Diabetes Health Center

Combination Therapy for Diabetes

Many people with type 2 diabetes can manage blood sugar levels effectively on oral diabetes medications and lifestyle changes alone. Others will need to combine oral diabetes medications with injectable diabetes drugs in order to bring their blood glucose levels into a healthy range. Finding the right combination is the key to managing diabetes successfully.

For years, insulin was the only injectable diabetes medication available to help control blood sugar. Today, several newly approved injectable diabetes drugs are available. A growing number of medication options are also available, so doctors can individualize diabetes treatment with greater precision than ever before.

Combining Diabetes Medications for Optimal Effect

How will your doctor decide the best diabetes drug regimen for you? “The first principle is to make life as easy and therapy as effective as possible,” says Daniel Einhorn, MD, president of the American Association of Clinical Endocrinologists and medical director of the Scripps Whittier Diabetes Institute in La Jolla, Calif. “Type 2 diabetes is a lifelong problem. We want to choose therapies that people can easily live with.”

One factor is how comfortable people feel giving themselves injections. “Some patients are fine with injectable medications. Others will do anything not to have to give themselves injections,” says Eleftheria Maratos-Flier, MD, professor of medicine at Beth Israel Deaconess Medical Center in Boston.  

 The second principle of combination diabetes drug therapy, according to Einhorn, is choosing medication therapies that work in complementary ways. “Today we have a variety of drugs that work in very different ways, so combinations can be especially effective,” says Einhorn.

One of the most commonly used oral drugs, metformin (sold under the brand names Blumetza, Fortamet, Glucophage, and Riomet), is considered the cornerstone of most combination therapy. It works by decreasing the amount of glucose produced by the liver. Metformin can be paired with insulin or with a GLP-1 agonist, which stimulates insulin production.

Doctors may also combine insulin with a GLP-1 agonist and a thiazolidinedione oral medication  (Actos and Avandia), which sensitizes the body to insulin. For people comfortable with using injectable drugs, doctors may recommend one of the two new GLP-1 agonists, Byetta and Victoza.  For people who don’t want an injectable drug, the alternative is a DPP-4 inhibitor (Januvia, Tradjenta, and Onglyza), which is taken orally. Both of these classes of drugs work in a similar way and are considered equivalent.

Weighing the Pros and Cons of Drug Combinations

Minimizing adverse effects is also important. Some diabetes medications can cause blood sugar levels to drop too low, causing hypoglycemia. The oral medication sulfonylurea (DiaBeta, Glynase, Micronase), which has long been used for type 2 diabetes, poses a moderate risk of causing hypoglycemia. Many doctors prefer to prescribe metformin, which is much less likely to cause hypoglycemia. Metformin is often paired with a GLP-1 agonist because these new injectable drugs work only when blood sugar levels are high, further avoiding  hypoglycemia.