Glibenclamide

Absorption

Elderly patients taking glyburide reached a Cmax of 211-315ng/mL with a Tmax of 0.9-1.0h, while younger patients reached a Cmax of 144-302ng/mL with a Tmax of 1.3-3.0h. Patients taking glyburide have and AUC of 348ng*h/mL.

Toxicity

The oral LD50 in rats is >3200mg/kg, in mice is >1500mg/kg, in rabbits is >10,000mg/kg, and in guinea pigs is >1500mg/kg.
Patients experiencing an overdose may present with hypoglycemia. Mild hypoglycemia should be treated with oral glucose and adjustments to drug doses or meal schedules. Severe hypoglycemia may present with coma, seizure, and neurological impairment. This should be treated immediately in hospital with intravenous glucose and monitoring for 24-48 hours.

Description

Glyburide (10238-21-8) is a second generation oral hypoglycemic agent. Acts via ATP-dependent K+ channel (Kir6, KATP) block.1?Inhibits Kir6 currents in the pancreas, causing an increase in intracellular Ca2+ and insulin secretion. Glyburide also inhibits recombinant CFTR Cl- channels with an IC50 of 20 μM.2?Cell permeable.

The Uses of Glibenclamide

Glyburide (Glibenclamide) is a sulfonylurea compound that modulates insulin production. Sulfonylureas bind to ATP-dependent K+ channels in beta cells of the pancreas, depolarizing them and stimulating the release of Ca2+, which in turn stimulates insulin production. Glyburide (Glibenclamide) is an ATP-dependent K+ channel (KIR6, KATP) and CFTR Cl- channel blocker. This compound inhibits recombinant CFTR Cl- channels (IC50 = 20 ?M).

What are the applications of Application

Glyburide (Glibenclamide) is an ATP-dependent KIR6 and CFTR Cl- channel blocker

Background

Glyburide is a second generation sulfonylurea used to treat patients with diabetes mellitus type II. It is typically given to patients who cannot be managed with the standard first line therapy, metformin. Glyburide stimulates insulin secretion through the closure of ATP-sensitive potassium channels on beta cells, raising intracellular potassium and calcium ion concentrations.
Glyburide was granted FDA approval on 1 May 1984. A formulation with metformin was granted FDA approval on on 31 July 2000.

Indications

Glyburide is indicated alone or as part of combination product with metformin, as an adjunct to diet and exercise, to improve glycemic control in adults with type 2 diabetes mellitus.

Pharmacokinetics

Glyburide is a second generation sulfonylurea that stimulates insulin secretion through the closure of ATP-sensitive potassium channels on beta cells, raising intracellular potassium and calcium ion concentrations. Glibenclamide has a long duration of action as it is given once daily, and a wide therapeutic index as patients are started at doses as low as 0.75mg but that can increase as high as 10mg or more. Patients taking glyburide should be cautioned regarding an increased risk of cardiovascular mortality as seen with tolbutamide, another sulfonylurea.

Metabolism

Glyburide is metabolized mainly by CYP3A4, followed by CYP2C9, CYP2C19, CYP3A7, and CYP3A5. These enzymes metabolize glyburide to 4-trans-hydroxycyclohexyl glyburide (M1), 4-cis-hydroxycyclohexyl glyburide (M2a), 3-cis-hydroxycyclohexyl glyburide (M2b), 3-trans-hydroxycyclohexyl glyburide (M3), 2-trans-hydroxycyclohexyl glyburide (M4), and ethylhydroxycyclohexyl glyburide (M5). The M1 and M2b metabolites are considered active, along with the parent molecule.