Dec. 4, 2009 -- Concerns that the diabetes drugs Avandia and Actos raise the risk for heart failure led the FDA to require label changes warning of the potential risk two years ago.
Now a new study suggests this concern might be unfounded, but it also raises questions about a different class of oral diabetes drugs that have been used since the 1950s: sulfonylureas.
Researchers reported that diabetes patients who used sulfonylureas had a higher risk of death from all causes and a higher risk of heart failure than diabetes patients who used the most widely prescribed diabetes drug, metformin.
Compared with metformin, also known as Glucophage, single-drug treatment with first- and second-generation sulfonylureas was associated with up to a 61% increased risk for death. Users of second-generation sulfonylureas had up to a 30% higher risk for congestive heart failure.
Patients treated with Actos or Avandia did not appear to have a greater risk for heart attacks than those treated with metformin.
As many as 180 million people worldwide have type 2 diabetes, and heart attacks and heart failure are among the major killers associated with the disease.
Over the past two decades, a host of drugs have been approved to treat diabetes. The drugs improve blood sugar control, but there have also been concerns that some may raise the risk of cardiovascular events in people who are already at high risk.
In an effort to explore the issue, researchers in the U.K. examined the treatment records of more than 91,000 diabetes patients enrolled in a national database between 1990 and 2005.
During the follow-up, almost 36,000 patients had heart attacks, 6,900 developed congestive heart failure, and just over 18,500 died.
Metformin was the most widely prescribed drug, followed by second-generation sulfonylureas. Many patients took more than one diabetes drug.
Among the major findings:
Compared with metformin, single-drug treatments with first- or second-generation sulfonylureas was associated with a 24% to 61% increased risk for death from all causes.
Compared to metformin, second-generation sulfonylurea use was associated with an 18% to 30% increased risk for heart failure.
Compared to metformin, treatment with Actos was associated with a 31% to 39% decreased risk for death.