Pharmacology and clinical experience with repaglinide

Repaglinide (NovoNorm((R))) is a novel oral antidiabetic agent, the first of a new class of insulin secretagogues known as the prandial glucose regulators to be approved for use in patients with Type 2 diabetes. Prandial glucose regulation is aimed at restoring the first-phase insulin response that follows consumption of a meal, which is missing in patients with Type 2 diabetes. After repaglinide administration, the resulting insulin profile reflects that of healthy individuals more closely, providing tighter glycaemic control and reducing the risk of hypoglycaemic events. Repaglinide is quickly absorbed and rapidly eliminated through biliary excretion, making it suitable for use in patients with renal impairment. It appears in the bloodstream within 15 to 30 min of dosing, stimulating short-term insulin release from the pancreatic beta-cells by binding to a unique site on the beta-cell membrane. Rapid elimination ensures that postprandial insulin levels quickly return to preprandial levels as the high prandial glucose level subsides. Repaglinide is given on a 'one meal, one tablet; no meal, no tablet' basis. It is particularly effective in patients who have not previously been treated with an oral antidiabetic agent, significantly reducing glycosylated haemoglobin (HbA(1c)) levels by 1.6%. It also offers increased mealtime flexibility and safety, compared with other oral antidiabetic agents. As a result of the short plasma half-life and lack of accumulation of repaglinide with repeated dosing, the risk of between-meal and nocturnal hypoglycaemia is substantially reduced compared with other oral antidiabetic agents. Repaglinide acts synergistically with metformin, consistently improving glycaemic control in patients who were insufficiently controlled by metformin alone. Results from recent studies have shown similar synergistic effects with neutral protamine Hagedorn (NPH)-insulin or troglitazone.