The British Medical Journal has published the results of a retrospective cohort study that aimed to assess the risk of acute myocardial infarction, heart failure and death in patients with type 2 diabetes treated with rosiglitazone and pioglitazone.
The study collected data for 39,736 individuals aged 66 years and older who were prescribed pioglitazone (16,951) or rosiglitazone (22,785) between April 2002 and March 2008. The composite primary outcome was reached by 5.3% of the patients taking pioglitazone compared to 6.9% of those taking rosiglitazone. The adjusted hazard ratio was 0.83 with a 95% confidence interval between 0.76 and 0.91.
Each of the endpoints in the primary outcome was analysed individually and statistically significant reduction in death and heart failure in those taking pioglitazone. This study found no significant difference in the risk of myocardial infarction.
By using rosiglitazone rather than pioglitazone in 93 patients for a period of one year would result on one additional patient being harmed through experiencing the composite outcome. The authors of the study conclude that, "continued use of rosiglitazone may not be justified" especially since rosiglitazone offers no distinct clinical advantage over pioglitazone.
Action: Rosiglitazone continues to be linked to an increased risk of harm. Clinicians should consider whether continued use of this drug is appropriate in any circumstance.