Following reports of a link between pioglitazone and bladder cancer, the European Medicines Agency (EMA) carried out a safety review of the drug using all the available data from preclinical studies, the PROactive study (1) and population-based studies.
Pioglitazone is a second generation in the group of drugs known as thiazolidinediones. Pioglitazone is an oral treatment for diabetes which improves insulin sensitivity and may help the patient avoid or delay the need for insulin injections. As well as improving diabetes control, it has been shown to reduce the number of heart attacks in people living with diabetes.
In July 2011 the EMA’s Committee for Medicinal Products for Human Use (CHMP) found that: "There was a small increased risk of bladder cancer. However, because the Committee considered that there are a number of patients who cannot be adequately treated by other treatments, the Committee concluded that pioglitazone should remain as a treatment option, but that prescribers should carefully select patients and monitor their response to treatment." (2)
Diabetes UK calls to action
To assist both patients and prescribers the following advice is suggested
Advice to patients
- Immediately report to your doctor any blood in your urine or any bladder condition such as pain when passing urine or urinary urgency (needing to pass urine without delay)
- Make sure that your doctor looks at your treatment options at your next appointment.
- If you smoke, consider stopping. Smoking cigarettes is the principal preventable risk factor for bladder cancer in both men and women. In Europe it is estimated that two-thirds of bladder cancer cases in men and a third in women are caused by cigarette smoking (3)
- Certain workplace and environmental chemicals have been linked to bladder cancer, for example, substances used in the rubber and dye industries, so tell your doctor if you work or have worked in that type of industry.
Advice to prescribers
- Discontinue treatment with pioglitazone in those patients who have, or have had, bladder cancer, include those who are awaiting investigation of haematuria.
- Patients treated with pioglitazone for three to six months should have their treatment reviewed, with treatment discontinued in those not deriving sufficient benefit.
- Patients’ risk factors for bladder cancer should be considered before commencing treatment; these include age (most common in those older than 50), smoking, exposure to certain chemicals and treatment. such as those used in rubber and dye industries. (4)
The CHMP noted that there are some patients who cannot be adequately treated by other treatments and who will benefit from pioglitazone. Considering the risks associated with pioglitazone and its benefits to some patients, the CHMP concluded that the benefits outweigh the risks in those patients responding well to pioglitazone. Prescribers are advised to carefully select patients and monitor how they respond to treatment. (3)
Other position statements relating to the conclusion of the EMA:
The Association of British Clinical Diabetologists (ABCD)
Primary Care Diabetes Society (PCDS)