UPDATE 3-Botox must carry strong warning on risks-U.S. FDA
* No problems seen with wrinkle use at approved dose
* Action comes after deaths, hospitalizations reported
* Allergan shares fall 1.3 percent (Adds consumer group, company comment, updates shares)
WASHINGTON, April 30 (Reuters) - Allergan Inc's (AGN.N) wrinkle-smoother Botox and rival injections must carry a strong warning about potentially deadly complications if the product spreads in the body, U.S. health officials said on Thursday.
The move is a response to reports of deaths and hospitalizations in adults and children treated with botulinum toxin for medical conditions.
"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 approved doses were used for cosmetic purposes, such as smoothing wrinkles between the eyebrows, Unger said.
Allergan shares fell 1.3 percent to close at $46.66 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 distant 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 (MRX.N) and Ipsen's (IPN.PA) Dysport.
The makers of Dysport announced its 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 treatment of spasticity, which is not approved, and neck spasms known as cervical dystonia.
The FDA said it could not attribute any of the adult deaths to botulinum toxin because the patients also had complications from other conditions.
Doses for cosmetic use are lower than medical applications, Unger said. If used as directed to fight wrinkles, "the risk of distant spread may well be zero," he said.
But people often receive more injections at more sites than recommended, he added.
"They are at somewhat of an increased risk depending upon the number of injections and the number of sites, and I think patients should know that," Unger said.
No more than five separate injections are recommended for smoothing frown lines around the forehead, he said.
Public Citizen's Health Research Group, which petitioned the FDA last year for stronger warnings, welcomed the move.
"For people considering this for cosmetic use, this will get them to think twice and that's appropriate," said Peter Lurie, deputy director of the consumer group.
In its petition, Public Citizen said it had reviewed 180 reports of muscle weakness, difficulty swallowing and other problems, including 16 fatal cases.
Allergan said in a statement the company would work with the FDA to update the label for Botox, which has been sold in the United States for nearly 20 years. The product's safety and effectiveness "are well understood, and reports of suspected distant spread have been rare," the company said.
Solstice Neurosciences "believes that the safety of Myobloc is adequately described in the current prescribing information" but is reviewing the FDA request, said Paul Nemeth, the company's vice president of regulatory affairs.
The FDA said doctors will be required to hand out patient-friendly guides explaining the risks. The agency also warned doctors that the products cannot be interchanged because they come in different dosage strengths.
(Additional reporting by Susan Heavey)
(Editing by Tim Dobbyn, Bernard Orr)
