In-depth analysis of the application of sulfonylurea hypoglycemic drugs: from mechanism of action to usage and adverse reaction monitoring of commonly used varieties.

Why are biguanides the first-line treatment for obese patients with type 2 diabetes, rather than glibenclamide?

Obese patients with type 2 diabetes often have insulin resistance. Glibenclamide promotes insulin secretion, potentially increasing insulin resistance; while biguanides or glucosidase inhibitors inhibit intestinal glucose absorption, reducing energy intake in obese patients and having weight-loss and insulin-sensitizing effects. Therefore, biguanides are the first-line treatment.

Which hypoglycemic drug is suitable for underweight patients with type 2 diabetes? Underweight patients with type 2 diabetes should choose sulfonylureas (such as Glipizide or Mepiride) or benzoic acid drugs (such as NovoLog), and should not choose biguanides or alpha-glucosidase inhibitors.

What are the drug treatment options for type 2 diabetes?

For newly diagnosed type 2 diabetes, depending on whether the patient is overweight, obese, or of normal weight, dietary control and exercise therapy should be initiated for 2-3 months. If blood glucose control is unsatisfactory, sulfonylureas, meglitinides, biguanides, or alpha-glucosidase inhibitors can be selected based on body type. If blood glucose control remains unsatisfactory, consider combining two oral hypoglycemic agents, or further insulin supplementation and multiple injections. Oral Hypoglycemic Agents

How are oral hypoglycemic agents classified?

Oral hypoglycemic agents are mainly used for type 2 diabetes and are classified into the following categories based on insufficient insulin secretion and insulin resistance:

① Drugs that stimulate insulin secretion: such as sulfonylureas and meglitinides (non-sulfonylurea) insulin secretagogues.

② Drugs that increase insulin sensitivity: such as biguanides and thiazolidinediones.

③ Alpha-glucosidase inhibitors: such as acarbose.

What are the oral hypoglycemic drugs?

Oral medications include insulin secretagogues (sulfonylureas such as glibenclamide, glipizide, gliclazide, glimepiride, and glipizide; meglitinides such as repaglinide and nateglinide), insulin sensitizers (biguanides such as phenformin and metformin; thiazolidinediones such as rosiglitazone and pioglitazone), and glucosidase inhibitors (acarbose and voglibose).

Sulfonylureas: Insulin Secretion Stimulants

What are sulfonylurea hypoglycemic drugs? Sulfonylureas are among the earliest oral hypoglycemic drugs used. Now in their third generation, they remain a first-line treatment for type 2 diabetes. They primarily work by stimulating insulin secretion from pancreatic beta cells. First-generation sulfonylureas include tolbutamide (D860) and chlorpropamide; second-generation sulfonylureas include glibenclamide (Euglucon), glipizide (Mepiride), gliclazide (Diamicron), and gliquidone (Glucon); third-generation sulfonylureas include glimepiride (Amaryl). Sulfonylureas can also be classified into short-acting, intermediate-acting, and long-acting formulations based on their duration of action. Short-acting formulations include gliquidone and glipizide, taken three times daily. Intermediate-acting formulations include glibenclamide and gliclazide, taken twice daily. Long-acting formulations include glimepiride, taken once daily.

What are some commonly used sulfonylurea hypoglycemic drugs? What are their characteristics, usage, and dosage?

① Glibenclamide (Euglucon): This is a second-generation oral short-acting sulfonylurea hypoglycemic drug. Its potency is 200-250 times that of tolbutamide, making it a relatively strong sulfonylurea hypoglycemic drug. It takes effect half an hour after administration, with peak effect lasting 2-5 hours and a duration of action of 16-24 hours. It is metabolized in the liver, with 50% excreted by bile and 50% by the kidneys. Therefore, it is best not to use it in patients with impaired renal function. Oral administration: Initially, 2.5 mg once before breakfast or once before breakfast and once before lunch, gradually increasing the dose. The usual dosage is 5-10 mg/day. It can be used in combination with insulin or biguanides. Glibenclamide is the most likely sulfonylurea drug to cause hypoglycemia, which can be fatal in severe cases. Hypoglycemia is often caused by improper medication use. For example, both the traditional Chinese medicine Xiaoke Wan and Xiaoke Jiangtang capsules contain glibenclamide. Many patients take Xiaoke Wan and then glibenclamide, leading to hypoglycemic reactions and serious consequences. This should be noted.

② Glipizide (Meipida): This is a short-acting hypoglycemic drug that significantly enhances the ability of peripheral tissues to take up glucose and enhances the function of glucose-stimulated insulin-producing beta cells. In addition, this product also has certain effects in lowering serum cholesterol and triglycerides, increasing high-density lipoprotein cholesterol levels, reducing platelet aggregation, and increasing fibrinolytic activity, thereby reducing the risk of vascular damage and capillary blockage. Clinically, it is used for moderate diabetes, especially in patients with significant postprandial hyperglycemia. It begins to take effect 30 minutes after administration. Individual differences are significant, so the dosage should be varied from person to person. Initially, the dosage is 2.5–5 mg daily, taken 30 minutes before meals, and can be taken once. The dosage should be adjusted according to blood glucose and urine glucose levels, with each adjustment ranging from 2.5 to 5 mg. For doses below 15 mg, a single dose should be taken; for doses exceeding 15 mg, divide into 2 to 3 doses before meals.

