In 1999, the FDA approved the drug Actos for Type 2 diabetes. Its popularity grew substantially after its primary competitor, Avandia, was linked to increased risk of heart attack. In 2010, the drug generated $3.4 billion in sales for its manufacturer, Takeda Pharmaceuticals.

Now, Actos is under fire, too.

The drug was recalled this summer in France and Germany in the wake of increased incidents of bladder cancer among people who took Actos. Similar reports have occurred in the U.S., where the FDA has allowed the drug to remain on the market provided warning labels are added to the packaging.