Each film-coated tablet contains: Metformin hydrochloride 500 mg.
Pharmacology: Pharmacokinetics: Metformin hydrochloride is slowly and incompletely absorbed from the gastrointestinal tract; the absolute bioavailability of a single 500 mg dose is reported to be about 50 to 60%, although this is reduced somewhat if taken with food. Once absorbed, protein binding in plasma is negligible; the drug is excreted unchanged in the urine. The plasma elimination half-life is reported to range from about 2 to 6 hours after oral doses. Metformin is distributed into breast milk in small amounts.
Metformin hydrochloride is a biguanide antidiabetic. It is given by mouth in the treatment of type 2 diabetes mellitus, and is the drug of first choice in overweight patients.
Initial dosage is 500 mg two or three times daily or 850 mg once or twice daily with or after meals, gradually increased if necessary, at intervals of at least 1 week, to 2 to 3 g daily; doses of 3 g daily are associated with an increased incidence of gastrointestinal adverse effects. Gastrointestinal effects are also common in the beginning of therapy hence a starting dose of 500 mg at breakfast for at least 1 week is recommended, then increased gradually to 500 mg twice daily and can be further increased as necessary up to a maximum dose of 2 g daily. In children aged 10 years and older, a starting dose of 500 mg or 850 mg once daily, or 500 mg twice daily, with or after a meal may be used. It may be gradually increased if needed, at intervals of at least 1 week, to a maximum of 2 g daily given in 2 or 3 divided doses.
Metformin is inappropriate for patients with diabetic coma and ketoacidosis, or for those with severe infection, trauma, or other severe conditions where Metformin is unlikely to control the hyperglycemia; insulin should be used in such situations. Metformin should not be given to patients with even mild renal impairment, as it may predispose patients to lactic acidosis and renal function should be monitored throughout therapy. Dehydration may contribute to renal impairment. Conditions associated with hypoxia, such as acute heart failure, recent myocardial infarction, or shock, may increase the risk of lactic acidosis. Other conditions that may also predispose to lactic acidosis in a patient taking a Metformin include excessive alcohol intake and hepatic impairment. Biguanides should be temporarily stopped 48 hours before examinations using contrast media because of the risk of contrast media-induced renal impairment; biguanides should be withheld for at least 48 hours after the examination, and until normal renal function is confirmed. Insulin is preferred for the treatment of diabetes in pregnancy. Owing to the possibility of decreased vitamin B2 absorption, annual monitoring of vitamin B2 concentrations is advisable during long-term treatment.
Gastrointestinal adverse effects including anorexia, nausea, vomiting, and diarrhea may occur with biguanides; patients may experience taste disturbance and there may be weight loss. Absorption of various substances including vitamin Bi, may be impaired. Skin reactions have been reported rarely. Hypoglycemia is rare with a biguanide given alone, although it may occur if other contributing factors or drugs are present. Lactic acidosis, sometimes fatal, has occurred with biguanides, primarily with phenformin. When it has occurred with metformin most cases have been in patients whose condition contra-indicated the use of the drug, particularly those with renal impairment. Phenformin has been implicated in the controversial reports of excessive cardiovascular mortality associated with oral hypoglycemic therapy.
Use of a biguanide with other drugs that lower blood glucose concentrations increases the risk of hypoglycemia, while drugs that increase blood glucose may reduce the effect of biguanide therapy. In general, fewer drug interactions have been reported with biguanides than with sulfonylureas. Alcohol may increase the risk of lactic acidosis as well as of hypoglycemia, Care should be taken if biguanides are given with drugs that may impair renal function.
Store at temperatures not exceeding 30°C.
A10BA02 - metformin ; Belongs to the class of biguanides. Used in the treatment of diabetes.