Australia to doctors: tell diabetics of ‘small absolute increased risk’ of bladder cancer from pioglitazone
(Oct. 7, 2011) Australian health officials – concerned over published reports in British and U.S. medical journals – now believe the country’s physicians should avoid prescribing pioglitazone for diabetics who had or have bladder cancer.
“Until there is a better understanding of the link between bladder cancer and pioglitazone, it is prudent to avoid pioglitazone in patients with bladder cancer or a history of bladder cancer,” said the Therapeutic Goods Administration (Australia’s version of the U.S. Food and Drug Administration) in a recent newsletter.
Additionally, the TGA advises doctors to tell other diabetic patients taking pioglitazone that they face a “small absolute increased risk of bladder cancer” with continued use of the drug.
However, the TGA said its advice “is based on assumptions rather than clinical evidence.”
The TGA’s concern was sparked by two medical journal articles. The first appeared in the prestigious British medical The Lancet. Published six years ago, the article raised the possibility that pioglitazone use for longer than 12 months may lead to an increased risk of bladder cancer. In considering cardiovascular outcomes of patients with type 2 diabetes, investigators observed 14 cases of pioglitazone takers who developed bladder cancer.
Pioglitazone is used to treat type 2 diabetes mellitus when diet and exercise prove insufficient to control the disease.
The second article was published in 2011 in the journal Diabetes Care. It described a pair of recent observational cohort studies involving diabetic patients age 40 and older the found an association between pioglitazone and bladder cancer. One of those efforts calculated the adjusted hazard ratio for bladder cancer in pioglitazone users to be 1.2.
In the U.S., pioglitazone is available under the brand name Actos. It is made by Takeda Pharmaceutical Co., based in Osaka, Japan.