The average price of insulin tripled between 2002 and 2013, according to a research letter published today in JAMA, and that has led to higher costs for diabetics. Meanwhile, the cost of noninsulin therapies has trended downward, the researchers found.
A major driver of the increasing cost is analog insulin, a man-made insulin developed in the 1990s, according to the study. Analog insulin is considered superior to the other man-made insulin, known as human insulin, which was first engineered in the 1980s to to be genetically identical to the body's naturally-produced insulin.
Analog insulin is faster-acting than human insulin, is considered more convenient to use and may lead to fewer low blood sugar reactions, says Dr. Bill Herman, a University of Michigan professor of medicine and epidemiology and co-author of the research letter.
But analog insulin is also more expensive, he says. A vial can cost $300 and diabetics generally need two to three vials a month, adds Herman, which he says can be hard to afford for those who have to pay out-of-pocket for their drugs.
Analog insulin now accounts for about 90 percent of the insulin market, says Herman, who adds that for many people with Type 2 diabetes, human insulin is safe and effective, in addition to being more affordable.
"The evidence that the advantages of analog insulin are worth the price for everyone with Type 2 diabetes is just not there, at least not in my mind," he says.
"I think providers should have a frank discussion with their patients, particularly those with Type 2 diabetes, about using the older, less expensive human insulin, if it's going to make the difference between being able to afford and take insulin," says Herman.
Insulin is a naturally-occurring hormone secreted by the pancreas. People with diabetes are prescribed insulin if their bodies don't produce it, as is the case with Type 1 diabetes, or their bodies don't use insulin properly, as with Type 2 diabetes.
The cost of insulin is increasing at a time of growing national anger over the skyrocketing costs of various prescription drugs.
Today's insulin products required significant research and development and are expensive to manufacture, says Herman. Still, "you have to balance that with the fact ... that the cost of the medications, even since the time that they were launched, has continued to go up each year," he says.
"There's just not a lot of transparency in terms of what is actually research and development and manufacturing costs, versus what is profit," he says.
Noninsulin therapies, which are less expensive than analog or human insulin, are also an option for some patients.
Herman and his co-authors say the increases in the cost of insulin "suggest a need to reassess the effectiveness and cost-effectiveness" of the noninsulin treatments.