By: Ann Marie Aubin
The FDA recently approved a new drug that offers excellent benefits for people with type 2 diabetes. Metformin, marketed under the name Glucophage by Bristol-Myers Squibb, is an oral medication for people with non-insulin dependent diabetes. Although metformin has been in use in other countries for over two decades, its approval in the United States has taken 38 years. An earlier form of the drug was removed from the market because it caused serious complications. Metformin has been observed in other countries and can be used with confidence by most people with diabetes.
Sulfonylurea drugs work by stimulating insulin release. Metformin on the other hand does not increase insulin production. Instead, it increases sensitivity to insulin, and it increases the muscles’ ability to use the insulin. Glucose production in the liver is also decreased.
Metformin is the first alternative to sulfonylureas, which go by such names as Glucotrol, Micronase and DiaBeta. Metformin increases the body’s response to its natural insulin, lowering blood glucose levels without causing hypoglycemia, a common side effect of sulfonylureas.
Metformin does not promote weight gain, great news for those patients whose diabetes is aggravated by obesity. The drug also leads to small decreases in cholesterol and triglyceride levels.
Dr. Peter Lodewick, Medical Director of the Diabetes Care Center in Birmingham, Ala., does warn that while the drug is good for certain patients, it is by no means a miracle prescription.
“A doctor can switch a patient (from sulfonylureas) for the secondary benefits of weight loss and improved lipid profile. But there is not a difference in glucose control.”
All the doctors we asked agree that metformin is safe for most people, but in rare cases (3 per 100,000) patients can develop lactic acidosis as a result of metformin use. Lactic acidosis is a condition caused by the buildup of lactic acid in the blood and can be fatal.
Metformin is not recommended for patients with impaired kidney or liver function. Why? First, the kidney is responsible for metabolizing metformin and if the kidney is impaired, metformin levels can go too high. Second, although metformin is not processed by the liver, that organ is responsible for metabolizing lactic acid. If the liver is overloaded by diminished function or alcohol, metformin’s tendency to promote lactic acidosis is increased. If the tissue does not get enough oxygen (ischemia), lactic acid will also increase. For this reason, Dr. Gary Arsham, of the California Pacific Medical Center in San Francisco, notes that those with acute ischemic disease (such as heart attack patients) should avoid metformin.
Dr. Alan O. Marcus of South Orange County Endocrinology in Laguna Hills, Calif., agrees that the kidneys produce bicarbonate which buffers acids in the body and any impairment in this function will affect the level of acid in the body.
However, most users of metformin will experience mild gastrointestinal symptoms as the most severe side-effects, and these tend to abate once the body has a chance to get use to the new drug. For these patients, the benefits of metformin may outweigh the drawbacks.
Dr. Lodewick notes that, “In a study of 73 type 2 patients already taking insulin, adding 2500 mg per day of metformin decreased daily insulin requirements by 16%.”
Metformin has been used outside of the United States for more than 20 years and has been proven generally safe and effective for type 2 diabetics. You should consult your doctor about whether or not this drug is right for you.
D.I. consulted one popular pharmacy chain and found that 120 500mg. tablets (approximately one month’s worth of Metformin) costs around $63.