Boxed warnings ordered for botulinum toxin

WASHINGTON, May 4 (UPI) -- The U.S. Food and Drug Administration says it has ordered safety label changes, including a boxed warning, for all botulinum toxin products.

The federal agency said it took the action because of reports that the effects of the botulinum toxin may spread from the area of injection to other areas of the body, causing symptoms similar to those of botulism. Symptoms include unexpected loss of strength or muscle weakness, hoarseness or trouble talking, trouble saying words clearly, loss of bladder control, trouble breathing, trouble swallowing, double vision, blurred vision and drooping eyelids.

"These symptoms have mostly been reported in children with cerebral palsy being treated with the products for muscle spasticity, an unapproved use of the drugs," the FDA said. "Symptoms have also been reported in adults treated both for approved and unapproved uses."

The agency said it also took the action because of the potential for serious risks associated with the lack of interchangeability among the three licensed botulinum toxin products.

The products required to add the new label are Botox and Botox Cosmetic (botulinum toxin type A), marketed by Allergan; Myobloc (botulinum toxin type B), marketed by Solstice Neurosciences; and a new FDA-approved product, Dysport (abobotulinumtoxinA), marketed by Ipsen Biopharm Ltd.