One of the most interesting drugs on pharmacy shelves is an old diabetes medication called metformin (Glucophage).
Where It Came From
In medieval Europe, healers used French lilac (Galega officinalis) to treat a range of symptoms, including some that might have been caused by type 2 diabetes. By the 17th century doctors were beginning to recognize diabetes and treat it with extracts of this plant.
Metformin was synthesized from compounds derived from French lilac in the 1920s. The drug was found to lower blood sugar in rabbits. Around the same time, however, physicians developed a way to use insulin to treat diabetes, and metformin languished for several decades.
In 1957, metformin was being used to treat type 2 diabetes in France. Its brand name, Glucophage, means glucose eater. It took until 1994 for the FDA to approve its use for type 2 diabetes in the US. It may now be the most widely used diabetes drug in the world.
Diabetes Drug Against Cancer
The story doesn’t end there, however. This inexpensive generic drug is getting attention because of other possible health benefits. The most exciting new discoveries have to do with metformin’s anticancer potential.
Preliminary research has shown that metformin may reduce the risk of some cancers or prevent their spread. There is evidence that metformin lowers the risk of breast or pancreatic cancers, perhaps by tamping down the activity of cancer stem cells (Annals of Translational Medicine, June, 2014). A large epidemiological study of more than one million people demonstrated that the drug lowers the chance of thyroid cancer in people with type 2 diabetes (PLoS One, Oct. 10, 2014).
It may also have a positive impact on prostate cancer. In one study, prostate cancer cells were less likely to form metastases in the presence of metformin (Biochemical and Biophysical Research Communications, Sept. 26, 2014). In another, men with diabetes were less likely to be diagnosed with prostate cancer if they were taking metformin to control blood sugar (European Journal of Cancer, Nov., 2014).
Although metformin is not a weight loss drug, it may also be useful in helping overweight people shed pounds, especially if they are insulin resistant (Experimental and Clinical Endocrinology & Diabetes, Jan, 2013).
As intriguing as its potential benefits may be, metformin does have side effects. Many people experience digestive distress early in treatment. Gas, cramps, nausea, indigestion and diarrhea are not unusual, though they often fade over time. Loss of appetite is another side effect that may contribute to weight loss.
Regular use of metformin can lead to vitamin B12 deficiency. This should be monitored with periodic blood tests and can be corrected with appropriate supplementation.
The most serious adverse effect of metformin is lactic acidosis. Although rare, this is a potentially life-threatening complication. Symptoms such as rapid pulse, palpitations, anxiety, lethargy, low blood pressure and severe nausea call for immediate medical attention.
Because metformin is available as an inexpensive generic drug, no pharmaceutical company is likely to pursue research on its anticancer applications. We hope that will not prevent further study of this fascinating drug.
More About Metformin
Should you wish to learn more about metformin, you will find information about the pros and cons of this fascinating drug in our diabetes chapter in the book, Best Choices from The People’s Pharmacy. Find out why you should not take metformin at mealtime if you are consuming a salad with low-fat salad dressing or frozen desserts containing guar gum.
Share your own experience with metformin below.