③ Gliclazide (Diamicron): This is a second-generation intermediate-acting sulfonylurea hypoglycemic agent. Its hypoglycemic effect is lower than that of glibenclamide, and its hypoglycemic effect is milder. However, due to its long duration of action (lasting 24 hours), its clinical efficacy is stronger, making it particularly suitable for elderly patients. In addition to stimulating insulin secretion, this product can also regulate blood lipids, reduce blood viscosity, reduce platelet aggregation, and prevent and treat diabetic vascular complications. Therefore, it is clinically used for adults with non-insulin-dependent diabetes mellitus, obese diabetes mellitus, senile diabetes mellitus, and diabetes mellitus with cardiovascular complications. Oral administration: 40-80 mg each time, taken half an hour before meals, initially 2-3 times daily for 2-3 weeks. Then, adjust the dosage according to blood glucose and urine glucose levels, with a daily range of 80-240 mg, but elderly patients are limited to 80 mg daily.

④ Gliquidone (Glucobay, Gliquidone): This product has a relatively weak hypoglycemic effect among sulfonylurea drugs. It is rapidly absorbed after administration, and its most notable characteristic is that 95% is excreted through bile, with less than 5% excreted through the kidneys. It is the only second-generation sulfonylurea drug primarily excreted through the liver. It has a short half-life (1-2 hours) and is suitable for patients with a short course of disease and mild symptoms, especially those over 60 years of age, those with weak constitutions, and those with significant cardiovascular or cerebrovascular sclerosis and renal insufficiency. It is taken before meals, generally starting with a small dose, ranging from 30 to 180 mg daily, 2-3 times daily. Due to significant individual differences, within the above dose range, the daily dose can usually be increased by 15 mg, with the optimal dose being 45-90 mg daily, and the maximum daily dose not exceeding 180 mg.

⑤ Glimepiride (Amaryl): This is a third-generation sulfonylurea hypoglycemic drug. It has a strong effect with a small dose. Its hypoglycemic effect is related to blood glucose levels; the hypoglycemic effect is not obvious when blood glucose is not high, so it is less likely to cause hypoglycemia. Oral administration, 1-8 mg once daily. If necessary, the dose can be increased to 4 mg/day. A few patients require a daily dose greater than 6 mg. Take before breakfast, with water, and do not chew.

What are the adverse reactions of sulfonylurea hypoglycemic drugs?

The incidence of adverse reactions to sulfonylurea drugs is low, ranging from 2% to 5%. The incidence of adverse reactions to second-generation sulfonylureas is even lower than that of first-generation drugs. The most common adverse reaction is hypoglycemia, followed by gastrointestinal reactions. Less common adverse reactions include liver damage, allergies, and bone marrow suppression.

① Hypoglycemia: This is the most common and important adverse reaction, often occurring in elderly patients or those with impaired liver or kidney function. Common triggers include advanced age, liver or kidney disease, excessive drug dosage, excessive physical activity, irregular eating habits, alcohol or spirits, and drug interactions. Due to the long course of the disease and damage to the autonomic nervous system, the patient's ability to regulate hypoglycemia decreases, and the symptoms of hypoglycemia become less obvious and less noticeable. Therefore, high vigilance is necessary.

② Weight gain: The best way to avoid weight gain is to adhere to a strict, balanced, low-fat diet and regular, appropriate exercise. Glipizide controlled-release formulations and glimepiride have little or no effect on weight gain compared to other sulfonylureas.

③ Digestive symptoms: Some patients may experience constipation, diarrhea, heartburn, bloating, loss of appetite, nausea, or cramping abdominal pain, but these symptoms are usually mild and disappear with prolonged use. Liver function impairment and cholestatic jaundice are occasionally observed. Gliquidone has a significant stimulating effect on gastric acid and pepsin secretion; therefore, patients with peptic ulcers should use gliquidone with caution.

④ Skin allergies: May cause mild skin reactions such as rashes, itching, and urticaria. These usually disappear after a few weeks of medication.

⑤ Alcohol intolerance: Alcohol intolerance can occur with any sulfonylurea medication. Some patients may experience headaches, facial flushing, or tingling sensations, and may also experience nausea and dizziness 10–30 minutes after consuming alcoholic beverages or medications, or even very small amounts of alcohol (such as half a glass of wine).

⑥ Other: Leukopenia, agranulocytosis, thrombocytopenia, hemolytic anemia, aplastic anemia, and pancytopenia.