Metformin is a drug commonly used in the treatment of Type 2 diabetes. It is sold as a generic and under several brand names, including Glucophage, Glumetza, Riomet, and Fortamet. Both the American Diabetes Association (ADA) and the American Association of Clinical Endocrinologists (AACE) recommend metformin as a cornerstone of therapy for Type 2 diabetes when exercise and dietary changes aren’t enough to keep blood glucose levels in target range. The low cost of the generic forms along with a long history of use make it a good choice for many individuals with Type 2 diabetes.
Although metformin has helped many people lower their blood glucose levels, it does have some potential side effects that are worth knowing about. Understanding the risks and benefits of metformin is key to using it successfully. Take this quiz to test your knowledge of this popular diabetes medicine. (You can find the answers later in the article.)
1. How does metformin work to lower blood glucose levels?
A. It stimulates the pancreas to make more insulin.
B. It decreases the amount of glucose produced by the liver and makes it easier for cells to accept glucose from the bloodstream.
C. It slows the digestive system’s breakdown of carbohydrates into glucose, allowing more time for insulin to work.
D. It suppresses appetite, slows stomach emptying, and inhibits the release of glucagon (a hormone that raises blood glucose levels).
2. In addition to lowering blood glucose, metformin sometimes causes moderate weight loss.
3. In research studies, metformin use was associated with which of the following benefits in people with Type 2 diabetes?
A. Reduced risk of morning high blood glucose.
B. Reduced neuropathy (nerve damage).
C. Reduced retinopathy (damage to the retina, a membrane in the eye).
D. Reduced nephropathy (kidney disease).
4. Which of the following are potential side effects of metformin?
B. Gastrointestinal upset.
C. Vitamin B12 deficiency.
D. Heart attack.
5. Metformin should be used with caution by people with nephropathy (kidney disease), severe liver disease, or decreased kidney function.
6. Under which of the following circumstances should you remind your doctor that you are taking metformin?
A. Before an x-ray test that uses an injected dye.
B. Before surgery.
C. Before starting any new drugs, for your diabetes or for any other condition.
D. Before beginning an exercise regimen.
1. B and C. Metformin works by activating an enzyme called AMP-activated protein kinase (AMPK), that in turn signals the liver to produce less glucose and encourages cells to store glucose from the bloodstream (thus lowering blood glucose levels). AMPK also affects the body’s metabolism by inhibiting the production of cholesterol and fatty acids and lowering insulin resistance. Additionally, metformin may decrease the absorption of glucose by the gastrointestinal tract, allowing more time for insulin to work and reducing postmeal spikes in blood glucose level.