Federal regulators are calling on Proctor & Gamble, and other manufacturers of denture adhesive products, to remove zinc from their denture cream due to a risk of zinc poisoning, which could cause users to suffer severe neurological injury.
In an FDA letter to all denture adhesive manufacturers sent out last week, the agency indicates that it has seen a growing number of reports of zinc poisoning from denture cream products, such as Fixodent and Super Poligrip.
The agency is calling on manufacturers to take a number of steps to remedy the denture adhesive problems, including the removal of zinc from the products or significant label changes to warn consumers.
According to the FDA, research indicates that the side effects of denture cream with zinc can include zinc toxicity and neurological damage, including symptoms of myeloneuropathy of the extremities and blood dyscrasias.
Myeloneuropathy is neurological damage often caused by copper deficiency. It can manifest as tremors and weakness in the extremities and difficulty walking. Blood dyscrasia is a catch-all term for unspecified blood disorders, usually due to abnormal material in the blood.
The FDA letter says that those most at risk include people who use excessive amounts of denture cream to address ill-fitting dentures.
GlaxoSmithKline already agreed to reformulate Super Poligrip to remove zinc last year. However, Proctor & Gamble has denied that zinc in their denture cream products is causing any problems, and continues to sell Fixodent denture adhesive with zinc.
The FDA said that a number of factors may be contributing to the reports of denture adhesive zinc poisoning, including the excessive overuse of cream by some consumers and labels that do not clearly warn about the presence of zinc or the risk of problems.
The FDA made four recommendations to manufacturers to address the denture adhesive zinc poisoning problems, including:
- Performing a risk analysis of their labeling.
- Conducting a human factors study to assess consumer understanding of labeling and potential misuse of their products.
- Modifying the labeling to clearly indicate that the denture cream contains zinc and defining maximum safe usage in clear terms.
- Removing zinc from denture cream products and replacing it with something that has less health risks for consumers.
The FDA is requiring all denture adhesive manufacturers to acknowledge that they have received the letter and also reminded the manufacturers that they are required to report adverse events to the agency.
A growing number of Fixodent lawsuits and Super Poligrip lawsuits have already been filed against Proctor & Gamble and GlaxoSmithKline for allegedly failing to adequately warn that their denture cream contains zinc or that excessive use of the product may cause severe and debilitating neurological damage when too much zinc enters the body.
According to allegations raised in the lawsuits, increased levels of zinc in the body can deplete copper levels, causing a condition known as hypocupremia, which is known to increase the risk of significant neurological problems that can leave users with permanent and debilitating physical injuries, such as neuropathy, numbness, tingling, pain, weakness, loss of sensation, loss of balance, paralysis and difficulty breathing.
Super Poligrip settlements have reportedly been reached in most of the lawsuits filed against GlaxoSmithKline, and the first Fixodent trial in the federal denture adhesive litigation is expected to take place later this year.