Using data collected from the General Practice Research Database, Canadian researchers have concluded through a nested case-control study that two or more years of daily use of pioglitazone—the active drug in Actos—almost doubled a user’s risk of developing bladder cancer.
It is estimated that there are approximately 20 million Actos users worldwide. Notwithstanding, this bladder cancer risk, the bladder cancer risk truly comes as no surprise. Preclinical data on pioglitazone reflected a marked increase in bladder cancer in rats. Further, an examination of accounts collected in the U.S. Food and Drug Administration’s (“FDA”) Adverse Event Reporting System led, in part, to a September, 2010 warning regarding pioglitazone use and potential side effects.
This recent study consisted of individuals with type 2 diabetes who were exposed to the drug. Additionally, the researchers utilized various control mechanisms to reduce any potential influence a user’s specific diabetes would have on the results, thereby further ensuring accuracy. The study found that the incidence of bladder cancer was higher among participants randomized to pioglitazone than those taking placebo to a degree of statistical significance.
In short, as an article from a French publication titled “Pioglitazone and the Risk of Bladder Cancer” reporting on the study suggests, “it can confidently be assumed that pioglitazone increases the risk of bladder cancer. It also seems that this association could have been predicted earlier.” Because in many researchers’ eyes the benefit of pioglitazone in reducing cardiovascular events is questionable, it may be wise for practitioners to conduct a risk/benefit analysis before writing an Actos prescription.