We keep working our way through all of the diabetes medicines that are available. No matter how you feel about taking medicine to help manage your diabetes, you have to admit that today, in the year 2021, there are a lot of options to choose from! Are any of them perfect? No. Do they have side effects? Yes. But the point is that you have options. Granted, you may not tolerate a particular medicine or perhaps your health plan doesn’t cover the cost, and those are issues of concern. But chances are, in the whole mix of meds, there are one or two that will help you better manage your blood sugars.
This week, we’ll look at a much newer class of medicines called DPP-4 inhibitors.
What are DPP-4 inhibitors?
In 2006, the FDA approved a diabetes medicine from a brand-new class called DPP-4 inhibitors. DPP-4 stands for “dipeptidyl peptidase-4,” a type of enzyme. They’re also called “gliptins.” Sitagliptin (brand name Januvia) was the first drug in this class to be approved. To understand how DPP-4 inhibitors work, it helps to take a step back. When we eat, a type of hormone called incretin is released. Incretins, such as GLP-1, signal the body to release insulin, which, as you know, helps to lower blood sugar. Incretins also inhibit the release of glucagon from the pancreas. Glucagon is a hormone that works to raise blood sugar.
When the body makes incretins, DPP-4 removes them. This process works fine for people who don’t have type 2 diabetes, but it’s not a desirable action in people who do have diabetes. So the DPP-4 inhibitors work to block the enzyme and help the incretins do their job of triggering insulin release to lower blood sugar. Studies show that DPP-4 inhibitors can lower A1C by 0.5% to 0.8%.
There are now other DPP-4 inhibitors besides sitagliptin: saxagliptin (Onglyza), linagliptin (Tradjenta), and alogliptin (Nesina). These drugs also come combined with other medicines, like metformin and pioglitazone; brand names include Janumet, Jentadueto, Kazano, Komboglyze and Oseni. Now discontinued, Juvisync was a combination of sitagliptin and simvastatin, which is a cholesterol-lowering medicine.
How are DPP-4 inhibitors taken?
DPP-4 inhibitors are taken once a day, with or without food. They come in varying doses, depending on the type you take.
What are the side effects of DPP-4 inhibitors?
The main side effects of DPP-4 inhibitors include upper respiratory tract infections, headaches, skin rash, facial swelling and urinary tract infections (mostly linked to taking saxagliptin).
Gastrointestinal symptoms, such as diarrhea and nausea, may occur, too. These medicines have been linked with an increased risk for pancreatitis, which is a very serious condition that requires immediate attention. If you take a DPP-4 inhibitor and have severe stomach pain that may be accompanied by nausea and vomiting, seek medical attention right away.
What else should you know about DPP-4 inhibitors?
These medicines are usually prescribed as second- or even third-line forms of therapy; in other words, your doctor will likely first prescribe a drug such as metformin or a sulfonylurea before turning to a DPP-4 inhibitor.
DPP-4 inhibitors don’t cause low blood sugars, but you are at risk for lows if you take them along with a drug that can cause hypoglycemia, such as a sulfonlyurea.
DPP-4 inhibitors may reduce your appetite, which can be beneficial if you’re trying to lose weight.
If you take a DPP-4 inhibitor and are planning a pregnancy or become pregnant, talk with your doctor as to whether you should continue taking this medicine or switch to something else. DPP-4 inhibitors are not recommended for women who are nursing.
These medicines can expensive and as such, may not be covered by your health plan. Check into your coverage if your doctor prescribes one of them for you.
Want to learn more about the role of medicines in treating diabetes? Read the rest of diabetes educator Amy Campbell’s eight-part series on diabetes drugs, covering metformin, sulfonylureas, meglitinides, thiazolidinediones, SGLT2 inhibitors, alpha-glucosidase inhibitors, bile acid sequestrants and dopamine receptor agonists, non-insulin injectable diabetes medications, and insulin.