By David Liu, PHD

Saturday July 07, 2012 (foodconsumer.org) -- All diabetes drugs have side effects or adverse effects.  But a new study suggests diabetes drugs sulfonylureas including glipizide, glyburide and glimepiride are associated with increased risk of death, compared to another diabetes drug called metformin.

Sulfonylureas are a group of drugs indicated to help decrease blood sugar levels in type 2 diabetes patients by stimulating the production of insulin in the pancreas. In the past, all three drugs are considered comparable in terms of their effectiveness and safety. But the current study found all the three drugs are not the same in terms of their safety.

"We have clearly demonstrated that metformin is associated with a substantial reduction in mortality risk, and, thus, should be the preferred first-line agent, if one has a choice between metformin and a sulfonylurea," said Kevin M. Pantalone, D.O., of Summa Western Reserve Hospital in Cuyahoga Falls, OH, who as lead author conducted this study in conjunction with researchers from Cleveland Clinic in Cleveland, OH.

The study was based on data from 23,915 patients, mostly Caucasian, at an average age of 62 with type 2 diabetes who previous had received treatment with one of the four drugs and had their treatments recorded in the electronic health-record system at Cleveland Clinic.  All patients were followed for a period of two years.

Researchers found all three sulfonylureas were correlated with a more than 50 percent increased risk of death, compared to metformin and among diabetics with heart disease, only glimepiride did not seem to increase the risk of death compared to metformin.  Specifically, glipizide was linked to a 41 percent higher risk and glyburide with a 38 percent higher risk of death.

"Since many patients with type 2 diabetes also have coronary artery disease, our results could potentially impact the care of a large number of patients," Pantalone said. "In these patients, we now know that glimepiride appears to be safer than the other commonly prescribed sulfonylureas, glipizide and glyburide, available in the United States."

In the United States, about 26 million people, or 8 percent of the population, live with type 2 diabetes mellitus, according to the Centers for Disease Control and Prevention. Many diabetes patients also have other underlying medical conditions, including heart, or coronary heart disease.

The study was scheduled to be presented Sunday at The Endocrine Society's 94th Annual Meeting in Houston.