A bladder cancer cohort followed 193,099 persons aged 40 years or older and a cohort analysis of 10 additional cancers included 236,507 persons aged 40 years or older. Cohorts were from Kaiser Permanente Northern California.
Two related editorials discuss these findings and the impact/relevance of emerging data suggesting that establishing guideposts for how to tell the difference between “wait and see” and “act now” will help prevent every safety issue from reopening core questions about how drugs are evaluated by regulatory agencies.
The MHRA had previously issued a “Drug Safety Update” (2011) advising healthcare professionals that:
• patients with active bladder cancer or with a history of bladder cancer, and those with uninvestigated haematuria, should not receive pioglitazone
• prescribers should review the safety and efficacy of pioglitazone in individuals after 3–6 months of treatment to ensure that only patients who are deriving benefit continue to be treated. Pioglitazone should be stopped in patients who do not respond adequately to treatment (eg, reduction in glycosylated haemoglobin, HbA1c)
• before starting pioglitazone, the following known risk factors for development of bladder cancer should be assessed in individuals: age; current or past history of smoking; exposure to some occupational or chemotherapy agents such as cyclophosphamide; or previous irradiation of the pelvic region
• use in elderly patients should be considered carefully before and during treatment because the risk of bladder cancer increases with age - elderly patients should start on the lowest possible dose and be regularly monitored because of the risks of bladder cancer and heart failure associated with pioglitazone