Metformin (brand names Glucophage, Glucophage XR, Fortamet, Riomet, Glumetza, and others) is believed to be the most commonly prescribed diabetes medicine in the world, with more than 48 million prescriptions written in 2010 in the United States alone. Now, new research from the University of Gothenburg in Sweden suggests that this drug may be useful for treating even more people than previously thought.
Metformin is an oral medicine for Type 2 diabetes that belongs to a drug class known as biguanides. It helps lower blood glucose levels by making muscle and fat cells more sensitive to insulin and by preventing the liver from making excess glucose. The medicine also lowers triglyceride (blood fat) and cholesterol levels and does not cause weight gain. Beyond lowering blood glucose and lipid levels, research has suggested that metformin may reduce the risk of death in people with Type 2, lower cancer risk, increase lifespan, and improve heart health.
Although metformin is generally considered safe, it has been known to cause a rare but serious side effect called lactic acidosis (a condition in which lactic acid builds up faster in the bloodstream than it can be removed), and so is not prescribed to people with reduced kidney function. But recently, researchers in Sweden looked at nearly 51,700 men and women with Type 2 diabetes from the Swedish national diabetes register who were being treated with oral diabetes medicines or insulin and who had varying degrees of kidney function.
The researchers discovered that the risks of metformin to people with mild kidney impairment have been overstated. They also found that metformin was more effective than other blood-glucose-lowering drugs at reducing the risk of cardiovascular disease, serious infection, and death in people with both normal kidney function and with mild kidney impairment.
“Patients with mild to moderate kidney impairment do not run an elevated risk of adverse effects from metformin. Thus, the drug can be prescribed for many more patients with diabetes than is currently the case,” noted study author Nils Ekström, who added that various countries already recommend metformin for people who have mild kidney impairment. He further noted, however, that “Metformin still cannot be recommended for patients with severe kidney impairment and should be prescribed with great caution for those patients.”
To learn more about the research, read the article “Considerably More Patients May Benefit From Antidiabetic Drug, Study Suggests” or see the study in the journal BMJ Open. And for more information about metformin, read the entry on this medicine in our series, “Diabetes Drugs.”