If you’ve had Type 2 diabetes for a number of years, there’s a good chance you’re taking at least one drug to help control your blood glucose levels — and possibly two or more drugs, including insulin. Any changes made to your prescriptions will most likely have been based on problems you’ve had with previous therapies, including less than adequate blood glucose control.
While changes to your medical needs are a key factor in what your doctor prescribes, it’s also true that outside factors play a role — after all, new diabetes drugs are constantly being introduced, and certain older (and newer) drugs may fall out of favor. So how have diabetes drug prescriptions changed over the years, and what might explain these changes?
Drug ups and downs
A study published in November 2017 in the journal Diabetes Care sheds some light on prescribing practices over the last few years. Using electronic medical records, researchers looked at the drugs prescribed to over 1 million people, ages 18 to 80, with Type 2 diabetes between 2005 and 2016. They identified drugs used as first-line treatments, as well as those added later if needed to help boost blood glucose control.
As noted in an article on the study at Healio, the most popular first-line drug in both 2005 and 2016 was metformin. But over that period, it grew even more popular — from a share of 60% of study participants to 77%. At the same time, use of sulfonylureas as a first-line treatment dropped from 20% to 8%, and the rate for thiazolidinediones dropped from 11% to 0.7%. The use of insulin as a first-line treatment stayed similar, rising slightly from 8% to 10%.
When it came to add-on or second-line treatments, sulfonylureas were the most popular choice — notwithstanding their fall from 60% to 46% of prescriptions for this purpose. Use of DPP-4 inhibitors saw the biggest rise in second-line prescriptions, from 0.4% in 2006 to 20% in 2016. But insulin also saw a large increase in second-line use, from 7% in 2005 to 17% in 2016.
Link to hypoglycemia?
One factor that may explain why some drugs have fallen out of favor, while others have surged in popularity, is the risk of hypoglycemia (low blood glucose) associated with each drug.
In a study published in November 2017 in the journal Pharmacoepidemiology & Drug Safety, researchers looked at the risk of hypoglycemia associated with different kinds of oral diabetes drugs. They only looked at drugs taken alone for first-line treatment of Type 2 diabetes — including metformin, sulfonylureas, meglitinides, and thiazolidinediones — within a group of Medicaid enrollees in California, Florida, New York, Ohio, and Pennsylvania. The outcome used for their analysis was severe hypoglycemia within 180 days of starting on the drug.
As noted in an article on the study at Monthly Prescribing Reference, the researchers found that sulfonylureas carried the highest risk of hypoglycemia. Specifically, glyburide carried the highest risk, at 3.95 times the risk associated with metformin. Glimepiride came in second, at 2.57 times the risk, with glipizide in third at 2.03 times the risk. Next were the meglitinides: repaglinide at 1.21 times the risk of metformin, and nateglinide at 0.90 times the risk. The thiazolidinedione drug pioglitazone came in at 0.80 times the risk of metformin.
Based on their hypoglycemia risk, this study may help explain why sulfonylureas are less popular now than they used to be. And metformin’s relatively low risk of hypoglycemia, as shown in the study, may also account, in part, for its popularity. But although it wasn’t included in the study, insulin is well known to carry a substantial risk of hypoglycemia — yet it has increased in popularity, especially as a second-line treatment. This suggests that hypoglycemia risk alone can’t explain the rise and fall of various diabetes drugs.
(In the case of thiazoladinediones like pioglitazone, other health and safety concerns probably explain the fall in popularity seen in the first study.)
What’s your take on the possible causes of diabetes drugs’ popularity — have you switched your primary diabetes drug, or added a second drug? If so, why did you and your doctor decide on the change? Have you experienced hypoglycemia more while taking some diabetes drugs, compared with others? If so, was this a major reason for any switch you made? Leave a comment below!
Want to learn more about diabetes drugs? Read the “Diabetes Medicines” series from certified diabetes educator Amy Campbell, covering metformin, sulfonylureas, meglitinides, thiazolidinediones, DPP-4 inhibitors, SGLT2 inhibitors, alpha-glucosidase inhibitors, bile acid sequestrants and dopamine receptor agonists, and non-insulin injectable diabetes medications.