The linked study by Loke and colleagues (doi:10.1136/bmj.d1309) summarises the observational evidence of the adverse cardiovascular effects of thiazolidinediones (glitazones) in patients with type 2 diabetes.1 Meta-analyses of randomised trials yielded similar results: both available glitazones increase the risk of heart failure, with a higher risk of heart failure, myocardial infarction, and mortality with rosiglitazone than with pioglitazone. The process of accruing this evidence has confirmed the apparently narrow interest in profits of corporations that bring drugs to the marketplace.2 Much has also been revealed about the roles that regulators, prescribers, and patients can play in promoting patient safety⇑.

In North America, regulators used safety alerts to increase prescribers’ awareness of the increased risk of cardiovascular side effects with glitazones. Boxed warnings followed. The use of glitazones declined—more so for rosiglitazone than for pioglitazone, with threefold differences across US states in the use of rosiglitazone well into 2009.3 In September 2010, as revelations emerged of …