Metformin-Teva, 500 mg 60 pcs

Metformin has hypoglycemic effect.

Pharmacodynamics

Metformin is an oral hypoglycemic drug of biguanide group. In patients with diabetes, it decreases the concentration of glucose in the blood by inhibiting gluconeogenesis in the liver, reducing the absorption of glucose from the gastrointestinal tract (GIT) and increasing its utilization in tissues by increasing their sensitivity to insulin (mainly in striated musculature and to a lesser extent in adipose tissue). Does not stimulate insulin secretion and does not cause hypoglycemic reactions. Has an effect on lipid metabolism – reduces the concentration of triglycerides, cholesterol and low-density lipoproteins in the blood serum. It stimulates intracellular glycogenesis by activating glycogen synthase.

Pharmacokinetics

Intake
After oral administration metformin is completely absorbed from the gastrointestinal tract. Absolute bioavailability is 50-60%. Maximal concentration (Cmax) in plasma is approximately 2 µg/ml or 15 µmol/L and is reached after 2.5 h. After 7 hours, absorption from the gastrointestinal tract ends, and plasma concentration of metformin gradually decreases. With concomitant intake of food, absorption of metformin is reduced and slower.

Distribution
Metformin is almost not bound to plasma proteins and is rapidly distributed to the tissues of the body. It penetrates red blood cells. It accumulates in salivary glands, liver and kidneys. The apparent volume of distribution is 63-276 liters.

Metabolism and excretion
Is excreted unchanged by the kidneys. Clearance of metformin in healthy individuals is 400 ml/min, indicating active glomerular filtration and tubular secretion. The half-life (T1/2) is approximately 6.5 h.

Pharmacokinetics in special clinical cases

In patients with renal impairment, metformin renal clearance decreases in proportion to decreased creatinine clearance, T1/2 increases, which leads to increased metformin blood concentrations. Cumulation is possible.

Indications

Several type 2 diabetes mellitus in adults (especially in obese patients) when diet and exercise are ineffective as monotherapy or in combination with other oral hypoglycemic agents or insulin.

Active ingredient

Composition

Active ingredient: metformin hydrochloride 500 mg;

Auxiliary substances: povidone K30; povidone K90; colloidal silicon dioxide; magnesium stearate; Opadray White Y-1-7000H (hypromellose (E464); titanium dioxide (E171); macrogol 400

How to take, the dosage

Overly, during or immediately after a meal.

Monotherapy and combined therapy with other oral hypoglycemic agents

The initial dose is 500-1000 mg once daily in the evening. In 7-15 days with absence of adverse effects of gastrointestinal tract it is prescribed 500-1000 mg 2 times a day in the morning and in the evening. Further gradual dose increase is possible, depending on the blood glucose concentration.

The maintenance dose is 1500-2000 mg/day. To reduce gastrointestinal side effects, the dose should be divided into 2-3 doses. The maximum daily dose is 3000 mg/day in 3 doses.

Slow dose increases may improve gastrointestinal tolerance of the drug.

Patients taking metformin at doses of 2000-3000 mg/day can be switched to a dose of 1000 mg. The maximum recommended dose is 3000 mg/day in 3 doses.

When switching to therapy with another hypoglycemic drug, the other drug should be discontinued and Metformin-Teva should be started at the dose stated above.

Combinations with insulin

Metformin-Teva and insulin can be used as combination therapy to achieve better glycemic control.

The drug is prescribed in the usual starting dose of 500 or 850 mg 2-3 times daily. The dose of insulin is adjusted on the basis of the results of blood glucose measurements. The dose is adjusted after 10 to 15 days depending on the blood glucose concentration.

The maximum dose of metformin in combination therapy is 2 g/day in 2-3 doses.

In elderly patients the daily dose should not exceed 1000 mg/day.

Interaction

Unrecommended combinations
Simultaneous use of metformin with danazol may result in hyperglycemic effects. If treatment with danazolol is necessary and after discontinuation of its use, metformin dose should be corrected under glycemic control. Concomitant use of metformin with alcohol and ethanol-containing drugs increases the risk of lactoacidosis during acute alcohol intoxication, especially when fasting or following a low-calorie diet, as well as liver failure.

