidence of its efficacy and safety”. These conditions include muscle spasms and stiffness, twitching and excessive sweating.
“Botulinum toxin is reported to be useful in more than 50 conditions,” he added. “Some of the ‘off-licence’ indications are substantiated by some evidence, but its efficacy in other conditions is based on observations made in small numbers of patients.”
Studies show it affects the transmission of nerve impulses to the brain while a version of the poison plays a part in inhibiting neurotransmitters, he said.