[1994-Dec-30] Metformin
http://web.archive.org/web/20070929152824/http://www.fda.gov/bbs/topics/ANSWERS/ANS00627.html
Metformin.cdx
T94-64 Susan M. Cruzan Dec. 30, 1994 301-443-3285 FDA APPROVES NEW DIABETES DRUG We have been receiving inquiries about the approval of metformin, a new drug for treatment of adult onset non-insulin dependent, or type II, diabetes, a serious disorder of blood sugar control. Type II diabetes afflicts 12 million Americans and can cause damage to the eyes, kidneys, heart and peripheral circulation. The following may be useful in answering questions. Patients with type II diabetes are generally advised to lose weight and maintain a strict diet. If these measures fail to control blood sugar levels, they are generally prescribed oral drugs and, if these fail, insulin injections. Metformin is an oral medication for controlling elevated blood sugar levels in type II diabetes. It differs from other currently approved antidiabetic drugs chemically and in how it works. It can be used together with currently available oral antidiabetic drugs. In March 1994, an FDA advisory committee voted unanimously to recommend that FDA approve metformin for people with diabetes who cannot achieve adequate blood sugar control with diet alone. At this meeting the president of the American Diabetes Association urged approval of metformin as a safe and effective drug that controls blood glucose by mechanisms different from currently available drugs. In people with diabetes, the pancreas does not produce enough insulin to control blood sugar, which then rises to harmful levels. Metformin and other oral anti-diabetic drugs lower these elevated blood sugar levels. Currently approved and marketed anti-diabetic drugs work by stimulating the pancreas to secrete more insulin. Metformin increases the body's response to its own insulin. Unlike the other drugs, metformin rarely causes hypoglycemia and generally does not cause weight gain. It may cause temporary anorexia (loss of appetite), abdominal discomfort or nausea. One concern with oral antidiabetic drugs -- including metformin -- is the potential risk of cardiovascular death. A warning to this effect is contained in the labeling for these drugs. Studies are under way to gain more information about this and other complications. Safety concerns about a related drug -- phenformin -- resulted in its being removed from the market in 1977. Phenformin was found to promote the development of lactic acidosis, a life-threatening buildup of lactic acid in the blood that was fatal in about one patient in one thousand treated for a year. Numerous studies with metformin and marketing experience in other countries have shown that, although it can cause lactic acidosis, the risk is much less than that of phenformin. Patients given metformin should be made aware of lactic acidosis symptoms -- malaise, rapid breathing, shortness of breath and severe weakness -- and be advised to contact their doctors immediately if they experience any of these. Lactic acidosis can be diagnosed with laboratory tests and requires that metformin therapy be stopped immediately and proper supportive care initiated. During worldwide marketing, patients on metformin have developed lactic acidosis at about one tenth the rate of those on phenformin. Metformin has been approved in about 80 countries and has never been withdrawn for safety reasons. The manufacturer, Lipha Pharmaceuticals Co. of New York, N.Y., submitted an application for marketing to FDA in September l993. A patient package insert will be included with metformin. Lipha will conduct an educational campaign to inform health professionals and patients about the drug's risks and benefits and appropriate precautions. The company will also conduct a postmarketing study in 10,000 patients to increase knowledge about potential safety problems. Metformin will be sold under the trade name Glucophage. The product will be distributed in the United States by Bristol-Myers Squibb of Princeton, N.J.