DPP-IV inhibitors

Dipeptidyl peptidase-4 inhibitors, also known as DPP-4 or DPP-IV inhibitors, were first approved for the treatment of type 2 diabetes in 2007. This class of medicine works to increase the level of insulin in the body by preventing the breakdown of GLP-1, a naturally occurring substance that helps reduce blood glucose and stimulates the pancreas to produce insulin. In addition, these drugs help prevent the liver from producing an excess amount of sugar. The federal Agency on Healthcare Research and Quality (AHRQ) reports DPP-IV inhibitors reduce A1C levels by less than one point.

Who should use a DPP-IV inhibitor?

DPP-IV inhibitors may be prescribed when diet, exercise and other diabetes medications are ineffective at keeping blood sugar levels within a target range. In addition, this class of medication may be particularly useful for individuals who experience high spikes in their blood sugar after meals. While it is not known if DPP-inhibitors are safe and effective when used with insulin, they may be prescribed in combination with other diabetes medications.

Individuals with type 1 diabetes or those with diabetic ketoacidosis should not take a DPP-IV inhibitor. In addition, those with pancreatitis should consult with a physician about whether a DPP-IV inhibitor is right for them.

Medications in the DPP-IV inhibitor class

There are three generic forms of DPP-IV inhibitors available. Each is sold under its own brand name:

• Januvia (sitagliptin)
• Onglyza (saxagliptin)
• Tradjenta (linagliptin)

Another option for patients is a combination drug that includes both sitagliptin and metformin, another type of diabetes medication. This combination drug is sold under the brand name Janumet.

Common side effects and dosages of DPP-IV inhibitors

As a relatively new medication, there is not yet a consensus on the frequency and severity of side effects associated with DPP-IV inhibitors. Writing for ABC News shortly after the drug's approval, Dr. David Nathan, Director of the Massachusetts General Hospital Diabetes Center, commented that DPP-IV inhibitors are generally well-tolerated with few side effects. However, the AHRQ states that not enough is yet known about the side effects of these medications. Meanwhile, the Food and Drug Administration reports common side effects include upper respiratory infections and headaches.

DPP-IV inhibitors are typically taken once a day as a tablet.

Important: As with any treatment regimen, individuals should consult with a health care professional to discuss possible side effects and drug interactions before taking a DPP-IV inhibitor.