After being hit with dozens of lawsuits and growing questions about product safety, GlaxoSmithKline Consumer Healthcare Inc. announced yesterday it will stop selling denture creams that contain zinc.
Excessive zinc intake can cause serious neurological problems and lead to numbness, tingling or weakness in the limbs as well as difficulty walking and balancing or anemia and other blood problems, the company said.
The company said it's a precautionary move designed to prevent any potential long-term health problems in people who use zinc-containing Poli-Grip in excess of the amount indicated on the label.
And they're also warning consumers who are using too much of the product to immediately stop and see their doctor if they have any concerns.
The decision to remove zinc from all Poli-Grip products came after the company received numerous reports of problems and mounting research indicated zinc-containing denture adhesives could cause problems in some patients.
"The product remains safe when used as directed, but because of these new reports, and because of the increased number of adverse reports that we've seen, we've taken this precautionary step to try to avoid further potential risks to people who would continue to use the product in excess of the label directions," said Howard Marsh, chief medical officer at GSK Consumer Healthcare in an interview.
The company has received about 400 reports from consumers with "neurological symptoms," with most of those reports coming from the U.S. in 2009. Four of the reports came from Canada, Dr. Marsh said. However, he said the reports came directly from consumers and weren't medically confirmed, so it's difficult to definitively link denture adhesive to their problems.
In addition, some studies have identified denture adhesives such as Poli-Grip as the source of excessive zinc exposure in some patients that caused serious health problems. For instance, a study published last year in the journal NeuroToxicology by researchers from Vanderbilt University found denture cream was responsible for excessive zinc levels and diminished copper levels in 11 patients. (Excessive exposure to zinc depletes copper in the body).
GSK will no longer sell Poli-Grip advanced care, Poli-Grip extra strength or Poli-Grip ultra fresh with zinc. But those products aren't being pulled from store shelves. Rather, they will be phased out as the company introduces the new zinc-free formulations in Canada, expected in April or May.
There are already some types of zinc-free Poli-Grip available in Canada: Poli-Grip original, Poli-Grip comfort strips and Poli-Grip denture adhesive powder.
Procter & Gamble markets Fixodent, another zinc-containing denture adhesive that has been identified as problematic in some scientific research. A company spokeswoman said there are no plans to remove zinc from the product and that it is safe when used as directed.
The U.S. law firm representing many patients in suits against denture cream makers said GSK's move will help many consumers, but that companies such as P&G should follow suit to prevent future harm.
The public is "still largely unaware of the dangers posed by zinc-based denture adhesives," Scott Nabers, partner at Blizzard, McCarthy and Nabers, said in a statement.