Glipizide

Glipizide is a second-generation sulfonylurea antidiabetic medication used to improve glycemic control in adults with type 2 diabetes and, in some settings, in pediatric patients aged 10 years and older when diet and exercise alone are insufficient. It acts by stimulating pancreatic beta cells to release insulin. The drug binds to sulfonylurea receptors on beta-cell membranes, closing ATP-sensitive potassium channels, which leads to cell depolarization and insulin secretion in the presence of circulating glucose. It is typically used as part of a comprehensive diabetes management plan that includes diet and exercise and may be combined with other glucose-lowering agents.

Glipizide is available as immediate-release tablets and extended-release tablets. The usual starting dose is 5 mg once daily with breakfast for the immediate-release form, or 2.5 mg once daily with the first meal for the extended-release form, with gradual titration to achieve glycemic targets (up to 20 mg daily in most regimens). Onset of action for the immediate-release form is generally within 30 minutes to an hour; extended-release formulations provide more prolonged activity. It is extensively metabolized in the liver, primarily by CYP2C9, and eliminated in the urine and feces. The half-life is approximately 6–12 hours, and clearance may be reduced in hepatic impairment.

Contraindications include hypersensitivity to sulfonylureas, type 1 diabetes, and diabetic ketoacidosis. It is generally avoided in pregnancy and lactation. Caution is advised in the elderly, and in patients with renal or hepatic impairment, due to an increased risk of hypoglycemia. Common adverse effects include hypoglycemia, weight gain, nausea, and, less commonly, allergic reactions. Drug interactions that increase hypoglycemia risk include other antidiabetic agents and certain antibiotics; conversely, some medications may reduce glycemic control. Monitoring of blood glucose is essential to adjust therapy safely.