Glimepiride

• Type 2 Diabetes Mellitus
• Blood Sugar Control
• Sulfonylurea Therapy
• Diabetes Management

Glimepiride is a second-generation sulfonylurea used as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. This oral medication stimulates insulin secretion from pancreatic beta cells and provides effective blood sugar lowering with once-daily dosing.

Mechanism of Action

Glimepiride stimulates insulin release from functioning pancreatic beta cells by binding to the sulfonylurea receptor (SUR1) on the beta cell membrane. This binding closes ATP-sensitive potassium (KATP) channels, leading to cell membrane depolarization, calcium influx, and exocytosis of insulin-containing granules. Glimepiride may also have extrapancreatic effects, potentially enhancing peripheral tissue sensitivity to insulin. Compared to first-generation sulfonylureas, glimepiride has a faster onset and shorter duration of action, and it associates and dissociates from the SUR1 receptor more rapidly, potentially resulting in a lower risk of prolonged hypoglycemia.

Available Formulations

Glimepiride is available as oral tablets in 1 mg, 2 mg, and 4 mg strengths. The tablets are scored and can be divided. Generic formulations are widely available. Combination tablets with pioglitazone (Duetact) and with rosiglitazone (Avandaryl) are also available.

Medical Uses

Glimepiride is FDA-approved as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. It can be used as monotherapy or in combination with metformin, insulin, or other antidiabetic medications. Glimepiride is typically reserved for patients who cannot achieve glycemic goals with diet and exercise alone. It is not appropriate for type 1 diabetes or diabetic ketoacidosis.

Dosing Guidelines

The recommended starting dose is 1-2 mg once daily with breakfast or the first main meal. Dose adjustments should be made in increments of no more than 2 mg at intervals of 1-2 weeks based on fasting blood glucose response. The usual maintenance dose is 1-4 mg once daily; maximum recommended dose is 8 mg once daily. When used with insulin, lower doses of glimepiride are recommended. When transferring from longer-acting sulfonylureas, a transition period may be needed.

Important Safety Information

Glimepiride can cause hypoglycemia, which can be severe and life-threatening. Risk factors include skipped meals, alcohol use, renal or hepatic impairment, and concomitant use of other glucose-lowering medications. Patients should be educated about recognizing and treating hypoglycemia. Sulfonylureas may increase cardiovascular mortality; this warning is based on a study of an older sulfonylurea. Hemolytic anemia may occur in patients with G6PD deficiency. Weight gain is common with sulfonylurea use.

Drug Interactions

Drugs that may enhance the hypoglycemic effect: NSAIDs, salicylates, sulfonamides, chloramphenicol, coumarins, probenecid, MAO inhibitors, beta-blockers, ACE inhibitors, fluconazole, and other antidiabetic agents. Drugs that may reduce the hypoglycemic effect: thiazides, corticosteroids, phenothiazines, thyroid products, estrogens, oral contraceptives, phenytoin, nicotinic acid, sympathomimetics, and calcium channel blockers. Beta-blockers may mask hypoglycemia symptoms.

Special Populations

Glimepiride is not recommended during pregnancy; insulin is preferred for diabetes management during pregnancy. It is unknown whether glimepiride is excreted in human breast milk; some sulfonylureas are present in milk. Safety and efficacy have not been established in pediatric patients. Elderly patients may be more susceptible to hypoglycemia; start at the lower end of the dosing range. Conservative initial and maintenance doses are recommended in renal impairment. Conservative initial dosing, careful titration, and regular monitoring are recommended in hepatic impairment.