Der sås øget incidens af hyperplasi (hos hanner og hunner) og tumorer (hos hanner) i urinblærens epitel hos rotter, der var blevet behandlet med pioglitazon i op til 2 år.
An increased incidence of hyperplasia (males and females) and tumours (males) of the urinary bladder epithelium was apparent in rats treated with pioglitazone for up to 2 years.