The biguanides are a class of drugs that share a common component of their chemical structure. They are used as anti-infective (mostly as antimalarials and antiseptics) and antidiabetic agents.
Antidiabetic biguanides (ADBs) include buformin, metformin and phenformin, all three of which work by reducing hepatic gluconeogenesis, amongst other actions, including sensitizing cells to the effects of insulin via increasing insulin receptor expression and increases the ability of the insulin receptor to communicate with the inner components of the cell. They are all useful only in the second subtype of diabetes mellitus (type II diabetes mellitus [T2DM]), as in type I diabetes mellitus very little residual insulin production is left.
Their historical origins of the ADBs can be traced back to the use of the European herb, Galega officinalis in the control of polyuria, which is often due to type II diabetes mellitus.