Repaglinide is a nonsulfonylurea insulin secretagogue belonging to the melgitinide class with hypoglycemic activity. Repaglinide is rapidly absorbed and has a rapid onset and short duration of action. This agent is metabolized in the liver by CYP2C8 and CYP3A4 and its metabolites are excreted in the bile. Repaglinide has a half-life of one hour. Repaglinide is rapidly metabolized via oxidation and dealkylation by cytochrome P450 3A4 and 2C9 to form the major dicarboxylic acid derivative (M2). Further oxidation produces the aromatic amine derivative (M1). Glucuronidation of the carboxylic acid group of repaglinide yields an acyl glucuronide (M7). Several other unidentified metabolites have been detected. Repaglinide metabolites to not possess appreciable hypoglycemic activity. Repaglinide activity is dependent on the presence functioning β cells and glucose. In contrast to sulfonylurea insulin secretatogogues, repaglinide has no effect on insulin release in the absence of glucose. Rather, it potentiates the effect of extracellular glucose on ATP-sensitive potassium channel and has little effect on insulin levels between meals and overnight. As such, repaglinide is more effective at reducing postprandial blood glucose levels than fasting blood glucose levels and requires a longer duration of therapy (approximately one month) before decreases in fasting blood glucose are observed. The insulinotropic effects of repaglinide are highest at intermediate glucose levels (3 to 10 mmol/L) and it does not increase insulin release already stimulated by high glucose concentrations (greater than 15 mmol/L). Repaglinide appears to be selective for pancreatic β cells and does not appear to affect skeletal or cardiac muscle or thyroid tissue. | 
