Tolbutamide is a first generation potassium channel blocker, sulfonylurea oral hypoglycemic drug sold under the brand name Orinase. This drug may be used in the management of type II diabetes if diet alone is not effective. Tolbutamide stimulates the secretion of insulin by the pancreas. Since the pancreas must synthesize insulin in order for this drug to work, it is not effective in the management of type I diabetes. It is not routinely used due to a higher incidence of adverse effects compared to newer second generation sulfonylureas, such as glyburide. It generally has a short duration of action due to its rapid metabolism, and is therefore safe for use in elderly diabetics.