Metformin has a significant hypoglycemic effect. It does not increase the risk of hypoglycemia when used alone. It also has good tolerability and safety, and its price is relatively inexpensive. Therefore, it remains a widely used oral hypoglycemic agent in clinical practice.
The hypoglycemic pharmacological effects of metformin.
1. Inhibition of hepatic glycogen output
Blood glucose is produced in the liver through gluconeogenesis (the conversion of non-carbohydrate substances into glucose). Metformin can reduce hepatic gluconeogenesis, thereby lowering fasting blood glucose levels.
2. Improve insulin sensitivity
Metformin activates adenosine monophosphate-activated protein kinase (AMPK) in fat and muscle cells. This promotes glucose uptake and utilization, thereby lowering postprandial blood glucose levels.
3. Increase glucagon-like peptide-1 (GLP-1) levels
GLP-1 can stimulate insulin secretion, delay gastric emptying, and reduce glucose absorption. Metformin, on the other hand, can promote GLP-1 secretion by acting directly on intestinal L cells or by regulating gut microbiota.
**Metformin is a potent oral hypoglycemic agent. As a monotherapy, it can reduce glycated hemoglobin (HbA1c) by 1% to 1.5%.
Other effects of metformin besides lowering blood sugar
1. Anti-cancer
People with type II diabetes are more likely to develop breast cancer, endometrial cancer, colorectal cancer, and other cancers. Clinical studies have found that metformin can be used to prevent breast and endometrial cancer in obese individuals. It also can reduce the risk of colorectal polyps developing into colorectal cancer. Metformin can also increase the sensitivity of tumors to chemotherapy drugs.
2. Improve Polycystic Ovary Syndrome (PCOS)
PCOS has a high prevalence among women of reproductive age. Its main manifestations include excessive androgens (acne, hirsutism), menstrual disorders, ovulation disorders, and polycystic ovarian changes. PCOS is also often accompanied by obesity and insulin resistance. Metformin can correct hyperandrogenemia by lowering blood insulin levels. This improves ovarian ovulation and enhances the effectiveness of ovulation induction treatment.
3. The preventive effect of diabetes
Prediabetes includes impaired fasting glucose (≥6.1 to <7.0 mmol/L) and impaired glucose tolerance (2-hour post-glucose load blood glucose ≥7.8 to <11.1 mmol/L). Clinical studies have shown that metformin can effectively reduce the risk of developing type II diabetes in people with prediabetes. In addition, metformin also has potential cardiovascular protective effects.
Dosage of metformin tablets
The minimum recommended dose is 500 mg/day. The optimal effective dose is 2000 mg/day. The maximum dose is 2550 mg/day. Metformin should be started at a low dose and gradually increased to reduce gastrointestinal reactions (such as diarrhea and nausea). Take 2 to 3 times daily, with or immediately after meals. Taking metformin after meals will slow down the absorption rate and reduce the extent of absorption, but it can reduce gastrointestinal reactions.
Dosage of metformin extended-release tablets
The maximum dose of metformin extended-release tablets is 2000 mg/day. Compared with regular tablets, extended-release tablets may have better gastrointestinal tolerability and improve patient medication adherence. Take once daily with dinner. Sustained-release tablets must be swallowed whole; do not crush or chew them. Taking on an empty stomach will reduce absorption by approximately 30%. Take once daily with dinner. Sustained-release tablets must be swallowed whole; do not crush or chew them. Taking on an empty stomach will reduce absorption by approximately 30%.
Dosage of Metformin enteric-coated tablets
The usual daily dose is 1 to 1.5g, with a maximum daily dose not exceeding 2g. Take 2 to 3 times daily, half an hour before meals. The coating of enteric-coated tablets needs to dissolve in the alkaline environment of the intestines. Taking it before meals allows the tablet to quickly enter the intestines, reducing stomach discomfort.
Regularly monitor vitamin B12 levels
Long-term use of metformin can cause vitamin B12 deficiency in patients. Therefore, it is recommended that patients with insufficient vitamin B12 intake or absorption have their vitamin B12 levels monitored annually before starting metformin treatment and after treatment. If deficiency is found, appropriate supplementation should be given, especially for patients with anemia and peripheral neuropathy.







