How Does Actos Cause Bladder Cancer?
On June 15, 2011, the FDA issued a safety announcement warning physicians and the public that long-term use of diabetes drug Actos—for a year or more—might increase the risk of bladder cancer. This announcement was released after the agency evaluated the 5-year interim results from an ongoing 10-year study, which showed that the use of Actos for more than 12 months was associated with a 40 percent increased risk of bladder cancer.
Since that announcement, more patients have come forward to file an Actos lawsuit, seeking to hold manufacturer Takeda liable for failing to more thoroughly test the drug for safety, and for failing to warn of the serious risk of Actos bladder cancer.
How does this diabetes drug increase the risk of the potentially deadly disease?
How does Actos work?
Those with diabetes are already at a higher risk for bladder cancer, as was demonstrated by researchers from the National Cancer Institute. Collecting data from 500,000 people ages 50 to 71, they found that diabetes was most likely to raise risk for pancreatic and bladder cancers in men. In women, diabetes was most likely to raise the risk of stomach, anal, and endometrial cancers.
Both men and women who take Actos, however, are at an increased risk for bladder cancer, and so far, scientists aren’t sure why. The active ingredient in Actos is pioglitazone. This drug belongs to a class of medications called “thiazolidinediones (TZDs)” which have a hypoglycemic action. (Other drugs included in this class include Avandia.) In other words, they attach to the insulin receptors on cells throughout the body, causing them to become more responsive to insulin. As a result, the body is better able to remove glucose from the blood, lowering blood sugar levels.
What causes the link between diabetes and Actos bladder cancer?
There has been some evidence linking TZDs with cancer. Some studies have shown that TZDs may actually help decrease the risk of some cancers, including lung, colon, and thyroid. Others have shown the opposite. A 2007 study, for example, published in BMC Medicine, found an association between TZD use and cancer in patients with diabetes. This, combined with the FDA study results showing a link between pioglitazone and Actos bladder cancer, have left scientists confused as to the potential risk of TZDs.
Those who took Actos with no knowledge of a potential link with bladder cancer and were later diagnosed with the disease may want to seek the advice of an Actos lawyer. A thorough evaluation of an individual case may yield evidence that would support a successful Actos lawsuit.