Biguanide
They are completely different from the hypoglycaemic sulfonamides both in its structur and its mode of action. They cause little or no hypoglycaemia in non-diabetic. Possible mode of action suggested is that they interfere with mitochondrial respiratory chains-promote peripheral glucose utilization by enhancing anaerobic glycolysis or they enhance binding of insulin to its receptors & potentiate its action. Other explanation is that they suppress hepatic glucon-eogenesis & inhibit intestinal absorption of glucose.Maturity onset (non-insulin dependet) obese diabetics, in whom diet alone has failed. Very unstable juvenile or maturity onset (non-insulin dependent) diabetics, where a combination of insulin and metformin is beneficial. In those diabetics where sulphonylureas and metformin, when given alone fail but a combination works.
500 mg orally twice a day or 850 mg orally once a day
1. Renal failure. 2. Cardiovascular collapse. 3. Diabetic ketoacidosis. 4. Severe hepatic insufficiency.
Patients should not consume alcohol as there is an interaction between Metfrmin and alcohol which could lead to increased risk of lactic acidosis.
G.I.disturbances,tolerence,lactic acidosis.