The FDA warns pioglitazone use longer than one year was associated with a 40 percent increase in risk for bladder cancer compared to never being exposed to the drug according to an on-going study.
Diabetes patients should tell their doctor if they have symptoms such as blood or red color in urine, an urgent need to urinate, pain while urinating, and pain in the back or lower abdomen.
The warning comes after a five-year study of more than 193,000 patients treated with the drug an average of two years.
The study shows although there is no overall increased risk of bladder cancer related to short-term use of Actos, patients who use the drug more than one year or who used the highest dose were at greatest risk of bladder cancer.
The warning comes just days after Germany and France banned use of the drug.
In response to the FDA warning, Takeda Pharmaceuticals, the Japanese company which makes Actos, stated it is committed to the drug and stressed the study showed short-term use of the drug was not associated with an increased risk of bladder cancer and use for more than two years was weakly associated with the increased risk.
Takeda is conducting a 10-year study through 2012 and said it will continue to investigate potential safety concerns. The company said they are working with the FDA to update prescribing information.
The FDA suggests physicians weigh the benefits of blood sugar control with pioglitazone against the unknown risk for cancer and recommends not prescribing the drug for patients with bladder cancer and to prescribe it cautiously for patients who have had bladder cancer.
Pioglitazone is the second medication in its class to be associated with serious side effects within the past year.
Last fall, the use of rosiglitazone (Avandia) was restricted in the United States because of concerns of increased risk of heart attack.
The FDA said it will continue to monitor data until the 10-year study is complete.