Many types of anti-hyperglycemic drugs are available to help patients with type 2 diabetes control their blood sugar levels. Most of these drugs are aimed at using or increasing sensitivity to the patient's own natural stores of insulin.
For the most part older oral hypoglycemic drugs -- particularly metformin -- are less expensive and work as well as newer diabetes drugs. Metformin is generally recommended as the first-line drug.
Adding a second oral hypoglycemic drug is usually recommended if adequate control is not achieved with the first medication. For the most part, doctors should add a second drug rather than trying to push the first drug dosage to the highest levels.
Metformin (Glucophage) is a biguanide, which works by reducing glucose production in the liver and by making tissues more sensitive to insulin. Doctors recommend it as a first choice for most patients with type 2 diabetes who are insulin resistant, particularly if they are overweight. Metformin may also be used in combination with other drugs.
Metformin does not cause hypoglycemia or add weight, so it is particularly well-suited for obese patients with type 2 diabetes. Metformin also appears to have beneficial effects on cholesterol and lipid levels and may help protect the heart. It is also the first choice for children who need oral drugs.
Side Effects. Side effects include:
- A metallic taste
- Gastrointestinal problems, including nausea, and diarrhea
- Interference with absorption of vitamin B12 and folic acid
- Rare reports of lactic acidosis, a potentially life-threatening condition, particularly in people with risk factors for it. Major studies, however, found no greater risk with metformin than with any of the other drugs used for type 2 diabetes.
Certain people should not use this drug, including anyone with heart failure or kidney or liver disease. It is rarely suitable for adults over age 80.
Review Date: 04/01/2010
Reviewed By: Harvey Simon, MD, Editor-in-Chief, Associate Professor of Medicine, Harvard Medical School; Physician, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.