Americans with diabetes nearly doubled their spending on drugs for the disease in just six years, with the bill last year climbing to an eye-popping $12.5 billion.
Newer, more costly drugs are driving the increase, said researchers, despite a lack of strong evidence for the new drugs' greater benefits and safety. And more people are being treated for diabetes.
The new study follows updated treatment advice for Type 2 diabetes, issued last week. In those recommendations, an expert panel told doctors to use older, cheaper drugs first.
And a second study, also out Monday, adds to evidence that metformin – an inexpensive generic used reliably for decades – may prevent deaths from heart disease while the newer, more expensive Avandia didn't show that benefit.
The studies, appearing in Monday's Archives of Internal Medicine, were both funded by federal grants.
In one, researchers from the University of Chicago and Stanford University looked at which pills and insulin that doctors prescribed and total medication costs. Diabetes drug spending rose from $6.7 billion in 2001 to $12.5 billion in 2007, a period when costs dropped for metformin.
More patients got multiple prescriptions as new classes of drugs came on the market. And more patients with diabetes were seeing doctors, increasing from 14 million patients in 2000 to 19 million in 2007.
Nearly 24 million Americans, 8 percent of the population, have Type 2 diabetes, which can lead to kidney failure, blindness and heart disease.
Current guidelines say doctors should prescribe metformin (about $30 a month) to lower blood sugar in newly diagnosed patients and urge them to eat healthy food and get more exercise.
Other drugs can be added later, on top of metformin, to help patients who don't meet blood-sugar goals. The updated guidelines don't include Avandia, which costs about $225 a month.