metformin and sitagliptin (Janumet)

  • Pharmacy Author:
    Omudhome Ogbru, PharmD

    Dr. Ogbru received his Doctorate in Pharmacy from the University of the Pacific School of Pharmacy in 1995. He completed a Pharmacy Practice Residency at the University of Arizona/University Medical Center in 1996. He was a Professor of Pharmacy Practice and a Regional Clerkship Coordinator for the University of the Pacific School of Pharmacy from 1996-99.

  • Medical and Pharmacy Editor: Jay W. Marks, MD
    Jay W. Marks, MD

    Jay W. Marks, MD

    Jay W. Marks, MD, is a board-certified internist and gastroenterologist. He graduated from Yale University School of Medicine and trained in internal medicine and gastroenterology at UCLA/Cedars-Sinai Medical Center in Los Angeles.

What is metformin and sitagliptin, and how does it work (mechanism of action)?

Janumet is a combination of two drugs, metformin and sitagliptin, that are used for reducing blood glucose (sugar) levels in individuals with type 2 diabetes. The FDA approved Janumet in March 2007.

Insulin is a hormone produced by the pancreas. It limits blood glucose levels by reducing the amount of glucose released by the liver into the blood and by increasing the removal of glucose from blood by muscle and fat tissues. Type 2 diabetes results when there is reduced sensitivity of muscle and fat to the effects of insulin. When the diabetes progresses, the pancreas produces less insulin. Both defects result in increased levels of glucose in the blood.

Metformin is an oral medication that lowers blood glucose by increasing the sensitivity of liver, muscle, fat, and other tissues to the effects of insulin. Increasing the sensitivity of tissues to insulin causes more glucose to be removed from blood and thereby reduces the level of glucose in the blood. In scientific studies, metformin reduced the complications of diabetes such as heart disease, blindness and kidney disease.

Sitagliptin is an oral drug that reduces blood glucose levels in patients with type 2 diabetes. Following a meal, incretin hormones such as glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) are released from the intestine, and their levels increase in the blood. GLP-1 and GIP reduce blood glucose by increasing the production and release of insulin from the pancreas. GLP-1 also reduces blood glucose by reducing the secretion by the pancreas of glucagon, a hormone that increases the production of glucose by the liver and raises the level of glucose in the blood. The net effect of increased release of GLP-1 and GIP is to reduce blood glucose levels. In addition, sitagliptin inhibits the enzyme, dipeptidyl peptidase-4 (DPP-4) that destroys GLP-1 and GIP and thereby increases the levels and activity of both hormones and thereby the release of insulin. As a result, blood glucose levels fall.

What brand names are available for metformin and sitagliptin?

Janumet

Is metformin and sitagliptin available as a generic drug?

GENERIC AVAILABLE: No

Do I need a prescription for metformin and sitagliptin?

Yes

What are the side effects of metformin and sitagliptin?

AND PRECAUTIONS The most common side effects of Janumet are:

Lactic acidosis is a serious side effect of metformin that occurs in one out of every 30,000 patients and is fatal in 50% of cases. The symptoms of lactic acidosis are weakness, trouble breathing, abnormal heartbeats, unusual muscle pain, stomach discomfort, light-headedness and feeling cold. Patients at risk for lactic acidosis include those with reduced function of the kidneys or liver, congestive heart failure, severe acute illnesses, and dehydration. Janumet should be discontinued immediately if lactic acidosis is suspected.

Quick GuideDiabetes Diet: Healthy Meal Plans for Diabetes-Friendly Eating

Diabetes Diet: Healthy Meal Plans for Diabetes-Friendly Eating
FDA Logo

Report Problems to the Food and Drug Administration

You are encouraged to report negative side effects of prescription drugs to the FDA. Visit the FDA MedWatch website or call 1-800-FDA-1088.

RxList Logo

Need help identifying pills and medications?

Use the pill identifier tool on RxList.

Subscribe to MedicineNet's Diabetes Newsletter

By clicking Submit, I agree to the MedicineNet's Terms & Conditions & Privacy Policy and understand that I may opt out of MedicineNet's subscriptions at any time.

Health Solutions From Our Sponsors