Biguanides reduce hepatic glucose output and increase uptake of glucose by the periphery, including skeletal muscle. Although it must be used with caution in patients with impaired liver or kidney function, metformin has become the most commonly used agent for type 2 diabetes in children and teenagers. Amongst common diabetic drugs, metformin, a biguanide, is the only widely used oral drug that does not cause weight gain.
- metformin (Glucophage). Metformin may be the best choice for patients who
also have heart failure.
- phenformin (DBI): used from 1960s through 1980s, withdrawn due to lactic
acidosis risk.
- buformin: also withdrawn due to lactic acidosis risk.
Metformin should be temporarily discontinued before any radiographic procedure involving intravenous iodinated contrast as patients are at an increased risk of lactic acidosis.