Diabetes patients who take drugs called sulfonylureas as an initial therapy have a higher risk of death than those who take the diabetes drug metformin, a new study says.
The British researchers said the findings suggest that it may no longer be appropriate to offer sulfonylureas as a first-line treatment.
Diabetes experts in the United States agreed that the study could have an impact on care.
The findings "will change the practice of glucose [blood sugar]-lowering therapy," said Dr Spyros Mezitis, an endocrinologist at Lenox Hill Hospital in New York City.
But he added that "more study is need to confirm this data," and use of the alternative drug, metformin, is not always the answer. "Metformin and other oral hypoglycemic agents have their drawbacks, and we will probably see earlier use of insulin in type 2 diabetics," Mezitis said.
Both metformin (brand names include Glucophage and Fortamet) and sulfonylureas (glyburide and glipizide) are commonly prescribed as first-line therapies for patients, and have been available since the 1950s.
The new study was funded by drugmaker Bristol-Myers Squibb, which makes Glucophage.
Researchers analysed data from thousands of people in the United Kingdom who were diagnosed with type 2 diabetes and began first-line blood sugar-lowering treatments between 2000 and 2012 and were followed for an average of three years.
Patients who took sulfonylureas only were 58% more likely to die from any cause than those who took metformin only, according to the study, which was presented at the annual meeting of the European Association for the Study of Diabetes in Barcelona, Spain.
The findings suggest "that treatment with first-line monotherapy [one-drug only] with sulfonylureas should be reconsidered," wrote a team led by Dr Craig Currie of Cardiff University.
Another US expert said sulfonylureas and metformin fight diabetes in different ways. Sulfonylureas work "by increasing insulin release from the beta cells in the pancreas," while metformin "acts by suppressing glucose production by the liver," explained Dr Patricia Vuguin, a paediatric endocrinologist at the Cohen Children's Medical Centre of New York in New Hyde Park, NY
Findings presented at medical meetings are typically considered preliminary until published in a peer-reviewed journal.
The US National Institute of Diabetes and Digestive and Kidney Diseases has more about diabetes medicine.