[Therapeutic utility of biguanides in the treatment of NIDDM].

Metformin, one of the biguanides, is an oral hypoglycemic agent which acts primarily by decreasing hepatic glucose output and by increasing peripheral glucose disposal, therefore it has different hypoglycemic mechanism from that of sulfonylureas. The hypoglycemic effects of metformin are observed not only in obese NIDDM patients, but also in non-obese NIDDM patients. Moreover, addition of metformin improves glycemic control in patients with suboptimal glycemic control while taking maximum sulfonylurea therapy. Therefore, it is complementary to sulfonylurea therapy and represents a useful additional drug for the treatment, irrespective of obesity. The rare but serious condition of lactic acidosis should be kept in mind as a potential side effect, however, if metformin is avoided in patients with contraindications, the medication is very safe.