Oral hypoglycemic agents.

The sulfonylureas remain the most important oral agents, although their chronic hypoglycemic actions are still unexplained and the evidence on their relative efficacy is inconclusive. Data on relative safety suggest that chlorpropamide is the most toxic sulfonylurea but glyburide causes dangerous hypoglycemia as often as chlorpropamide. For many patients, good blood glucose control will be achieved by taking tolbutamide or another sulfonylurea 30 minutes before breakfast and the main evening meal. The biguanide metformin, which is as safe as glyburide, is of use in treating overweight diabetic patients who do not have cardiovascular, hepatic, or renal dysfunction.