Which antidiabetic drug has an associated bladder cancer risk warning?

• A. Pioglitazone
• B. Metformin
• C. Liraglutide
• D. Gliclazide

Answer: (A)

The key idea is pharmacovigilance and cancer risk signals tied to specific diabetes medicines. Pioglitazone, a thiazolidinedione, carries a bladder cancer risk warning because observational studies suggested an association between its long-term use and bladder cancer, with risk increasing with higher cumulative dose and longer duration of therapy. Because of this, regulatory agencies require labeling that informs clinicians and patients to weigh the benefits against this potential risk, to monitor for symptoms like blood in the urine, and to avoid the drug in people with a history of bladder cancer or active disease. In practice, this guides careful patient selection and monitoring when considering pioglitazone.

The other drugs listed do not carry a bladder cancer warning in the same way. Metformin is primarily watched for gastrointestinal effects and rare lactic acidosis; liraglutide (a GLP-1 receptor agonist) has different safety considerations (like potential thyroid C-cell tumors in animal studies) but not a bladder cancer warning; gliclazide (a sulfonylurea) has its own hypoglycemia risk profile rather than cancer warnings.