Federal regulators have ordered that botulinum toxin  injections, including Botox, Botox Cosmetic and Myobloc, bear a new black box warning regarding their risk of potentially life-threatening complication when the effects of the toxin spread far beyond the injection site.  The black box, the Food & Drug Administration’s (FDA) most serious safety warning, will also apply  to Dysport, a new botulinum injection treatment just approved by the agency today.

Last February, the FDA launched a safety review of botulinum toxin injections, including Botox and Botox Cosmetic. The FDA said at the time that it had received reports of adverse reactions that resembled botulism infections in patients receiving the injections. The most serious cases had outcomes that included hospitalization and death, and occurred mostly in children treated for cerebral palsy-associated limb spasticity. Use of botulinum toxins for treatment of limb spasticity (severe arm and leg muscle spasms) in children or adults is not an approved use in the U.S. The FDA said that the adverse reactions may have been due to overdosing.

In addition to the new black box warning, the FDA said today that it will require that manufacturers develop and implement a Risk Evaluation and Mitigation Strategy [REMS], including a communication plan to provide more information regarding the risk for distant spread of botulinum toxin effects after local injection, as well as information to explain that botulinum toxin products cannot be interchanged. The REMS would also include a Medication Guide that explains the risks to patients, their families, and caregivers.

The FDA also said today that it is requiring the manufacturers to submit safety data after multiple administrations of the product in a specified number of children and adults with spasticity to assess the signal of serious risk regarding distant spread of toxin effects.

Botox, which is made with botulinum toxin type A, is approved for treatment of conditions such as blepharospasm (spasm of the eyelids), cervical dystonia (severe neck muscle spasms), and severe primary axillary hyperhydrosis (excess sweating).  Botox Cosmetic and  Dysport, which also use botulinum toxin Type A,  are approved for temporary improvement in the appearance of moderate to severe facial frown lines. A fourth product, Myobloc,  is made from botulinum toxin Type B and is approved for the treatment of adults with cervical dystonia.

The consumer advocacy group, Public Citizen had petitioned the FDA to issue warnings to doctors about  hospitalizations and deaths associated with the use of botulinum toxin products. The group had pressed for a black box warning.  At the time of the petition, the group said that their had been 180 serious adverse events and 16 deaths in the United States associated with botulinium toxin injections.