Drugs Approved for Type 2 Diabetes Treatment

The treatment of type 2 diabetes has been transformed in the past decade with the introduction of new medications, drug classes, and treatment approaches. These advances offer diabetics a wider range of combination therapies able to provide tighter glycemic control over the long term.

The approved medications are broken down by drug class, each of which offers different mechanisms of action.

Dipeptidyl peptidase-4 (DPP-4) inhibitors work by blocking the DPP-4 enzyme which destroys the hormone incretin. Incretins help the body produce more insulin when needed and reduce the amount of glucose being produced by the liver when it is not needed. There are currently five DPP-4 inhibitors approved by the U.S. Food and Drug Administration (FDA):

• Januvia (sitagliptin)
• Galvus (vildagliptin)
• Onglyza (saxagliptin)
• Tradjenta (linagliptin)
• Nesina (alogliptin)

As per their name, incretin mimetics work by mimicking the action of incretins to stimulate the production of insulin. They also slow the rate of digestion so that glucose enters the blood more slowly.

There are five incretin mimetics currently approved by the FDA which are delivered by injection and used in people who have not been able to control their blood sugar with oral medications:

• Byetta (exenatide)
• Victoza (liraglutide)
• Trulicity (dulaglutide)
• Tanzeum (albiglutide)
• Lyxumia (lixisenatide)

Also known as GLP-1 receptor agonists, the drugs are used in combination with oral medications and come in prefilled injector pens. They are not insulin or to be used in place of insulin.

Selective sodium-glucose transporter-2 (SSGT-2) inhibitors are able to lower blood sugar by causing the kidneys to remove glucose from the body through urine. There are three FDA-approved drug options:

• Invokana (canagliflozin)
• Farxiga (dapagliflozin)
• Jardiance (empagliflozin)

Amylin analogs are manmade versions of the hormone amylin which are used by the pancreas to lower blood sugar levels. Amylin analogs are also delivered by injection and used alongside insulin for tighter blood glucose control. There is currently one FDA-approved option:

• Symlin (pramlintide acetate)

Sulfonylureas are the oldest oral diabetic medications and, until 1995, the only ones available for managing type 2 diabetes. Sulfonylureas work by stimulating the pancreas to release more insulin into the bloodstream.

There are several generations of sulfonylureas; the second and third are the most commonly prescribed. Of those currently approved by the FDA:

• First-generation: Orinase (tolbutamide), Tolinase (tolazamide), and Diabinese (chlorpropamide)
• Second-generation: Glucotrol (glipizide), Micronase (glyburide), and Diabeta (glyburide)
• Third-generation: Amaryl (glimepiride)

Biguanides lower the amount of glucose being produced by the liver while making the body more sensitive to insulin. There are two FDA-approved formulations of the same drug:

• Glucophage (metformin)
• Glucophage XR (extended-release metformin)

Alpha-glucosidase inhibitors delay the conversion of carbohydrates to glucose during digestion. This helps to regulate blood glucose levels and prevent sugars from peaking too high. There are two options currently approved by the FDA:

• Precose (acarbose)
• Glyset (miglitol)

Thiazolidinediones sensitize muscle and fat cells to accept insulin more readily. Both pose certain health risks that require specialist consultation before starting treatment. The FDA has approved two thiazolidinedione drugs in the U.S.:

• Avandia (rosiglitazone)
• Actos (pioglitazone)

In May 2007, the FDA has issued a safety alert regarding the risk of heart attacks and other cardiovascular events when taking Avandia. Similar concerns led to the banning of both Avandia and Actos in France and Germany.

Meglitinides can help stimulate insulin production if there is glucose in the blood. If the blood sugar is low, the drug is far less effective. FDA-approved options include:

• Prandin (repaglinide)
• Starlix (nateglinide)