Glibenclamide (INN), also known as glyburide (USAN), is an anti-diabetic drug in a class of medications known as sulfonylureas, used in the treatment of type II diabetes. The drug works by inhibiting ATP-sensitive potassium channels in pancreatic beta cells. This inhibition causes cell membrane depolarization, opening of voltage-dependent calcium channels, thus triggering an increase in intracellular calcium into the beta cell which stimulates insulin release. It is sold in doses of 1.25mg, 2.5mg and 5mg, under the trade names Diabeta, Glynase and Micronase in the United States and Daonil, Semi-Daonil and Euglucon in the United Kingdom.

It is also sold in combination with metformin under the trade name Glucovance.

The drug is contraindicated in pregnant women. It is also a major cause of drug induced hypoglycaemia.

Recently published data suggests that glibenclamide is associated with significantly higher annual mortality when combined with metformin than other insulin secreting medications, after correcting for other potentially confounding patient characteristics. The safety of this combination has been questioned.