FDA Strengthens Warnings On Allergan's Botox

The U.S. Food and Drug Administration said Thursday it was strengthening warnings on Allergan Inc.'s (AGN) Botox and similar products about the possibility of life-threatening breathing and swallowing problems.

Specifically, the FDA said it would require the agency's toughest boxed warning regarding the risk of adverse events when the effects of the toxin - or the active ingredient used in the products - spread beyond the site where it was injected.

An agency safety review of Botox and another product, Myobloc, was touched off by reports of breathing problems and a "handful" of deaths in some patients when the products were being used for an unapproved, off-label use. Most of the deaths and serious problems were reported in children being treated cerebral palsy-associated limb spasticity. Neither product is approved for such use in the U.S.

Botox and Myobloc, made by Solstice Neurosciences Inc., a private firm in Malvern, Pa., are designed to block nerve impulses to certain muscles, causing them to relax. Both products are approved to treat cervical dystonia, or uncontrolled muscle contractions of the neck and shoulder muscles. Botox is also approved for cosmetic use to treat wrinkles between the eyebrows and to help control excessive underarm sweating.

-By Jennifer Corbett Dooren, Dow Jones Newswires; 202-862-9294; [e-mail]