A recent report in Diabetes Care (doi 10.2337/dc10-2412) suggests a link between pioglitzone and the development of bladder cancer. This is preliminary, not definitive proof. Further study may erase all concern about bladder cancer. The only other diabetic drug in this class (thiazolidinediones) is rosiglitazone: its use was just recently drastically reduced by the Food and Drug Administration.
Will pioglitazone eventually be pulled from the market because of this? How many will suffer from bladder cancer in the meantime? Nobody knows at this point.
We have 11 classes of drugs to treat diabetes. Would you believe we don’t know all the potential long-term adverse effects of most of these drugs? It’s true.
To me, that’s more reason to control diabetes with diet modification, such as the Low-Carb Mediterranean Diet or Dr. Bernstein’s Diabetes Solution.