Pioglitazone is used to control blood sugar levels in patients with Type 2 diabetes.
According to new research published in the British Medical Journal, taking the drug could increase a person's chances of developing bladder cancer by 63%.
Researchers were prompted to look into the health effects of pioglitazone after a number of bladder cancer cases were identified among people taking the drug in a trial in 2005.
Since then different studies have reported contradictory findings on the subject, PA reports.
In a new study, Canadian researchers looked at the data of more than 145,000 patients from the UK Clinical Practice Research Database, all of whom were newly treated with anti-diabetic drugs between January 2000 and July 2013, with follow-up until July 2014.
They set out to compare pioglitazone to other anti-diabetic drugs.
Overall, 622 of these patients received a diagnosis of bladder cancer during the follow-up period.
Researchers found that compared to other anti-diabetic drugs, pioglitazone was associated with an increased risk of bladder cancer.
This risk was heightened with increasing duration of use and dose.
"In this large population-based cohort study with up to 14.5 years of follow-up, pioglitazone was associated with an overall 63% increased risk of incident bladder cancer," the research team wrote.
In 2014, more than one million prescriptions for pioglitazone hydrochloride were dispensed in England, according to figures from the Health and Social Care Information Centre.