Can People With Type 1 Use Type 2 Drugs?
I've heard about people with type 1 using drugs meant for type 2 diabetes in addition to insulin. Is there a benefit to doing this?
Craig Williams, PharmD, responds
While people with type 1 diabetes must take insulin, there are times when additional therapies may play a role.
What to Know
There are now more than 10 different classes of medications that are available to help control blood glucose in people with diabetes. While medications that increase the natural production of insulin, such as sulfonylureas and meglitinides, are not helpful in people with type 1, other medicines may be.
Metformin, for instance, is generally prescribed for people with type 2 diabetes. It reduces the overproduction of glucose in the liver, which can occur in overweight people. But the medication also can benefit overweight adults with type 1.
Incretin-based therapies (oral DPP-4 inhibitors and injectable GLP-1 agents) work in multiple ways, including by reducing glucagon production (glucagon is a hormone involved in releasing glucose into the bloodstream) and slowing the movement of food through the stomach. This can be particularly helpful for people who have features of both type 1 and type 2 diabetes when it comes to post-meal glucose. In fact, an injectable medication with similar effects, pramlintide (Symlin), is approved by the Food and Drug Administration (FDA) for use in type 1.
Finally, due to their unique ability to eliminate excess glucose through the kidneys, SGLT-2 inhibitors (canagliflozin, dapagliflozin, and empagliflozin) can lower glucose levels in type 1 as well as type 2 diabetes.
Vigilance is warranted if you have type 1 and are thinking about using any of these medicines. First, none of them can replace insulin. Severe high blood glucose and diabetic ketoacidosis (DKA) can occur if insulin is stopped or even reduced too much. The FDA has issued a warning about SGLT-2s used for type 1 because they can cause a serious problem that requires immediate medical attention: euglycemic diabetic ketoacidosis (eDKA), which is DKA with near-normal blood glucose levels.
Second, the added glucose-lowering benefits are often quite modest, yet your new drug regimen will be more complex and more expensive. Plus, if you’re using an injectable type 2 medication on top of insulin, you’ll be doing additional injections daily. Increased side effects may accompany any added medications.
Ultimately, the best reason for a person with type 1 to combine therapies with insulin may be to reduce the risk of severe hypoglycemia. But more studies are needed to understand if the benefits of combo therapies outweigh the risks. In the meantime, for people with type 1 who have achieved glucose control without worrisome episodes of severe hypoglycemia, the added benefits of additional therapies are probably minimal.
Find Out More
You can find the American Diabetes Association’s recommendations for managing diabetes, as well as a greater discussion of these therapies, at diabetes.org/standards/glycemictreatment. For information on individual medications, visit fda.gov, then click on the “Drugs” tab at the top of the screen.
The mainstay of therapy for people with type 1 diabetes will always be insulin. However, some other medications work in ways that can be beneficial to people with type 1. Whether they offer enough benefit to be worthwhile is still being studied and will ultimately vary from person to person.