Glimepiride

Glimepiride is a second-generation sulfonylurea antidiabetic medication used to improve glycemic control in adults with type 2 diabetes mellitus, typically when diet and exercise alone are insufficient. It is often considered when monotherapy with metformin does not achieve adequate control, and it may be used in combination with other antidiabetic agents.

Mechanism of action

Glimepiride lowers blood glucose by stimulating insulin release from pancreatic beta cells. It closes ATP-sensitive potassium channels, leading to depolarization and increased insulin secretion in response to rising blood glucose. Some additional, less well defined effects on hepatic glucose production and peripheral glucose uptake may contribute to its activity.

Pharmacokinetics

Glimepiride is taken orally and is well absorbed with peak plasma levels occurring about 2 to 3 hours after dosing. It is highly bound to plasma proteins and is extensively metabolized in the liver, primarily by the CYP2C9 system, to several metabolites. The drug and its metabolites are excreted in urine and feces, with an elimination half-life generally around 5 to 9 hours. Dose adjustments may be needed in hepatic impairment or in the elderly.

Contraindications and cautions

Glimepiride is contraindicated in type 1 diabetes and in diabetic ketoacidosis. It should be avoided in patients with a known hypersensitivity to glimepiride or other sulfonylureas. Use during pregnancy and lactation is generally discouraged. Caution is advised in hepatic or renal impairment, elderly patients, and in situations that increase the risk of hypoglycemia.

Adverse effects and interactions

The principal adverse effect is hypoglycemia, which can be severe in some cases and may be accompanied by weight gain, nausea, or dizziness. Potential drug interactions include other antidiabetic agents, alcohol, and drugs that inhibit or induce CYP2C9, which can alter glimepiride levels. When starting or adjusting therapy, monitoring of blood glucose is important. Brand names include Amaryl among others.