Treatment of type 2 diabetes, especially in obese patients, when proper diet of blood Glucose can not be obtained by means of diet and exercise. In adults, alone or in combination with other oral antidiabetic agents or insulin. In children over 10 years of age and adolescents in monotherapy or in combination with insulin.
An oral antidiabetic drug from the group of biguanide derivatives. It reduces blood glucose both on an empty stomach and after a meal. It does not stimulate insulin secretion and therefore does not cause hypoglycaemia. Metformin works by three mechanisms: reduces hepatic glucose production by inhibiting gluconeogenesis and glycogenolysis, increases the insulin sensitivity of cells in the muscles, improves peripheral glucose uptake and its consumption, delays the absorption of glucose in the intestines. Metformin stimulates intracellular glycogen synthesis. Increases the ability to transport across the cell membrane of all types of glucose carriers. In addition, it has a beneficial effect on lipid metabolism - reduces total cholesterol, LDL and triglycerides. After oral administration, the absorption of the drug undergoes saturation and is incomplete. The absolute bioavailability is 50-60%. The maximum concentration of the drug in the blood occurs 2.5 h after administration. Food reduces and slightly delays the absorption of the drug. The binding to plasma proteins is insignificant. Metformin penetrates into erythrocytes. T0,5 in the final phase of elimination is about 6.5 hours. It is excreted unchanged in the urine. In the case of impaired renal function, metformin renal clearance decreases, the half-life is prolonged, resulting in increased plasma concentrations of the drug.
Contraindications:
Hypersensitivity to metformin hydrochloride or other ingredients of the preparation. Diabetic ketoacidosis and pre-comistic conditions in diabetes. Renal failure (creatinine clearance <60 ml / min). acute diseases that involve the risk of renal failure: dehydration, severe infections, shock as well as intravascular administration of iodinated contrast agents. Acute or chronic diseases that can cause tissue hypoxia, i.e. heart failure or respiratory failure, a recent myocardial infarction, shock. Hepatic failure, acute alcohol intoxication, alcoholism. Breast-feeding.
Precautions:
Accumulation of metformin may lead to lactic acidosis (most commonly in patients with significant renal insufficiency); the risk of lactic acidosis can be reduced by carefully assessing other risk factors: poorly controlled glycemia, ketosis, prolonged fasting, alcohol abuse, hepatic failure and other conditions associated with hypoxia. If metabolic acidosis is suspected, the drug should be discontinued and the patient immediately hospitalized. Particular care should be taken in situations where renal function may be impaired eg at the beginning of the use of antihypertensive, diuretic and NSAIDs. The drug should be discontinued before or at the time of radiological examination with contrast-loaded iodinated contrast agents and its administration may be resumed not earlier than 48 hours after the test and only if the kidney function is normal. Metformin should be discontinued 48 h before planned surgery under general, spinal or epidural anesthesia. Drug administration can be resumed 48 hours after surgery or resumption of oral nutrition and only after confirmation that the kidney function is normal. Metformin hydrochloride alone does not cause hypoglycaemia, but caution should be exercised when using with sulphonylureas or insulin. When using the preparation in children and adolescents, caution should be exercised (in controlled clinical trials, no effect on growth and maturation, but no long-term studies), monitoring during metformin treatment is recommended. Special care should be taken in children aged 10 -12 years.
Pregnancy and lactation:
Metformin should not be used during the planned pregnancy and during pregnancy (the drug of choice is insulin). The drug is contraindicated during breastfeeding.
Side effects:
Very common: nausea, vomiting, diarrhea, abdominal pain, loss of appetite. Common: taste disorders. Very rare: skin reactions, ie erythema, pruritus, urticaria; lactic acidosis, decreased absorption of vitamin B12, decrease in vitamin B concentration12 in serum. Not known: abnormal liver function tests, hepatitis, which disappears after metformin discontinuation. Undesirable symptoms from the digestive system occur most often at the beginning of treatment and in most cases disappear spontaneously. Slowly increasing the dose may improve the tolerance of the drug.
Dosage:
Orally.Adults. Monotherapy or combination therapy with other oral antidiabetic agents: the usual starting dose is 500 mg or 850 mg 2-3 times a day during or after a meal. After 10-15 days, the final dose should be determined based on blood glucose. The maximum daily dose is 3 g, given in 3 separate doses. If you are switching from another oral antidiabetic agent to metformin hydrochloride, discontinue the previously used medicine and use metformin hydrochloride at the recommended doses. Combination therapy with insulin: the initial dose is 500 mg or 850 mg 2-3 times a day, while the insulin dose is determined based on the results of the blood glucose test.Youth and children over 10 years. Monotherapy or combination therapy with insulin: the usual starting dose is 500 mg or 850 mg once a day, during or after a meal. After 10-15 days, the final dose should be determined based on blood glucose. The maximum daily dose is 2 g in 2 or 3 divided doses. In elderly patients, the dose is determined based on the assessment of renal function. The gradual increase in the dose may improve the tolerance of the drug on the gastrointestinal tract.
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