Americans with diabetes have nearly doubled their spending on drugs for the disease in just six years. The bill last year climbed to $12.5 billion.
Researchers say newer, more costly drugs are driving the increase despite a lack of strong evidence for the new drugs' greater benefits and safety. Also, there are more people being treated for diabetes.
The new study follows updated treatment advice for Type 2 diabetes, issued last week. An expert panel is advising doctors to use older, cheaper drugs first.
And a second study, also out today, adds to evidence that metformin, an inexpensive generic used reliably for decades, may prevent deaths from heart disease while the newer, more expensive Avandia doesn't show that benefit.
The studies appear in today's Archives of Internal Medicine.