Metformin (INN; trade names Glucophage, Riomet, Fortamet, Glumetza, Obimet, Dianben, Diabex, Diaformin, and others) (IPAEng: mɛtˈfɔrmɪn) is an oral anti-diabetic drug from the biguanide class. It is the first-line drug for the treatment of type 2 diabetes, particularly in overweight and obese people and those with normal kidney function, and evidence suggests it may be the best choice for people with heart failure. It is also used in the treatment of polycystic ovary syndrome.

Metformin is the most popular anti-diabetic drug in the United States and one of the most prescribed drugs in the country overall, with nearly 35 million prescriptions filled in 2006 for generic metformin alone. When prescribed appropriately, metformin causes few adverse effects—the most common is gastrointestinal upset—and, unlike many other anti-diabetic drugs, does not cause hypoglycemia if used alone. It also helps reduce LDL cholesterol and triglyceride levels, and may aid weight loss. , metformin is one of only two oral anti-diabetics in the World Health Organization Model List of Essential Medicines (the other being glibenclamide).(March 2007) , 15^th edition, World Health Organization, p. 21. Retrieved on 2007-11-19.

History

The biguanide class of anti-diabetic drugs, which also includes the withdrawn agents phenformin and buformin, originates from the French lilac (Galega officinalis), a plant known for several centuries to reduce the symptoms of diabetes mellitus. PMC: 209536

Metformin was first described in the scientific literature in 1957. It was first marketed in France in 1979, but did not receive approval by the U.S. Food and Drug Administration (FDA) for Type 2 diabetes until 1994. Bristol-Myers Squibb's Glucophage was the first branded formulation of metformin to be marketed in the United States, beginning on March 3, 1995. Generic formulations are now available.

Indications

The main use for metformin is in the treatment of diabetes mellitus type 2, especially when this accompanies obesity and insulin resistance. Metformin is the only anti-diabetic drug that has been proven to protect against the cardiovascular complications of diabetes. This was first shown in the United Kingdom Prospective Diabetes Study, a large study of overweight patients with diabetes. Unlike the other most-commonly prescribed class of oral diabetes drugs, the sulfonylureas, metformin (taken alone) does not induce hypoglycemia. Hypoglycemia during intense exercise has been documented, but is extremely rare. It also does not cause weight gain, and may indeed produce minor weight loss. Metformin also modestly reduces LDL and triglyceride levels.