WASHINGTON (Reuters) - Allergan Inc’s wrinkle-smoother Botox and similar injections must carry a strong warning about potentially deadly complications if the product spreads in the body, U.S. regulators said on Thursday.
The move follows reports of deaths and hospitalizations in adults and children treated with botulinum toxin for medical conditions, health officials said.
“Botulinum products have benefits but also can cause serious problems so it’s important that anyone who administers or receives these products understand the risks involved,” Dr. Ellis Unger, acting deputy director of the Food and Drug Administration office that evaluates Botox, told reporters.
No definitive reports of serious harm have been seen when the injections are given at approved doses for cosmetic purposes, such as smoothing wrinkles between the eyebrows, Unger said.
Allergan shares fell 2.6 percent to $46.07 in afternoon trading on the New York Stock Exchange. Botox is a blockbuster product with 2008 sales topping $1.3 billion.
Botulinum toxin can relax or paralyze muscles and is used to smooth wrinkles and to treat conditions ranging from neck spasms to underarm sweating.
In some cases, the toxin can spread to other parts of the body. Possible complications include muscle weakness, trouble breathing or talking, blurry vision and loss of bladder control, the FDA said.
“The hospitalizations are very few. Deaths are very rare, but they have been reported,” Unger said.
A warning about the complications must be highlighted in a “black box,” the strongest type for prescription drugs, the FDA said. It applies to the three approved botulinum toxin products — Botox; Myobloc from Solstice Neurosciences Inc; and Medicis Pharmaceutical Corp and Ipsen’s Dysport.
The makers of Dysport announced the product’s approval earlier on Thursday and said the FDA had requested the boxed warning.
Most reports of harm in children involved treatment for cerebral palsy, an unapproved use, the FDA said.
The majority of problems seen in adults followed use of the products to treat spasticity, which is not approved, and neck spasms known as cervical dystonia.
The FDA said it could not attribute any of the deaths in adults to botulinum toxin because the patients also had complications from other conditions.
Allergan said in a statement the company would work with the FDA to update the label for Botox. An official at Solstice Neurosciences could not immediately be reached.
The FDA said doctors will be required to hand out patient-friendly guides explaining the risks. The agency also warned doctors not to interchange the botulinum products.
(Additional reporting by Susan Heavey)
Editing by Tim Dobbyn, Bernard Orr