Considerably more patients may benefit from effective antidiabetic drug

The antidiabetic drug metformin is not prescribed for patients with reduced kidney function because the risk of adverse effects has been regarded as unacceptably high. A study at Sahlgrenska Academy, University of Gothenburg, Sweden, has found that the risks have been substantially overrated. As a result, many more patients with diabetes may be able to enjoy the benefits of the medication.

Type 2 diabetes, a very common condition, is increasingly prevalent around the world. Keeping diabetes under control and preventing complications requires not only lifestyle changes, but drug therapy to reduce blood glucose levels.

Among the most effective and frequently prescribed antidiabetics is metformin, which has been shown in a number of studies to lower the risk of death from cardiovascular disease. Because the drug has been considered causing an increased risk of developing a rare but life-threatening adverse effect known as lactic acidosis, it is not prescribed for patients with reduced kidney function.

Researchers at Sahlgrenska Academy, University of Gothenburg and Uppsala University have conducted a study involving 51,700 patients with type 2 diabetes from the Swedish national diabetes register and found that the risks are exaggerated.

The Gothenburg study shows that metformin is more effective than other glucose lowering drugs when it comes to reducing the risk of cardiovascular disease, serious infection and death in patients with normal kidney function, but also in patients with mild kidney impairment.

"Furthermore, patients with mild to moderate kidney impairment do not run an elevated risk of adverse effects from metformin,"says Nils Ekström, a researcher at Sahlgrenska Academy. "Thus, the drug can be prescribed for many more patients with diabetes than is currently the case."

According to Nils Ekström, a number of other countries already recommend metformin for patients with mild kidney impairment. "It is important to keep in mind that the results are for patients with mild to moderate kidney impairment," he says. "Metformin still cannot be recommended for patients with severe kidney impairment and should be prescribed with great caution for those patients. During periods of acute illness with dehydration, metformin should never be used"