What is the mechanism of action of meglitinides (glinides)?

• A. Stimulate pancreatic insulin release
• B. Inhibit hepatic glucose production
• C. Increase insulin sensitivity
• D. Inhibit glucose absorption

Answer: (A)

Me glitinides are insulin secretagogues, meaning their main action is to boost the pancreas’s own insulin release. They bind to the sulfonylurea receptor (SUR1) on pancreatic beta cells and close the ATP-sensitive potassium (KATP) channels. This closes the potassium leak, depolarizes the cell, opens voltage-gated calcium channels, and triggers calcium influx that promotes exocytosis of insulin-containing granules. The result is a rapid, short-acting burst of insulin in response to a meal, helping to blunt postprandial glucose. This relies on remaining beta-cell function, so their effect won't occur if beta cells are severely impaired. In contrast, other mechanisms described in the options involve lowering hepatic glucose production, increasing insulin sensitivity, or slowing carbohydrate absorption, which is why the correct mechanism is to stimulate pancreatic insulin release.