The thiazolidinediones rosiglitazone (Avandia) and pioglitazone (Actos) have become popular drugs for type 2 diabetes in recent years for their potential to improve glycemic control by increasing insulin sensitivity. Concern over the safety of rosiglitazone was raised by a 2007 meta-analysis of 42 trials associating the drug with increased risk of myocardial infarction (MI) and cardiovascular death (N Engl J Med 2007 Jun 14;356(24):2457).
A new, large cohort study compared the safety of rosiglitazone vs. pioglitazone in 227,571 elderly patients (mean age 74 years) with diabetes who began taking 1 of the 2 drugs between July 2006 and June 2009. During a follow-up period of up to 3 years, there were 8,667 events of MI, stroke, heart failure, or death. The incidence rate per 100 person-years for the composite of these outcomes was significantly higher for rosiglitazone than for pioglitazone (9.1 vs. 7.42, p < 0.05) (level 2 [mid-level] evidence). The number needed to harm (NNH), calculated as the number of patients treated for 1 year to generate 1 excess event, was 60 for the composite outcome. Rosiglitazone was also associated with increased incidence rates of stroke (1.27 vs. 0.95, p < 0.05, NNH 313), heart failure (3.94 vs. 3, p < 0.05, NNH 106), and death (2.85 vs. 2.4, p < 0.05, NNH 222). Incidence rates of acute MI were not significantly different (1.83 vs. 1.63) (JAMA 2010 Jun 28 early online).
Also recently published was an update of the 2007 meta-analysis with 14 additional trials comparing treatment with vs. without rosiglitazone. Rosiglitazone was associated with increased risk of MI (odds ratio 1.28, 95% CI 1.02-1.63), but there was no significant difference in cardiovascular death (Arch Intern Med 2010 Jun 28 early online).
For more information, see the Rosiglitazone topic in DynaMed.
