Improper use of drugs not only compromises curative effect, but also causes drug intolerance or adverse reactions. Therefore, when using metformin in patients with diabetes, the doctor needs to formulate the dose and usage of the drug according to the actual situation of the patient to accurately grasp the efficacy of the drug.
I. Start with a small dose, gradually increase the amount
A 49-year-old male patient was newly diagnosed with type 2 diabetes. Metformin 500 mg was given 3 times a day before meals. The patient developed nausea, nausea, diarrhea, and other gastrointestinal reactions. He was considered for metformin and switched to use. 500 mg/time, once daily, after meals, the above symptoms disappeared.
Gastrointestinal reaction is a common adverse reaction of metformin, including nausea, vomiting, diarrhea, loss of appetite and so on. The minimum recommended dose for metformin is 500 mg/d, the maximum dose available to adults is 2550 mg/d, and the best effective dose is 2000 mg/d.
The dose adjustment principle for the use of metformin is: “start small doses, gradually increase the amount.” Take 500 mg/d or <1000 mg/d at the beginning, and increase the maximum effective dose to 2000 mg/d or maximum tolerated dose after 1-2 weeks. Pay attention to the elderly population and liver and kidney dysfunction patients need to adjust the dose.
Note that the hypoglycemic effect of metformin is positively related to the dose, and blood glucose monitoring is still required during the adjustment process.
In the case of patients taking metformin tablets, it is not only advisable to start with small doses, but it is also advisable to take them after meals in order to avoid the adverse reactions of the gastrointestinal tract.
II. Different dosage form, taking different
Patient female, 56 years old, diagnosed as type 2 diabetes 1 month ago. After meal control and exercise therapy, postprandial blood glucose control was poor. Metformin enteric-coated capsules were added. 500 mg/time, taken after three meals, but the effect Not significant, so taking the drug half an hour before the meal, blood glucose gradually reached the standard.
Currently in the market, metformin commonly used formulations are metformin tablets (or capsules), enteric-coated tablets (or capsules) and sustained-release tablets (or capsules). Different dosage forms of metformin may cause differences in efficacy, speed of onset, and side effects.
Different dosage forms of metformin, taking methods are also different, each possession of “mystery.”
1. Metformin tablets (or capsules):
Such dosage forms should be taken at the same time or after meals as daily meals, which is not only conducive to regular drug use, but also can be mixed with gastrointestinal foods to reduce the adverse reactions of the gastrointestinal tract.
If this regimen is followed and gastrointestinal reactions still occur, consider changing to metformin enteric-coated or sustained-release tablets (or capsules).
Special reminder: Gastro-intestinal response to metformin appears in the early stage of medication (about the first 10 weeks), and patients can gradually tolerate or disappear after treatment for a prolonged period.
2. Metformin enteric-coated tablets (or capsules)
Enteric-coated tablets (or capsules) are drugs that, under the wrapping of enteric material, reach the site of action, the small intestine, and function accordingly. This dosage form overcomes the stimulating effect of ordinary tablets on the upper digestive tract, which not only reduces the adverse reactions of the upper gastrointestinal tract, but also maximizes the absorption and utilization of drugs by the digestive tract.
Metformin should be given as an enteric solution half an hour before meals. When the postprandial blood glucose reaches a peak, the drug concentration is correspondingly higher, and the effect is stronger, and the postprandial blood glucose peak period is well covered, so that an effective hypoglycemic effect can be achieved.
3. Metformin sustained-release tablets (or capsules)
Sustained release tablets (or capsules) are gel-encapsulated drugs that are taken once daily to achieve slow release and smooth hypoglycemic effects. Due to the use of sustained-release technology, the amount of drug dissolved in the stomach is greatly reduced, thereby avoiding adverse reactions of the upper gastrointestinal tract.
It is best to take sustained-release formulations at mealtimes so that foods can slow their absorption slightly and increase their sustained-release effectiveness.
Individual patients have poor blood glucose control and can also take two meals at breakfast and dinner.
Special Note: If the sustained release tablet is opened or crushed, it will destroy the gel that contains the drug, and the sustained release tablet will become a normal tablet without sustained release. Therefore, once daily dose, it is impossible to control the whole-day blood sugar. . Therefore, one should swallow it whole, and do not open or chew.
III. Correct combination, 1+1>2
Female patient, 40 years old, treated with insulin for more than 20 years of type 1 diabetes, weight 50 kg, BMI: 24.6 kg/m2, total daily insulin 82 U, high blood sugar in empty and postprandial blood glucose, given metformin After oral administration of 500 mg/day, the amount of insulin dropped to 60 U/day, and blood glucose control improved.
Only choose the correct combination method to get 1+1>2.
1, metformin and α-glycosidase inhibitors: can take into account fasting blood glucose and postprandial blood glucose. Both drugs have a certain gastrointestinal adverse reaction, and combined use may increase gastrointestinal discomfort.
2, metformin and sulfonylurea hypoglycemic agents: metformin can improve insulin resistance, reduce glycogen output; sulfonylurea drugs can promote insulin secretion, the two types of drugs combined, the complementary mechanism of action, with a more comprehensive focus on T2DM pathophysiological defects Features.
3. Combination of metformin and thiazolidinediones: Metformin combined with thiazolidinediones can better reduce HbA1c, significantly improve islet function and insulin resistance, but adverse reactions such as weight gain, increase LDL-C ) Higher than metformin alone.
Glinides are insulin secretagogues at meal time and have a synergistic effect with metformin. In the case of metformin combined with sulfonylureas and a high risk of hypoglycemia, metformin and glinide may be considered.
4, metformin and insulin combination: Metformin can enhance liver and muscle tissue insulin resistance, oral hypoglycemic agents in the treatment of T2DM patients with poor blood glucose control start insulin therapy should be retained metformin.
Long-term use of insulin, resulting in weight gain is inevitable. Metformin can not only reduce the amount of insulin, but also can further reduce blood lipids, this lipid-lowering effect does not matter in blood sugar.
In the case, the patient was slightly overweight, insulin dosage was about 1.6 U/kg, and the dosage was larger, suggesting the existence of insulin resistance. This was evidenced by the gradual control of blood glucose after administration of metformin.
Patients with type 1 diabetes undergoing insulin therapy may be treated with metformin. The precondition is that there is no contraindication. Special attention should be paid to diabetic ketoacidosis or hyperosmolarity of diabetes, which is prevalent in patients with type 1 diabetes.