Clinical Pharmacokinetics of Metformin

Metformin, the only biguanide oral antidiabetic agent available, was first used clinically in the late 1950s. Metformin remains the first-line pharmacologic treatment for type 2 diabetes patients. It can be used as a single agent or in combination therapy with other antidiabetes agents, including insulin. Metformin is absorbed predominately from the small intestine. It is rapidly distributed following absorption and does not bind to plasma proteins. It is excreted unchanged in urine. The elimination half-life of Metformin during multiple dosages in patients with good renal function is approximately 5 hours.