FDA adds warning for Botox, similar products; changes generic names

Washington - The Food and Drug Administration (FDA) has approved a new warning on Allergan's Botox and a similar product about the possibility of life-threatening breathing and swallowing problems, following up on an earlier announcement about tougher warnings.

Along with signing off on a boxed warning for Botox and Myobloc, made by Solstice Neurosciences, a private firm in Malvern, Pa., the FDA said it was changing the generic names for both products to avoid medication errors. The brand names and product formulations are not changing.

The affected products are:

- Botox (new established name: onabotulinumtoxinA)

- Botox Cosmetic (new established name: onabotulinumtoxinA)

- Myobloc (new established name: rimabotulinumtoxinB)

- Dysport (abobotulinumtoxinA), which was approved in April 2009 with the boxed warning and is not making any name or label changes at this time.

The products are designed to relax block nerve impulses to certain muscles, causing them to relax. They treat cervical dystonia, and two products including Botox are approved for cosmetic use to treat glabellar lines.

In April, the FDA had said it would require the agency's toughest boxed warning regarding the risk of adverse events when the effects of the toxin spread beyond the site where it was injected, and the agency also will require a medication guide explaining such risks to patients.

At the time, the agency also approved a similar product, Dysport, with the same boxed warning. Medicis Pharmaceutical, Scottsdale, Ariz., markets Dysport in the United States to treat frown lines, and Ipsen, based in Paris, will market the product to treat cervical dystonia.