The British manufacturer will cease manufacturing and marketing Super Poligrip Original, Ultra Fresh and Extra Care products in the U.S. The company plans to reformulate the creams without zinc.
Glaxo's voluntary action comes as hundreds of patient lawsuits are poised to go to trial, alleging Poligrip caused nerve damage, leading to a loss of balance, loss of sensation in the hands and feet, and leaving patients unable to walk.
"They made the right decision in the sense that it's going to prevent the crippling of more people," said attorney Andy Alonso of Parker Waichman Alonso LLP. "But it's too late for many of my clients, unfortunately."
Alonso represents more than a hundred users of denture cream in Miami federal court, where several hundred lawsuits are being consolidated. The plaintiffs say the makers of zinc-based creams failed to warn consumers about the risks of their products.
Alonso estimates about 30 million people in the U.S. wear dentures and use products like Poligrip.
One of the lawsuit plaintiffs, 62-year-old Ronald Beaver of Tamarac, Fla., used PoliGrip for years before he began feeling weak and developed a blood disorder four years ago. He's now able to work only two days a week at his moving company job and feels "run down" much of the time.
Told of GlaxoSmithKline's decision on zinc products, Beaver said he was "shocked" because the company had consistently denied any problems in the past.
"It's like a complete admission. They went from outright denial to a complete admission," Beaver said.
Lawyers suing Glaxo said Thursday the company's decision will put pressure on other makers of zinc-containing denture cream, most notably Procter & Gamble, which makes Fixodent.
Calls to the Cincinnati-based company were not immediately returned Thursday.
Glaxo markets several zinc-free denture adhesive products, including Super Poligrip Free, Comfort Strips and Powder. The company reported more than $520 million in sales of denture adhesives last year.
Denture creams containing zinc were first approved by the FDA 15 years ago, and the agency has never issued a safety warning on the products, according to industry group Consumer Healthcare Products Association.
Zinc is believed to help with adhesion, and the denture products are considered safe when used at recommended levels.
However, in 2008 researchers at the University of Texas Southwestern Medical Center in Dallas described a possible link between denture cream zinc and nerve damage.
The researchers noted that excessive zinc can purge the body of copper, a chemical needed for normal brain and nervous system functioning.
A copper deficiency can cause anemia, as well as weakness and numbness in arms and legs; difficulty walking and loss of balance; and eventually permanent paralysis.
"Our typical Super Poligrip and Fixodent client uses a wheelchair, walker or cane for mobility and many of them have hands so spastic that they resemble claws," said Eric Chaffin, a partner with Chaffin Luhuana, which represents several dozen patients.
Glaxo and P&G only began disclosing the zinc in their products after the University of Texas researchers' findings were published.