Patients treated with botulinum toxin type A (Botox and Botox Cosmetic) and botulinum toxin type B (Myobloc) for a variety of conditions have experienced adverse reactions, including respiratory failure and death, according to a February notice from the FDA.
The FDA is reviewing safety data from clinical trials of these products and postmarketing adverse event reports. The agency said there is no evidence of a defect in the product and that the reactions may be related to overdosing.
The reactions mimic the symptoms of botulism, which may include difficulty swallowing, weakness, and breathing problems, and appear to be related to the toxin spreading to areas of the body far from the injection site. More information is available at the FDA's Web site (http://www.fda.gov/cder/drug/early_comm/botulinium_toxins.htm).
