A Comprehensive Analysis of Mealtime Glucose Regulators and Metformin: Mechanisms of Glinides and Multiple Benefits of Biguanides

What are meglitinides (or glinides) for lowering blood sugar?

Meglitinides, also known as non-sulfonylurea (or benzoic acid) insulin secretagogues, are prandial glucose regulators that increase insulin secretion after administration. These drugs are characterized by rapid onset and short duration of action, classifying them as ultra-short-acting drugs. They stimulate immediate insulin secretion and can be used alone or in combination with biguanides or thiazolidinediones. Examples of drugs in this class include repaglinide (NovoLog) and nateglinide (Tangli).

What is the mechanism of action of meglitinides for lowering blood sugar?

Meglitinides are non-sulfonylurea insulin secretagogues, belonging to the prandial glucose regulator class. Their mechanism of action involves closing ATP-sensitive potassium channels on the pancreatic β-cell membrane, causing calcium ion influx, increasing intracellular calcium ion concentration, and thus stimulating insulin secretion. These drugs act on different receptor sites than sulfonylureas, and do not enter pancreatic β-cells, nor do they inhibit protein synthesis or directly induce insulin release.

What are some commonly used meglitinides for lowering blood sugar? What are their characteristics? How are they used?

① Repaglinide (Novo Nordisk): This product is a benzoic acid derivative, a fast-acting, short-duration insulin secretion regulator for postprandial blood glucose. It is suitable for type 2 diabetic patients with some insulin secretion function of pancreatic β-cells, no acute complications, and normal liver and kidney function. It can be used alone or in combination with metformin to treat diabetic patients whose blood sugar cannot be controlled by metformin alone. This product is well tolerated, and the risk of hypoglycemia is lower than that of patients using sulfonylureas. Severe hypoglycemia has not occurred, and the blood glucose concentration returns to the pre-dose level about 8 hours after administration. This product is also suitable for special populations, such as the elderly or those with mild liver and kidney dysfunction. Compared with sulfonylureas, this product promotes insulin secretion faster and lowers postprandial blood glucose more quickly. An important characteristic of this product is that it does not accelerate the decline of pancreatic β-cell function. This product should be taken orally before meals. Insulin secretion occurs within 30 minutes of administration, usually 15 minutes before or during meals. The recommended starting dose is 0.5 mg, which can be adjusted weekly or bi-weekly. The maximum recommended single dose is 4 mg, but the maximum daily dose should not exceed 16 mg.

② Nateglinide (Tangli): This product is a phenylalanine compound, a novel mealtime glycemic regulator suitable for use with meals in patients with type 2 diabetes. It acts rapidly, with glucose levels returning to pre-dose levels within 4 hours. Its characteristics include rapid and short-lived action on pancreatic β-cells, greater sensitivity to external glucose concentrations, and a faster insulin response, effectively controlling glucose physiologically during meals and reducing the chance of hypoglycemia. Its effect is superior to repaglinide. Oral administration: 120 mg each time, four times daily, i.e., 10 minutes before three main meals and before a late-night snack (around 10 PM).

Which patients are suitable for using meglitinides?

① Type 2 diabetic patients whose hyperglycemia cannot be effectively controlled by diet and exercise.

② Type 2 diabetic patients whose hyperglycemia cannot be effectively controlled by metformin.

③ Type 2 diabetic patients who cannot tolerate metformin.

④ Patients for whom sulfonylureas have failed to treat their condition.

⑤ Obese or malnourished type 2 diabetic patients.

⑥ Elderly patients.

⑦ Type 2 diabetic patients with moderate renal impairment.

⑧ Patients with impaired glucose tolerance.

Which patients are not suitable for using meglitinides?

① Patients allergic to this product or any of its components.

② Type 1 diabetic patients.

③ Patients with diabetic ketoacidosis.

④ Pregnant and lactating women.

⑤ Children under 12 years of age.

⑥ Patients with severe hepatic or renal insufficiency.

⑦ Patients with severe infections or before and after surgery.

⑧ Elderly individuals over 75 years of age.

What are the adverse reactions of meglitinides? Adverse reactions to meglitinides are relatively rare, with only a small number of patients experiencing mild reactions. The main adverse reactions are as follows:

① Hypoglycemia: Usually mild and can be corrected by administering carbohydrates. If the reaction is severe, glucose infusion may be necessary. At higher doses, if the patient delays eating, hypoglycemia may occur.

② Abnormal liver function: A very small number of patients may experience elevated transaminase levels, mostly mild and transient, therefore, discontinuation of the drug is extremely rare.

③ Allergic reactions: Itching, redness, urticaria, etc., are extremely rare.

④ Gastrointestinal reactions: Abdominal pain, diarrhea, nausea, vomiting, and constipation, etc., are usually mild and rare.

What precautions should be taken when using meglitinides?

① This medication should be taken immediately before meals. Take the medication with meals, and do not take it without meals.

② When used in combination with thiazolidinediones or metformin, hypoglycemia may occur. Close monitoring is necessary, and the dosage may be adjusted according to the patient's condition.

③ If blood glucose is not controlled when used in combination with thiazolidinediones or metformin, insulin therapy should be initiated.

④ In cases of stress, such as infection, fever, trauma, or surgery, insulin therapy should be switched to this product, and the medication should be discontinued.

⑤ This product should not be used in combination with sulfonylureas.