The impact of pioglitazone on bladder cancer and cardiovascular events.

Type 2 diabetes mellitus (T2DM) is a chronic condition with increasing prevalence and severe complications. Thiazolidinediones have been marketed since 1997 and are effective glucose-lowering drugs, but individual drugs within the class have been linked to serious adverse effects that resulted in the removal of troglitazone from the market, restrictions to rosiglitazone's use, and a warning added to pioglitazone's label. In 2007, a meta-analysis linked rosiglitazone to myocardial infarction (MI). Pioglitazone does not appear to share this risk. To the contrary, pioglitazone may reduce risk for MI. However, retrospective evaluations have increasingly linked pioglitazone to a higher risk of bladder cancer that appears to be time- and dose-dependent. Pioglitazone remains a medication appropriate for consideration in the management of T2DM; however, clinicians and patients should weigh its risks compared with alternatives, with a regular review of risks.