The US Food and Drug Administration has told manufacturers of licensed botulinum toxin products to strengthen warnings in product labeling and include a boxed warning, according to a [removed]recent announcement[/removed] from the agency.

The warning should describe the risk of adverse events when the effects of the toxin spread beyond the injection site, the FDA continued.

The FDA supports the development and implementation of a Risk Evaluation and Mitigation Strategy (REMS), which would “ensure that the benefits of the product outweigh the risks,” according to the statement. The strategy would include a communication plan, designed to deliver more information about the effects of botulinum toxin after local injection. The plan also consists of explaining that botulinum toxin products cannot be interchanged.  Furthermore, the REMS would also include a Medication Guide, describing the risks to patients.

To study the signal of serious risk regarding distant spread of toxin effects, the FDA has also required manufacturers to submit safety data after multiple administrations of the product in a specified number of children and adults with spasticity.

The FDA has approved botulinum toxin products for one or more of the following uses:  temporary improvement in the appearance of glabellar lines (frown lines between the eyebrows), treatment of strabismus (crossed eyes), blepharospasm (abnormal tics and twitches of the eyelids), cervical dystonia (involuntary sustained or repetitive contraction of the neck muscles), and primary axillary hyperhidrosis (severe underarm sweating).  For these uses, botulinum toxin is injected into the skin or into muscle tissue.

Healthcare professionals and patients are urged to report side effects from the use of Botox and Botox Cosmetic (Botulinum toxin Type A), Myobloc (Botulinum toxin Type B), and Dysport (abobotulinumtoxinA) to the FDA’s MedWatch Adverse Event Reporting program.

[Source: Original press release]