Combinations requiring special caution
Chlorpromazine at high doses (100 mg/day) reduces insulin release and increases blood glucose concentrations. When concomitant use with neuroleptics and after discontinuation of them, metformin dose adjustment is required under glycemic control. Glucocorticosteroids (GCS) decrease glucose tolerance and increase blood glucose concentration, in some cases causing ketosis. Metformin dose adjustment is required with glycemic control if this combination is necessary and after discontinuation of GCS.

In concomitant use of loop diuretics and metformin there is a risk of lactoacidosis due to possible functional renal failure.

The radiological study with the use of iodine-containing radiopaque agents may cause lactocidosis in diabetic patients with a background of functional renal failure. Metformin administration should be discontinued 48 hours before and not resumed earlier than 48 hours after radiological study with contrast agents.

Injection of beta2-adrenomimetics decreases hypoglycemic effect of metformin due to stimulation of beta2-adrenoreceptors. In this case, blood glucose concentration should be monitored and, if necessary, insulin should be prescribed. Angiotensin-converting enzyme inhibitors and other antihypertensive drugs may decrease the blood glucose concentration. If necessary, the dose of metformin should be adjusted.

In concomitant use of metformin with sulfonylurea derivatives, insulin, acarbose and salicylates may increase the hypoglycemic effect. “Loop” diuretics and nonsteroidal anti-inflammatory drugs (NSAIDs) increase the risk of reduced renal function. In this case, caution should be exercised when using metformin.

Special Instructions

During treatment with Metformin-Teva, blood glucose concentrations should be monitored regularly on an empty stomach and after meals.

The patient should be warned to stop taking the drug and seek medical attention if vomiting, abdominal pain, muscle pain, general weakness and severe malaise occur. These symptoms may be a sign of incipient lactoacidosis. Metformin-Teva should be withdrawn 48 hours before and 48 hours after radiological examination (including urography, intravenous angiography) with the use of contrast agents.

The drug Metformin-Teva should be withdrawn 48 hours before and 48 hours after surgical interventions under general anesthesia, spinal or peridural anesthesia. Because metformin is excreted by the kidneys, CK should be determined before treatment and regularly thereafter: in patients with preserved renal function once a year, in patients with reduced CK and in elderly patients 2-4 times a year.

Particular caution should be exercised if renal function is impaired, e.g., during initial therapy with antihypertensives, diuretics, NSAIDs.

Patients should be advised to seek medical attention if they have symptoms of bronchopulmonary infection or urinary tract infection. During the use of the drug Metformin-Teva it is necessary to refrain from taking alcohol due to the increased risk of hypoglycemia and disulfiram-like effect. Hypovitaminosis B12 when taking Metformin-Teva is due to impaired absorption of vitamin B12 and is reversible. When discontinuing the drug Metformin-Teva signs of hypovitaminosis B12 quickly disappear.

Contraindications

Side effects

Central nervous system disorders: often – taste disorder (metallic taste in the mouth).

Digestive system disorders: very common – nausea, vomiting, abdominal pain, lack of appetite, occurring during the initial treatment and in most cases” spontaneously pass; single cases – liver dysfunction or hepatitis, which disappear completely after drug withdrawal.

Allergic reactions: very rare – erythema, skin itching, rash.

Metabolism: very common – lactoacidosis (requires discontinuation of the drug).

Others: very rare – with prolonged use hypovitaminosis B12 develops.

Overdose

Symptoms: When using metformin at a dose of 85 g, no hypoglycemia was observed, but the development of lactoacidosis was noted. Early symptoms of lactoacidosis are nausea, vomiting, diarrhea, decreased body temperature, abdominal pain, muscle pain; further, rapid breathing, dizziness, impaired consciousness and coma may be noted.

Treatment: If signs of lactoacidosis occur, the drug treatment should be stopped immediately, the patient should be immediately hospitalized and after determining lactate concentration the diagnosis should be confirmed. The most effective measure for lactate and metformin elimination from the body is hemodialysis. Symptomatic treatment is also administered.

Similarities