On April 30, 2009, the FDA announced a requirement that Botox and similar products must carry a black box warning on their labels. The new labels must highlight a warning about the risk of a potentially fatal complication if the effects of the drugs spread far beyond the injection site. Botox and similar products are used medically to treat muscle spasms and involuntary muscle movements. However, if the botulinum toxin spreads, it can cause botulism poisoning. There have been reports of hospitalizations and deaths in children with cerebral palsy who were treated with botulinum toxin. There have also been hospitalizations reported for adults being treated for muscle spasms, but suspected adult deaths could not be confirmed. Some symptoms of distant spread and botulism poisoning in Botox users include loss of bladder control, trouble breathing or swallowing, blurred or double vision, drooping eyelids, and sudden loss of strength or muscle weakness.
Botox and the related product Myobloc are also used for cosmetic purposes to treat frown lines between the eyebrows and excessive underarm sweating. The required doses for cosmetic use are generally smaller than for medical use, and the FDA told reporters that cosmetic use appears to be safe when the drugs are used as directed. Public Citizen, a health advocacy group petitioned the FDA for the black warning. According to Public Citizen, 180 serious adverse events and 16 deaths in the U.S. were attributable to Botox and Myobloc as of early 2008.
The products affected by the FDA black box warning requirement include Botox and Botox Cosmetic, sold by Allergan Inc., Myobloc, sold by Solstice Neuroscience and Dysport, a new product sold by Ipsen.