Drugs, such as phenformin (DBI and DBI-TD), have also been used in treating diabetes. They do not stimulate the pancreas to produce more insulin but prevent glucose uptake from the intestine, prevent gluconeogenesis, and promote the breakdown of glucose, among other actions. Although these drugs are not now available in the United States, a new phenformin called metformin is being tested. It is found to be less of a cause of lactic acidosis, a side effect seen in the use of the earlier drugs.