Sulfonylureas: stimulate insulin secretion from beta cells.
The most common drug from this class of drugs is Glipizide, which acts by blocking K+ channels in the Beta cells. By partially blocking the K+ channels, the Beta cells spend more time in the Calcium release stage of cell signaling, leading to an increase in Calcium. The increase in Calcium will initiate more insulin release from each beta cell.
Metformin: reduces liver gluconeogenesis
Metformin reduces hepatic gluconeogenesis, absorption of glucose from the intestine, and insulin insensitivity. The exact mechanism of Metformin is unknown, but it is said to stimulate hepatic enzyme AMP-activated protein kinase.
These inhibitors slows the digestion of starch in the small intestine, so that glucose enters the bloodstream more slowly. Each glucose molecule can then be matched more effectively by an impaired insulin response or sensitivity. Alpha glucosidase inhibitors are effective by themselves only in the earliest stages of Type 2 Diabetes