25.10 : Oral Hypoglycemic Agents: Sulfonylureas

Sulfonylureas are oral hypoglycemic agents utilized in treating type 2 diabetes. They are characterized by their unique sulfonylurea chemical structure. The family of sulfonylureas is divided into generations. First-generation sulfonylureas, including tolbutamide (Orinase), chlorpropamide (Diabinese), and tolazamide (Tolinase), trigger insulin release from pancreatic β cells and enhance peripheral tissues' insulin sensitivity. The second-generation members, such as glipizide (Glucotrol), glyburide (Diabeta), and glimepiride (Amaril), are preferred due to their enhanced potency and shorter duration of action.

The mechanism of sulfonylureas involves binding to ATP-sensitive potassium channels on pancreatic β cells. This interaction triggers cell membrane depolarization, leading to calcium influx and subsequent insulin release, effectively lowering blood glucose levels. Beyond stimulating insulin secretion, sulfonylureas reduce hepatic glucose production and augment peripheral glucose utilization, contributing to improved glycemic control. They are primarily prescribed when diet and exercise alone fail to manage type 2 diabetes and can be used solo or combined with other antidiabetic medications.

Despite their efficacy, sulfonylureas may cause adverse effects such as hypoglycemia, weight gain, and gastrointestinal disturbances. Hypoglycemia is the most common side effect, particularly in elderly patients or those with impaired kidney function. Careful dosage and monitoring are required to mitigate these risks. In conclusion, sulfonylureas are potent oral hypoglycemic agents that stimulate insulin release and improve insulin sensitivity, playing a critical role in managing type 2 diabetes. However, their use requires careful monitoring due to potential adverse effects.