Among older patients with diabetes, pioglitazone (Actos) is associated with a significantly lower risk of heart failure and death than is rosiglitazone (Avandia), according to a retrospective cohort study published Aug. 18 in the British Medical Journal.
These findings support recent meta-analyses which also found that the risks associated with Avandia from the London-based-GlaxoSmithKline may be higher than those associated with Actos from the Deerfield, Ill.-based Takeda Pharmaceuticals.
David N. Juurlink, MD, head of the division of clinical pharmacology and toxicology, department of medicine at Sunnybrook Health Sciences Centre in Toronto, and colleagues examined 39,736 outpatients aged 66 years and older who were started on rosiglitazone or pioglitazone between April 1, 2002 and March 31, 2008.
The researchers noted that the composite outcome of death or hospital admission for either acute MI or heart failure was the endpoint. In a secondary analysis, each outcome was also examined individually.
During the six-year study period, the composite outcome was reached in 5.3 percent of patients taking pioglitazone and 6.9 percent of patients taking rosiglitazone, the authors wrote. After extensive adjustment for demographic and clinical factors and drug doses, they found that pioglitazone treated patients had a lower risk of developing the primary outcome than did patients treated with rosiglitazone (adjusted hazard ratio).
The investigators said that the secondary analysis revealed a lower risk of death (adjusted hazard ratio 0.86, 0.75 to 0.98) and heart failure (0.77, 0.69 to 0.87) with pioglitazone but no significant difference in the risk of acute MI (0.95, 0.81 to 1.11). One additional composite outcome would be predicted to occur annually for every 93 patients treated with rosiglitazone rather than pioglitazone, the researchers noted.
Based on their findings, Juurlink and colleagues said that continued use of rosiglitazone may not be justified given that rosiglitazone lacks a distinct clinical advantage over pioglitazone.