drug used in the treatment of type II (non-insulin-dependent) diabetes (diabetes mellitus). Tolbutamide stimulates the release of insulin from the pancreas, thereby reducing the concentration of glucose in the blood.

Tolbutamide is one of a class of compounds called sulfonylureas and was the first agent of this type to be widely administered. Though discovered in the 1940s, sulfonylureas were not used until the mid-1950s to control type II diabetes. Tolbutamide is used to treat patients with mild to moderate diabetes that cannot be controlled by diet alone. It is quickly metabolized and is usually administered in divided doses. The drug has been associated with an increased mortality due to cardiovascular disease.