Pioglitazone is a medicine in the glitazone family which may slightly increase the risk of bladder cancer. This is still under investigation, but below is some information about the current concerns.
Why the concern about bladder cancer?
Since 2000, several studies have been running to try to identify a possible link between pioglitazone and bladder cancer. Initial studies were inconclusive. However, there were more spontaneous reports than expected of people on pioglitazone being found to have bladder cancer.
What are the facts?
A European-wide review in July 2011 found a small increase in the risk of bladder cancer in people taking pioglitazone, especially after long-term use.
What can we do to reduce the risk?
Assessing people for risk of bladder cancer before starting treatment could help to reduce this small risk and allow people for whom pioglitazone is the best option in terms of their diabetes, to benefit from the drug.
Risk factors for bladder cancer
- Older age
- Family history of bladder cancer
- Previous bladder cancer
- Blood in the urine
- Symptoms such as needing to pass urine frequently or pain on passing urine without a clear cause (such as a urine infection)
- Occupational exposure to certain dyes (used in textiles and industry, probably not standard hair dyes)
- Certain infections such as schistosomiasis (uncommon in the UK).
- The advantages of pioglitazone in terms of glucose control may outweigh the risks in some cases.
- For those taking pioglitaone, tell your doctor if you notice any blood in your urine or any other symptom relating to your urine or bladder.
- Doctors should review risk of bladder cancer before starting treatment and review the treatment every three to six months.
- Other factors may also be important as pioglitazone may increase the risk of fractures and of developing pneumonia.