Metfor XR Mechanism of Action

Pharmacology: Pharmacodynamics: Mechanism of Action: Metformin hydrochloride is an oral antihyperglycemic agent which improves glucose tolerance in patients with type 2 diabetes mellitus, lowering both basal and postprandial plasma glucose. Metformin (as hydrochloride) decreases hepatic glucose production, decreases intestinal absorption of glucose, and improves insulin sensitivity by increasing peripheral glucose uptake and utilization. Unlike sulfonylureas, metformin does not produce hypoglycemia in either patients with type 2 diabetes or normal subjects and does not cause hyperinsulinemia. With metformin therapy, insulin secretion remains unchanged while fasting insulin levels and day-long plasma insulin response may actually decrease.
Pharmacokinetics: Gastrointestinal absorption of Metformin hydrochloride is slow and incomplete. Absolute bioavailability of a single 500-mg dose is reported to be about 50 to 60% which may be decreased or slightly delayed by food. Protein binding in plasma is negligible once the drug is absorbed; it is excreted unchanged in the urine. The plasma elimination half-life ranges from about 2 to 6 hours after oral doses. Small amounts are distributed in breast milk.